Methods, systems and computer readable media for providing diameter signaling router with integrated monitoring and/or firewall functionality

IL 219214 /2

METHODS, SYSTEMS, AND COMPUTER READABLE MEDIA FOR PROVIDING DIAMETER SIGNALING ROUTER WITH INTEGRATED MONITORING AND/OR FIREWALL FUNCTIONALITY PRIORITY CLAIM

This application claims the benefit of U.S. Provisional Patent Application Serial No. 61/252,557 filed October 16, 2009.

TECHNICAL FIELD

The subject matter described herein relates to methods and systems for communications in a Diameter network. More particularly, the subject matter described herein relates to methods, systems, and computer readable media for providing a Diameter signaling router with integrated monitoring and/or firewall functionality.

BACKGROUND

In Diameter networks, messages and communications between nodes in the network include information identifying the name and location of each node in the network. For example, when a request message is sent to a server, the server's response includes information identifying the server to the network.

Diameter messages exist in the format of request-answer messages. All answer messages travel back to the request source via the same path through which the request message was routed using hop-by-hop transport. When one Diameter node needs information from another Diameter node, the first Diameter node sends a request identifying itself and its realm or domain, as well as identifying the realm or domain of the Diameter node from which the first Diameter node needs information. The Diameter answer message sent back from the Diameter node that receives the request will include information identifying the receiving Diameter node and its realm or domain. -1- IL 219214/3

Message exchange or interaction between Diameter nodes is vital for performing various functions. For example, a mobility management entity (MME) and a Home Subscriber Server (HSS) interact for authentication, authorization, and/or accounting (AAA) purposes. Such interaction is disclosed in 3rd generation partnership project (3GPP) technical specification TS 29.272 V9.0.0 (hereinafter referred to as “the technical specification”). While this technical specification discloses procedures, message parameters, and protocol for communications between the MME and HSS nodes, interaction between Diameter nodes present various issues, such as routing, security, and network monitoring, which are not adequately addressed in this technical specification. US Patent No. 7107041 discloses a system and a method for monitoring authentication performance in a wireless communication network. The system comprises: a mobile switching center associated with the wireless communication network and an external network node coupled to the mobile switching center by an inter-network transmission interface. The external network node of the system senses a Global Challenge Report Directive message to the mobile switching center, the Global Challenge Report Directive message including at least one authentication parameter. US Patent No. 8606901 discloses an application docking module (ADM) for use in a communication network. The ADM includes a message monitor, an application monitor, and an anomaly handler. The message monitor monitors messages exchanged between a monitored application server and a session control layer resource of the network and the application monitor monitors a heartbeat of the application server. Based on the monitoring, the module determines when the application server is in an anomaly state. The anomaly state may indicate abnormal or otherwise unexpected application server messaging activity and/or an unexpected heartbeat status. The ADM processes application server messages on behalf of the application server when the application server is operating in an anomaly state. -2- 219214/1

Accordingly, in light of these shortcomings associated with interaction between Diameter nodes, there exists a need for methods, systems, and computer readable media for a Diameter signaling router with integrated monitoring and/or firewall functionality. 5

SUMMARY

According to one aspect, the subject matter described herein includes a system for a Diameter signaling router with integrated monitoring functionality. The system includes a Diameter signaling router comprising a 10 network interface for receiving, from a first Diameter node, a first Diameter message having Diameter information. The system also includes an integrated monitoring module located within the Diameter signaling router for copying at least a portion of the first Diameter message and providing the copied information associated with the first Diameter message to an 15 application.

According to another aspect, the subject matter described herein includes a method for providing integrated monitoring functionality at a Diameter signaling router. The method includes receiving, from a first Diameter node and at a network interface, a first Diameter message having 20 Diameter information. The method also includes copying at least a portion -2a- IL 219214 /2

According to another aspect, the subject matter described herein includes a system for Diameter routing and firewall filtering. The system includes a Diameter signaling router comprising a network interface for receiving, from a first Diameter node, a first Diameter message having Diameter information. The Diameter signaling router also includes a firewall module for determining whether the first Diameter message satisfies a firewall policy. The firewall policy is based on at least a portion of the Diameter information in the first Diameter message. The Diameter signaling router further includes a routing module for forwarding, using the Diameter information, at least a portion of the first Diameter message towards a second Diameter node in response to the first Diameter message satisfying the firewall policy.

According to another aspect, the subject matter described herein includes a method for Diameter routing and firewall filtering at a Diameter signaling router. The method includes receiving, from a first Diameter node and at a network interface, a first Diameter message having Diameter information. The method also includes determining whether the first Diameter message satisfies a firewall policy. The firewall policy is based on at least a portion of the Diameter information in the first Diameter message. The method further includes forwarding, using the Diameter information, at least a portion of the first Diameter message towards a second Diameter node in response to the first Diameter message satisfying the firewall policy.

The subject matter described herein for providing a Diameter signaling router with integrated monitoring and/or firewall functionality may be implemented in hardware, a combination of hardware and software, firmware, or any combination of hardware, software, and firmware. As such, the terms “function” or “module” as used herein refer to hardware, a combination of hardware and software, firmware, or any combination of hardware, software, and firmware for implementing the features described herein. In one exemplary implementation, the subject matter described herein may be implemented using a computer readable medium having stored thereon computer executable instructions that when executed by the processor of a computer control the computer to perform steps. Exemplary -3- IL 219214 /2 computer readable media suitable for implementing the subject matter described herein include non-transitory devices, such as disk memory devices, chip memory devices, programmable logic devices, and application specific integrated circuits. In addition, a computer readable medium that implements the subject matter described herein may be located on a single device or computing platform or may be distributed across multiple devices or computing platforms.

As used herein, the term “node” refers to a physical computing platform including one or more processors and memory.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the subject matter described herein will now be explained with reference to the accompanying drawings, wherein like reference numerals represent like parts, of which:

Figure 1 is a block diagram illustrating an exemplary LTE network including the present invention according to an embodiment of the subject matter described herein;

Figure 2 is a signaling message flow diagram illustrating routing messages via a Diameter signaling router in a relay mode according to an embodiment of the subject matter described herein;

Figure 3 is a signaling message flow diagram illustrating routing messages via a Diameter signaling router in a proxy mode according to an embodiment of the subject matter described herein;

Figure 4 is a signaling message flow diagram illustrating routing messages to a foreign gateway via a Diameter signaling router according to an embodiment of the subject matter described herein;

Figure 5 is a diagram illustrating an exemplary table for storing data usable by a Diameter signaling router for translating LTE subscriber identifying information into LTE node addressing or routing information according to an embodiment of subject matter described herein;

Figure 6 is a signaling message flow diagram illustrating routing messages via a Diameter signaling router using address resolution according to an embodiment of the subject matter described herein; -4- IL 219214 /2

Figure 7 is a signaling message flow diagram illustrating a Diameter signaling router providing firewall functionality according to an embodiment of the subject matter described herein;

Figure 8 is a signaling message flow diagram illustrating a Diameter signaling router providing network address translation (NAT) functionality according to an embodiment of the subject matter described herein;

Figure 9A is a signaling message flow diagram illustrating screening a message based on an equipment identity register (EIR) database response according to an embodiment of the subject matter described herein;

Figure 9B is a signaling message flow diagram illustrating routing a message based on an equipment identity register (EIR) database response according to an embodiment of the subject matter described herein;

Figure 10 is a signaling message flow diagram illustrating a Diameter signaling router providing integrated message monitoring functionality according to an embodiment of the subject matter described herein;

Figure 11 is a flow chart illustrating exemplary steps for Diameter routing and firewall filtering according to an embodiment of the subject matter described herein;

Figure 12 is a flow chart illustrating exemplary steps for monitoring Diameter signaling messages according to an embodiment of the subject matter described herein; and

Figure 13 is a flow chart illustrating exemplary steps for routing

Diameter signaling messages according to an embodiment of the subject matter described herein.

DETAILED DESCRIPTION

In accordance with the subject matter disclosed herein, methods, systems, and computer readable media are provided for a Diameter signaling router with integrated monitoring and/or firewall functionality. Reference will now be made in detail to exemplary embodiments of the subject matter described herein, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. -5- IL 219214 /2

Figure 1 is a block diagram illustrating an exemplary Long Term Evolution (LTE) network 112 including a Diameter signaling router according to an embodiment of the subject matter described herein. Referring to Figure 1, network 112 may include user equipment (UE) 100, eNodeB 102 (also referred to herein as transceiver node), mobility management entity (MME) 104, Diameter signaling router 106, an equipment identity register (EIR) database 108, home subscriber servers (HSS), authentication, authorization, and accounting (AAA) servers (collectively referred to hereinafter as HSS/AAA) 110. UE 100 (e.g., mobile handsets) are connected to eNodeB or transceiver node 102, which performs radio access functions similar to a base transceiver station (BTS). Transceiver node 102 may provide UE-related information (e.g., location- or mobility-related data) or UE-initiated messages to a mobility management entity (MME) 104. MME 104 performs tracking of UEs 100 and may communicate information (e.g., mobility-related information) to other nodes in LTE network 112 via a Diameter signaling router 106.

Diameter signaling router 106 may be any suitable entity for routing Diameter signaling messages. For example, Diameter signaling router 106 may be an LTE signaling router, an LTE Diameter signaling router, a Diameter proxy, a Diameter routing agent, or a Diameter redirect agent. Router 106 may include functionality for processing various messages. In one embodiment, such functionality may be included in one or more modules (e.g., a firewall module, a network address translation (NAT) module, a subscriber location module, and a routing module). It will be appreciated that functionality and modules as used herein refers to hardware, software, firmware, or any combination of hardware, software, and firmware for implementing the features described herein.

In various embodiments, router 106 may include a Diameter proxy, a Diameter routing agent, or a Diameter redirect agent. For example, router 106 may operate in a proxy mode, relay mode, and/or a redirect mode as described in further detail below. -6- IL 219214 /2

In one embodiment, router 106 may screen, forward, redirect, and/or forward messages to various network nodes, such as MME 104, HSS/AAA 110, EIR database 108, and other Diameter-related nodes.

In one embodiment, router 106 may communicate with MME 104, HSS/AAAs 110, EIR database 108, and other LTE-related nodes via one or more signaling interfaces. For example, router 106 may exchange or communicate messages between MME 104 and HSS/AAAs 110 via one or more LTE S6 interfaces. In a second example, router 106 may exchange or communicate messages between EIR database 108 via one or more LTE S13 interfaces.

In another embodiment, router 106 may communicated with non-LTE-related nodes via one or more non-LTE signaling interfaces. For example, router 106 may communicate with IP multimedia subsystem (IMS) nodes, such as call session control functions (CSCF), using IMS-related interfaces. For instance, router 106 may receive Diameter messages from a CSCF via a Cx Diameter interface.

In one embodiment, Diameter signaling router 106 includes firewall and/or NAT functionality. As will be described in further detail below, firewall functionality may include using one or more policies or rules for determining whether to allow messages to be processed further (e.g., routed or forwarded by router 106) or deny messages from being processed further. Additionally, as will be described in more detail below, Diameter signaling router 106 may include NAT functionality for modifying information in received Diameter signaling messages or generating new Diameter signaling messages based on received messages. Additionally, router 106 may perform device authentication using EIR database 108. EIR database 108 (also referred to herein as an EIR node) includes information associated with device or UE 100 identification. In one embodiment, EIR database 108 may include a list of device identifiers (e.g., an international mobile equipment identifier (IMEI)) and their associated status regarding network accessibility. For example, EIR database 108 may include a list of device identifiers that are allowed to use a node or network (e.g., a whitelist). In another example, EIR database 108 may include a list -7- IL 219214 /2 of device identifiers that are not allowed to use a node or network (e.g., a blacklist). In a third example, EIR database 108 may include a whitelist and a blacklist for various devices (e.g., stolen devices, emergency devices) and/or situations (e.g., normal load activity, heavy load activity). HSS/AAAs 110 represents an HSS and/or an AAA server. In one embodiment, HSS/AAAs 110 may include HSS functionality. For example, HSS/AAAs 110 may maintain subscriber-related information, such as user identification, control information for user authentication and authorization, location information, and user profile data. In one embodiment, an HSS/AAAs 110 may also include AAA functionality. For example, HSS/ AAAs 110 may perform authentication, authorization, and accounting functions associated with the subscriber. In another embodiment, AAA functionality may be performed by or performed at a node separate or independent from an HSS.

It will be appreciated that Diameter signaling router 106 may additionally be connected to other network nodes, such as a multimedia messaging service center (MMSC), a Policy Charging Rule Function (PCRF), and a Policy and Charging Enforcement Function (PCEF), to provide additional functions and services to network subscribers.

Figure 2 is a signaling message flow diagram illustrating routing messages via Diameter signaling router 106 according to an embodiment of the subject matter described herein. In the embodiment illustrated in Figure 2, a portion of exemplary LTE network 112 is depicted and router 106 is configured to operate in a relay mode. In on embodiment, router 106 operating in relay mode may receive messages intended for other locations or nodes and, using the information in a received message and/or other accessible information (e.g., a subscriber/node location database, a domain name system (DNS) database, etc.), may relay or forward at least a portion of the received message toward an appropriate destination.

As stated above, in one embodiment, router 106 includes functionality for receiving or processing one or more Diameter signaling messages. For example, router 106 may receive and process Diameter messages via an LTE S6 interface, LTE S13 interface, or other LTE-related interfaces. -8- IL 219214 /2

In one embodiment, the received Diameter messages may include one or more messages defined in the technical specification mentioned above. For example, the Diameter messages may include one or more of an UpdateLocation Request (ULR) message, an UpdateLocation Answer (ULA) message, an AuthenticationInformation Request (AIR) message, an AuthenticationInformation Answer (AIA) message, a CancelLocation Request (CLR) message, a CancelLocation Answer (CLA) message, an InsertSubscriberData Request (IDR) message, an InsertSubscriberData Answer (IDA) message, a DeleteSubscriberData Request (DSR) message, a DeleteSubscriberData Answer (DSA) message, a PurgeUE Request (PUR) message, a PurgeUE Answer (PUA) message, a Reset Request (RSR) message, a Reset Answer (RSA) message, a Notify Request (NOR) message, a Notify Answer (NOA) message, an MEIdentityCheck Request (ECR) message, and an MEIdentityCheck Answer (ECA) message.

In the embodiment illustrated in Figure 2, MME 104 is configured for receiving location-related message from UE 100 or associated network nodes and communicating or attempting to communicate with one or more HSS/AAA 110 using Diameter signaling router 106. In one embodiment, MME 104, router 106, and HSS/AAAs 110 may exchange messages via one or more LTE S6 interfaces.

Referring to Figure 2, a Diameter message is received at MME 104. In one embodiment, the received Diameter message is a registration message referred to as a tracking area update (TAU) message. The TAU message or registration message may be initiated by a UE 100 when the UE 100 detects entering a tracking area that is not previously registered in the MME 104 for use by the UE 100. The TAU message may include UE-related information, such as an International Mobile Subscriber Identity (IMSI) value.

In one embodiment, in response to receiving the Diameter message, MME 104 may generate and launch a Diameter message that is intended for an HSS/AAA 110. In one embodiment, MME 104 may generate and launch an UpdateLocation Request (ULR) message in response to receiving the -9- IL 219214 /2 TAU message. The ULR message may include various parameters, such as the IMSI value associated with the TAU message.

In one embodiment, MME 104 may not determine or be unable to provide addressing or routing information for sending the generated message to a particular HSS/AAA 110. In this embodiment, router 106 may be configured to receive and route such messages. In another embodiment, router 106 may be configured to receive and forward routable messages (e.g., using accessible databases). In yet another embodiment, router 106 may be configured to route, block, or redirect messages.

Diameter signaling router 106 may receive a message launched by MME 104. For example, as illustrated in Figure 2, router 106 receives the ULR message launched by MME 104. Router 106 may examine the received message and determine whether and/or how to route the message.

For example, it may be desirable for a network operator to include multiple HSS/AAAs 110 in a communications network to distribute or reduce processing load on any particular HSS/AAA 110. If each of the multiple HSS/AAAs 110 is identically provisioned, i.e., includes copies of the same subscriber data, the HSS/AAAs 110 may operate in a load sharing manner. As such, it may be unnecessary to determine which HSS/AAAs 110 holds a particular subscriber's data. However, if HSS/AAAs 110 do not include identical data, it may be necessary to identify the HSS/AAA 110 that contains a particular subscriber's data when attempting to route messages.

In an embodiment where subscribers are handled by a plurality of HSS/AAAs 110, router 106 may use the IMSI value and/or other information in determining addressing or routing information for appropriate destinations. For example, router 106 may include functionality (e.g., located in a subscriber location module) for accessing one or more subscriber/node location databases. A location database may store associations between subscriber-related information (e.g., IMSI values, or IMSI value ranges) and appropriate nodes, such as serving HSS/AAAs 110. In one embodiment, a location database may include a hierarchical data structure that contains a range-based section that includes associations between groups and/or ranges of subscriber identifiers (e.g., IMSI values) and associated node -10- IL 219214 /2 identifiers (e.g., URIs of HSS/AAAs 110). Likewise, the database may also contain an exceptions-based section, which includes associations between subscriber identifiers and associated node identifiers that are exceptions or different from associations in the range-based section.

In an embodiment where router 106 includes subscriber/node location database access functionality, router 106 may use subscriber-related information (e.g., an IMSI value or a portion thereof) associated with a received message for performing one or more lookups on a location database. For example, router 106 may use the IMSI value associated with a received ULR message in searching the exceptions-based section of the location database. If a matching entry is found in the exceptions-based section of the location database, then the associated node identification information may be obtained and used in routing the Diameter message (e.g., forwarding the message towards the HSS/AAA 110 identified by the lookup). If a match is not located in the exceptions-based section of the location database, the range-based section may be subsequently searched.

In one embodiment, router 106 searches the exceptions-based section for determining whether the IMSI value or a portion thereof is associated with a designated group of identifiers specified by an entry. For example, an IMSI value may be a 14 or 15 digit value. The IMSI value may include portions representing various subscriber-related information, such as 3 digits representing the Mobile Country Code (MCC), followed by 2-3 digits representing the Mobile Network Code, and the remaining digits representing the mobile station identification number (MSIN) within the network's customer base.

In one embodiment, router 106 may use only a portion of the IMSI value (e.g., the MNC) in determining which HSS/AAA 110 is the appropriate destination. For example, in network 100, each HSS/AAA 110 may maintain subscriber-related information for subscribers of a particular service provider (e.g., Verizon, AT&T, or T-Mobile). In such an example, router 106 may use an MNC of an IMSI value (e.g., “012” or “12” is the MNC of the IMSI value “310012353464342”) associated with a received message for determining -11- IL 219214 /2 that the message should be routed to an HSS/AAA 110 associated with that MNC (e.g., MNC “12” is associated with Verizon).

In one embodiment, if a match is located in the range-based section 110, then the associated node identification information may be obtained and used in forwarding the Diameter message. For example, the addressing or routing information may be used in forwarding a ULR message towards the HSS/AAA 110 identified by the lookup.

In one embodiment, if a match is not located, router 106 may route message to a default node. In another embodiment, router 106 may notify an originating node (e.g., MME 104) or previous hop that a received message is un-routable. For example, router 106 may generate and launch an error message towards MME 104 indicating that a destination for a particular message is unknown, inaccurate, or un-routable.

In one embodiment, after determining an appropriate destination (e.g., an HSS/AAA 2 110) for a received message, router 106 may modify the message, e.g., to include the destination information. In an alternative embodiment, router 106 may not modify the message. Router 106 may route the message towards the appropriate destination. For example, in Figure 2, router 106 may relay or send a modified ULR message towards HSS/AAA 2 110.

In one embodiment, HSS/AAA 2 110 may receive a Diameter message and respond. For example, in response to receiving an ULR message, HSS/AAA 2 110 may send an UpdateLocation Answer (ULA) message indicating that location information was received and stored. In one embodiment, a response message corresponding to the routed message (e.g., from HSS/AAA 2 110) may be processed or routed by router 106. For example, router 106 may use stored state information or other information (e.g., addressing or routing information in the message) for sending the response message towards MME 104. In another embodiment, a response message corresponding to the routed message (e.g., from HSS/AAA 2 110) may not be processed or routed by router 106. For example, HSS/AAA 2 110 may provide destination addressing or routing information for sending the message towards MME 104 without router 106. -12- IL 219214 /2

Figure 3 is a second signaling message flow diagram illustrating routing messages via Diameter signaling router 106 according to an embodiment of the subject matter described herein. In the embodiment illustrated in Figure 3, a portion of exemplary LTE network 112 is depicted and router 106 is configured to operate in a proxy mode.

In one embodiment, router 106 operating in proxy mode may receive messages addressed to itself and may route at least a portion of the received messages to other locations or nodes using the information in a received message and/or other accessible information. Router may also be configured to receive response messages corresponding to the routed messages and may route the response messages or a portion thereof to appropriate destinations (e.g., the node that launched the associated query message).

In the embodiment illustrated in Figure 3, except as disclosed herein, the nodes depicted in Figure 3 are essentially the same as described in reference to Figure 2. Further, the first two messages of Figure 3, (Figure 3, messages 1 and 2), are essentially the same as the first two messages of Figure 2. Therefore, descriptions of the nodes and the first two messages will not be repeated herein.

In the embodiment illustrated in Figure 3, in response to receiving a Diameter message, router 106 may generate and launch a new Diameter message based on the original received message. For example, router 106 may terminate a received ULR message and use information in the message, such as an IMSI value or portion thereof, for determining which HSS/AAA 100 to send at least a portion of the received ULR message. After determining an appropriate destination (e.g., an HSS/AAA 2 110), router 106 may generate a new ULR message and include addressing or routing information for the appropriate destination and may routes the new ULR message to the destination (e.g., HSS/AAA 2 110).

In an alternative embodiment, router 106 may receive a Diameter message and, using the IMSI to determine or identity an appropriate destination, route the message towards the appropriate destination (e.g., -13- IL 219214 /2 HSS/AAA 2 110). In this embodiment, router 106 may or may not modify the message to include the destination information. HSS/AAA 2 110 may receive a Diameter message and respond. For example, in response to receiving a ULR message, HSS/AAA 2 110 may send a ULA message indicating that location information was received and stored. In one embodiment, a response message corresponding to the routed message (e.g., from HSS/AAA 2 110) may be processed or routed by router 106. For example, as illustrated in Figure 3, router 106 may receive a ULR message from HSS/AAA 2 110. Router 106 may terminate the ULA message and generates a new ULA message that is based on the ULA message received from the HSS/AAA 2 110. In one embodiment, the generated ULA message may include source addressing or routing information associated with router 106 and/or other information such that router 106 acts as a proxy for HSS/AAA 2 110. In this embodiment, Router 106 may route the generated message to an appropriate destination, e.g., the node that launched the associated query message.

In another embodiment, a response message corresponding to the routed message (e.g., from HSS/AAA 2 110) may not be processed or routed by router 106. For example, HSS/AAA 2 110 may provide destination addressing or routing information for sending the message towards MME 104 without router 106.

Figure 4 is another signaling message flow diagram illustrating routing messages via Diameter signaling router 106 according to an embodiment of the subject matter described herein. In the embodiment illustrated in Figure 4, a portion of exemplary LTE network 112 is depicted and, MME 104 is configured to communicate with an out of network Diameter gateway (also referred to herein as a foreign gateway) 400 using Diameter signaling router 106.

Foreign gateway 400 represents an entity associated with roaming or foreign subscribers, such as subscribers that are not associated with the current network or service provider. For example, foreign gateway 400 may be contacted for receiving or providing AAA-related or mobility-related information associated with foreign subscribers. In this embodiment, router -14- IL 219214 /2 106 may include functionality for routing at least a portion of a message sent by MME 104 to an appropriate foreign gateway 400.

Except as disclosed herein, the other nodes depicted in Figure 4 are essentially the same as described in reference to Figure 3. Further, the messages of Figure 4, (Figure 4, messages 1-5), are essentially the same as the messages of Figure 3 except that the messages of Figures 4 are associated with or intended for foreign gateway 400. Therefore, descriptions of these nodes and messages will not be repeated herein.

In the embodiment illustrated in Figure 4, in response to receiving a Diameter message associated with or intended for foreign gateway 400, router 106 may generate and launch a new Diameter message based on the original received message. For example, router 106 may terminate a received ULR message and use information in the message, such as an IMSI value or portion thereof, for determining an appropriate node towards which to route at least a portion of the received ULR message. After determining an appropriate destination (e.g., foreign gateway 400), router 106 may generate a new ULR message and include addressing or routing information for the appropriate destination and may routes the new ULR message to the destination (e.g., foreign gateway 400).

In another embodiment, router 106 may receive a Diameter message and, using the IMSI to determine or identity an appropriate destination, route the message towards the appropriate destination (e.g., foreign gateway 400). In this embodiment, router 106 may or may not modify the message to include the destination information.

In yet another embodiment, router 106 may receive a Diameter message and, using the IMSI to determine or identity an appropriate destination, determine not to route message. In this embodiment, router 106 may be configured to operate in a redirect mode.

In one embodiment, in redirect mode, router 106 may determine a destination or a node for further processing. Router may send a message or otherwise notify the originating node (e.g., MME 104) or a previous hop of addressing or routing information for communicating with the appropriate node. For example, router 106 may determine that a ULR message should -15- IL 219214 /2 be sent to foreign gateway 400. In this example, router 106 may be unable to communicate with foreign gateway 400 and may provide addressing or routing information to MME 104 so that MME 104 can redirect the ULR message to gateway 400.

Foreign gateway 400 may receive a Diameter message and respond. For example, in response to receiving a ULR message, foreign gateway 400 may send a ULA message indicating that location information was received and stored. In one embodiment, a response message corresponding to the routed message (e.g., from foreign gateway 400) may be processed or routed by router 106. For example, as illustrated in Figure 4, router 106 may receive a ULR message from foreign gateway 400. Router 106 may terminate the ULA message and generates a new ULA message that is based on the ULA message received from foreign gateway 400. In one embodiment, the generated ULA message may include source addressing or routing information associated with router 106 and/or other information such that router 106 acts as a proxy for foreign gateway 400. Router may route the generated message to an appropriate destination, e.g., the node that launched the associated query message.

In another embodiment, a response message corresponding to the routed message (e.g., from foreign gateway 400) may not be processed or routed by router 106. For example, foreign gateway 400 may provide destination addressing or routing information for sending the message towards MME 104 without router 106.

Figure 5 is a diagram illustrating an exemplary table for storing information usable by Diameter signaling router 106 for translating LTE subscriber identifying information into LTE node addressing or routing information according to an embodiment of subject matter described herein. In particular, Figure 5 depicts a table 500 that includes exemplary data that may be accessed and/or stored by router 106. Table 500 includes an LTE subscriber ID field, an LTE network node uniform resource identifier (URI) field, an LTE network node fully qualified domain name (FQDN) field, and an LTE network node Internet protocol (IP) address field. -16- IL 219214 /2

Subscriber ID field may include LTE subscriber or device identifiers (or portions thereof), such as an IMSI, a mobile subscriber integrated services digital network (MSISDN) number, a short code, a URI, IMEI, and a mobile identification number (MIN). LTE network node URI, FQDN, and IP address fields represents fields for storing addressing or routing information for nodes that are associated with a subscriber ID or group of subscribers. For example, table 500 may include subscriber location information (e.g., as found in a location database disclosed above). In this example, table 500 may include an entry with an IMSI value (e.g., IMSI value: “310012353464342”) in the subscriber ID field and an URI value (e.g., URI value: “aaa://host.example.com:1813;transport=udp;protocol=radius”) in the network node URI field. The URI value may be associated with a serving HSS/AAA 110 (e.g., HSS/AAA 2 110) for the subscriber identified by the IMSI value. In a second example, table 500 may include an entry with a portion of an IMSI value (e.g., IMSI portion value: “314024*”) in the subscriber ID field and an FQDN value (e.g., FQDN value: “HSS1@VZW.NET”) in the network node FQDN field. This table entry may indicate a group of subscribers (e.g., subscribers having the same initial 6 digits for their IMSI values) that are associated with a particular node identified by the FQDN value. In a third example, table 500 may include an entry with an IMSI value or a portion thereof (e.g., IMSI value: “310012353464342”) in the subscriber ID field and one or more types of network node identifiers for identifying an associated node. As such, in this third example, router 106 may use a URI, a FQDN, and/or an IP address information for routing a message to an appropriate network node for processing.

It will be appreciated that the information stored, accessed, or used by router 106 may vary depending on the communications network, configuration, messages, and network nodes involved. For example, types of addressing or routing information may vary for network nodes. In one embodiment, each entry may include a subscriber ID or portion thereof and addressing or routing information for one associated node in the network node Uniform Resource Identifier (URI) field, network node fully qualified -17- IL 219214 /2 domain name (FQDN) field, and network node Internet protocol (IP) address fields. In this embodiment, multiple entries may be used to identify additional nodes. In another embodiment, each entry may include one or more associated nodes (e.g., backup or secondary node addresses). In this embodiment, additional fields (e.g., backup node fields) may be used to identify additional nodes. In some embodiment, table 500 may include one or more status fields for identifying whether an associated node is currently available.

Figure 6 is another signaling message flow diagram illustrating routing messages via Diameter signaling router 106 according to an embodiment of the subject matter described herein. In the embodiment illustrated in Figure 6, a portion of exemplary LTE network 112 is depicted and router 106 is configured for accessing a DNS database 600 and using such information when determining whether and/or how to route the Diameter message. DNS database 600 represents a storage element or function for maintaining subscriber-related or node-related mapping information. For example, DNS database 600 may include associations between subscriber identifiers (e.g., IMSI values, subscriber URIs, MSISDN number) and addressing or routing information for associated nodes(e.g., URIs, FQDNs, IP addresses), such as information of table 500. In one embodiment, DNS database 600 may associate IMSI values to URI values. In this embodiment, database 600 may be used for performing IMSI-to-URI queries or lookups (also referred to herein as UTI dips). In one embodiment, database 600 may be located as an external or separate node from router 106. In another embodiment, database 600 may be co-located or integrated with router 106.

Except as disclosed herein, the other nodes depicted in Figure 6 are essentially the same as described in reference to Figure 2. Further, the first two messages of Figure 6, (Figure 6, messages 1 and 2), are essentially the same as the first two messages of Figure 2. Therefore, descriptions of the nodes and the first two messages will not be repeated herein. -18- IL 219214 /2

Referring to Figure 6, in response to receiving a Diameter message having subscriber or node identifying information, router 106 may use the identifying information (e.g., an IMSI value) in querying DNS database 600.

In one embodiment, the query message may include an IMSI value for determining addressing or routing information (e.g., URI address) of an associated node (e.g., a serving HSS/AAA 100). DNS database node (e.g., DNS server) may receive the query message, perform one or more lookups on database 600, and respond based on results of lookups.

In another embodiment, the query message may include an IMSI value and/or routing information (e.g., a FQDN or IP address of an associated node) for determining alternate addressing or routing information (e.g., a URI address of an associated node). For example, router 106 may be unable to use FQDN values for routing messages and, instead, may need an URI or IP address. As such, router 106 may launch a DNS query message that includes a FQDN value identifying a destination. In this example, a DNS response message may include an IP address associated with the FQDN value. Router 106 may use the returned IP address for routing messages to the destination.

In one embodiment, DNS database node (e.g., DNS server) may receive the query message, perform one or more lookups on database 600, and respond based on results of lookups. If a match is found in the location database 600, the associated identification information may be obtained and used in routing the Diameter message towards the node identified by the lookup. For example, as illustrated in Figure 6, DNS database node may send a response message to router 106 for providing appropriate routing information of an associated node (e.g., a session initiation protocol (SIP) URI associated with HSS/AAA 110). If a match is not located, DNS database node may send a response message to router 106 indicating that appropriate routing information was not found.

In one embodiment, if a response message indicates that a match is not located, router 106 may route message to a default node associated with that network or service provider. In another embodiment, if a response message indicates that a match is not located, router 106 may notify an -19- IL 219214 /2 originating node (e.g., MME 104) or previous hop that a received message is un-routable. For example, router 106 may generate and launch an error message towards MME 104 indicating that a destination for a particular message is unknown, inaccurate, or un-routable.

In response to receiving a response message that includes routing information, router 106 may use routing information in routing a message to a destination identified by the routing information. In one embodiment, router 106 may generate and launch a new Diameter message based on the original received message. The new Diameter message may include addressing or routing information for the appropriate destination. For example, as illustrated in Figure 6, the routing information returned by the ITU server may identify an in-network URI, such as HSS/AAA 110. In this example, the new Diameter message may include routing information for HSS/AAA 110 and route the message accordingly.

In an embodiment where returned routing information identifies the subscriber as belonging to another network (e.g., ported out), router 106 may act in a relay mode and forward the Diameter message to the ported-out network. The forwarded Diameter message may or may not be modified to include the destination information. In yet another embodiment, router 106 may act in a proxy mode and contact the out-of-network HSS/AAA 110 on behalf of an originating MME 104. In still another embodiment, router 106 may act in a redirect mode and respond back to an originating MME 104. Router 106 may instruct MME 104 to contact an appropriate node. It will be appreciated that these embodiments may be similar to the relay, proxy, and redirect embodiments illustrated and discussed above. HSS/AAA 110 may receive a Diameter message and respond. For example, in response to receiving a ULR message, HSS/AAA 110 may send a ULA message indicating that location information was received and stored. In one embodiment, a response message corresponding to the routed message (e.g., from HSS/AAA 110) may be processed or routed by router 106. For example, as illustrated in Figure 6, router 106 may receive a ULR message from HSS/AAA 110. Router 106 may terminate the ULA message and generates a new ULA message that is based on the ULA message -20- IL 219214 /2 received from HSS/AAA 110. In one embodiment, the generated ULA message may include source addressing or routing information associated with router 106 and/or other information such that router 106 acts as a proxy for HSS/AAA 110. Router 106 may route the generated message to an appropriate destination, e.g., the node that launched the associated query message.

In another embodiment, a response message corresponding to the routed message (e.g., from HSS/AAA 110) may not be processed or routed by router 106. For example, HSS/AAA 110 may provide destination addressing or routing information for sending a message towards MME 104 without router 106.

Figure 7 is a signaling message flow diagram illustrating a Diameter signaling router providing firewall functionality according to an embodiment of the subject matter described herein. In the embodiment illustrated in Figure 7, a portion of exemplary LTE network 112 is depicted and router 106 includes firewall/NAT module 700. Diameter signaling router 106 may include a network interface 702 that receives Diameter signaling messages from a network node, such as MME 104 or HSS 110. Firewall/NAT module 700 filters Diameter signaling messages based on information in the Diameter portions of the messages. For messages that pass the filtering or satisfy a Diameter firewall policy, a routing module 704 routes those messages to a different Diameter node.

Firewall/NAT module 700 may be implemented in software in combination with hardware and/or firmware. It will be appreciated that firewall/NAT module 700 may be included in one or more modules (e.g., a firewall module, a NAT module, a firewall/NAT module). For example, a firewall module may include any or all functionality as described herein.

In one embodiment, router 106 that includes firewall/NAT module 700 is operable to enforce one or more firewall policy rules and/or perform NAT. For example, router 106 may perform Diameter router and firewall filtering functions. Firewall/NAT module 700 may include functionality for accessing one or more databases, such as firewall policy rules database 706. Rules database 706 may include information associated with policies and/or rules -21- IL 219214 /2 for determining whether to allow or deny further processing of a received message. For example, rules may be used for determining whether a received message is forwarded towards a destination by router 106.

In one embodiment, policies include one or more rules in database 706. The rules may involve various characteristics or conditions associated with a message or subscriber, e.g., a subscriber, an origination network, a destination node, a destination network, a device, a service provider, network conditions, message characteristics, and/or message parameters. In one embodiment, database 706 may include rules indicating characteristics associated with a message and/or a subscriber for allowing messages to be forwarded or processed by router 106. Database 706 may also include rules indicating characteristics associated with a message and/or a subscriber for denying or blocking messages from being routed or further processed by router 106.

In one embodiment, database 706 may include various data structures for representing firewall policies or firewall rules for a subscriber, device, or group of subscribers (e.g., subscribers of a particular service provider). For example, database 706 may include one or more policy tables for subscribers of different service providers.

In one embodiment, rules may be associated with at least one of a message parameter, a value, a parameter length, a message length, a destination, an origination, a session, a network address in a Diameter message processed by a network address translator, a network address in a Diameter message not processed by a network address translator, exclusion of a message parameter, inclusion of a message parameter, a message type, manner in which a message is received, time of day, and time of week.

In one embodiment, policy or rules may also include information for accessing data structures. For example, firewall policy rules may specify whitelists and/or blacklists for parameters in a Diameter message (e.g., blacklists and/or whitelists for IMSI, MSISDN, SGSN, Visited-PLMN-Id, etc.). For example, a firewall policy may include information for accessing a whitelist associated with emergency devices in a particular network. In a -22- IL 219214 /2 second example, a firewall policy may include information for accessing a blacklist associated with stolen devices.

In an embodiment where router 106 includes firewall/NAT module 700, router 106 may be configured for receiving, examining and/or modifying one or more Diameter messages. For example, router 106 (e.g., using firewall/NAT module 700) may be configured for examining and/or modifying information in Diameter messages. For example, examinable and/or modifiable Diameter information may include Diameter header portion information, a Diameter version, a Diameter message length, a Diameter flag, a command code (CC), a Diameter application identifier (ID), a hop by hop ID, an end to end ID, Diameter data portion information, a Diameter attribute value pair (AVP), an AVP parameter, an AVP code, an AVP flag, an AVP length, a vendor ID, AVP data, a parameter, a subscriber identifier, a device identifier, an international mobile subscriber identifier (IMSI), a mobile subscriber integrated services digital network (MSISDN) number, a short code, a uniform resource identifier (URI), an international mobile equipment identifier (IMEI), a mobile identification number (MIN), an Auth-Session-State parameter, a Origin-Host parameter, a Origin-Realm parameter, a Destination-Host parameter, a Destination-Realm parameter, a User-Name parameter, a Supported-Features parameter, a Terminal-Information parameter, a RAT-Type parameter, a ULR-Flags parameter, a Visited-PLMN-Id parameter, a SGSN-Number parameter, a Proxy-Info parameter, and a Route-Record parameter.

In the embodiment illustrated in Figure 7, MME 104 is configured to communicate or attempt to with one or more HSSs and/or AAA servers (hereinafter referred to as HSS/AAAs) 110 using Diameter signaling router 106. Router 106 may provide firewall functionality. In one embodiment, MME 104, router 106, and HSS/AAAs 110 may exchange messages via one or more LTE interfaces, such as an S6 interface. Diameter messages sent or received via an LTE S6 interface or other LTE-related interfaces may include one or more messages defined in the technical specification mentioned above. -23- IL 219214 /2

As illustrated in Figure 7, a Diameter message may be received at MME 104. In one embodiment, the received Diameter message is a registration message referred to as a tracking area update (TAU) message. The TAU message may include UE-related information, such as an International Mobile Subscriber Identity (IMSI) value. In response to receiving the Diameter message, MME 104 may generate and launch a Diameter message that is intended for an HSS/AAA 110. In one embodiment, MME 104 may generate and launch a ULR message in response to receiving the TAU message. The ULR message may include the IMSI value associated with the TAU message.

In one embodiment, Diameter signaling router 106 may receive the message launched by MME 104. For example, as illustrated in Figure 7, router 106 receives a ULR message launched by MME 104. Router 106 may use firewall/NAT module 700 for examining the received message and determining whether and/or how to process the message.

In one embodiment, router 106 using firewall/NAT module 700 may access database 706 for determining whether a received message satisfies a relevant firewall policy. For example, router 106 may query database 706 using an IMSI value and/or other parameters associated with a received Diameter message.

In one embodiment, if a received Diameter message satisfies a relevant firewall policy (e.g., as determined by an IMSI value and/or other information associated with the message), router 106 may route the Diameter message towards an appropriate destination (e.g., HSS/AAA 110). If the received Diameter message fails to satisfy a relevant firewall policy, router 106 may perform a mitigating action.

In one embodiment, mitigating actions may include, but are not limited to, discarding a Diameter message, generating an error code, generating an error message, communicating an error message to a Diameter node, generating an event record, generating a log entry, modifying a Diameter message, generating a second Diameter message based on a first Diameter message; modifying information in a Diameter message, modifying a Diameter message to satisfy a firewall policy, triggering NAT processing for -24- IL 219214 /2 a Diameter message, triggering routing of a message, and notifying an entity.

In response to receiving an indication that a received Diameter message fails to satisfy a firewall policy, router 106 (e.g., using firewall/NAT module 700) may deny, stop, or block further processing of the received message. Router 106 may also generate and launch a message towards an originating entity (e.g., MME 104) indicating that the message is blocked or deny from being forwarded or routed. For example, as illustrated in Figure 7, router 106 (e.g., using firewall/NAT module 700) may determine that a rule associated with the IMSI value of a received message is not satisfied and subsequently may send a ULA message indicating that the message is blocked or denied further processing.

In one embodiment where a policy includes multiple rules, if one or more of these rules are not met (e.g., one or more parameters or characteristics indicate a blocked status), the message may be denied or blocked by router 106. In another embodiment where a policy includes multiple rules, if one or more of these rules are met (e.g., one or more parameters or characteristics indicate a allow status), the message may be allowed to be processed further by router 106.

In one embodiment, policies or rules may be associated with various priority or relevance values. For example, a message may be associated undesired characteristics associated with a blocked status and may also be associated with desired characteristics associated with an allowed status. In such situations, priority or relevance information may be used for determining whether a policy is satisfied.

It will be appreciated that the present subject matter herein contemplates using various policies and rules as appropriate. In one embodiment, router 106 (e.g., using firewall/NAT module 700) may enforce particular policies or rules depending on network configurations, network activities, and various other factors. For example, dynamic policies may be enforced based on suspicious network activity so as to prevent or mitigate denial of service (DoS) attacks or other security issues. -25- IL 219214 /2

Figure 8 is a signaling message flow diagram illustrating a Diameter signaling router providing network address translation (NAT) functionality according to an embodiment of the subject matter described herein. In the embodiment illustrated in Figure 8, a portion of exemplary LTE network 112 is depicted and router 106 includes firewall/NAT module 700 as described above. In this embodiment, router 106 using firewall/NAT module 700 may perform NAT-related functions, e.g., address translation and/or other parameter modification for communication between nodes.

In one embodiment, firewall/NAT module 700 may include functionality for accessing a NAT database 800 for maintaining NAT-related information. Database 800 may include information associated with NAT policies and/or NAT rules for determining whether and/or how to modify received messages or generate messages based on received messages (e.g., replacing an internal node identifier with an external node identifier being forwarding or routing a message).

In one embodiment, NAT database 800 may include various data structures representing NAT policies or NAT rules for a subscriber, device, or group of subscribers (e.g., subscribers of a particular service provider or cell). For example, database 800 may include one or more policy tables for subscribers of different service providers.

In one embodiment, database 800 may include information (e.g., state information, policies, rules) associated with NAT-related functions. For example, router 106 (e.g., using firewall/NAT module 700) may change or modify the value of any parameter in a received Diameter message prior to routing the Diameter message to HSS/AAA 110 and may maintain the original parameter information or other related data in database 800.

In one embodiment, router 106 (e.g., using firewall/NAT module 700) may use maintained information (e.g., stored in database 800) for providing associated NAT processing on related or corresponding messages, such as response messages returned by HSS/AAA 110. In another embodiment, router 106 may perform associated NAT processing on related or corresponding messages, such as response messages returned by HSS/AAA 110, without maintaining original message information. For -26- IL 219214 /2 example, message parameter values may identify a particular NAT policy to use on a response message.

In the embodiment illustrated in Figure 8, MME 104 is configured to communicate or attempt to with one or more HSSs and/or AAA servers (hereinafter referred to as HSS/AAAs) 110 using Diameter signaling router 106. Router 106 may provide firewall functionality. In one embodiment, MME 104, router 106, and HSS/AAAs 110 may exchange messages via one or more LTE S6 interfaces. Diameter messages sent or received via an LTE S6 interface or other LTE-related interfaces may include one or more messages defined in the technical specification mentioned above.

As illustrated in Figure 8, a Diameter message may be received at MME 104. In one embodiment, the received Diameter message is a registration message referred to as a tracking area update (TAU) message. The TAU message may include UE-related information, such as an International Mobile Subscriber Identity (IMSI) value. In response to receiving the Diameter message, MME 104 may generate and launch a Diameter message that is intended for an HSS/AAA 110. In one embodiment, MME 104 may generate and launch a ULR message in response to receiving the TAU message. The ULR message may include the IMSI value associated with the TAU message.

In one embodiment, Diameter signaling router 106 may receive the message launched by MME 104. For example, as illustrated in Figure 8, router 106 receives a ULR message launched by MME 104. Router 106 may use firewall/NAT module 800 for examining the received message and determining whether and/or how to route the message. In one embodiment, router 106 (e.g., using firewall/NAT module 700) may access NAT database 800 in making this determination.

In one embodiment, router 106 may use firewall/NAT module 700 for determining whether to perform NAT-related functions before routing a message. For example, after determining that a message is allowed to be processed further (e.g., routed) and determining an appropriate destination, router 106 may perform NAT-related functions. In a second example, a message may be modified by NAT-related functions concurrently, prior to, or -27- IL 219214 /2 after determining an appropriate destination for the message. In one embodiment, determining whether to perform NAT-related functions may be based on NAT policies or NAT rules.

For example, NAT database 800 may include an entry that associates a particular transaction with information for modifying the Origin Host and Origin Realm values in associated messages. In this example, router 106 may query NAT database 800 using an IMSI value and/or other transaction identifying information associated with a received Diameter message. NAT database 800 may indicate that the message associated with this subscriber or transaction requires one or more parameter values to be modified.

In one embodiment, router 106 (e.g., using firewall/NAT module 700) may modify parameter values of a message before routing the message. For example, as illustrated in Figure 8, router 106 may modify origin host and origin realm parameter values of a ULR message such that the ULR message appears to originate from the same realm as destination. Router 106 may forward the modified ULR message towards HSS/AAA 110.

In one embodiment, HSS/AAA 110 may receive a Diameter message and respond. For example, in response to receiving a ULR message, HSS/AAA 110 may send a ULA message indicating that location information was received and stored. In one embodiment, a response message corresponding to the routed message (e.g., from HSS/AAA 110) may be processed or routed by router 106. For example, as illustrated in Figure 8, router 106 may receive a ULR message from HSS/AAA 110. In one embodiment, router 106 (e.g., using firewall/NAT module 700) may perform associated reverse NAT processing on related or corresponding messages, such as response messages returned by HSS/AAA 110. For example, router 106 may use database 800 for obtaining original parameters or other information for modifying the received message before forwarding the message. In a second example, router 106 may use information in database 800 for generating a new message based on the received message. As illustrated in Figure 8, the generated ULA message may include destination addressing or routing information associated with MME 104. Router 106 -28- IL 219214 /2 may route the generated message to an appropriate destination, e.g., the node that launched the associated query message.

In another embodiment, a response message corresponding to the routed message (e.g., from HSS/AAA 110) may not be processed or routed by router 106. For example, HSS/AAA 110 may provide destination addressing or routing information for sending a message towards MME 104 without router 106.

It will be appreciated that various NAT policies or NAT rules may be enforced by router 106 (e.g., using firewall/NAT module 700). Additionally, one or more policies or rules may have higher or lower priorities. It will be further appreciated that the present subject matter herein contemplates using various policies and rules as appropriate. In one embodiment, router 106 that includes firewall/NAT module 700 may perform NAT-related functions depending on network configurations, network activities, and various other factors. For example, NAT policies may be enforced based on network congestion, e.g., certain features or quality of service (QoS) parameters are modified to reduce bandwidth usage.

Figure 9A is a signaling message flow diagram illustrating screening a message based on an equipment identity register (EIR) database response according to an embodiment of the subject matter described herein. In the embodiment illustrated in Figure 9, a portion of exemplary LTE network 112 is depicted and router 106 is configured for performing device authorization. In one embodiment, router 106 (e.g., using firewall/NAT module 700) is configurable to access an Equipment Identity Register (EIR) database 108 for authorizing or blocking devices. For example, firewall/NAT module 700 may include functionality for accessing an EIR Database 108 to determine whether a device is authorized or blocked. In one embodiment, querying an EIR database 108 may be referred to as performing an EIR dip.

As stated above, EIR database 108 includes information associated with device or UE identification. In one embodiment, EIR database 108 may include a list of device identifiers (e.g., an International Mobile Equipment Identifier (IMEI)) and associated status regarding network accessibility. For example, EIR database 108 may include a list of device identifiers that are -29- IL 219214 /2 allowed to use a node or network (e.g., a whitelist) or not allowed to use a node or network (e.g., a blacklist).

In one embodiment, performing an EIR dip includes accessing EIR database 108 for determining whether equipment-related information associated with a Diameter message is present in EIR database 108 and allowing or blocking the Diameter message based on the response to determining whether equipment-related information associated with the Diameter message is present in EIR database 108.

In the embodiment illustrated in Figure 9A, a Diameter message is received at MME 104. As illustrated in Figure 9A, the received Diameter message may be a TAU message that includes an IMEI and IMSI value. In response to receiving the Diameter message, MME 104 may generate and launch a Diameter message that is intended for an HSS/AAA 110. For example, MME 104 may generate and launch a ULR message in response to receiving the TAU message. The ULR message may include the IMSI and IMEI values associated with the TAU message.

In Figure 9A, Diameter signaling router 106 may receive the message launched by MME 104. For example, router 106 may receive the ULR message launched by MME 104. Router 106 may use firewall/NAT module 700 for examining the received message and determining whether and/or how to route the message.

Router 106 (e.g., using firewall/NAT module 700) may use the IMEI value in querying EIR database 108 for obtaining authorization information associated with the IMEI value. EIR database 108 or an appropriate node (e.g., an EIR database server) may respond indicating that the IMEI value or an associated device or subscriber is blocked or not allowed.

In one embodiment, in response to a receiving message indicating that the IMEI value associated with a message is blocked, router 106 (e.g., using firewall/NAT module 700) may deny, stop, or block further processing of the received message. Router 106 may also generate and launch a message towards an originating entity (e.g., MME 104) indicating that the message is blocked or deny from being forwarded or routed. -30- IL 219214 /2

For example, as illustrated in Figure 9A, router 106 (e.g., using firewall/NAT module 700) may determine that the IMEI value of a received message is blocked and may subsequently send a ULA message indicating that messages associated with the IMEI value is blocked or denied further processing. As such, router 106 (e.g., using firewall/NAT module 700) may shield or prevent HSS/AAA 100 or other network nodes from unnecessary signaling traffic, thereby reducing the load on network resources.

In one embodiment, EIR database 108 may be located externally of router 106. In another embodiment, EIR database 108 may be co-located or integrated with router 106.

Figure 9B is a signaling message flow diagram illustrating routing a message based on an equipment identity register (EIR) database response according to an embodiment of the subject matter described herein. In the embodiment illustrated in Figure 9B, the nodes depicted in Figure 9B are essentially the same as the nodes described in reference to Figure 9A. Further, the first three messages of Figure 9B, (Figure 9B, messages 1, 2, and 3) are essentially the same as the first three messages of Figure 9A. Therefore, descriptions of these nodes and the first three messages will not be repeated herein.

In the embodiment illustrated in Figure 9B, in response to an EIR query for determining device authorization, an allowed or authorized response message is returned.

In one embodiment, in response to receiving an allowed or authorized message, router 106 may perform further processing (e.g., route messages associated with the authorized device). For example, as illustrated in Figure 9B, router 106 may route a ULR message associated with the authorized IMEI towards an appropriate HSS/AAA 110. HSS/AAA 110 may receive the Diameter message and respond. For example, in response to receiving a ULR message, HSS/AAA 110 may send a ULA message indicating that location information was received and stored. In the embodiment illustrated in Figure 9B, a response message corresponding to the routed message (e.g., from HSS/AAA 110) may be processed or routed by router 106. In another embodiment, a response message corresponding to the routed -31- IL 219214 /2 message (e.g., from HSS/AAA 110) may not be processed or routed by router 106.

Figure 10 is a signaling message flow diagram illustrating a Diameter signaling router providing integrated message monitoring functionality according to an embodiment of the subject matter described herein. In the embodiment illustrated in Figure 10, a portion of exemplary LTE network 112 is depicted and router 106 is configured for performing message monitoring.

In one embodiment, router 106 includes message monitoring (MM) functionality 1000 for monitoring Diameter signaling message traffic transiting or traversing the node. MM module 1000 may be implemented in software in combination with hardware and/or firmware. Router 106 may also include network interface 702 and routing module 704 described above. In one exemplary embodiment, Diameter router 106 may include plural network interfaces 702 for receiving signaling messages from plural different sources. Integrated monitoring module 1000 may be implemented as a message copy function associated with each network interface 702 that identifies and copies Diameter signaling messages received by each network interface 702. Routing module 704 routes the original Diameter signaling messages received by each network interface 702 to its destination. MM module 1000 may copy information from Diameter signaling messages that traverse Diameter signaling router 106. For example, MM module 1000 may identify and copy Diameter signaling messages associated with the establishment, progress, and tear down of a media session and generate or provide information for generating a transaction detail record (TDR) for the session. In another example, MM module 1000 may generate or provide information for generating usage measurements information, such as peg counts, for Diameter signaling messages that traverse router 106. Such peg counts can be configurable, for example, so that the network operator can obtain counts of Diameter signaling messages of a particular type, from a particular source, and/or to a particular destination flowing through router 106. -32- IL 219214 /2

In one embodiment, MM module 1000 may provide information (e.g., copied portions) associated with an observed Diameter message to one or more applications. For example, applications for receiving copied information provided by router 106 may include a billing application, a billing verification application, a TDR generating application, a TDR database application, a lawful surveillance application, a network analysis application, a network statistics application, and a fraud mitigation application. In one embodiment, an application for receiving copied information provided by router 106 may be co-located or integrated with router 106. In another embodiment, an application for receiving copied information provided by router 106 may be located external of router 106.

In the embodiment illustrated in Figure 10, router 106 (e.g., using MM module 1000) is configurable for monitoring Diameter signaling messages transiting the node. In one embodiment, monitored messages may include one or more messages defined in the technical specification mentioned above.

Router 106 (e.g., using MM module 1000) may maintain or provide information for maintaining a TDR database 1002. TDR database 1002 may include functionality for storing one or more TDRs associated with observed messages. In one embodiment, TDRs may include at least of a complete copy of an observed Diameter message, a portion of an observed Diameter message, and information (e.g., statistics, metrics) associated with observed Diameter signaling traffic.

In one embodiment, TDR database 1002 may be co-located or integrated with router 106. In another embodiment, TDR database 1002 may be located external of router 106.

In the embodiment illustrated in Figure 10, the messages depicted are essentially the same as described in reference to Figure 3 and, as such, their description will not be repeated herein. However, in the embodiment illustrated in Figure 10, one or more of the messages, portions thereof, or information associated with the message that transit router 106 may be copied and the copied information may be provided to an application using MM module 1000. For example, a TDR generating application may -33- IL 219214 /2 generate one or more TDRs using copied information provided by router 106. The TDR generation application or other entity may the one or more TDRs in TDR database 1002. The TDRs may include information associated with the messages that transited router 106, e.g., via an LTE interface, such as an LTE S6 or S13 interface.

Router 106 or another entity (e.g., an accounting module or network operator) may use TDR-related information for various purposes, e.g., network analysis, accounting, and billing purposes. In a second example, TDR-related information may be used for lawful surveillance of messages. It will be appreciated that various other uses and purposes may be readily apparent and are within the scope of the present disclosure.

Figure 11 is a flow chart illustrating exemplary steps for Diameter routing and firewall filtering according to an embodiment of the subject matter described herein. In one embodiment, one or more exemplary steps described herein may be performed at or performed by Diameter signaling router 106.

Referring to Figure 11, in step 1100, a first Diameter message having Diameter information may be received via a network interface from a first Diameter node. For example, a ULR message may be received as illustrated in Figure 2. In one embodiment, the first Diameter node may be an MME (e.g., MME 104). In another embodiment, the first Diameter node may be an HSS or AAA (e.g., HSS/AAA 110).

In step 1102, it may be determined whether the first Diameter message satisfies a firewall policy, where the firewall policy is based on at least a portion of the Diameter information in the first Diameter message. In one embodiment, the portion includes any information in a Diameter header portion and a Diameter data portion. For example, the Diameter header portion may include information regarding a Diameter version, a Diameter message length, a Diameter flag, a command code (CC), a Diameter application identifier (ID), a hop by hop ID, and an end to end ID. In one embodiment, the Diameter data portion may include any information associated with attribute values pairs. For example, the Diameter Data -34- IL 219214 /2 portion may include information regarding an AVP code, an AVP flag, an AVP length, a vendor ID, and AVP data.

In one embodiment, a firewall policy includes at least one of a rule for determining whether a Diameter message is associated with a desired characteristics, a rule for determining whether a Diameter message is associated with an undesired characteristics, information for accessing a data structure for determining whether a Diameter message satisfies a firewall policy, information for accessing a whitelist, and information for accessing a blacklist.

In one embodiment, a firewall module may determine whether the first Diameter message satisfies a firewall policy. In this embodiment, the firewall module may include any or all firewall/NAT module 700 described above. For example, firewall module may include a network address translation (NAT) module for performing network address translation (NAT) processing on the first Diameter message and performing NAT on the first Diameter message. In one embodiment, the NAT module may also be configured to perform NAT processing on a response message destined to the first Diameter node that corresponds to the first Diameter message.

In step 1104, in response to determining that the first Diameter message satisfies a firewall policy, forwarding, using the Diameter information, at least a portion of the first Diameter message towards a second Diameter node. In one embodiment, a routing module may forward, using the Diameter information, at least a portion of the first Diameter message towards a second Diameter node. In this embodiment, routing module may include any or all forwarding and routing functionality described above. For example, a ULR message may be routed as illustrated in Figure 2. In one embodiment, the second Diameter node may be an HSS or AAA (e.g., HSS/AAA 110). In another embodiment, the second Diameter node may be an MME (e.g., MME 104).

In one embodiment, router 106 or firewall module may include a mitigation module for performing a mitigating action in response to the first Diameter message failing to satisfy the firewall policy. In one embodiment, mitigating actions may include discarding the first Diameter message, -35- IL 219214 /2 generating an error code, generating an error message, communicating an error message to a Diameter node, generating an event record, generating a log entry, modifying the first Diameter message, generating a second Diameter message based on the first Diameter message; modifying the Diameter information in the first Diameter message, modifying the first Diameter message to satisfy the firewall policy, triggering NAT processing for a Diameter message, triggering the routing module to handle the modified first Diameter message, triggering the routing module to handle the second Diameter message, and notifying an entity.

Figure 12 is a flow chart illustrating exemplary steps for monitoring Diameter signaling messages according to an embodiment of the subject matter described herein. In one embodiment, one or more exemplary steps described herein may be performed at or performed by Diameter signaling router 106.

Referring to Figure 12, in step 1200, a first Diameter message having Diameter information may be received via a network interface from a first Diameter node. For example, a ULR message may be received as illustrated in Figure 2. In one embodiment, the interface may include an LTE interface, such as an S6 interface or an S13 interface. In one embodiment, the first Diameter node may be at least one of an MME (e.g., MME 104), an HSS, an AAA server (e.g., HSS/AAA 110), and an EIR node.

In step 1202, at least a portion of the first Diameter message may be copied and the copied information associated with the first Diameter message may be provided to an application. For example, monitoring module may include functionality for providing copied information to at least one of a billing application, a billing verification application, a TDR generating application, a TDR database application, a lawful surveillance application, a network analysis application, and a fraud mitigation application.

In one embodiment, the copied portion of the first Diameter message includes at least one: a copy of the first Diameter message, a portion of the first Diameter message, and statistics associated with the first Diameter message. For example, statistics may include characteristics about a -36- IL 219214 /2 session (e.g., the number of packets exchanged in a session and the bandwidth usage). In one embodiment, the monitoring module may include functionality for updating or providing information to an application (e.g., a network statistics or metrics application) for updating LTE network usage measurements information based on the first Diameter message.

Figure 13 is a flow chart illustrating exemplary steps for routing Diameter signaling messages according to an embodiment of the subject matter described herein. In one embodiment, one or more exemplary steps described herein may be performed at or performed by Diameter signaling router 106.

Referring to Figure 13, in step 1300, a first Diameter message having LTE subscriber identifying information may be received via an LTE interface from a first Diameter node. For example, a ULR message may be received as illustrated in Figure 2. In one embodiment, the LTE subscriber identifying information may include one or more of a subscriber identifier, a device identifier, an international mobile subscriber identifier (IMSI), a mobile subscriber integrated services digital network (MSISDN) number, a short code, a uniform resource identifier (URI), an international mobile equipment identifier (IMEI), a mobile identification number (MIN)).

In step 1302, LTE node addressing or routing information corresponding to the LTE subscriber identifying information may be determined. In one embodiment, a subscriber location module may determine LTE node addressing or routing information corresponding to the LTE subscriber identifying information. In this embodiment, the subscriber location module may include any or all processing functionality described above. For example, subscriber location module may inspect or examine a received message for LTE subscriber identifying information. In one embodiment, the subscriber location module may query one or more databases to obtain the LTE addressing or routing information for forwarding the first Diameter message.

In one embodiment, the one or more databases include at least one of: a range-based section for associating groups of subscriber identifiers and addressing or routing information for associated nodes and an exception- -37- IL 219214 /2 based section for associating subscriber identifiers and addressing or routing information for associated nodes that are different from associations in the range-based section.

In one embodiment, the subscriber location module may perform address resolution for determining the addressing or routing information. For example, the subscriber location module may obtain addressing or routing information and determining that the addressing or routing information needs to be resolved (e.g., addressing or routing information may be in a non-preferred format, such as an FQDN value or non-routable address). The subscriber location module may query a DNS server or other appropriate node for suitable or preferred addressing or routing information (e.g., a SIP URI). In one embodiment, addressing or routing information may include one or more of a node identifier, a uniform resource identifier (URI), a fully qualified domain name (FQDN), and an Internet protocol (IP) address.

In step 1304, using the LTE node addressing or routing information, at least a portion of the first Diameter message may be forwarded in response to determining the LTE node addressing or routing information corresponding to the LTE subscriber identifying information. In one embodiment, a routing module may perform the forwarding. In this embodiment, routing module may include any or all forwarding and routing functionality described above. For example, a ULR message may be routed as illustrated in Figure 2. In one embodiment, forwarding at least a portion of the first Diameter message includes generating a new message based on the first Diameter message.

In one embodiment, the Diameter signaling router may be configured for forwarding in a relay mode such that the first Diameter message is relayed towards the second Diameter node. In another embodiment, the Diameter signaling router may be configured for forwarding in a proxy mode such that the Diameter signaling router acts as proxy for the first Diameter node or a second Diameter node. In yet another embodiment, the Diameter signaling router may be configured for forwarding in a redirect mode such -38- IL 219214 /2 that the first Diameter node is instructed to forward the first Diameter message towards a second Diameter node.

In one embodiment, nodes may include one of a home subscriber server (HSS), a gateway node, a foreign gateway node, a server, a mobility management entity (MME) node, an authentication, authorization, and accounting (AAA) server, a Policy Charging Rule Function (PCRF), a Policy and Charging Enforcement Function (PCEF), and an equipment identity register (EIR) node.

Various LTE-based embodiments for performing various message processing-related (e.g., routing and security) functions have been described above. It will be appreciated that the above examples are illustrative and that the functionality described herein may implemented for use with or applicable for various Diameter messages, various Diameter-related interfaces and various Diameter-related nodes, including messages, interfaces, and nodes not explicitly described above, without departing from the scope of the subject matter described herein.

Any of the embodiments described herein can be combined with each other without departing from the scope of the subject matter described herein. For example, any of the embodiments above of a Diameter signaling router with integrated monitoring functionality as described above can be combined with any of the embodiments above of a Diameter signaling router with firewall filtering functionality to produce a Diameter signaling router with integrated monitoring and firewall filtering functionality without departing from the scope of the subject matter described herein.

It will be understood that various details of the subject matter described herein may be changed without departing from the scope of the subject matter described herein. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation. -39-