Testing network equipment

0001The present disclosure relates to the generation and reception of traffic for testing a network or network device.

0002In many types of communication networks, each message to be transmitted is divided into fixed-length or variable-length portions. Each part may be referred to as a packet, frame, cell, datagram, data unit, or other unit of information, all of which are referred to herein as packets.

0003Each packet contains a portion of the original message, commonly referred to as the packet payload. The payload of the packet may include data and may include audio or video information. The payload of the packet may include network management control information. In addition, each packet contains identification and routing information, commonly referred to as packet headers. Packets are sent individually across the network through multiple switches or nodes. Before the message is delivered to the target device or end user, the packet is reconstructed into a message at its final destination, using the information contained in the packet header. On the receiving side, the reconstructed message is passed to the end user in a format compatible with the user's device.

0004A communication network that sends a message as a packet is called a packet switching network. Packet-switched networks generally include a mesh of transmission paths that intersect at a hub or node. At least some nodes may include switching devices or routers that receive packets arriving at the node and retransmit the packets along the appropriate outbound route. The packet switching network is controlled by the hierarchical structure of industry standard protocols.

0005To test a packet-switched network or device included in a packet-switched communication network, test traffic containing a large number of packets may be generated, sent from one or more ports to the network, and received on different ports. Each packet of test traffic may be a unicast packet intended to be received on a particular destination port, or a multicast packet intended to be received on more than one destination port. There may be. In this context, the term "port" refers to a communication connection between a network and the equipment used to test the network. The term "port device" refers to a module that has a network test device that connects to a network at a port. You may analyze the received test traffic to measure the performance of your network. Each port device connected to the network may be both a source of test traffic and a destination of test traffic. Each port device may emulate multiple logical source or destination addresses. The number of port devices and communication paths that connect the port devices to the network are generally fixed during the test session. For example, a communication path or hardware device failure can change the internal structure of the network during a test session.

0006As used herein, a series of packets originating from a single port device and having a particular type of packet and a particular speed are referred to as "streams". The source port device may support multiple outgoing streams simultaneously and in parallel, for example, to accommodate multiple packet formats, speeds, or destinations. "At the same time" means "at exactly the same time." "Parallel" means "within the same time range".

0007Multiple parallel streams may be combined to form test traffic output from the source port. The streams in the test traffic may be transmitted sequentially or in parallel by interleaving. Interleaving may be balanced, disproportionate, or distributed among the streams represented. To test modern "triple play" networks and network equipment, test traffic may include simulated data streams, audio streams, and video streams.

0008The test traffic may be divided into multiple "traffic items". Each traffic item is effectively a separate test from each other traffic item. Test traffic for some or all of multiple traffic items may be generated and sent in parallel. Each traffic item may contain multiple streams. Each stream may generally be part of a single traffic item.

0009For the purpose of collecting test data, test traffic for each traffic item may be organized into packet groups. A "packet group" is any plurality of packets for which network traffic statistics are to be accumulated. Packets within a given packet group may be distinguished by the packet group identifier (PGID) contained in each packet. The PGID may be, for example, a dedicated identifier field or a combination of two or more fields in each packet.

0010Test traffic for each traffic item may be organized into flows for the purpose of reporting network traffic data. A "flow" is any plurality of packets for which network traffic statistics are to be reported. Each flow may consist of a single packet group or a small number of packet groups. Each packet group may generally belong to a single flow.

0011As used herein, the term "engine" means a set of hardware that can be augmented by firmware and / or software that perform the described functions. The engine may generally be designed using a hardware description language (HDL), which defines the engine primarily by functional language. The HDL design may be verified using HDL simulation tools. The validated HDL design may generally be translated into an engine gatenet list or other physical description in a process then referred to as "synthesis". The compositing may be performed automatically using a compositing tool. Gate netlists or other physical descriptions go further into programming code to implement engines in programmable devices such as field programmable gate arrays (FPGAs), programmable logic devices (PLDs), or programmable logic arrays (PLA). It may be converted. The gatenet list or other physical description may be translated into process instructions and masks for building an engine inside an application specific integrated circuit (ASIC).

0012As used herein, a hardware "device" means a set of hardware that can be augmented by firmware and / or software that can be larger or smaller than an "engine." For example, the device may include multiple engines, some of which may perform similar functions in parallel. The terms "engine" and "equipment" do not mean any physical separation or boundary. All or part of one or more devices and / or engines may be located on a common card such as network card 114 or inside an FPGA, ASIC or other circuit device.

0013As used herein, the term "logic" refers to combination logic circuits, sequential components such as latches and registers, adaptive logic circuits and / or processors controlled by firmware, and other performing specified functions. Intended to include digital circuits. The engine or device may include a plurality of logic elements.

0014<figref num="1">It is a schematic block diagram which shows the test structure.</figref><figref num="2">It is a schematic block diagram which shows the test structure.</figref><figref num="3">It is a schematic block diagram which shows the test structure.</figref><figref num="4">It is a schematic block diagram which shows the test structure.</figref><figref num="5">It is a schematic block diagram which shows the test structure.</figref><figref num="6">It is a functional block diagram which shows a test module.</figref><figref num="7">It is a functional block diagram which shows a test module.</figref><figref num="8">It is a flowchart which shows the process for testing a network.</figref>

0015Throughout the specification, the components shown in the schematic block diagram are assigned a three-digit reference code, the most significant digit of the reference code indicates the drawing number, and the least significant two digits identify the component. Is. Components not shown on the block diagram may be considered to have the same properties and functions as the previously described components having the same least significant two-digit reference code. In the block diagram, the arrow lines can indicate the data path rather than the signal. The width of each data path may be a plurality of bits. For example, each data path may consist of 4, 8, 16, 32, 64, or more parallel connections.

0016Device description FIG. 1 shows a schematic block diagram of a test configuration including a network device 190 and a test device 110 to be tested. The network device 190 may be a router, a switch, a load balancer, or any other type of device used within a communication network. The network device 190 may be one or more physical devices linked together to perform an integrated function, eg, two or more routers assembled to form a single logical device. There may be. The network device 190 may include all or part of the network, and may be all or part of the network.

0017As shown in the example of FIG. 1, the network device 190 may include a plurality of network cards 192, also commonly referred to as line cards or blades. The network card 192 may be mounted inside the chassis and attached to the motherboard (these are not shown in Figure 1). The network device 190 may include other cards such as a switch configuration card or a processor card (also not shown in FIG. 1). The network device 190 may be configured as some other physical form without a network card.

0018The network device 190 may include a plurality of ports for communicating with other devices such as the test device 110. A low-end switch or router may have, for example, 32, 48 or 64 ports. High-end network devices may have 1000 or more ports.

0019Each network card 192 may provide one or more ports. The port of the network device 190 may be connected to the corresponding port of the test device 110 by the link 120. The link 120 may be a wire cable or an optical cable. Communication over the link 120 between the network device 190 and the test device 110 is in accordance with the ETHERNET® standard, SONET (Synchronous Fiber Optic Network) standard, FIBRECHANNEL (Fibre Channel) standard, or any other communication standard. May be compliant. Each standard may define a plurality of communication speeds. The link 120 may be implemented using different types of optical fibers, different optical wavelengths, and different types of light source lasers, depending on the required communication speed and the length of the link. Since communication over fiber optics is generally half-duplex, separate fiber optic links 120 are provided for bidirectional communication.

0020To provide compatibility with a variety of different communication links to each network card 192, each network card may include a connector 194 that accepts the removable transceiver module 196. A network card that provides multiple ports may have multiple connectors 194 corresponding for the removable transceiver module 196. Each removable transceiver module may transmit and receive via a separate link 120, and thus the link 120 may also be connected to connector 198 on the transceiver module. Each removable transceiver module 196 may communicate with the corresponding network card 192 via a predetermined electrical interface (for each type of transceiver module) accessed at connector 194. Each removable transceiver module 196 may receive power from the corresponding network card via connector 194. Therefore, by selecting and installing the appropriate removable transceiver module 196, each network card 192 can be adapted to various communication links 120.

0021Various removable transceiver modules have been developed according to multi-source agreements between competing manufacturers. For example, for communication speeds of 155 MHz to 4.25 GHz and maximum link lengths of 500 meters to 160 kilometers, more than 40 different removable small form factor (SFP) transceiver modules are available. SPF transceiver modules are available for copper cables or fiber optic links. SPF transceiver modules for fiber optic links can function at optical wavelengths of 850 nanometers, 1310 nanometers, or multiple optical wavelengths from 1470 to 1610 nanometers. SFP transceiver modules intended for short-range communication may use light emitting diodes or vertical resonator lasers and may be compatible with multimode optical fibers. SFP transceiver modules intended for longer range communications may use distributed feedback or Fabry-Perot lasers and may be compatible with single-mode fiber optics.

0022Similarly, various improved removable small form factor (SPF +) transceiver modules are available for communication speeds up to 10.2 GHz, and 10 GHz removable small form for communication speeds up to 11.3 GHz. A factor (XFP) transceiver module is available. The CFP transceiver module, which is currently under development, will support communication speeds of up to 100 GHz. Other types of removable optical transceiver modules include GBIC, XPAK, X2 and XENPAK transceiver modules. Further types of removable transceiver modules can be developed.

0023The test device 110 may include a plurality of test network cards 112. The test network card 112 may be mounted inside the chassis and attached to the motherboard (these are not shown in Figure 1). The test device 110 may include other cards, such as processor cards (also not shown in FIG. 1). In the example of FIG. 1, the test device 110 and the network device 190 are shown to have the same number of network cards. The network card included in the test apparatus 110 may be more or less than the network card included in the network apparatus 190. The test device 110 may be configured as some other physical form without a network card.

0024The test device 110 may include a plurality of ports for communicating with the network device 190. Each test network card 112 may provide one or more ports. Each port of the device under test 190 may be connected to the corresponding port of the test device 110 by a link 120. To provide compatibility with a variety of different optical links to each test network card 112, each network card 112 may include a connector 114 that accepts the removable transceiver module 116. The test network card 112, which provides multiple ports, may include a plurality of corresponding connectors 114 for the removable transceiver module 116.

0025Each transceiver module 116 of the test device 110 may be connected to the corresponding transceiver module 196 on the network device 190 side via the link 120. The corresponding transceiver modules must function at the same optical wavelength and must be compatible with the link 120 connecting the corresponding modules. However, the corresponding transceiver modules do not have to be the same. For example, SFP +, XFP, X2 and XPK transceiver modules are available to provide 10 GHz ETHERNET® communication over single-mode optical fiber with an optical wavelength of 1310 nanometers. In test equipment 110, one of these types of modules may be used, and in network equipment, another one of these types of modules may be used.

0026To test device 190 under test, at least part of the test network card 112 in test device 110 may generate and send test traffic to network device 190, and at least part of test network card 112. , Test traffic may be received from network device 190. Packets sent from one of the ports of test device 110 may then be received by one or more other ports of test device 110.

0027To test network device 190, suitable removable transceiver modules (if no such module is available) may be installed on all ports under test. Second, compatible removable transceiver modules may be installed in the same number of ports as test device 110, and optical fiber links may be connected between the corresponding ports of network device 190 and test device 110. Good. Detachable transceiver modules, fiber optic cables, and the labor required to install the transceiver modules and cables can represent a significant portion of the cost of performing the test.

0028FIG. 2 shows a schematic block diagram of another test configuration 200, including network equipment 290 and test equipment 210 under test. The network device 290 may be a router, a switch, a load balancer, or a cluster of two or more devices. The network device 290 may be an entire network or a part of the network.

0029The network device 290 may include a plurality of network cards 292, the network cards 292-1, 292-2 and 292-3 being identified in FIG. As shown in FIG. 2, each network card 292-1, 292-2, 292-3 may have one port for communicating with other devices such as test device 210. A network card may provide one or more ports.

0030As already shown in FIG. 1, in the conventional test configuration, each port of the network device may be connected to the corresponding port of the test device by a communication link. In the exemplary test configuration of FIG. 2, the port on the network card 292-1 is the network card in test equipment 210 via the detachable transceiver module 296, the communication link 220, and the second detachable transceiver module 216. You may communicate with the corresponding port on the 212. However, in the test configuration in Figure 2, the ports on network cards 292-2 and 292-3 were replaced (instead) with removable transceiver modules and installed on network cards 292-2 and 292-3. It may communicate with the removable test module 230.

0031Each removable test module 230 may be physically compatible with the replaced removable transceiver module. That is, each test module may be replaced with a removable transceiver module and connected to connector 294 on the corresponding network card without interfering with the network card or other parts of the network device. In addition, each removable test module may be mechanically mounted on the corresponding network card using the on-board equipment provided for the replaced removable transceiver module (if any). The external dimensions of the removable test module 230 may or may not be the same as the external dimensions of the replaced removable transceiver module.

0032Each removable test module 230 may be electrically compatible with the replaced removable transceiver module. That is, each removable test module may be electrically connected to the corresponding network card via connector 294 using a predetermined interface for the replaced removable transceiver module. In addition, each removable test module 230 may be configured to function with one or more power forms supplied by the network device 290. Each removable test module 230 may receive power only from the network device 290. Each removable test module may be configured to consume less power than the replaced removable transceiver module.

0033For example, a test module used in place of an SFP + removable transceiver module may have a power consumption of 1.5 watts or less. The test module used in place of the XFP removable transceiver module may have a power consumption of 3.5 watts or less. The SFP + and XFP specifications allow for several types of equipment with different power consumption limits. Depending on the intended use, the power consumption of the SFP compatible removable test module can be less than 1 watt, and the power consumption of the XFP compatible removable test module can be less than 2.5 watts or 1.5. Can be less than or equal to watts. The specifications for the CFP removable transceiver module have not been finalized, but the power consumption of the test module used by replacing the CFP removable transceiver module is less than the maximum power consumption of the specifications of the replaced CFP module. There may be.

0034Each removable test module 230 can also communicate with the test manager 240 inside or connected to the test device 210 via network cards 292-1, removable transceiver modules 216, 296, link 220, and port device 218. Good. Since each detachable test module 230 communicates with the test manager 240 via the network device 290, the detachable test module 230 is referred to herein as an "in-band" detachable test module ("wireless" described below). To distinguish it from "wired" removable test modules). Each in-band removable test module 230 may receive configuration data contained in a packet transmitted from port device 218 through network device 290. Conversely, each in-band removable test module 230 may report test results via packets transmitted through network device 290 to port device 218.

0035The in-band removable test module 230 may send and receive test traffic via the network device 290. Specifically, at least some of the in-band removable test modules 230 may generate and transmit test traffic according to the stream definition data stored in each removable test module. At least some removable test modules 230 may receive test traffic and accumulate traffic statistics and other test results. Part or all of the removable test module 230 may send and receive test traffic.

0036Each removable test module 230 may receive configuration data from the test manager 240 before or during the test session. The configuration data may include one or more addresses that the in-band removable test module can emulate during a test session. Configuration data is stream definition data for one or more packet streams that the in-band removable test module can generate and send during a test session, and the in-band removable test module stores test statistics and other test results. And instructions on how to report may be further included. The configuration data may include criteria and instructions for acquiring and storing specific received packets. Each in-band removable test module 230 may report test statistics, acquired packets, and other test results to the test manager 240 on a regular or on-demand basis during the test session and all accumulated. The test results may be reported to the test manager after the test session.

0037In some circumstances, the in-band removable test module may generate and transmit packets that are partially based on received packets. However, the in-band removable test module is not just a loopback module that iterates or retransmits received packets. All packets generated and transmitted by the in-band removable test module may be based to some extent on the stream definition data stored in the in-band removable test module.

0038Since each in-band removable test module 230 can receive a limited amount of power from the network device 290, the capabilities of the individual in-band removable test modules are compared to the capabilities of port devices such as port device 218. , Can be restricted. For example, the limited power available to an in-band removable test module may limit the amount of memory contained in the module. Limited memory may limit the number of different packet streams that can be generated by the test module, and may limit the number of packet groups for which traffic statistics can be stored. Limited memory may limit the total size of packets acquired by the in-band removable test module, or in-band detachable to either accumulate traffic statistics or acquire packets at any time. Possible test modules may need to be configured. The limited power may limit the processing power within the in-band removable test module, which may result in, for example, limiting the number of protocols that the in-band removable test module can use for communication. ..

0039Each in-band removable transceiver module 230 may have limited ability to receive packets through network device 290 before receiving configuration data. In a typical test state, the configuration data sent to each removable transceiver module may differ, at least to some extent, from the configuration data sent to all other removable transceiver modules. At least one predetermined unique address may be assigned or embedded in each in-band removable test module 230 in order for each individual in-band removable test module 230 to receive appropriate configuration data. For example, the predetermined address may be a MAC (Media Access Control) address or an IP (Internet Protocol) address. The predetermined unique address may be used only for communication of configuration data. Once configured, each in-band removable test module 230 may emulate a virtual device or network with a large number of addresses.

0040To measure temporal performance parameters such as minimum latency, maximum latency, and packet arrival rate, each in-band removable test module 230 has a time clock in the test device 210 that synchronizes with the master time clock. May be good. The time clock in the in-band removable test module 230 may be synchronized by exchanging synchronization packets with the test device 210 via the network device 290. Time-synchronized packets may conform to, for example, IEEE (Institute of Electrical and Electronics Engineers) standard 1588, also known as Precision Time Protocol (PTP). As a further example, each in-band removable test module 230 may include a timecode receiver that receives a wireless timecode signal. The wireless timecode signal may be, for example, a GPS (Global Positioning System) signal or a patented signal transmitted from the test device 210.

0041Cables for individual in-band removable test modules are not required when the in-band removable test module 230 communicates with the test manager 240 via network device 290. Sometimes it is only necessary to install a pair of optical cables (link 220) to test network device 290. In addition to this, depending on the test requirements, a combination of an in-band detachable test module and a cable connection may be used. For example, 5% or 20% of the ports of the network device 290 or a portion other than that may be connected to a port device such as the port device 218 in the test device 210 via an optical cable. The remaining ports of network device 290 may accept in-band removable test modules. If the number of cables is reduced, the cost and time required to test the network equipment can be significantly reduced. In addition to this, the power required to test a network device may be substantially lower than the power of a traditional test configuration as shown in Figure 1. This is because the in-band removable test module 230 may be powered by the network device 290 using the power pre-stored for the removable optical transceiver module.

0042When the in-band removable test module 230 communicates with the test manager 240 through the network device 290, the configuration packets, report packets, and time communicated between the test module 230 and the test manager 240 (if necessary). Synchronous packets are added to the load on network device 290. In some situations, the load of configuration packets, reporting packets, and time-synchronized packets can affect the performance of network device 290 and, to some extent, affect the results of running tests.

0043FIG. 3 shows a schematic block diagram of another test configuration 300, including network equipment 390 and test equipment 310 under test. The network device 390 may be a router, a switch, a load balancer, or a cluster of two or more devices. The network device 390 may be an entire or part of the network. The network device 390 may include a plurality of network cards 392, the network cards 392-1, 392-2 and 392-3 being identified in FIG. As shown in FIG. 3, each network card 392-1, 392-2, 392-3 may have one port for communicating with other devices such as test device 310. A network card may provide one or more ports.

0044In the exemplary test configuration of FIG. 3, the wireless test module 332 may be installed at a port on network cards 392-1, 392-2, 392-3. The wireless test module 332 communicates with the test manager 340 in the test device 310 via the wireless communication link 322 and with at least one wireless master transceiver 318 in the test device 310 or attached to the test device 310. You may go. Each wireless removable test module 332 may generally have the same characteristics as the in-band removable test module 230 by adding a wireless transceiver for communication with the test device 310. The wireless detachable test module 332 may be replaced with a conventional detachable transceiver module and installed on network cards 392-1, 392-2, 392-3. Each wireless detachable test module 332 may receive power only from the network device.

0045Each wireless detachable test module 332 may send and receive test traffic via network device 390. Each wireless detachable test module 332 may send and receive test traffic according to the configuration data received from the test manager 340 via the wireless link 322. Each wireless detachable test module 332 may report test statistics, acquired packets, and other test results to test manager 340 via wireless link 322. Test results may be reported regularly or on request during the test session and / or after the test session.

0046The wireless communication link 322 may comply with a standard such as the IEEE 802.11 standard or the IEEE 802.11 standard. The wireless communication link 322 may comply with industry work group standards such as WIFI or WIMAX, which may be based on one of the IEEE standards. The wireless communication link 322 may comply with another existing communication standard or a future communication standard. The wireless communication link 322 may be patent protected and may not comply with existing standards.

0047Each wireless detachable test module 332 may include a time clock that synchronizes with the master time clock in the test apparatus 310. The time clock in the wireless detachable test module 332 may be synchronized by exchanging synchronization packets with the test device 310 via the wireless communication link 322. The time clock in the wireless detachable test module 332 may be synchronized with the time code provided to control the wireless communication link 322. Each wireless detachable test module 332 may include a time code receiver that receives a wireless time code signal, which may be transmitted, for example, from a GPS (Global Positioning System) signal or test device 310. It may be a signal protected by a patent right.

0048No cables are required to connect the individual wireless detachable test modules 332 to the test device 310, which can significantly reduce the cost of testing the network device 390. In addition to this, the power required to test network device 390 can be substantially lower than the power required for the traditional test configuration in Figure 1. This is because the wireless detachable test module 332 may be powered by the network device 490 using the power pre-stored for the detachable optical transceiver module.

0049Although not shown in FIG. 3, a combination of a wireless detachable test module and a cable connection may be used depending on the test requirements. For example, 5% or 20% of the ports of the network device 390 or other part may be connected to a port device such as the port device 318 in the test device 310 via an optical cable. The remaining ports of network device 390 may accept the wireless detachable test module 332.

0050When the wireless detachable test module 332 communicates wirelessly with the test manager 340, the configuration packets, report packets, and time synchronization packets that are communicated between the test module 332 and the test manager 340 (if necessary) are network devices. It is not added to the load on the 390 and may not affect the results of running tests.

0051FIG. 4 shows a schematic block diagram of another test configuration 400, including network equipment 490 and test equipment 410 under test. The network device 490 may be a router, a switch, a load balancer, or a cluster of two or more devices. The network device 490 may be an entire or part of the network. The network device 490 may include a plurality of network cards 492, the network cards 492-1, 492-2 and 492-3 being identified in FIG. Each network card 492-1, 492-2, 492-3 may have one port for communicating with other devices such as test device 410. A network card may provide one or more ports.

0052In the exemplary test configuration 400 of FIG. 4, the ports on the network cards 492-1, 492-2, 492-3 are in the wired detachable test module 434, the low bandwidth wired communication link 424, and the test device 410. It may communicate with the test manager 440 in the test apparatus 410 via one or more low bandwidth transceivers 418. In this context, the term "low bandwidth" means a bandwidth that is substantially less than the bandwidth of the connection between the wired detachable test module 434 and the port of network device 490. The bandwidth of the low bandwidth communication link 424 may be a small fraction (eg, less than a few percent) of the bandwidth of the ports of network device 490.

0053The wired detachable test module 434 may generally have the same characteristics as the in-band detachable test module 230 by adding a low bandwidth transceiver for communication with the test apparatus 410. The wired detachable test module 434 may be replaced with a conventional detachable transceiver module and installed on network cards 492-1, 492-2, 492-3. The wired detachable test module 434 may receive power only from the network device 490. Alternatively, each wired detachable test module 434 may receive power from the network device 490 and may receive additional power from the test device 410 via the low bandwidth wired communication link 424. For example, each wired detachable test module 434 may receive power in accordance with IEEE standard 802.3af for Power over Ethernet® (PoE). [0064] Each wired detachable test module 434 may send and receive test traffic via network device 490. Each wired detachable test module 434 may send and receive test traffic according to the configuration data received from the test manager 440 via the low bandwidth communication link 424. Each wired detachable test module 434 may report test statistics, acquired packets, and other test results to test manager 440 via the low bandwidth communication link 424. Test results may be reported regularly or on request during the test session and / or after the test session.

0054The low bandwidth communication link 424 may comply with a standard such as a USB (Universal Serial Bus) standard, an IEEE1394 standard, or an Ethernet® standard. The low bandwidth communication link 424 may comply with another existing communication standard or a future communication standard. The low bandwidth communication link 424 may be patent protected and may not comply with existing standards. The low bandwidth communication link 424 may be physically realized, for example, by a low cost twisted pair cable conforming to the FCC standard RJ14, RJ25 or RJ45.

0055Each wired detachable test module 434 may include a time clock that synchronizes with the master time clock in the test apparatus 410. For example, the time clock in the wired detachable test module 434 may be synchronized by a signal transmitted from the test apparatus 410 to each wired detachable test module 434 via a cable used for the wired communication link 424.

0056Although not shown in FIG. 4, a combination of a wired detachable test module 434 and a full bandwidth cable connection may be used, depending on the test requirements. For example, 5% or 20% of the ports of the network device 490 or a portion other than that may be connected to a port device such as the port device 218 in the test device 410 via an optical cable. The remaining ports of network device 490 may accommodate the wired detachable test module 434. The remaining ports of the network device 490 may accept a combination of the wired detachable test module 434 and the wireless detachable test module 332.

0057When the wired detachable test module 434 communicates with the test manager 440 via the low bandwidth communication link 424 outside the network device 490, it is between the wired test module 434 and the test manager 440 (if necessary). Configuration packets, report packets, and time-synchronized packets that are communicated may not add to the load on network device 490 and may not affect the results of running tests.

0058When testing network equipment with the Wired Detachable Test Module 434, a cable must be connected between network equipment 490 and test equipment 410. However, in contrast to the fiber optic cable required in the conventional test configuration of FIG. 1, the cable required here is a low cost cable. In addition to this, high cost optical transceiver modules are not required on all ports of network and test equipment. In addition to this, the power required to test a network device may be substantially lower than the power of a traditional test configuration. This is because the wired detachable test module 434 may be powered by the network device 490 using the power pre-stored for the detachable optical transceiver module.

0059A single computing device if the network device has multiple ports for accepting a wireless detachable test module such as the wireless detachable test module 332 or a wired detachable test module such as the wired detachable test module 434. Can be impractical to act as a test manager for all removable test modules. In such a state, a hierarchical test manager as shown in FIG. 5 may be used.

0060FIG. 5 shows an exemplary test configuration 500, including multiple wireless or wired detachable test modules 532/534 installed in network device 590. Each of the plurality of removable test modules may communicate with the hierarchical test manager 540 via a wireless or wired communication link 522/524. The hierarchical test manager 540 may include a master test administrator device 542 and two or more controller / aggregator devices 544-1, 544-2. Each controller / aggregator device 544-1, 544-2 may communicate with each part of the test module 532/534. In the example of FIG. 5, each of the two controller / aggregator devices 544-1, 544-2 may communicate with approximately half of the test modules 532/534.

0061The hierarchical test manager may include two or more controller / aggregator devices. For example, a network device with 1024 ports may be tested with 32 controller / aggregator devices, and each controller / aggregator device may have 32 ports installed on the 32 ports of the network device. Communicate with the removable test module. A network device with 1024 ports is a 16 controller / aggregator device, each communicating with 64 removable test modules, or a 64 controller / aggregator device, each communicating with 16 removable test modules. , Or some other controller / aggregator device may be used.

0062Each controller / aggregator device 544-1, 544-2 may provide configuration data to its respective removable test module 532/534. For example, each controller / aggregator device 544-1, 544-2 may relay the configuration data received from the test administrator device 542 to their respective detachable test modules 532/534. Each controller / aggregator device 544-1, 544-2 may generate configuration data based on the instructions received from the test administrator device 542, and the generated configuration data may be used in the detachable test module 532 /. It may be sent to 534. Each controller / aggregator device 544-1, 544-2 may receive traffic statistics and other test results from its respective removable test module. Each controller / aggregator device 544-1, 544-2 may aggregate the received traffic statistics and report the aggregated traffic statistics to the test administrator device.

0063Referring to FIG. 6, the detachable test module 630 (which may be the detachable test module 230) includes a traffic receiver 640 for receiving a packet stream from the port of the network device 690 under test. You may. The received traffic stream may include test traffic and configuration packets. The configuration packet may transfer configuration data 656 that controls at least some functions of the detachable test module 630.

0064The traffic receiver 640 may direct the test traffic 658 to the acquisition engine 644 and / or the statistics engine 642. The acquisition engine 644 may acquire and store received packets according to acquisition criteria included as part of configuration data 656. The statistics engine 642 may extract test data from received test traffic or accumulate traffic statistics for multiple packet groups. The accumulated traffic statistics may include quantitative information about each packet group, such as the number of packets received and / or the number of packets received out of order. The accumulated traffic statistics may include temporal information such as minimum latency, maximum latency and average latency for packets within each packet group. Configuration data 656 may include data defining traffic statistics to be accumulated by the statistics engine 642.

0065The packets acquired by the acquisition engine 642 and the traffic statistics accumulated by the statistics engine 644 may be formed in the test report by the report packet generator 646. The report packet generator 646 may generate and send a test report via a network device. The report packet generator 646 may generate and send a test report during a test session, periodically or on request, and / or after a test session. May be sent.

0066Configuration data 656 received via network device 690 may include stream definition data that defines one or more packet streams to be generated by the detachable test module 630. Stream definition data includes, for example, data that defines the type and format of one or more packet streams to be generated, data that indicates the communication speed of each packet stream, instructions that fill variable content fields within each packet, and other data. Information may be included. The traffic generator 648 may generate and send test traffic according to the stream definition data contained in the configuration data 656. The multiplexer 650 may insert the test report generated by the report packet generator 646 into the flow of test traffic generated by the traffic generator 648.

0067The detachable test module 630 may be configured to maintain a stateful connection such as TCP (Transmission Control Protocol Connection), or may be configured to simulate a stateful connection. In any case, the detachable test module 630 may generate a transmission packet as a reply to a specific received packet. For example, the traffic receiver 640 may identify a received packet requesting a response and may provide data or instructions 660 to the traffic generator. The traffic generator 648 may generate a stateful response packet (a response generated considering the state or history of the connection) or a simulated stateful response packet (a response based solely on the content of the received packet).

0068The removable test module 630 synchronizes the internal timecode generator or clock with the master timecode generator in the network device and / or the test device (not shown) connected to the removable test module 630. A code synchronization device 652 may be provided. The timecode synchronization device 652 may receive time synchronization packets from the test device via the network device 690 and the traffic receiver 640, for example, in accordance with IEEE standard 1588. The timecode synchronization device 652 may include a receiver for directly receiving the synchronization signal or synchronization data from the test device via a wired communication link or a wireless communication link (not shown). The time code synchronization device 652 may include a receiver such as a GPS receiver for receiving the synchronization signal or synchronization data from some other source.

0069The removable test module 630 may include a boot loader 654 for receiving initial configuration data before the traffic receiver 640 and other parts of the removable test module 630 are fully configured. The boot loader 654 may be configured to receive at least one type of packet addressed to a unique address pre-assigned to the detachable test module 630. The bootloader may extract configuration data from these packets and supply the configuration data to other parts of the detachable test module 630. Removable test module, the actual using the stored programmable gate arrays or other programmable logic device at least in part when it is revealed, the boot loader 654 extracts the programming data from the received packet, the programming data It may be configured to use to configure a programmable logic device or device.

0070The removable test module 630 may receive power only from the network device. The removable test module may be replaced with a removable transceiver module and installed in the network device. The removable test module may be configured to consume less power than the replaced removable transceiver module.

0071As shown in FIG. 6, the division of the removable test module 630 into functional elements does not mean the corresponding physical division. All or part of the traffic receiver 640, the statistics engine 642, the acquisition engine 646, the traffic generator 648, the multiplexer 650, the timecode synchronizer 652, and the bootloader 654 may be implemented in one or more physical devices. All or part of the removable test module 630 may be implemented by one or more application specific integrated circuits (ASICs). All or part of the removable test module 630 may be implemented by one or more field programmable gate arrays (FPGAs) or other programmable logic circuits. The programming code used to configure one or more FPGAs or programmable logic circuits may be uploaded to the removable test module 630 each time power is turned on. Each FPGA may return to its unprogrammed state each time it is powered down. All or part of the functionality of the removable test module 630 may be achieved by software or firmware executed by one or more processors in the removable test module.

0072With reference to Figure 7, the detachable test module 732/734, which can also be the wireless detachable test module 332 or the wired detachable test module 434, is a traffic receiver 740, statistics engine 742, acquisition engine 744, report packet generator 746, traffic generator It may include a 748, a multiplexer 750, a timecode synchronizer 752, and a bootloader 754. The functionality of these components of the removable test module 732/734 may be similar to that of the equivalent components of the removable test module 630. The description of the functions of these components will be omitted.

0073The removable test module 732/734 may include a control transceiver 762 that can communicate with the test manager 740 via wireless communication link 722 or wired communication link 724. Some or all of the programming data used to program the FPGA or other programmable device in the removable test module 732/734 is received from the test manager 740 via communication link 722/724 and control transceiver 762. You may. Part or all of the configuration data 756 that defines and controls the operation of the removable test module 732/734 may be received from the test manager 740 via communication link 722/724 and control transceiver 762. Some or all of the test reports generated by the report packet generator 746 may be sent to the test manager 740 via control transceiver 762 and communication link 722/724.

0074Each removable test module 732/734 may receive power only from network device 790. Alternatively, the wired detachable test module 734 may receive power from the network device 790 and further power from the test device accommodating the test manager 740 via the low bandwidth wired communication link 724. May be good. For example, each wired detachable test module 734 may receive power in accordance with IEEE standard 802.3af for Power over Ethernet® (PoE).

0075Detachable test modules 630, 732 and 734 are exemplary and other removable test module configurations are possible. For example, the detachable test module may be configured to communicate with the test manager via the network device under test and receive timecode synchronization over another wired or wireless connection. The detachable test module may be configured to receive some or all of the power via a wired connection and communicate with the test manager over a wireless link and / or via a network device under test. Detachable test modules configured to communicate with the test manager via a wire drink or wireless link may communicate with the test manager via the network device under test.

0076Process description With reference to FIG. 8, step 800 for testing the network device can start at step 810 and end at step 890. At least the operations from step 860 to step 880 may be cyclical and may be repeated many times during the test session.

0077In step 820, one or more removable test modules may be replaced (instead of) with the corresponding number of removable transceiver modules and installed in the network equipment. The removable test modules installed in step 820 are in-band removable test modules (such as in-band removable test modules 230), wireless removable test modules (such as wireless removable test modules 332), and (wired removable test modules). It may be a wired detachable test module (such as test module 434), or a combination of these with other types of detachable test modules. If the detachable test module installed in step 820 includes an in-band detachable test module, it will continue to use, for example, a detachable transceiver module and fiber optic cable to provide one or more ports on the network device. , May be connected to the corresponding test equipment port. If the detachable test module installed in step 820 is a wireless detachable test module and / or a wired detachable test module, some of the network device ports will continue to be the corresponding test device ports. It may be connected to as an option. If the detachable test module installed in step 820 comprises a wired detachable test module, the low bandwidth wire cable should be placed between each wired detachable test module and the corresponding low bandwidth test equipment port. , May be installed.

0078Communication may be established between the test manager external to the network device in step 830 and the removable test module installed in the network device in step 820. Communication between the test manager and the in-band removable test module may be established by exchanging packets via a network device. Communication between the wireless detachable test module and / or the wired detachable test module and the test manager may be established using a wireless communication link or a low bandwidth wired communication link, respectively, independently of the network device. .. In all cases, each removable test module may have at least one predetermined unique communication address used to establish initial communication with the test manager.

0079In step 840, programmable devices such as field programmable logic arrays in each removable test module may be programmed using programming data received from the test manager via the communication link established in step 830. Each of the plurality of removable test modules may be programmed in the same way or differently. If multiple removable test modules are programmed in the same way, the programming data may be broadcast from the test manager to multiple removable test modules, or individually to the removable test modules. May be good.

0080After the removable test modules are programmed in step 840, each removable test module may be configured in step 850. Specifically, in step 850, each removable test module may receive configuration data from the test manager via the communication link established in step 830. The configuration data may include one or more addresses that the in-band removable test module can emulate during a test session. Configuration data is defined for one or more packet streams that the in-band removable test module can generate and send during a test session, and the in-band removable test module accumulates and reports test statistics and other test results. It may further include instructions on how to do it. The configuration data may include criteria and instructions for acquiring and storing specific received packets.

0081At least some types of removable transceiver modules are hot swappable. That is, the transceiver module may be removed and replaced while the network device is functioning. Detachable test modules used to replace hot-swappable transceiver modules may also be hot-swappable. Hot-swappable test modules may be available for programming and configuration immediately after being installed in the network equipment. In this case, communication establishment, programming, and configuration of each removable test module may start immediately after each module is installed in the network device, so that the operations in steps 830, 840, and 850 , May proceed in parallel for multiple removable test modules.

0082A test session may be initiated after all removable test modules have been configured in step 850. In step 860, at least some removable test modules may send test traffic through the network device, and at least some removable test modules may receive test traffic from the network device. Part or all of the removable test module may both send and receive test traffic. The removable test module may send and receive test traffic according to the configuration data received from the test manager in step 850.

0083In step 870, some or all of the removable test modules may report test statistics, acquired packets, and other test results to the test manager. The removable test module may report test results in step 870 on a regular basis during the test session and / or at the request of the test manager during the test session. Some or all of the removable test modules may report all accumulated test results to the test manager after the test session.

0084In step 880, it may be determined whether the test session has ended. Completing a combined network device test may involve the transmission and accumulation of traffic statistics for a group of 100,000 or more packets containing millions of packets. If it is determined in step 880 that the test session has not ended, the test session may be continued in step 860. In some circumstances, changes may be made to the configuration of at least some removable test modules during the duration of the test session, as indicated by the dashed arrow 885. The operations in steps 860, 870, and 880 are shown as sequential operations for ease of description, but may be performed continuously or substantially in parallel.

0085If it is determined in step 880 that the test session has ended, step 800 may be terminated in step 890.

0086Summary The embodiments and examples presented throughout this specification do not limit the devices and processing procedures disclosed or claimed and should be considered as typical examples. Many of the examples presented herein include specific combinations of method actions or system elements, but it is noted that those actions and elements can achieve the same purpose when combined in other ways. Should be understood. With respect to the flow chart, more steps or fewer steps may be included, and the steps shown may be combined or further refined to achieve the methods described herein. Actions, components and features described in relation to only one embodiment are not intended to be excluded from similar roles in other embodiments.

0087As used herein, the term "plurality" means two or more. As used herein, a "set" of items may include one or more such items. The terms "provide," "include," "have," "have," "contain," and "accompany" as used herein, whether described in the specification or in the claims, are restricted. It should be understood that it is not intended to be, i.e., intended to include but not be limited. The transitional phrases "consisting of" and "basically consisting of" are, with respect to the claims, limited or semi-limited transitional phrases, respectively. The use of ordinal numbers such as "first," "second," and "third" that modify a component in a claim is due to the effect of the order or method of one claim on a priority, order, or other claim. It does not mean the temporal order to be executed alone, but distinguishes one claim component with a certain name from another component with the same name (without ordinal numbers), and those claim components. It is used simply as a label to distinguish the elements. As used herein, "and / or" means that the items listed are options, but those options also include any combination of the items listed.