Automatic negotiation of an internet protocol address for a network connected device

The present invention relates to a method of arranging an Internet Protocol (IP) address, and more specifically, automatically generates an IP address for a device connected to a network via network hardware such as a network adapter having a reduced configuration. Regarding making arrangements. Such auto-arrangements can include, for example, automatic allocation of IP addresses or renewal of leases for existing IP addresses.

What is known for peripheral devices such as printers is that by connecting to networks such as Ethernet (registered trademark), local area network (LAN), which operates with TCP / IP as a network protocol, servers, computers, etc. Alternatively, each of a large number of network-connected devices such as hosts can access shared peripheral devices. To function across this network, shared peripherals connected to that network use the Internet Protocol (IP) address that the networked device uses to communicate directly with the shared peripheral. Must have.

Dynamic Host Configuration Protocol (DHCP) is a protocol for assigning dynamic IP addresses to devices on TCP / IP networks. This DHCP is well defined in Non-Patent Document 1. Dynamic addressing allows a device to have a different IP address each time it is connected to a network. In some systems, the device's IP address can change even while it is connected. DHCP also supports a mixture of both fixed and dynamic IP addresses. DHCP simplifies network operations because it monitors IP addresses rather than requiring the administrator to manage the task. This means that, for example, a new computer can be added to the network without the additional task of manually assigning a unique IP address to the new computer.<nplcit num="1"><text>Published by FRC 2131, Internet Engineering Task Force (IETF)</text></nplcit>

Through DHCP, devices connected to a network also request an IP address from a DHCP server connected to that network. The DHCP server then allocates one IP address to the device for a specific lease period. The device is obliged to renew or extend the lease if it wishes to continue using the IP address after the lease expires. The DHCP protocol requires considerable processing power to generate DHCP network packets, select offers from DHCP servers, and monitor lease terms.

A reduced configuration network adapter (reduced configuration network adapter) can be used to connect the printer to a network such as an Ethernet® LAN. Such reduced configuration network adapters retain minimal hardware and processing power. Above all, the cost of adding networking capabilities to the printer is significantly reduced. Reduced Configurations To keep the cost of network adapters low, there are no configurations that facilitate network connectivity and save time and effort for network users. Reduced Configurations Such configurations that are not currently valid in connection with network adapters include, for example, the automatic allocation of IP addresses using DHCP, i.e., the acquisition and use of IP addresses using DHCP. Instead of auto-allocating IP addresses, this reduced configuration network adapter utilizes proprietary or private networking protocols to allocate IP addresses within a particular networking environment, but in all other cases manually by the user. Request to allocate an IP address.

<p> What is needed in the industry is a method that enables automatic IP address arrangements, such as by using DHCP, for peripheral devices connected to the network via a reduced configuration network adapter.</p>

<p> In one embodiment, the present invention provides a method that enables automatic IP address arrangement by using DHCP or the like for peripheral devices connected to a network via networking hardware such as a reduced configuration network adapter. provide. However, as you can see, a number of embodiments of the invention are also available in fully configured networking hardware.</p><p> In one form thereof, the present invention relates to a method of arranging an Internet Protocol (IP) address for an image forming apparatus connected to a network. This method is a step of controlling network communication between the image forming apparatus and the network and a step of defining an image forming state when the image forming apparatus is effective for image forming, and the image is formed during the image forming state. A stage consisting of the forming device waiting in an idle state during a period of non-image formation, a step of defining an automatic IP address arrangement state when the image forming device is not effective for image formation, and a stage in which the image forming device is idle. The stage of determining whether or not the image is in the state, and the stage of determining whether or not the image forming apparatus should leave the image forming state and enter the automatic IP address agreement state if the image forming apparatus is in the idle state. If the image forming apparatus is in an automatic IP address agreement state, it includes various stages of an attempt to automatically assign a first IP address to the image forming apparatus.</p><p> In another embodiment, the present invention relates to an image forming apparatus, which comprises an image forming engine having firmware defining logic and processing functions, and networking hardware communicatively coupled with the firmware. Be prepared. Firmware and networking hardware selectively provide image formation status and automatic IP addressing arrangements. When the image forming apparatus is in the image forming state, the image forming apparatus is effective for image forming, and during the image forming state, the image forming apparatus waits in an idle state during the non-image forming period. When the image forming apparatus is in the automatic IP address arrangement state, the image forming apparatus is not effective for image forming. If the image forming apparatus is idle, the firmware determines whether the image forming apparatus should leave the image forming state and enter the automatic IP address arrangement state. When the image forming apparatus is in the state of automatic IP address arrangement, the firmware conforms to the attempt of automatic IP address allocation to the image forming apparatus.</p><p> In yet another embodiment, the present invention relates to a method of communicating with a shared image forming apparatus connected to a computer network, comprising communication over the network being facilitated by the use of network packets. This method includes providing networking hardware to the shared imager, providing imager firmware to the shared imager, and defining the data channels associated with the networking hardware. Automatic Internet by image-forming device firmware at the stage of instructing networking hardware to receive information on a data channel from the user who owns the data channel, and when the data channel is not owned. A second that differs from the automatic IP addressing network packet due to the stage of processing the protocol (IP) addressing network packet and when the data channel is owned, depending on the networking hardware of the shared imager. Includes the stages of processing network packets of this type and the stages of processing.</p><p> An advantage of one embodiment of the present invention is that a network device having a reduced configuration network adapter can be adapted seamlessly to facilitate DHCP IP address arrangements in a network environment.</p><p> The previously mentioned features and strengths of the present invention, other features and strengths, and methods for achieving them will become clearer with reference to the following description of the examples of the present invention in combination with the accompanying drawings. , The present invention is better understood.</p><p> Throughout some drawings, the corresponding reference numerals indicate the corresponding parts. The illustrations detailed herein describe various embodiments of the invention and should not be construed as limiting the scope of the invention in any way.</p>

Hereinafter, with reference to various drawings, particularly with reference to FIG. 1, an image forming apparatus 10 connected to an Ethernet (registered trademark) local area network (LAN) via a bidirectional communication link 14 is shown. There is. A host 16 such as a personal computer is also shown, which is communicatively coupled to the network 12 via a two-way communication link 18. In one embodiment, the present invention adds automatic IP addressing capability to the image forming apparatus 10 by using DHCP or the like, while preserving the low cost advantages of networking hardware that would normally have a reduced configuration. ing.

The image forming apparatus 10 serving as a shared networking apparatus includes an image forming engine 20 communicatively coupled with networking hardware 22. The image forming engine 20 includes an image forming data buffer 24, an image forming apparatus firmware 26, an image forming processor 28, and an image forming hardware 30. The image forming data buffer 24 includes a random access memory (RAM) used to store image data and related image forming instructions. The image forming apparatus firmware 26 includes non-volatile memory such as, for example, read-only memory (ROM), flash memory, or electrically erasable programmable ROM (EEPROM), and the logic executed by the image forming processor 28. And the processing function is specified. The image forming processor 28 includes a microprocessor and associated RAM and ROM. The image forming hardware 30 can be, for example, the hardware mechanism of an inkjet printer or a laser printer well known in the art.

Networking hardware 22, which may be, for example, a reduced configuration network adapter, includes media access controller 32, status and instruction control logic 34, hardware filter 36, and state control logic 38. The media access controller 32 is connected to the network 12 via a two-way communication link 14 to facilitate communication over a particular type of network, such as Ethernet®. Further, the media access controller 32 is connected to receive status information regarding the image forming apparatus 10 from the status and instruction control logic 34 via the communication path 40. The media access controller 32 is connected so as to provide the data received from the network 12 in the form of a network packet to the hardware filter 36 via the communication path 42. The media access controller 32 is connected to receive data such as a DHCP packet from the image forming apparatus firmware 26 via the communication path 44. The status and instruction control logic 34 is connected to receive image forming apparatus status information from the image forming apparatus firmware 26 via the communication path 46.

The hardware filter 36 is connected to provide received network packets containing image data and associated image forming instructions to the image forming data buffer 24 via the data channel 48. The hardware filter 36 is connected to provide the received network packet, such as a DHCP packet containing network data and related network instructions, to the image forming apparatus firmware 26 via the communication path 50. The hardware filter 36 is connected via the instruction channel 51 to deliver instructions to the status and instruction control logic 34. The state control logic 38 is connected to receive data from the image forming apparatus via the communication path 52. The state control logic 38 is connected to provide a state selection instruction to the hardware filter 36 via the communication path 54.

Data channel 48 prints the object to be printed from a print driver based on the workstation host of host 16 into a "payload" within the frame of the image-forming network packet, such as within a proprietary protocol and associated packet with pre-defined instructions. Is used to transmit to the image forming apparatus 10. In order to minimize the cost of networking hardware 22 with minimal complexity, in one example, only the hardware filter 36 would allow one workstation, such as host 16, to use data channel 48 at any given time. Allow to "own". In an exemplary embodiment, any information directed to the data channel 48 that does not originate from the host "owner" is immediately discarded by the hardware filter 36.

The instruction channel 51 is used to signal instruction activity to the networking hardware 22. Any host-based networking device can send instructions to the networking hardware 22 via network packets and is processed by the media access controller 32 and the hardware filter 36. Various instruction signals can be specified. For example, the signals "connect", "close", "end", and "status" can be defined as follows. A "connection" is a request to acquire data channel 48 in a request to transmit data. A "close" is a request to open data channel 48. "End" is a request to release data channel 48 and suspend the print job. In one scenario, only network devices based on hosts, such as host 16, which owns data channel 48, can send "close" instructions. A "status" is a request for printer status due to no request to send data. The networking hardware 22 responds with a status response to a status request instruction directed to the instruction channel 51 received from any user while the image forming apparatus 10 is in the image forming state.

To facilitate printing, a print driver loaded on a workstation such as host 16 produces a host-based networking printer-specific data packet in a format that conforms to a pre-specified protocol and that data packet. and tidy the packet And it is delivered to the host-based networking printer such as the image forming apparatus 10 without any change. Workstation host-based networking print drivers are designed to work together in an orderly manner to facilitate "fair sharing" of host-based networking printers across a large number of workstations. The common standard for transferring data onto media must be adhered to by all devices so that they co-exist with multiple other networking devices. For example, DIX or IEEE 802.3 sets the standard for Ethernet®. Each device is UAA (Universally Administered) while adhering to the standard. Address) will have. In addition, each network connection device will have its own IP address in order to communicate on the TCP / IP network. Further adherence commands host-based networking devices to use these addresses to exchange basic units of data (frames) in networking packets. The address is used by networking hardware 22 to deliver the frame to its intended destination.

As a simplified example, and assuming that the image forming apparatus already has an IP address, communication by the host 16 with the image forming apparatus 10 is initiated via the network 12 and communication links 14 and 18. To. Host 16 takes ownership of data channel 48 and provides image data and related image forming instructions to image forming apparatus 10 in the form of network packets, which are processed and stored in the image forming data buffer 24. Will be done. During image formation, the image forming processor 28 executes the image forming instruction stored in the image forming apparatus firmware 26 to search the image data and related image forming instructions stored in the image forming data buffer 24. The image forming processor 28 then processes the retrieved image data and related image forming instructions to generate a signal for controlling the operation of the image forming hardware 30 to form a printed image.

In some networking environments, the IP addresses of networked devices can be fixedly or dynamically assigned. However, in order to take advantage of dynamic allocation, such as by using DHCP, the receiving device must be able to handle associated automatic IP address arrangement network packets such as DHCP packets. In general, one embodiment of the invention uses networking hardware 22 to perform a number of networking protocol functions, such as those associated with proprietary protocols, while auto-IP address arrangements by image-forming device firmware 26. By processing the network packet, the cost of adding an automatic IP addressing protocol such as DHCP to the image forming apparatus 10 is minimized. This is in part by providing an "image forming state" to the image forming apparatus 10 when the image forming apparatus 10 is effective for image forming but not for automatic IP address arrangements. And, although the image forming apparatus 10 is not effective for image forming, it is achieved by providing an "automatic IP addressing arrangement" for the image forming apparatus 10 when an automatic IP address arrangement can be attempted. To.

A method according to an embodiment of the present invention will be described in more detail with reference to FIGS. 2 and 3A-3D. To simplify the discussion, the following methods are described for DHCP environments, but as those skilled in the art will understand, the principles of the invention do not deviate from the spirit of the invention and other automatic IPs. It can also be applied to address arrangement protocols.

In step S102, it is assumed that the image forming apparatus 10 has just suffered a power-on reset. In step S104, it is determined whether or not to attempt automatic IP address acquisition. The image forming apparatus firmware 26 makes such a decision, for example, whether or not the maximum number of attempts have been made to automatically allocate the IP address, a valid IP address and lease time have already been obtained, and the IP address is manually assigned. It is based on various factors including whether it is allocated or the automatic allocation function is disabled. Thus, if this decision is no, the process proceeds to step S110 to ensure that the image forming apparatus 10 is in the image forming state as further described below. If yes, the process proceeds to step S106.

In step S106, the image forming apparatus firmware 26 provides the state control logic 38 with an instruction signal to enter the automatic IP address arrangement state and exit the image forming state, and then the image forming apparatus 10 is idle. To reach. The image forming apparatus firmware 26, the state control logic 38, and the hardware filter 36 determine what type of network packet is transmitted and the destination of the transmitted network packet. During the automatic IP address state, the data channel 48 is not owned, and the state control logic 38 blocks any image formation data directed to the image formation data buffer 24 against the hardware filter 36, and is optional. Instructs to block the proprietary network instruction packet. The control logic 38 further instructs the hardware 36 to send a DHCP packet to be processed by the image forming apparatus firmware 26.

The automatic IP address arrangement is executed in step S108. Details of one embodiment of step S108 are discussed in more detail below with reference to FIGS. 3A-3D. The result of an automatic IP address arrangement is, for example, successful automatic allocation of IP address and lease, failure to successfully arrange automatic allocation of IP address and lease, successful update of current IP address, or update of current IP address. Can be a failure to successfully negotiate.

In step S110, the image forming apparatus firmware 26 provides the state control logic 38 with an instruction signal to enter the image forming state and exit the automatic IP address agreement state. During the image formation state, the state control logic 38 causes the hardware filter 36 to send the image formation data packet received from the owner of the data channel 48 to the image formation data buffer 24, and the hardware filter. Causes 36 to send an instruction to block other network packets, including DHCP packets.

In step S112, it is determined whether it is time to renew the current IP address lease. If no, the process returns to step S110. If yes, the process proceeds to step S114.

In step 114, it is determined whether or not the image forming apparatus 10 is in the idle state. The idle state is a sub-state of the image formation state. When the image forming apparatus 10 is idle, the data channel 48 is not owned by a user such as host 16. During image formation, the image forming apparatus waits in an idle state during the period of non-image formation. During the idle state, it is allowed to return to step S106, enter the automatic IP address arrangement state, and exit the image formation state. However, if in step 114 it is determined that the image forming apparatus 10 is not idle, the data channel 48 is owned and the process returns to step S110 to form the image until the time of renewal of the current IP address lease. The image forming apparatus 10 is in an idle state, essentially maintaining the state.

Details of step S108 of FIG. 2 are discussed here with reference to FIGS. 3A-3D.

Step S200 represents the start of an automatic IP address arrangement routine.

In step S202, it is determined whether a lease renewal of the existing IP address is desired. If yes, the process proceeds to an IP address lease renewal routine, such as that shown by the flowchart in Figure 3D, which is described in more detail below. However, if no, the process proceeds to step S204.

In step S204, it is identified that an attempt is made to obtain a new IP address for the image forming apparatus 10. In essence, this attempt is performed by steps S206-S250 of FIGS. 3A-3C.

In step S206, the networking hardware 22 requires the image forming device firmware 26 to construct a DHCP discover packet.

In step S208, the image forming apparatus firmware 26 transmits the DHCP discover packet to the media access controller 32 over the communication path 44, which leads to the transmission of the DHCP discover packet over the network 12. respond.

In step S210, any DHCP offer packet received by the media access controller 32 is forwarded through the hardware filter 36 and processed by the image forming apparatus firmware 26. It is the image forming apparatus firmware 26 that determines how to respond to the receipt of the DHCP offer packet or to the failure to receive the optional DHCP offer packet.

In step S212, the image forming apparatus firmware 26 determines whether any DHCP offer packet has been received. If no, it is determined that an error condition has occurred in step S214, at which time the process proceeds to step S246 (see Figure 3C) to determine if the maximum number of attempts has been exceeded. .. If at least one DHCP offer packet is received, the process proceeds to step S216.

In step S216, the image forming apparatus firmware 26 selects one of the plurality of DHCP offer packets to be responded to. Such choices can be, for example, random choices.

In step S218, the image forming apparatus firmware 26 builds a DHCP request packet.

In step S220, the image forming apparatus firmware 26 transmits a DHCP request packet to the media access controller 32 via the communication path 44, and then transmits the DHCP request packet over the network 12. A device such as a host 16 that functions as a DHCP server responds to a DHCP request packet with either a DHCP ACK (acknowledge) packet or a DHCP NACK (not acknowledge) packet.

In step S222, the DHCP ACK and NACK packets are received by the media access controller 32, and then the DHCP ACK and NACK packets are transferred through the hardware filter 36 for processing by the image forming apparatus firmware 26.

In step S224, the image forming apparatus firmware 26 determines whether any DHCP ACK packet has been received. If no, then step 226 determines that an error condition has occurred, at which time the process proceeds to step S246 (see Figure 3C) to see if the maximum number of attempts has been exceeded. To determine. If at least one DHCP ACK packet is received, the process proceeds to step S228.

In step S228, the image forming apparatus firmware 26 selects one of the plurality of DHCP ACK packets. Such choices can be, for example, random choices.

In step S230, the image forming apparatus firmware 26 searches the IP address and the IP address lease time from the selected DHCP ACK packet.

In step S232 (see Figure 3C), the imager firmware 26 builds an Address Resolution Protocol (ARP) request packet.

In step S24, the image forming apparatus firmware 26 transmits an ARP request packet to the media access controller 32 via the communication path 44, and then transmits the ARP request packet over the network 12.

In step S236, the image forming apparatus firmware 26 determines whether any ARP reply packet has been received. If no, the process proceeds to step S238, where the IP address and lease time present in the selected DHCP ACK packet is adopted by networking hardware 22. The process proceeds to step S240, where the process is oriented back to step S110 (Figure 2).

In step S236, if the image forming apparatus firmware 26 determines that the ARP reply packet has been received, the process proceeds to step S242.

In step S242, the image forming apparatus firmware 26 builds a DHCP gradient packet.

In step S244, the image forming apparatus firmware 26 transmits a DHCP inclined packet to the media access controller 32 via the communication path 44, and then transmits the DHCP inclined packet over the network 12.

In step S246, the image forming apparatus firmware 26 determines whether the maximum number of attempts has been exceeded to automatically allocate the IP address. If yes, in step S248 the process returns to step S110, where the image forming apparatus 10 enters the image forming state and exits the automatic IP address arrangement state.

However, if in step S246 it is determined that the maximum number of attempts to automatically allocate the IP address has not been exceeded, the process returns to step S200 (Figure 3A) and the automatic IP address arrangement routine To start again.

As mentioned above, if in step S202 (Figure 3A) it is determined that an IP address lease renewal is desired, no attempt is made to obtain a new IP address, but the process proceeds to step S300. Perform the IP address lease renewal routine as shown in the flowchart in Figure 3D.

In step S300, the image forming apparatus firmware 26 constructs a PDHCP request packet to request a renewal of the current I address lease. The image forming apparatus firmware 26 transmits the DHCP request packet to the media access controller 32 via the communication path 44, and then transmits the DHCP request packet over the network 12. The DHCP ack and knuckle packets are received by the media access controller 32, and then the DHCP ACK and / or DHCP NACK packets are transferred to the image forming apparatus firmware 26 via the hardware filter 36.

In step S302, the image forming apparatus firmware 26 determines whether or not an arbitrary DHCP ACK or NACK packet has been received.

If at least one NACK packet is received without ACK in step S302, the image forming apparatus firmware 26 constructs a DHCP release packet in step S304. The image forming apparatus firmware 26 transmits the DHCP release packet to the media access controller 32 via the communication path 44, and then transmits the DHCP release packet over the network 12. Then, in step S306, the process returns to step S200 and restarts the automatic IP addressing routine.

If an ACK packet is received in step S302, the process proceeds to step S308.

In step S308, the image forming apparatus firmware 26 searches the DHCP ACK packet for the IP address and the new IP address lease time, and the new IP address lease time is adopted by the networking hardware 22. Then, in step S310, the process proceeds to step S110 (FIG. 2), where the image forming apparatus 10 enters the image forming state and exits the automatic IP address arrangement state. In an exemplary embodiment, during the automatic IP address arrangement state, the data channel 48 cannot be owned by a network device such as host 16 connected to network 12. However, during the image formation state, the data channel 48 is valid to be owned by the network device connected to the network 12.

If neither the ACK packet nor the NACK packet is received in step S302, the process proceeds to step S310, the process returns to step S110, where the image forming apparatus 10 enters the image forming state and automatically. Retire from the IP address agreement status.

Although the invention has been described as having a suitable design, the invention may be further modified within the spirit and scope of this disclosure. Therefore, this application is intended to surround any modification, use, or application of the invention that uses its general principles. Furthermore, this application also surrounds deviations from this disclosure, etc., which fall within the limits of the claims relating to and attached to the invention, which fall within the well-known or customary practical examples in the art. Intended to be.

<figref num="1">FIG. 1 is a block diagram of an embodiment of a network system including the present invention.</figref><figref num="2">FIG. 2 is a general flowchart of the method according to the present invention.</figref><figref num="3">3A to 3D are flowcharts that describe the automatic IP address arrangement stage of FIG. 2 in more detail.</figref>

Code description

10 Image forming device 12 Network 14,18 Communication link 16 Host 20 Image forming engine 22 Networking hardware 24 Image forming data buffer 26 Image forming device Firmware 28 Image forming processor 30 Image forming hardware 32 Media access controller 34 Instructions Control logic 36 Hardware filter 38 State control logic 40,42,44,45,46,48,50,51,52,54 Communication path