JP3475192B2 - Internetwork equipment and router - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication network system for connecting a plurality of networks, and in particular, an internetwork device called a router device for connecting a plurality of networks at a network layer level and a plurality of data network layer levels. An internetwork device called a bruta that has both a bridge function for connecting networks and a router function for connecting a plurality of networks at a network layer level.

[0002]

2. Description of the Related Art As a device for connecting a plurality of networks, a bridge for interconnecting at a data link layer (particularly, a media access sublayer) of a network system layer, and an interconnect at a network layer which is an upper layer thereof. There is a router, etc.

In the bridge, MAC (Media Access Cont
rol) address is managed, and the judgment of whether to relay a received frame (also called received packet data) from a certain network to another network is the contents of the destination MAC address in the received frame and the relay control information. Follow the filtering address table.

Also, in the router, a predetermined route or an optimum route is selected according to the internetworking address in the received frame and the address resolution (route information) table in the router, and the received frame is relayed. .

There are several types of protocols used in the network layer, and a typical example is IP.
(Internet Protocol) is well known. In this IP protocol, an IP address is used as an internetworking address. Then, in the address resolution table, the MA of the adjacent route corresponding to the destination IP address
The C address is described.

Further, in recent years, a device having both a bridge function and a router function has appeared, and has come to be used for connecting different networks. This device is called Bruta. Of the various protocols used in the network layer, this brouter performs routing for frame data that is supported by the device, that is, according to a routable protocol, and interconnects at the network layer. On the other hand, this Bruta
For frame data that the device does not support, that is, according to a non-routable protocol, relay processing of frame data in the media access sublayer, that is, bridge processing is performed.

As described above, a network device such as a bridge, a router device, and a bruta device has at least two communication ports and at least a processor for performing the above-mentioned relay process called routing or bridging.

As a conventional example having such a configuration, general operation of the router device will be described in more detail. By storing the packet data received from a certain communication port in the buffer memory and performing the routing process on the packet data by the processor, the router device obtains the destination network. Then, by transmitting the packet data from another communication port corresponding to the destination network, the router device routes the packet data.

FIG. 2 is a diagram schematically showing a plurality of networks connected by using a router. In this figure, 8
One network is connected by five routers. Looking at router A among these routers,
Networks A, B, C and D are connected to the ports a, b, c and d of the router A, respectively. Now, if it is desired to send data from the terminal A1 in the network A to the terminal G2 in the network G connected to the router E, the terminal A1
Packet data addressed to the terminal G2 is transmitted with the physical destination address addressed to the port a of the router A. Router A
Receives this packet data, the network B, C,
Relay to any one of D, that is, perform routing. In order to perform this routing, the router A needs to know in advance to which of the networks B, C and D the packet data addressed to the terminal G2 should be relayed. In this example, it is assumed that the packet should be transmitted to the network B, that is, the router B, and the physical destination address of the packet data is transmitted to the port e of the router B. Similar routing processing is performed in the routers B and E, and the packet data finally arrives at the terminal G2.

As a conventional technique for performing such routing processing at high speed, there is a technique described in Japanese Patent Application Laid-Open No. 62-181551 (Patent Document 1). According to this, the buffer memory for storing the packet data received from one port and the buffer memory for storing the packet data received from the other port are separately and independently provided, and the buffer memory is managed by hardware. Is going.

As a technique for performing high-speed packet transfer between ports, "TCP / IP and INTERNET" issued on Dec. 19, 1990 by Net One Systems Co., Ltd.
The technology described on page 17 (Non-Patent Document 1) can be given. According to this, a high-speed bus is provided for high-speed port transfer.

[0012]

[Patent Document 1] JP-A-62-181551

[Non-Patent Document 1] Net One Systems Co., Ltd. 1990
Published on December 19, 2012, "TCP / IP and INTERNE
T overview "page 17

[0013]

However, these conventional techniques have the following problems.

The conventional router can transfer packet data at high speed, but since there is only one means for performing routing, the routing process becomes a bottleneck, and the number of ports and communication traffic that can be supported are limited.
Therefore, it is difficult to smoothly expand the configuration of the port menu of the router from small scale to large scale and improve the performance according to the traffic and number of ports.

Further, the network configuration or the like is recognized during the operation of the network, and the relay information for the routing process (the information for the relay which each router previously knew in the above-mentioned conventional example) is dynamically changed. The need for dynamic routing to create, add, modify, and delete has been increasing in recent years. That is, a routing protocol (for example, RI in the TCP / IP protocol group) for exchanging information about the network between the routers.
P: Routing Information Protocol and OSPF: Open S
hortest Path First etc.) is required. Furthermore, a network management protocol (for example, SNMP: Simple Network Management Protocol in TCP / IP protocol group) for communicating management information such as performance information of the router itself with a management master station on the network.
Since the means for performing routing in the conventional example also has to be used for processing (such as ocol), the original relay performance cannot be fully exerted. Therefore, in the conventional router, a high-speed L of 100 Mbps (Megabit per second) which has recently appeared
FDDI (Fiber Distr) which is AN (local area network)
ibuted Data Interface), wideband ISDN (hereinafter abbreviated as B-ISDN) that is expected to become widespread in the future, and ATM (Asynchronous Transfer Mode) which is one form thereof, and it is difficult to support a high-speed line of 155 Mbps.

An object of the present invention is to provide an internetwork device capable of performing routing and packet transfer at high speed and easily expanding the scale and improving the performance.
To provide a relay device and a router.

A further object of the present invention is to provide an internetwork device, a relay device and a router in consideration of data transfer during bridging processing and routing processing when the above-mentioned function as a brouter is provided.

A further object of the present invention is to provide a router device and a communication processing method capable of connecting to an existing device in order to increase the types of protocols that can be processed.

[0019]

In order to achieve the above object, an internetwork apparatus of the present invention comprises one or more communication ports each connected to a network and transmitting / receiving packet data to / from the network. And a management unit for managing the internetwork device connected to the at least one relay processing unit, the relay processing unit performing a relay process for the packet data received at each communication port. The management unit processes a network management protocol for communicating management information with a management device connected to a network, and generates / changes relay route information, and stores the relay route information in the at least one of the at least one. Means for distributing to the relay processing unit, wherein the at least one relay processing unit is distributed from the management unit. In order to achieve the above-mentioned object, the interface of the present invention is further provided with means for storing relay route information, and means for performing a relay process on the received packet data based on the relay route information. The network device has a first coupling means for coupling between the routing accelerators, and a main processor is connected to the first coupling means as a management unit for managing the entire internetwork device. Then, it has a second coupling means for coupling the plurality of communication port units for transmitting and receiving data to and from the network and the routing accelerator independently of other routing accelerators.

Further, in order to achieve the above object, the internetwork apparatus of the present invention is provided with a third coupling means for coupling between the main processor and the routing accelerator independently of the first coupling means.

Further, in order to achieve the above object, the internetwork apparatus of the present invention has an auxiliary processor in addition to the main processor and the routing accelerator.
Then, the auxiliary processor and the routing accelerator are coupled by the first coupling means or the third coupling means. As functions of the auxiliary processor, a broadcast transfer function for bridge relay, an interface function with another device, or a processing function of a routing protocol that cannot be processed by the main processor are provided to expand the function.

Further, in order to achieve the above-mentioned object, the internetwork apparatus of the present invention includes a routing accelerator as a router circuit, a buffer for storing data, and filtering under a predetermined condition in parallel with the storing operation. It has a filtering assisting means for performing and a routing assisting means for extracting necessary information of the received packet data and searching the relay route selection information table.

[0023]

The routing accelerator performs a routing process on the received packet data and transfers the data to another routing accelerator as needed. That is, the type of the data frame is discriminated, and when it is recognized that the data frame is in accordance with the protocol in which the routing relay process cannot be performed, the data is transferred to the other plurality of routing accelerators for the bridge relay.

The management unit distributes this routing table to all routing accelerators after generating / changing the routing table for router relay. Each routing accelerator performs a routing process on the received packet data from the communication port unit connected by the second coupling means by referring to the distributed routing table, and uses the first coupling means as necessary. And transfer the data to another routing accelerator. That is, the type of the data frame is determined,
When it is recognized that the data frame is based on a protocol that cannot perform routing relay processing, the data is transferred to a plurality of other routing accelerators for bridge relay. The routing accelerator to which the data is transferred further transmits the packet data to the network using the communication port unit connected by the second coupling means. Therefore, the internetwork apparatus of the present invention can perform distributed routing / packet relay by a plurality of sets of the routing accelerator and the communication port unit.

The management frame addressed to the main processor for the main processor to generate / change the routing table and to communicate with the network management master is sent from the routing accelerator to the main processor using the first coupling means. Transferred. In addition, the routing accelerator receives the received data from the communication port unit connected by the second coupling means, determines the type of the data frame, and is a data frame according to a protocol that cannot perform routing relay processing. If it is recognized, it can be transferred to the main processor. The main processor performs the routing process if it can handle the protocol and retransmits the data frame to the appropriate destination routing accelerator,
Performs packet data routing relay according to a special protocol.

The third coupling means performs an operation in which the main processor distributes the routing table to all the routing accelerators and an operation in which the management frame addressed to the main processor is transferred from the routing accelerator to the main processor.

The auxiliary processor has a broadcast transfer function for bridge relay according to the function implemented in the auxiliary processor,
In response to the interface function with other devices and the processing function of the routing protocol that cannot be processed by the main processor, the processing of the main processor or the bridge relay function of the destination routing accelerator is assisted. For example, when the auxiliary processor assists the broadcast transfer function for bridge relay, when the routing accelerator receives a data frame according to a protocol that cannot perform routing relay processing, the frame data to be bridge relayed to this auxiliary processor. To transfer. The auxiliary processor temporarily stores the transferred frame data in the buffer memory and then transfers the data to all other routing accelerators using the first coupling means.

In the routing accelerator, in parallel with storing the received packet data in the buffer, the filtering assist means performs filtering under predetermined conditions, and discards the packet data that need not be relayed. For received packet data that requires relaying,
The processor and the routing assist means determine the destination and transfer the packet to the routing accelerator which is the destination.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Although the internetwork device of the present invention has the function of the above-mentioned brouter device, in the following description, the routing process, which is the original purpose, will be mainly described, and therefore the device will also be referred to as a router. 1. Configuration of Router First, the overall configuration of a router, which is an embodiment of the present invention, will be described with reference to FIG. The router of this embodiment has a plurality of modules for performing routing, and the performance can be easily improved by adding modules.
Each module has one routing accelerator, and each routing accelerator further has one or more communication ports. FIG. 1 is an overall block diagram of a router. In FIG. 1, 1 is 200 MBytes which is the first coupling means.
It is a high-speed router bus with a throughput of 1 / sec. The router bus 1 is connected to a router management unit 2 which is a main processor having a function of managing the entire apparatus and a function of generating and distributing a routing table. Further, to the router bus 1, a routing accelerator 3 having a function of performing high-speed routing can be connected to 1 to 8 modules. The router management unit 2 distributes the routing table to the routing accelerator 3, and each routing accelerator 3 performs route selection, that is, routing processing of the received packet data based on this, and connects the relay destination network to the subordinate. The packet data is transferred to the routing accelerator 3 via the router bus 1.

Further, each routing accelerator 3
Underneath, as shown in 4, a bus that is the second coupling means, for example, 33MBytes /
Second EISA Bus (Extended Industry Standard Archit
ecture Bus) 4. Various communication control units 51 to 56 (hereinafter also referred to as ports) are connected to this bus.
Here, only one 100 Mbps class FDDI high-speed communication port 51, which is a communication port suitable for the throughput of this EISA bus, is connected to the routing accelerator 3 in a one-to-one correspondence. Similarly, only one 155 Mbps ATM (B-ISDN) communication port 52, which is a high-speed line, is connected to the routing accelerator 3. Also, for example, Ethernet (registered trademark) communication ports 53, 4M, which is a LAN of 10 Mbps
Token, which is a LAN of bps to 16 Mbps
Ring LAN communication port 54 or 1.5 Mb
Two or more communication ports for medium and low speed communication such as the communication port 55 of N-ISDN which is a ps line can be connected with the capability of one routing accelerator 3 and the throughput of one EISA bus. is doing. The routing accelerator 3 and the set of communication ports 51 to 56 may be mounted on different boards or the same board. 2. Routing Routing in the router having the above-mentioned basic configuration will be described below.

First, as a premise, the management unit 2 distributes the routing table to all the routing accelerators 3, and each routing accelerator 3 has a routing information. For example, the management unit 2 collects routing information by exchanging with other routers by the above-mentioned routing protocol such as RIP, OSPF, or statically set in advance by the user.

The routing table is a set of routing information indicating one piece of routing information for each network address. Further, with respect to so-called sub-networks, in which the network address is divided and operated as a plurality of small-scale networks, routing information is defined for each sub-network.

FIG. 14 shows an example of one piece of routing information. In this example, only the IP protocol is targeted, and additional information such as the type of network service is omitted. In FIG. 14, the routing table 400
Is a field 401 of the IP address indicating the destination network, subnet mask data 402 indicating the subnet information of the destination network, and the IP address 4 of the next router.
03, sending interface 4 for relaying to the next router
04 and a pointer 405 to the next entry.

In this embodiment, the transmission interface 404 has the identification number (RA number) of the transfer destination RA (routing accelerator) and the identification number (LC number) of the port in the transfer destination RA to be transmitted. The pointer 405 to the next entry is a field necessary for structuring the routing information inside the RA, but it has no meaning when distributed from the RM (router management unit) described above.

The routing table, which is an aggregate of the routing information 400 in the RA, has the structure shown in FIG. 15 for high-speed search. Hash function 410
Projects some data onto a smaller amount of data. In this embodiment, for example, 24 bits of the network address part of the IP address are projected to 8 bits. Since the output of the hash function is 8 bits, the number of entries in the hash entry table 420 is 256. Each entry in the hash entry table 420 stores a pointer to the routing information 400 corresponding to the result of hashing the network address. Since the hash compresses the amount of data, different network address values may result in the same 8-bit address value as a result of hashing. Therefore,
As shown in FIG. 15, the routing information 400 having the network address that gives the same result by hashing
Are linked by a pointer 405.

Regarding the structure of searching the routing table corresponding to the IP address and the structure of the routing table described here, Douglas E. Come
r "Internet working with TCP / IP VOLUME II" (81-
Page 84), the present embodiment also employs a routing table and its data structure in RA according to this method.

FIG. 3 is a diagram showing various routing cases in the router of the present invention having multiple modules / multiple ports. In FIG. 3, the management unit 2
Is abbreviated as RM, the routing accelerator 3 is abbreviated as RA, and the communication ports 51 to 56 are abbreviated as LC.

Case 1 shows the case of disposal. The routing accelerator RA (A) temporarily stores the packet received by the communication port LC (a) under its control in the packet buffer, and performs filtering and routing. Here, as a result of filtering / routing, the communication port LC that the packet destination has just received
If it is in the direction of (a), the packet is discarded.

Case 2 shows a case where routing is performed between the ports in the routing accelerator RA (A). The routing accelerator RA (A) is
The packet received by the communication port LC (a) under its control is temporarily stored in the packet buffer, and filtering and routing are performed. Here, as a result of filtering / routing, the destination of the packet received by the communication port LC (a) is the own routing accelerator RA.
When it is in the communication port LC (b) under the control of (A), the received packet is returned, transferred to the communication port LC (b), and relayed. In this case, only one routing accelerator RA (A) functions as a router.

Case 3 shows a case where routing is performed between the two routing accelerators RA (A) and (B) via the router bus. The routing accelerator RA (A) is a communication port LC under its control.
The packet received by (a) is temporarily stored in the packet buffer, and filtering and routing are performed. Here, when the routing accelerator RA (A) checks the destination of the received packet and it is the communication port LC (d) under the control of the other routing accelerator RA (B), the routing accelerator RA (A) and the routing Information is transferred between the accelerators RA (B) for packet transfer so that packets are transferred from the routing accelerator RA (A) to the routing accelerator RA (A).
(B) is transferred.

Case 4 shows the case where the received packet is a packet addressed to the own router. The packet addressed to the own router is the routing protocol frame (RI
(P or OSPF frame) or network management protocol SNMP frame data. The routing accelerator RA (A) temporarily stores the packet received by the communication port LC (a) under its control in the packet buffer, and performs filtering and routing. Here, for example, when the destination IP address of the IP packet is its own IP address, the received packet is transferred to the management unit 2. 3. Configuration of Routing Accelerator Next, the configuration of the routing accelerator 3 will be described.

FIG. 4 shows a block diagram of the routing accelerator 3. The routing accelerator 3 includes a filtering assist unit 302 that filters received packets by hardware, a lower processor 306 that is mainly in charge of filtering, and a lower processor 30.
6 local memory 305, routing assist unit 3 that routes received packets by hardware
08, upper processor 31 mainly responsible for routing
0, local memory 309 for upper processor 310, filtering assist unit 302 and lower processor 306
Command descriptor buffer 303 for exchanging information with the lower processor 306 and mutual information between the lower processor 306 and the upper processor 310, and converting a network address (eg IP address) into a physical address (eg MAC address). An address translation assist unit 304, an interface unit 301 with the EISA bus 4,
Packet buffer 307 and router bus transfer controller 3
It is composed of 11.

First, the routing process will be described with reference to FIG. 16 along the upstream data path for transferring data from the communication port 5 to the router bus 1 via the routing accelerator 3.

All packets received by the communication port 5 are EI by the DMA transfer performed by each communication port 5.
It is temporarily stored in the packet buffer 307 via the SA bus interface unit 301 (1601). In parallel with the packet transfer operation to the packet buffer 307, the filtering assist unit 302 performs filtering by extracting only the head portion of the packet necessary for filtering, and performing comparison and determination under predetermined conditions. As the filtering process, in this embodiment, the type of protocol to be handled, for example, TCP / IP
Alternatively, one of the OSIs is recognized, and if the protocol type is other than that, only filtering as a bridge is performed without performing subsequent filtering / routing (1602). It should be noted that it is also possible to perform filtering by comparing with a template, which is an address data pattern corresponding to the application set by the user.

The filtering assist unit 302 stores this result in the command descriptor buffer 303 in association with the pointer of the packet to the packet buffer 307. The lower processor 306 takes over this result, continues further filtering by software, and discards the packet if it is judged as an unnecessary packet (1603). The lower processor 306 also performs buffer management such as monitoring of an upstream buffer empty state. Then, if the packet is not discarded, the routing instruction indicates the command descriptor buffer 303.
Are stored in association with the pointer to the packet buffer 307. The filtering process is completed, and the routing process is performed as follows (1604) and the packet data is transmitted to the router bus (1605).

The IP routing process in the up direction will be described with reference to FIGS. FIG. 17 is a flowchart showing the upstream IP routing processing of the upper processor 310. First, the upper processor 310
Receives a routing instruction from the lower processor 306, refers to the pointer to the packet buffer stored in the command descriptor buffer 303, and reads the received packet data. It is assumed here that the received packet data is an IP packet.

In FIG. 17, first, the destination IP address of the received packet is read and the network portion of the IP address is subjected to the hash function processing shown in FIG. 15 to obtain the entry pointer of the routing table (176).
0). Next, the destination IP address (provisionally a) in the routing information indicated by the entry pointer is obtained (1
761). Since the destination IP address (32 bits) of the received packet may use a subnet, the network address value (probably b Is obtained (1762). And
a and b are compared (1763), and if they match, it is determined that the routing information is information for managing the destination of the received packet, and the IP address 403 of the next router in the routing information and the transmission interface 404 are determined. Get (1
764). If a and b do not match, the routing table is management information of another network address that has the same value in the hash processing, so the pointer 405 to the next entry in the routing information is read (1765). , And the same processing is repeated for the routing information indicated by the pointer. In addition, I received
Depending on the P packet, additional option processing may be required.

Upon completion of this IP processing, the upper processor 310 activates the router bus transfer control unit 311 and transfers it to the destination module, specifically, the destination routing assist unit 308. As a transfer operation, the transfer source router bus transfer control unit 311 notifies the transfer destination router bus transfer control unit 311 in advance of command data such as a transfer request, a next hop IP address, and a destination port number, and the transfer destination host processor. 310 receives this. When the higher-level processor 310 of the transfer destination is ready to accept the transfer, by returning a response to the router bus transfer control unit 311 of the transfer source,
Start packet transfer.

The above is the processing in the up direction by the routing accelerator 3 of the transfer source. Next, processing along the packet flow in the downstream direction (direction from the router bus to the communication port) by the transfer destination routing accelerator 3 will be described with reference to FIG.

When the router bus transfer control unit 311 receives a transfer request from the router bus transfer control unit 311 which is the transfer source,
The upper processor 310 is notified of that fact. Downstream buffer management is performed by the upper processor 310. The upper processor 310 gives a storage destination start pointer for the packet buffer 307 to the router bus transfer control unit 311. The router bus transfer control unit 311 stores the packet received from the router bus 1 in the packet buffer 307 while handshaking with the transfer source router bus transfer control unit 311 and updating the buffer address. After storing the packet, the upper processor 310 stores the storage end notification, the destination port number, and the pointer to the buffer in the command descriptor buffer 303 (1801).

The lower processor 306 receives this and performs the following processing. The lower processor 306 uses the next hop I.
The P address is entered in the address conversion assist unit 304.
On the other hand, the address translation assisting unit 304 translates a network address (IP address) into a physical address (MAC address) and informs the lower processor 306 (18
02). Regarding the method of converting the IP address into the MAC address, the ARP protocol (Address Res
It is generally known that this is possible with the Solution Protocol. As another method, the IP address and MA
It is possible to have a conversion table with the C address in advance and perform the conversion process using the conversion table, or to construct a learning type conversion table for registering the result by the ARP protocol and perform the conversion process.

Further, the lower processor 306 divides the packet in the packet buffer 307 if it is necessary to divide (segment) the packet data for adjusting the packet length according to the destination communication port (180).
3).

Thereafter, the lower processor 306 adds the destination physical address to the packet data (or a plurality of segmented packet data) to form the packet format of the corresponding port. In this way, when the lower processor 306 is ready for the transmission packet, it activates the subordinate communication port 5 to transmit to the network (1804).

The router of this embodiment can support multi-protocol. That is, in the above-described filtering process, the TCP / IP protocol and the OSI protocol are discriminated from the received packet header. Based on the result, IP routing or OSI routing is continued. If the protocol cannot be determined, the packet is routed as a bridge. The bridge relay function will be described later.

In this embodiment, the filtering is performed by the filtering assist unit 302 and the lower processor 306.
The upper processor 310 and the routing assist unit 308 perform routing, and the lower processor 306 and the address translation assist unit 304 perform address translation. However, the above-described hardware assist means is not provided, and It is also possible for the processor to do so by software processing. 4. Extensibility Next, the extensibility (scalability) that is a feature of the present invention
Will be described. As described above, in the router of the present invention, a small-scale router can be configured by a module including a low-speed line having eight or less communication ports and one routing accelerator, and a module of the management unit. Then, by adding a module by combining the communication port and the routing accelerator, it is possible to realize a medium to large scale router with the same architecture as the small scale router. 5. Separation of Packet Data Transfer Bus and Control Data Transfer Bus Next, another embodiment for further speeding up the above-described embodiment will be described with reference to FIG. In this embodiment, the above-mentioned router bus 1 is dedicated to the packet data transfer between the routing accelerators 8, and the control frame such as the management frame and the relay information between the router management unit 2 and the routing accelerator 8 is transferred to the third. Another bus as a coupling means, that is, the control system bus 5 is provided. As a result, the pair of routing accelerators having the packet data to be relayed by the router can transfer the packet data using the router bus 1 even if another routing accelerator is transferring data with the router management unit 2. Routers are faster as devices. To connect the control bus 5 to the routing accelerator 8, the bus interface of the router bus transfer control 311 in FIG. 4 described above is replaced by a 2-channel DMA control circuit corresponding to the router bus 1 and the control bus 5. realizable.

Further, the expandability of the router system using this third coupling means will be described with reference to FIGS. 6 and 7. According to this embodiment, by connecting the routing accelerator of the present invention to the conventional router by the bus, the performance as a router can be improved and it can be applied to a large-scale network.

FIG. 6 shows an embodiment of a router obtained by expanding the conventional device. The part surrounded by the dotted line in FIG. 6 is a component of a conventional router. FIG. 7 is a block diagram showing only the components of this conventional router. In FIG. 7, 5
Is a bus used as a standard in a router or a small-sized information processing device, and is a VME bus here. To the VME bus 5, a main processor unit 6 including a main memory and a microprocessor, and a line control unit 71 and LAN control units 72 and 73 as communication port units are connected.
Usually, in this conventional router, routing is performed as follows.

For example, the main processor unit 6 receives all the packets received by the LAN control unit 72, and selects the destination port. Then, for example, if the destination port is the LAN control unit 73, the packet data is transferred to the LAN control unit 73 via the VME bus 5 to perform routing relay. Therefore, the VME bus 5 is used for exchanging both packet data and control information between the main processor unit 6 and the respective communication control units 71 to 73.

Now, returning to FIG. 6, the description of the embodiment of the present invention will be continued. Here, the routing accelerator 8 can be connected to a third bus in addition to the above-mentioned first and second buses.
Then, by using the VME bus used in the conventional router as the third bus, it is coupled with the main processor unit 6. On the other hand, the high-speed router bus 1 transfers only packet data between the routing accelerators 8.
That is, in the present embodiment, the main processor unit 6 manages the entire router, and the function of distributing the relay information table to each routing accelerator 8 is substituted by the router management unit 2 of FIG. The conventional router can be expanded to the router of the present invention having both high speed and expandability.

Although a router is used as a conventional device in this embodiment, a small information processing device such as a workstation and a routing accelerator 8 are not dedicated router devices.
If you connect with, the workstation-specific extensibility such as early response to new protocols will occur. 6. Function Expansion by Addition of Auxiliary Processor Next, another embodiment for further improving the function expandability of the router of the present invention will be described with reference to FIG. The block diagram of FIG. 8 further comprises an auxiliary processor 7 as compared to the router of the block diagram of FIG. This auxiliary processor 7
May share part of the processing of the router management unit 2, that is, the management function of the entire apparatus, or the processing of the routing protocol and the function of creating the relay route selection information table. However, here, in order to improve the function expandability of the router, an example of realizing an interface function for connecting to another information processing device, that is, a substitute function for the coupling function using the above-mentioned third bus is described. explain.

In FIG. 9, the router 100 is equipped with an external interface board 101 connecting an external connection bus (for example, SCSI) 200 and the router bus 1 as an auxiliary processor. The information processing apparatus 200 such as a workstation uses the SCSI bus 20 as an external connection bus.
Have one. Here, it is assumed that the information processing apparatus 200 can process a protocol that the router 100 cannot process, such as a connection-oriented conventional host-terminal communication protocol. Upon receiving the packet data according to the conventional protocol from the line control port 56, the router 100 transfers the received packet data from the routing accelerator 3 connected to the line control port 56 to the external interface board 101 via the router bus 1. . Further, the external interface board 101 transfers the received packet data to the information processing device 200 via the SCSI bus 201, thereby performing a relay process of the received packet data.

FIG. 10 shows the external interface board 10.
FIG. 3 is a block diagram showing a configuration example of 1. The external interface board 101 can also realize a logical interface between the routing accelerator 3 and the external information processing device 200. Therefore, the interface processor 102 is provided, and the local memory 103 for operating the processor 102 is provided. Further, the external interface board 101 includes a router bus transfer control unit 104, S
It has a CSI bus transfer control unit 105, a packet buffer 107 for accumulating packet data, and a control unit 106 therefor. Then, the processor 102 and the packet buffer 10
The bus switch 108 is provided so that the external access to 7 can be performed simultaneously. Therefore, the operation of the external interface board 101 is as follows. The router bus transfer control unit 104 stores the packet data from the packet bus 1 in the packet buffer 107. Processor 1
Reference numeral 02 denotes an external information processing device 2 for the packet data.
00 adds a descriptor for access as necessary and notifies the external information processing apparatus 200. The external information processing device 200 reads the packet data from the packet buffer 107 via the SCSI bus transfer control unit 105. As described above, since the router has the auxiliary processor having the interface function with the outside, the function can be expanded. 7. Mixed processing of router processing and bridge processing Next, an embodiment of the bridge relay processing when the routing processing is impossible in the internet apparatus according to the present invention will be described below.

When the received packet data follows a protocol that cannot be processed by the routing accelerator, the routing accelerator is connected to another router or an information processing device, and the processing by another device is performed as described above. If expected, the routing accelerator can process the received packet data by forwarding it to another router or information processing device. The same applies when the processing in the auxiliary processor or main processor can be expected. However, since there are various communication protocols, the whole internetwork apparatus of the present invention may naturally receive packet data that cannot be routed. In this case, a bridge relay process is performed in which only the conversion at the data link level is performed and relayed for all possible networks. That is, the routing accelerator broadcasts to a plurality of other routing accelerators to perform bridge relay. However, in this internetwork apparatus, it is possible that router relay and bridge relay may coexist. In this case, it takes time for the broadcast transfer to the router bus, and the relay performance as a device may deteriorate. About this
This will be described using 1.

In the internetwork apparatus of FIG. 11, the routing accelerator RA (2) performs the routing process on the received packet of the subordinate communication port LC (2), and as a result, another routing accelerator RA (3).
Routing accelerator RA (3) via the router bus for relaying to the communication port LC (3) of
Suppose that the transfer of the packet data is started to (t in FIG. 11).
The data transfer path indicated by 1.).

On the other hand, the routing accelerator RA
As a result of (1) attempting to route the received packet of the subordinate communication port LC (1), it is determined that the packet data cannot be routed by the routing accelerator RA (1), and bridged to all other routing accelerators. Attempts to broadcast packet data for relay. However, since the routing accelerator RA (3) is transferring data from the routing accelerator RA (2) at this point, the routing accelerator RA (1) cannot perform data transfer by broadcast. Therefore, the routing accelerator RA (1) is the routing accelerator R (1).
It waits until A (3) is ready to receive data from the router bus (incomplete data transfer indicated by t2 in FIG. 11).

Further, the routing accelerator RA
If the data transfer from (2) to the routing accelerator RA (3) is not completed, and the data transfer from another routing accelerator RA (4) to the routing accelerator RA (5) for router relay occurs. (Data transfer indicated by t3 in FIG. 11), the routing accelerator RA (1) waits until the routing accelerator RA (5) is ready to receive data from the router bus.

In other words, the routing accelerator which is trying to broadcast-transfer to all other routing accelerators for bridge relay waits for the completion of the data transfer between the other routing accelerators, so that routing can be performed from the communication port under the routing accelerator. The received data must continue to be accumulated. As a result, the routing processing performance of the internetwork device connected to the network that causes a relatively large number of bridge relays deteriorates.

In order to solve such a problem, the present invention uses the above-mentioned auxiliary processor as an auxiliary function of bridge relay. This embodiment will be described with reference to FIGS. 12 and 13.

Also in the internetwork apparatus of FIG. 12, it is assumed that data transfer occurs from the routing accelerator RA (2) to the routing accelerator RA (3) (data transfer indicated by t1 in FIG. 12). Here, the routing accelerator RA (1) is shown in FIG.
Similarly, it judges that the received packet data from the subordinate communication port should be bridge-relayed. At this time, the routing accelerator RA (1) does not perform the broadcast transfer to all other routing accelerators but transfers the packet data to the bridge relay assist unit 700 (shown by t2 ′ in FIG. 12). Data transfer). After that, the bridge relay assist unit 700
Attempts to do a broadcast transfer to all routing accelerators. Here, similarly, from the routing accelerator RA (4) to the routing accelerator RA (4).
Even if the data transfer to (5) occurs (the data transfer indicated by t3 in FIG. 12), the bridge relay assist unit 70
At 0, it only causes a wait for the broadcast transfer,
RA (1) does not need to continue to store subsequent routable received data. Therefore, it is possible to prevent the deterioration of the routing processing performance.

Next, the structure of the bridge relay assist unit 700 will be described with reference to FIG. The bridge relay assist unit 700 mainly includes a buffer management processor 701 for buffer management, a local memory 702 for storing programs and variables of the processor 701, and a packet buffer 703 for temporarily storing data to be bridge relayed. A transfer control circuit 704 for the router bus, and a bus switch circuit 705 for controlling disconnection of the bus for simultaneously performing data transfer from the router bus and accessing the local memory 702 of the processor 701. As described above, the packet data to be bridge-relayed from the routing accelerator is stored in the packet buffer 703 via the router bus transfer control circuit 704. At this time, the packet buffer 703 is queue-managed by the buffer management processor 701, and the buffer management processor 701 performs the broadcast transfer to all the routing accelerators in the order stored in the packet buffer 703.

As described above, according to this embodiment, the bridge processing is assisted by using the auxiliary processor, so that the router processing performance in the bruta can be improved.

[0072]

As described above, the present invention has the following effects. Since the management unit that performs non-routing processing, such as the network management function, and the routing accelerator that performs routing processing are independent, the routing accelerator is dedicated to the routing processing, so that the processing speed can be increased.

Since a plurality of packet data can be simultaneously routed by a plurality of routing accelerators, the routing performance of the entire device becomes faster.
Also, because you can add more routing accelerators,
The router configuration can be easily expanded according to the required number of networks and communication traffic.

Further, by using the auxiliary processor of the present invention, it becomes possible to perform the bridge relay processing at high speed and to expand the function by connecting to an external device. Therefore,
According to the present invention, it is possible to realize an internetwork apparatus having expandability and high-speed router processing and bridge processing.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an internetwork apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a network system using a router.

FIG. 3 is a diagram showing a case of routing relay when an embodiment of the present invention is used.

FIG. 4 is a block diagram illustrating a routing accelerator according to an exemplary embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of an internetwork device of an embodiment of the present invention in which a dedicated packet bus and a control data bus are separated.

FIG. 6 is a block diagram showing a configuration of an internetwork device in which a routing accelerator according to an embodiment of the present invention and a conventional router device are combined.

FIG. 7 is a block diagram showing a configuration of a conventional router device.

FIG. 8 is a block diagram showing the configuration of an embodiment of the present invention in which an auxiliary processor is provided.

FIG. 9 is a block diagram showing a configuration of an internetwork device in which an embodiment of the present invention and an information processing device are connected by an external bus.

FIG. 10 is a block diagram showing a configuration of an external interface board according to an embodiment of the present invention.

FIG. 11 is a diagram showing a case of bridge relay without a bridge relay assist unit in the embodiment of the present invention.

FIG. 12 is a diagram showing a case of bridge relay with a bridge relay assist unit according to an embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a bridge relay assist unit according to an embodiment of the present invention.

FIG. 14 is a diagram showing a configuration of routing information according to an embodiment of the present invention.

FIG. 15 is a diagram showing a configuration of a routing table according to an embodiment of the present invention.

FIG. 16 is a flowchart showing upstream routing processing according to an embodiment of the present invention.

FIG. 17 is a flowchart showing upstream IP routing processing according to an embodiment of the present invention.

FIG. 18 is a flowchart showing a downlink routing process according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Router bus, 2 ... Router management unit, 3 ... Routing accelerator, 4 ... Lower bus, 5 ... Control system bus,
7 ... Auxiliary processor, 51-56 ... Communication control unit, 301
... EISA bus interface section, 302 ... Filtering assist section, 303 ... Command descriptor buffer, 304 ... Address translation assist section, 305 ... Local memory, 306 ... Lower processor, 307 ... Packet buffer, 308 ... Routing assist section, 3
09 ... Local memory, 310 ... Upper processor, 31
1 ... Router bus control unit.

Front Page Continuation (72) Inventor Hiromichi Enomoto 1 Horiyamashita, Hadano City, Kanagawa Hitachi, Ltd. Kanagawa Plant (72) Inventor Toshiaki Koyama 1 Horiyamashita, Hadano, Kanagawa Hitachi Ltd. Kanagawa Plant (72) ) Inventor Osamu Takada 1099, Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture System Development Laboratory, Hitachi, Ltd. (56) Reference JP-A-4-364625 (JP, A) JP-A 1-101750 (JP, A) Special Kaihei 2-112366 (JP, A) JP 2001-86149 (JP, A) Patent 3113742 (JP, B2) Patent 3352073 (JP, B2) Patent 3435130 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/28-12/46 H04L 12/56 H04L 12/66

Claims (12)

(57) [Claims] 1. An internetwork apparatus for connecting a plurality of networks to each other and relaying received packet data from each network, the management section having a management function for the entire internetwork apparatus, and a first coupling means. A plurality of relays connected to each other by means of the above-mentioned first coupling means for relaying the received data packets to the relay destination network determined by the relay route information and the address information included in the received packet data. A plurality of processing units and a plurality of first connection units that are connected to the relay processing units via the second coupling unit independently arranged for each of the relay processing units and that transmit / receive packet data to / from the networks connected to the respective relay processing units. 1 communication port and a network that is connected to the management unit via the third coupling means and is connected to each of them. A plurality of second communication ports for transmitting and receiving data, the relay processing units are connected to the management unit via the third coupling means, and the management units receive at the second communication ports. Means for relaying the generated packet data to a relay destination network determined by the relay route information and address information included in the received packet data, means for creating the relay route information, and the relay route information And means for distributing the information to each of the relay processing units via the third coupling means. 2. The third coupling means transfers control information between the management unit and each of the relay processing units, and control information between the management unit and each of the second communication ports. The internetwork device according to claim 1, wherein the internetwork device is used for transferring packet data. 3. The relay route information creating means creates or changes the relay route information by executing a routing protocol for communicating information about a network with another internetwork device. The internetwork device according to claim 1. 4. The internetwork apparatus according to claim 1, wherein the relay route information creating means creates the relay route information based on preset information. 5. An internetwork device for connecting a plurality of networks to each other and relaying received packet data from each network, wherein the plurality of first network devices transmit and receive the packet data to and from the networks connected to each. Packet data received at the first communication port, the communication port being connected to each other by a first coupling means, each being connected to at least one of the first communication ports via a second coupling means Is connected to each of a plurality of relay processing units that perform relay processing between the relay destination networks determined by the relay route information and the address information included in the received packet data, via the first coupling means. The plurality of second communication ports for transmitting and receiving packet data to and from the network and the third coupling means. Connected to two communication ports, receives the received packet data from each second communication port, and relays the received packet data to a relay destination network determined by relay route information and address information included in the received packet data. Each of the relay devices and the processor unit are connected via the third coupling means, and the processor unit has means for creating the relay route information, and the relay route. Means for distributing information to each of the relay processing units via the third coupling means, the internetwork device. 6. An internetwork device that interconnects a plurality of networks and relays received packet data from each network, the plurality of first network devices transmitting and receiving the packet data to and from the networks connected to each. A communication port and a first coupling means, which are connected to each other, are connected to at least one of the first communication ports via second coupling means which are independent of each other, and are received by the first communication port. A plurality of relay processing units for relaying the packet data to the relay destination network, which is determined by the relay route information and the address information included in the received packet data, via the first coupling means; And a processing device connected to each of the relay processing units via the coupling means of No. 3, and the processing device is connected to each of the processing devices. A plurality of second communication ports for transmitting and receiving packet data to and from the network, and packet data received by the second communication ports connected to the second communication ports via the third coupling means. A processor unit for performing relay processing to a relay destination network determined by relay route information and address information included in the received packet data, wherein the processor unit creates means for creating the relay route information, and the relay unit. Means for distributing the route information to the relay processing units via the third coupling means. 7. The internetwork device according to claim 6, wherein the processing device is a router. 8. The internetwork device of claim 6, wherein the processing device is a workstation. 9. The third coupling means transfers control information between the processor unit and each relay processing unit, and control information between the processor unit and each second communication port. 7. The internetwork device according to claim 5, wherein the internetwork device is used for transferring packet data. 10. The processor unit creates or modifies the relay route information by executing a routing protocol for communicating information about a network with another internetwork device. The internetwork apparatus according to claim 6. 11. The internetwork apparatus according to claim 5, wherein the processor section creates or changes the relay route information based on preset information. 12. A first filtering unit, wherein each relay processing unit filters the received packet data under a first predetermined condition, based on information contained in each received packet data, and the first filtering. 7. A second filtering unit for further filtering the received packet data filtered by the unit under a second predetermined condition, any one of claims 1, 5, and 6. An internetwork device according to claim 1.