WO2003065655A1

WO2003065655A1 - Transmission apparatus

Info

Publication number: WO2003065655A1
Application number: PCT/JP2002/000727
Authority: WO
Inventors: Souichi Takahashi
Original assignee: Fujitsu Limited
Priority date: 2002-01-30
Filing date: 2002-01-30
Publication date: 2003-08-07
Also published as: JPWO2003065655A1; JP3866242B2

Abstract

In a TARP (Tid Address Resolution Protocol) of a transmission apparatus in which a node ID, a network address, an area address, and a system type are set, a node ID of the TARP search PDU received is compared to a node ID of the local transmission apparatus, and when the node ID’s coincide, a TARP response PDU containing a network address of the local transmission apparatus is transmitted to a transmission apparatus of the transmission origin, when the node ID’s do not coincide, and the local transmission apparatus is of a first system type, the TARP search PDU is discarded, and when the node ID’s do not coincide, the local transmission apparatus is of a second system type, and the TARP search PDU is of a first type inhibiting delivery to a transmission apparatus adjacent to a different area, the TARP search PDU is discarded.

Description

Description Transmission equipment Technical field

The present invention relates to a PDU (Packet Data Unit) that searches for a TARP (Tid Address Resolution Protocol) on a LAN (Local Area Network) to which an SI (Open System Interconnection) network communication node connects. Related to the distribution process.

Background technology

It connects multiple network communication nodes (NEs) accommodating LANs via transmission lines such as optical fibers, and transmits packets transmitted by terminals accommodated in the LANs between the nodes. By relaying and transmitting a packet to the LAN side by a node accommodating a LAN accommodating a packet destination terminal, communication can be performed between different LANs. Each node connected to the network has a unique TID (Target ID) that can be identified by the communication application, and a 0 SI network protocol for performing communication between nodes is specified.

Fig. 13 is a diagram showing the communication application protocol stack. In Fig. 13, the OSI reference model is shown on the left, and the OSI network and protocol stack is shown on the right. As shown in FIG. 13, the physical layer is OSSI (RS449), DCC (Data Communication Channel), which is section data communication based on SDH frame overhead, and Ethernet (Ethernet). LAP B, LAPD, C SMA / CD and its higher LLC-11 are the overnight link layer. X.25 and its higher-level CLNP (Connectionless Network Protocol), and its higher-level ES-IS / IS-IS and CLNP are network layers. TARP is located in the upper layer of CLNP and corresponds to the address translation interface with the TL1 application layer. TP4 is the transport layer, X.215 / X.225 is the session layer, and X.216 / X.226 is the presentation layer. ACSE, F TAM and TL 1 are application layers. In a network to which the OSI protocol is applied, each node has a network address (NS AP address) that can identify a CLNP corresponding to the network layer of the OSI reference model. The CL NP sees the destination NS AP address and performs routing so that all data packets can be transmitted and received between nodes. At the application layer, remote login to the node, setting of the system type / network address to the node, and reading of the node setting information are performed using the respective T1 commands. In this TL1 command, the TID is interfaced from the viewpoint of operability, and the NSAPP address is not interfaced. Therefore, when the communication application transmits a data packet including the destination TID, it is necessary to convert the TID into an NSAP address handled by the 0SI network layer. The protocol that performs that function is called TARP.

One of the T ARP functions is an NSAP address search function. This is because the NSAP address of the TID that is not registered in the TAR P data cache held by the search source node propagates the TARP search PDU over the network, and the NS of the node that matches the search TID (target TID) This is a function to acquire the AP address. When operating the address search function, the search source node delivers the TA.RP search PDU to the adjacent node.

FIG. 14 is a diagram showing a configuration of a packet including the T ARP search PDU. As shown in Figure 14, Ding 11? Search? 011 is composed of a TARP header as a TARP layer (a TAR P search PDU includes a CLNP header as a network layer, and a packet with an additional DLC header added to an LLC as a data link layer). Sent.

FIG. 15 is a diagram showing a CLNP header. The network layer protocol identifier is a value identified by IS08473 and is 0x81. The header length is the octet length of the header. The version / protocol extension is 0x01 in IS0873. The lifetime is decremented each time it is relayed and discarded when it reaches 0. The type is 0x1c. The segment length is the octet length including the header and data. The checksum is the checksum value of the entire PDU. The destination address length is the length of the destination NSAP address. The destination address is the destination NSAP address. Source address length is source N SAP address length It is. The source address is the source N SAP address.

FIG. 16 is a diagram showing an NSAP address. As shown in FIG. 16, the NSAP address is a 40-digit address composed of an IDP (Initial Domain Part) and a DSP (Domain Specific Part). IDP is for identifying a network address domain. D SP means the corresponding sub-domain address. The configuration in the DSP is determined by the type of network address authority identified by the IDI in the IDP. The content of the DSP differs depending on the format type such as SONET or X.121 / E.163, but the area address, system ID and SEL are commonly included. The area address is the address of the routing area in the routing domain and can be changed. The system ID is an address of a node, and is an initial ID written to each device at the time of product shipment, for example, a MAC address, and cannot be changed. SEL is provided for the network layer to identify contacts between different layers such as TARP and TP4. The initial value of the NSAP address is set when the product is shipped.

FIG. 17 is a diagram showing a TAR PPDU field, a TAR search P.DU, and a TAR reply PDU. As shown in Fig. 17, the TARP. PDU field contains the TARP lifetime (Tar-lif) ヽ TAR P sequence No. (Tar-seq), the protocol address type (Tar-pro), and the TARP type code (Tar-pro). Tar-tcd), Target TID length (Tar-tln), Search source TID length (Tar-oln), Search source NSAP address length (Tar-pln), Target TID (Tar-ttg), Search source It consists of the TID (Tar-tor) and the NSAP address (Tar-por) of the search source.

The T ARP lifetime is decremented by 1 each time a node is relayed, and when it reaches 0, the PDU is discarded. 011 ゃ 11 Reply For 0 U, 50 is the initial value. In the TAR P sequence No., a sequence number is set. For the protocol address type, a value indicating an NSAP address is set in the T ATP search PDU or the TAR P reply PDU.

For the TARP type code, type 1 or 2 indicating the search target range is set in the tarp search PDU, and type 3 is set in the tarp reply PDU. TARP search PDU type 1 indicates that the packet is forwarded to a node in the same area to which the search source node belongs. It is. For TARP search PDU type 2, the packet is transferred to a node in a different area from the search source node. The reason for distinguishing types 1 and 2 is that the search range is limited by specifying type 1 during the first stage search. If the address cannot be searched for in Type 1, the second step is to specify Type 2 to expand the search range. This is to prevent an increase in traffic due to the TARP search PDU being propagated more than necessary.

The search TID length is set as the target TID length. The search source N SAP address length is set to the search source NSAP address length. In the target TID, the search target and the TID of the search result are set in the TARP search PDU and the TARP reply PDU. In the search source T ID, the T ID of the search source node is set. For the search source NSAP address, the TSAP search PDU sets the search source node NSAP address, and the 11th response NDU sets the search result node NSAP address.

FIG. 18 is a diagram showing a TAR P search PDU distribution procedure. As shown in Fig. 18, when the search source node searches for the NSAP address, it sets the search target TID and type 1, etc., and transmits TARP search. PDU. The TAR P search PDU is propagated within the same area as the area of the search source node. If there is a node having the target T ID in the same area, the node sets type 3, and transmits a TAR P reply PDU to the search source node. If there is no node with the target TID in the same area, the T1 response timer of the search source node times out, sets type 2 etc., and sends a TARP search PDU. . TARP search PDU is propagated to nodes in different areas. If there is a node having the target T ID in a different area, the node sets type 3, and transmits a TAR P reply PDU to the search source node.

In the C LNP applied to the OSI network layer, a system type is defined for each node. The system types can be classified into three system types: IS1 (Levell Intermediate System), IS2 (Level2 Intermediate System) and ES (End System). IS 1 is responsible for relay work within the same area address defined by 0 SI. IS2 is responsible for relaying between different area addresses defined by IS1 and 〇SI. ES is not responsible for relaying, All other than packets are forwarded to IS1 or IS2 to be connected, that is, routing work cannot be performed. NMS has the system type ES.

When these IS 1 or IS 2 nodes are connected on the same LAN segment, the neighboring nodes recognized by each node are given as follows. On the node adjacent to the IS1 node, IS1, IS2, ES in the same area address defined by 0SI. The adjacent node of the IS 2 node is the adjacent node recognized by the IS 1 node and IS 2 within the different area address defined by 0 SI. Neighbor nodes are recognized by the IS-IS / ES-IS layer, and information about the neighbor nodes is stored in the neighbor database.

FIG. 19 is a configuration diagram of the adjacent data pace. As shown in Fig. 19, the neighbor database stores the NSAP address and system type of the neighbor node. Figure 20 is a network configuration diagram of the nodes connected to the LAN. In the network shown in Fig. 20, the area consists of area # 1 and area # 2. Area # 1 belongs to NE2 # 11, NE2 # 12 and GNE4 # 1, Area # 2 includes, NE2 # 21, NE2 # 22 and GNE4 # .2 Belongs .. NE2 # 11, NE2 # 12, GNE.4 # 1, NE2 # 2.1, NE2 # 22 and GNE4 # 2 are connected to LAN6. FIG. 21 is a diagram illustrating an example of an adjacent node. As shown in Fig. 21, in the case of the network shown in Fig. 20, GNE 4 # 1 of IS2 is the same as NE2 # 11 and NE2 # 12 in the same area, and G2 of IS2 in a different area. NE 4 # 2 is an adjacent node, but NE 2 # 1 1 of IS 1 recognizes GNE 4 # l and NE 2 # 1 2 as adjacent nodes in the same area, but IS 2 of a different area GNE 4 # 2 is not recognized as an adjacent node.

FIG. 22 is a flowchart of a conventional TARP search PDU processing of the IS1 node. <Step S2 receives a TARP search PDU. In step S4, it is determined whether or not the target sequential N 0. is registered in an LDB (Loop Detection Buffer). If it is not registered in the LDB, go to step S6. <If it is registered in the LDB, go to step S14. In step S6, the evening gate sequential No. is registered in the LDB. In step S8, it is determined whether or not the evening gate TID matches the TID of the own node. If they match, Proceed to step S10. If not, go to step S12. In step S10, a TARP reply PDU including the NSAP address of the own node is returned to the search source in Tar-POR. In step S12, a TARP search PDU is delivered to all adjacent nodes other than the transmission source. In step S14, it is determined that the same TAR P search PDU has already been received, and the TAR P search PDU is discarded.

2 3 in _c Suchippu S 2 0 a TAR P retrieval PDU processing Furochiya one bets conventional IS 2 nodes, receives the TAR P search PDU. In step S22, it is determined whether or not the target sequential No. is registered in the LDB. If not registered in the LDB, go to step S24. If it has not been registered in LD B, go to step S36. In step S24, the target sequential No. is registered in the LDB. In step S26, it is determined whether or not the evening gate T D matches the TID of the own node. If they match, go to step S • 28. If they do not match, go to step S30. In step S28, search for the TARP reply P'DU containing the NSAP address of the own node in the Tar-POR. In step S30, it is determined whether or not the Tar-tcd is type 1. If not type 1, go to step S34. If it is type 1, go to step S32. In step S32, a TARP search PDU (type 1) is delivered to an adjacent node in the same area other than the transmission source. In step S34, the TARP search PD ϋ (type 2) is delivered to all adjacent nodes other than the transmission source. In step S36, it is determined that the same TARP search PDU has already been received, and the TARP search PDU is discarded.

Figure 24 is a diagram showing the procedure for distributing a TARP search PDU (type 1) in the same area. As shown in FIG. 24, GNE 4 # 1 sends, for example, to NE 2 # 1 1 and NE 2 # 1 2 to search for the NSAP address of NE 2 # 21 in area # 2. As shown in (2) and (4), a TARP search PDU (type 1) is transmitted. When NE 2 # 11 receives the TARP search PDU (2), as shown in (6), the target TID is different from the own node's TID. Deliver the TAR P search PDU. NE 2 # 12 receives TARP search PDU (4) In response, as shown in (8), since the one-gate TID is different from the own node's TID, a TAR P search PDU is delivered to the adjacent node NE 2 # 11.

FIG. 25 is a diagram showing a procedure for distributing a TAR P search PDU (type 2) in the same area. GNE 4 # 1 sends a T ARP search PDU (type 1) to NE 2 # 11 and NE 2 # 12, for example, to search for the NSAP address of NE 2 # 21 in area # 2. ) Was transmitted, but no TARP reply PDU was returned from these NE 2 # 11 and NE 2 # 12.

■ As shown in Fig. 25, GNE4 # 1 is sent to NE2 # ll, NE2 # 12 and GNE4 # 2 as shown in (.20), (22) and (24). Send a TARP search PDU (type 2). When NE 2 # 11 receives the TAR P search PDU (20), the target TID is different from its own node's TID as shown in (26). Deliver the P Search PDU. When NE 2 #, 1 2 receives the TAR P search PDU (24), as shown in (28), the target TID is different from that of its own node. TARP search PDU (Type 2) is distributed. Upon receiving the TARP search PDU, the GNE 4 # 2 transmits a TARP search PDU (type 2) to NE2 # 21 and NE2 # 22 as shown in (30) and (32). . When NE 2 # 21 receives the TAR P search PDU (30), the target TID matches its own node's TID as shown in (34). Deliver the TAR P reply PDU. When NE 2 # 21 receives the TAR P search PDU (32), the target TID is different from its own node's TID as shown in (36). Deliver a P Search PDU (Type 2).

When multiple nodes are connected on the same LAN segment, they are recognized as adjacent nodes. When a TAP search PDU is delivered from a certain node by the address search function, the T ARP search PDU is delivered to all adjacent nodes on the same LAN segment. When the adjacent node receives the TAR P search PDU, it registers the Tar-seq in the LD B, and if the Tar-ttg does not match the TID of the node, the TARP search PD is sent to all adjacent nodes other than the transmission source. Deliver ϋ.

In other words, in the conventional TARP search PDU discarding flow associated with LDB processing, the same T ARP search PDU had to be received at least twice. The TAR P search PDU received this second time is a wasteful PDU that is always discarded at the node <Moreover, those TARP search PDUs are a huge number in relation to the number of nodes connected on the LAN. Ρ ί> ϋ. If Ν IS 1 nodes are connected on the same LAN segment, each IS 1 node recognizes (N-1) adjacent nodes. When (N—1) TAR P search PDUs are distributed from a specific node to (N—1) adjacent nodes by the address search function, the (N—1) ) Neighbor nodes deliver (N-2) TARP search PDUs to neighboring nodes other than the source node. Therefore, the number P of the TAR P search PDUs delivered on the LAN is (N-1) + (N-1) X (N-2), and theoretically, the following equation (1 ).

TARP search number of PDUs P = (N-I) ² · · · (1) where N is the number of IS 1 nodes connected on the same segment

In this way, if the number N of nodes connected on the weekly LAN segment increases, the number of nodes that are connected to the LAN is reduced. The number of TARP search PDUs P increases exponentially. Generates excessive traffic on the segment. Nodes share the bandwidth (100 Mb ps or 100 Mb ps) on the same LAN segment, so the occurrence of traffic causes data collision and retransmission, which significantly reduces transmission efficiency. You.

An object of the present invention is to provide a transmission apparatus having a TARP search function capable of suppressing an increase in traffic.

Disclosure of the invention

According to one aspect of the present invention, there is provided a transmission device connected to a LAN segment and set with a node ID, a network address for routing, an area address, and a system type, wherein the LAN segment The node ID of the own transmission device matches the address search PDU receiving unit that receives the address search PDU and the no FID set in the address search PDU received by the address search PDU reception unit. Address transmitting the address response PDU including the network address of the own transmission device to the transmission device of the transmission source, and receiving the address search PDU. If the node ID of the own transmission device does not match the node ID set in the address search PDU received by the transmitting unit and the system type of the own transmission device is the first system type, the address search PDU is discarded The first address search PDU discarding section, and the node ID set in the address search PDU received by the address search PDU receiving section described above do not match the node ID of the own transmission device, and the address search PDU is If the type is the first type that prohibits delivery to a different area adjacent transmission device and the system type of the own transmission device is the second system type, the address search PDU is discarded.The second address search PDU is discarded. And a transmission device comprising:

According to another aspect of the present invention, there is provided a transmission device connected to a LAN segment and set with a node ID, a network address, an area address, and a system type, and connected to the LAN segment. Adjacent database that stores the net address, system type, and area address of the adjacent transmission device, and the address that includes the first type that prohibits distribution to the adjacent transmission device in the target node ID and the different nodes. First address to send search PDU to adjacent transmission equipment Search PUU sending unit and address search even after a certain time has passed since delivery of the address search PDU to the LAN segment If the address reply PDU to the PDU cannot be received, the target node ID included in the addressless search PDU and the distribution to the transmission device adjacent to the different PDU are transmitted. Address search including the permitted second type PDU is transmitted to the adjacent transmission device of the second system type Address search Second address search that distributes PDU PDU transmission unit, and address search based on the LAN segment An address search PDU receiving unit that receives the PDU; and, when the node ID of the own transmission device matches the node ID set in the address search PDU received by the address search PDU reception unit, the own transmission device An address reply PDU transmitting unit that transmits an address reply PDU including a network address to the transmission device of the transmission source, and a self transmission device to the node ID set in the address search PDU received by the address search PDU reception unit. A first address search PDU discarding unit for discarding the address search PDU when the node ID of the transmission device does not match and the system type of the own transmission device is the first system drive; To search PDU § dress is set to search P DU received by the receiver The node ID of the own transmission device does not match the acquired node ID, the type of the address search PDU is the first type that prohibits delivery to the adjacent area transmission device, and the system type of the own transmission device is the second type. A transmission apparatus characterized by comprising a second address search PDU discard unit for discarding the address search PDU when the system type is used.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is the principle diagram of the present invention;

FIG. 2 is a network configuration diagram according to an embodiment of the present invention;

Fig. 3 is a functional block diagram of GNE and NE in Fig. 2;

FIG. 4 is a configuration diagram of the TARP processing unit according to the present invention in FIG. 3;

Figure 5 is a flowchart of the operation of the T ARP search PDU source node;

Fig. 6 is a flowchart of the distribution of the TARP search P DU at the node of IS1; Fig. 7 is a flowchart of the distribution of the TARP search PDU at the node of IS2; Fig. 8 is the distribution of the TARP search PDU of type 1 when the source node is IS2. Figure showing;

Figure 9 shows the delivery of a TAR P search PDU of type 2 with the source node IS 2;

Figure 10 is an explanatory diagram of the effect;

Figure 11 shows the delivery of a TAR P search PDU of type 1 with source node IS 1;

Figure 12 shows the distribution of a type 2 T ARP search PDU with source node IS 1;

Figure 13 is a diagram showing the communication abrication protocol;

Figure 14 shows a TARP search packet;

Figure 15 shows the CLNP header;

Figure 16 shows the NSAP address;

Figure 17 shows the TAR PPD U field;

Figure 18 is a diagram showing the distribution sequence of the TAR P search PDU;

Figure 19 shows the adjacent database; Figure 20 shows a network configuration example;

Figure 21 shows the neighboring nodes in the network configuration of Figure 20;

FIG. 22 is a flowchart showing a delivery process in a conventional IS 1 node; FIG. 23 is a flowchart showing a delivery process in a conventional IS 2 node; FIG. 24 is a diagram showing delivery of a conventional type 1 TARP search PDU;

FIG. 25 is a diagram showing the distribution of the T ARP search PDU of the evening Eve 2 according to the related art.

BEST MODE FOR CARRYING OUT THE INVENTION

Before describing the best mode for carrying out the present invention, the principle of the present invention will be described. FIG. 1 is a diagram illustrating the principle of the present invention. The network shown in FIG. 1 has a configuration in which a plurality of NEs 20 # i (i = l to 6) are connected to LAN 22. Each NE 20 # i (i = 1 to 6) has a node ID, a network address, and a system type. It is assumed that the system type of NE 2 0 # 1 and NE 2 0 # 4 is IS 2. The system type of NE 20 # 2, NE 20 # 3, NE 20 # 5, and NE 20 # 6 is IS 1. When NE 20 #i distributes the address search PDU including the node ID of the evening gate, it distributes the type 1 address search PDU to the adjacent node, and within a certain period of time. When the address reply PDU cannot be received, the address search p DU is delivered to the neighboring NE of IS2. NE 20 # i receives the address search PDU, discards the address search PDU if the system type is IS 1 and the node ID of the address search PDU does not match its own node ID. S 70 in FIG. 6).

When NE 2 0 #i receives the address search PDU, if the system type is IS 2 and the node ID of the address search PDU does not match its own node ID (S 90 in Fig. 7), (i) transmission If the source NE is IS2 in the same area, the address search PDU is discarded (S98 in FIG. 7), and (ii) the source NE is not IS2 in the same area and the source node is in the same area. When IS 1 or ES, address search PD 配信 is delivered to the adjacent node other than the source (S100 in Fig. 7). (Iii) The source NE is not IS 2 in the same area and When the source node is not IS1 or ES in the same area, it delivers an address search PDU to neighboring NEs in the same area other than the source (S966 in Fig. 7). For example, when searching for the address of NE 2 0 # 5, NE 20 # 1 sends the address search PDU (type 1) to the neighboring NE 2 of IS 1 as shown in (40) and (42). Delivery to 0 # 2, 2 0 # 3 Since NE 20 # 2 and 20 # 3 do not match the node ID of the address search PDU, NE 20 # 1 cannot receive the address reply PDU. As shown in (44), the NE 20 # 1 distributes the address search PDU (type 2) to the NE 2 # 4 adjacent to the IS 2 in a different area. As shown in (46) and (48), NE 2 0 # 4 is an adjacent NE 2 in the same area.

The address search PDU (type 2) is distributed to 0 # 5 and 2 0 # 6. NE 20 # 5 returns an address reply PDU as shown in (49). NE 20 # 6 discards the address search PDU.

FIG. 2 is a network configuration diagram according to the embodiment of the present invention. As shown in Figure 2, the network consists of NMS 50, GNE 52 # 1, GNE 52 # 2, GNE 52 # 3, NE 54 * 11, 54 * 12, 54 # 1 3, 5 4 # 2 1, 5 4 # 2 2, 5 4 # 23, lan 56 and rings 58 # 1, 58 # 2. · NMS 50 monitors and controls GNEs and NEs. Specifically, TL1 commands are used to set system types and network addresses in GNEs and NEs, and to set system types and network addresses. It displays the setting information of the network address. GNE 5 2 #

1 (i = l, 2, 3) and NE 5 4 # ij, except that the former has a system type of IS 2 and the latter has a system type of IS 1 Have substantially the same function.

FIG. 3 is a functional block diagram of GNE 52 #i (i = 1, 2, 3) and NE 54 #ij (i = 1, 2, j = 1, 2, 3) in FIG. As shown in FIG. 3, GNE 52 #i and NE 54 #ij (i = 1, 2) are composed of a LAPD frame processing unit 70 #i, a LAN frame processing unit 72 #i, and IS-IS / ES— IS routing processor 7 4 # i, TP 4 processor 80 # i, X. 2 15 / X. 2 25 processor 8 2 # i, X, 2 16 / X 2 2 6 It has a processing unit 84 # i, an association processing unit 86 # i and a TL1 processing unit 88 # i. The LAP D frame processing unit 70 #i has the following functions. (L) Receive the LAP D frame from DCC 58 #i, analyze the LAP D header, and process the frame addressed to the own node. (2) Analyze the LAPD header and The CNL PP DU is output to the C LNP PDU processing section 76 #i or IS—IS / ES—IS routing processing section 74 #i. (3) C LNP PDU processing unit 76 #i or IS-IS / ES-IS routing processing unit When a C LNP PDU is input from 74 #i, a header is added to LAP D and the transmission path 58 # Send LAP D frame on DCC of sync frame of i.

The LAN frame processing section 7 2 #i has the following functions. (1) Receive an Ethernet frame from LAN 566, analyze the DLC header, and process the frame addressed to the own node. (2) Analyze the LLC header and send CNLPPPDU to the CLNPPPU processing unit 76 # i. (3) CLNPPDU processing unit 7 6 # i or IS— IS / ES— IS routing processing unit 7 4 # i Receives C LNP PD より from-i, adds a DLC / LLC header, and puts it on LAN 56. Send one sun frame. IS— IS / ES— IS routing processor 74 # i has the following functions: (1) LA-PD frame processor 70 # i or LAN frame processor 72 # i from IS-ISPDU / ES—Receives the ISP DU and builds a routing table. The ruling tables include an adjacent database, a level 1 forging table, and a level 2 forging table. In the adjacent database, the network address and system type of the adjacent node are registered. In the Level 1 forwarding table, information on all NEs including the own station in the same area is registered. Area information such as an area address existing in the routing domain is registered in the level 2 forwarding table. (2) 1 S-I S / E S — Transmits the I SDU to the LAP D frame processing unit 70 #i or the LAN frame processing unit 72 # i.

The CLNP frame processing unit 76 #i has the following functions. (L) When a C LNP PDU is received from the LAPD frame processing unit 70 #i or the LAN frame processing unit 72 #i, the CLNP header is analyzed and the frame addressed to the own node or another node is processed. Manage. (2) Identify the SEL field of the CLNP header and send a TP 4 PDU to the TP 4 processing unit 80 #i. (3) Identify the SEL field in the CL NP header and send a TARP search PDU to the TARP search PDU processing unit 78 #i. (4) Analyze the CLNP header and convert the C LNP PDU to IS-IS / ES-IS Sent to processing unit 7 4 # Send to i. (5) When receiving a CLNP data de-duplication PDU from TP4 processing section 80 # i, a CLNP header is added to the LAPD frame processing section 70 # i or LAN frame processing section 7 2 # Send to i. (6) When receiving a TAR P search PDU or a TAR P reply PDU from the TAR P processing unit 78 #i, a header is added to the CLNP and the LAP D frame processing unit 70 #i or LAN frame processing unit 7 2 # Send to i. The TARP processing unit 7 8 #i has the following functions. (L) A TAR P search PDU is issued to the LAN 56 or the transmission line 58 #i. (2) LAN 56 or transmission line 58 # i or the source node receives the TAR P search PDU from the ES node and distributes the TARP search PDU to LAN 56 and transmission line 58 # i Control.

FIG. 4 is a functional block diagram according to the present invention of the TARP processing section 78 #i in FIG. The T ARP processing section 78 #i according to the present invention is applied to the following cases. (1) When issuing a TAR @ search PDU to LAN56. (2) LA Ν 56 or transmission line 58 #i If the source node receives a TAR P search from the ES node, receives a PDU, and sends a TARP search PDU to the LAN 56 If you want to deliver ... This is to suppress the increase in traffic by controlling the issuance or distribution of T ARP search PDU to LAN5 &. .

As shown in FIG. 4, the TARP processing section 78 #i is composed of a TDC search processing section 100 #i, a TARP search PDU reception section 102 #i, and a Tar—ttg analysis section 104 # i , TARP search PDU transmission destination judgment processing part 106 #i, TARP search PDU transmission part 108 #i, TARP reply PDU transmission part 110 0 #i, TARP reply PDU reception part 112

# i and TAR P data cache 1 1 4 # i. T D C search processing unit 1 0 0

# i has the following functions. (1) When the search TID is received from the TL 1 processing unit 8 8 # i, if the NS AP address corresponding to the search TID is registered in the TAR P data cache 1 14 # i, the NS AP address is used. Return to TL 1 processing unit 8 8 # i. (2) If the NS AP address corresponding to the search TID is not registered in the TARP data cache 1 1 4 # i, the TAR P search destination determination processing unit 1 06 # i is instructed to perform the TAR P search. I do. (3) TAR P search PDU transmission destination determination processing unit 106 # # When receiving NSAP address corresponding to the evening TID from i, processing TL1 Part 7 8 # Send to i.

Upon receiving the TARP search PDU, the TARP search PDU receiving unit 102 #i performs the following processing. (1) TARP search Identifies the type of PDU. (2) Decrement the LIFE time, and if the LIFE time is 0, discard the TAR P search PDU _c

(3) T ARP search It is determined whether Tar-Seq of PDU is registered in LDB.

(4) When the Tar-Seq is registered in the LDB, the TARRP search PDU is discarded.

(5) When the Tar-Seq is not registered in the LDB, the T ARP search PDU is registered in the LDB and transmitted to the T.a r — tt g analysis unit 104 #i.

The T ar — tt g analysis unit 104 # i receives the TARP search PDU and performs the following processing. (L) TAR P search It is determined whether or not the target TID included in the PDU matches the TID of the own node. (2) When it matches with the TID of the own node, it notifies the TAR P reply PDU transmitting unit 110 #i to transmit the TAR reply PDU. (3) When it does not match the TID of its own node, it transmits the TARP search PDU to the TARP search PDU transmission destination determination processing section 104 #i. -.,

TAR.P search. PDU. Destination determination processing unit 106 #i receives the TARP search instruction from T.D.C search processing unit 10.6 # i and performs the following processing. (I) I S — I S / Έ S — I S routing processing section 74 # Searches the adjacent NE of IS 1 as a target of type 1 TAR P search PDU distribution from the adjacency database of # i. Then, it instructs the TARP search PDU transmission unit 108 # i to distribute the TARP search PDU to the adjacent NE. (Ii) Start T1 response. (Iii) Upon receiving the TAR P reply from the TAR P reply PDU receiver 1 1 2 #i, the T 1 response timer is stopped and the TAR reply PDU is transmitted to the TDC search processor 106 #i. (iv) When the Tl response timeout expires, the IS—IS / ES—IS routing processing unit 74 4 # from the adjacent database of #i, the distribution target of the Type 2 TARP search PDU is It instructs the TARP search PDU transmitting unit 108 # i to search for the second NE and to deliver the TARP search PDU to the adjacent NE. At this time, the NE whose system event is IS 1 is not a destination.

Further, upon receiving the TARP search PDU from the Tar-ttg analyzer 104 # i, the TARP search PDU transmission destination determination processing unit 106 # i performs the following processing. (1) When the own node is ISI, the TAR P search PDU is discarded unconditionally. (2) When the own node is IS2, perform processing in the following order. (I) When the source node has ES and the Tarcd is Type 1, the TARP search PDU is delivered to the adjacent node in the same area. (Ii) When the source node has ES and the Tar-tcd is evening 2, the TA RP search PDU is delivered to the adjacent node in the same area. ((Iii) The Tar-tcd is type 1 At some point, the TARP search PDU is discarded (iv) When the source node is IS 2 in the same area, the corresponding TARP search PD ϋ is discarded The source node is addressed to an adjacent node in a different area (V) When the source node is not IS1 in the same area, the source node does not need to distribute the TARΡ search PDU. The TARP search PDU transmission unit 108 # i to deliver the TARP search PDU to an adjacent node in the same area other than the above. (Vi) When the source node is IS 1 of the same area, Instructs the TAR.P. search PDU transmission unit 108 # i to deliver the TAR P search PDU to an adjacent node in a different area other than the transmission source. When transmitting PD, U, the same type as the type of the received TA.RP search PDU is used. 011 Receiving unit When receiving a TARP reply PDU from the receiving unit 1 1 2 # i, transmits the NSAP address corresponding to the target ID to the TDC search processing unit 100 # i.

The TARP search PDU transmitting section 108 #i has the following functions. (1) When receiving a TARP search PDU transmission instruction from the TARP search PDU transmission destination determination processing unit 106 #i to the destination of type 1 from the i, a type 1 TARP search PDU is created. C LNP PDU processing unit 7 6 # Send to i. (2) TARP search PD ϋDestination judgment processing unit 106 # In response to the transmission instruction of the TARP search PDU to the destination destination of type 2 from i, a TARP search PDU of type 2 is created. LNP PD U processing section 7 6 # Transmit to i. The TARP reply PDU transmitting section 110 #i, upon receiving an instruction from the Tar — "ttg analyzing section 102 #i", creates a TARP reply PDU and transmits it to the CLNPPDU processing section 76 #i. Upon receiving the TARP reply PDU, the TAR P reply PDU receiving unit 108 # i writes the relationship between the TID and the NSAP address into the TARP cache memory 114 # i, and sends the TAR P reply PDU to the TAP search PDU. Sent to destination determination processing unit 106 #i. T ARP Data Cache 1 1 4 #i is a table that holds the relationship between TID and NSAP address.

FIG. 5 is an operation flowchart of the TRAP processing unit 78 #i in the source NE / GNE. In step S50, a Type 1 TAR P search PDU is issued to the adjacent node of IS1. In step S52, it is determined whether or not the T1 response timer has timed out. When the T1 response timer times out, the flow advances to step S54. If the TARP reply PDU is received before the T1 response time expires, the process proceeds to step S56. In step S54, the type 2 TARP search PDU is delivered to the adjacent node of IS2. In step S56, since the response T P RP was received, the search was completed. 011 is not distributed.

Fig. 6 is an operational flowchart of the TARP processor 78 # i in the NE / GNE of IS1. In step S60, the TAR P search PDU is received. In step S6.2, it is determined whether Tar-seq is registered in the LDB. If not registered in LDB, go to step S64. If it is registered in LDB, go to step S70. In step S 6, Tarseq is registered in LDB. In step S66, it is determined whether or not it matches tar-ttg or the TID of its own node. If they match, go to step S68. If they do not match, the process proceeds to step S70. In step S68, a TAR reply PDU including the NSAP address of the node in Tarpor is returned to the search source. In step S70, the TAR P search PDU is discarded.

Fig. 7 is an operational flowchart of the TARP processor 78 # i in the NE / GNE of IS2. In step S80, a TAR P search PDU is received. In step S82, it is determined whether the Tar-seq is registered in the LDB. If not registered in the LDB, go to step S84. If it is registered in LDB, go to step S102. In step S84, Tar-seq is registered in LDB. In step S86, it is determined whether or not Tar-ttg matches the TID of the own node. If they match, go to step S88. If they do not match, go to step S90. In step S88, Tar-por stores N TARP reply including SAP address P DU is returned to the search source.

In step S90, it is determined whether or not Tar-tcd is type 1. If it is type 1, go to step S92. If not, go to step S98. This is because the type 1 TAR P search PDU is not distributed on the LAN56. In step S92, it is determined whether or not the source node is IS2 in the same area. If it is not I S2 in the same area, go to step S94. If it is I S2 in the same area, go to step S98. This is because the source nodes in the same area with the system type IS 2 have already delivered the T ARP search PDU to the same area adjacent nodes.

In step S94, it is determined whether or not the source node is IS 1 in the same area. If it is not I S1 of the same area, go to step S96. If I S 1 in the same area, go to step S 100. In step S96, the TARP search PDU is delivered to an adjacent node in the same area other than the transmission source. In step S98, T ARP search. PDU is discarded. In step S100, the TAR P search PDU is delivered to a different area adjacent node other than the transmission source. The TP4 processing unit 80 # i in FIG. 3 has the following functions. (L) Receives the SESSPDU from the CLNPPPU processing section 76 # i, analyzes the SESS header, and transmits the PRESPDU to the X.215 / X.225 processing section 82 # i. (2) The PRESPDU is received from the X.215 / X.225 processing unit 82 # i, an SESS header is added, and the packet is transmitted to the CLNP PDU processing unit 76 # i.

The X.215 / X.225 processing unit 82 # i has the following functions. (1) The SES SPDU is received from the T P4 processing section 80 #i, the SES S header is analyzed, and the PRES PDU is transmitted to the X.216 / X.226 processing section 84 #i. (2) Receives PRESPDU from the X.216 / X.226 processing unit 84 #i, adds a header to SESS, and transmits it to the TP4 processing unit 80 # i.

The X.216 / X.226 processing section 84 # i has the following functions. (1) Receives PRESPDU from X.215 / .225 processing unit 82 # i, analyzes PRESPDU, and transmits AC SEPDU to association processing unit 86 # i I do. (2) Association processing section 8 6 # Receive ACSEP DU from #i and An S header is added, and the packet is transmitted to the X.215 / X.225 processing unit 82 # i.

The association processing unit 86 #i has the following functions. (1) Establishes and disconnects associations between other nodes, and controls higher-level applications. (2) Receives ACSEP DU from X.216 / X.226 processing unit 84 # i, analyzes ACSE header, and sends TL 1 PDU to TL 1 processing unit 88 # i . (3) The TL1 PDU is received from the TL1 processing unit 888 # i, a header is added to ACSE, and the ACK is transmitted to the X.216 / X.226 processing unit 8.4 # i.

The T P1 processing unit 8 8 #i has the following functions. (1) In accordance with a request from the application, an address function search request is requested to the TARP processing unit 78 #i. (2) TARP processing section 7 8 # Receives the address search / search function result notification from i and notifies the application case. (3) Association processing section 86 Receives TL1PDU from #i and analyzes the TL1 command. (4) Transmit TL1PDU to the association processing unit 8.6 # i.

GNE 5 2 # 1, GNE 5 2 # 2, GNE 5 2 # 3 and ΝΕ 5 4 # 1 1, ΝΕ. 5 4 # 1 2, ΝΕ 5 4 # 2 1, Ν.Ε 5 4 # 2 • 2. This is a local area network. The transmission line 58 # 1 and the transmission line 58 # 2 are optical transmission lines that transmit the main signal to the payload and the sub-signal to the overhead by using synchronous frames such as SD Η and S0 Ν Ε. is there. Although not shown, the main signal is an Ethernet frame transmitted from a terminal accommodated by GN # 52 # i or NE54 # ij. The sub signal is a signal used for communication between GNEs and NEs such as a TARP search PDU, and communication is performed using DCC.

Hereinafter, distribution of the TAR P search PDU will be described.

(1) When GNE 5 2 # 1 is the TARP search P DU search source

The GNE 52 # 1 sets the TID of the NE 54 # 21 in the TL 1 command to acquire the setting information such as the NS AP address and system settings of the NE 54 # 21. , TL 1 command shall be issued. If the NE AP address corresponding to the NE 54 # 21 TID is stored in the TARP cache table, the GNE 52 # 1 sends the NE 54 # 21 NSAP address to the destination. Send the C LNP PDU including the added TL1 command to NE54 # 21. NE 5 4 # 2 When 1 receives the TL1 command, it analyzes the TL1 command and sends the PDU containing the setting information to the GNE 52 # 1 of the transmission source.

FIG. 8 is a diagram showing distribution of a type 1 TARP search PDU. GNE 5 2 # 1 is of type 1 and IS 1 of type 1 as shown in (50) and (52) if the N SAP address corresponding to the TID of NE 54 # 21 is not stored in the TARP cache memory. After issuing a TAR P search PDU to the neighboring NEs 5 4 # 11 and 5 4 # 12, activate the T1 response timer. NE 5 4 # 1 1, 5 4 # 1 2 receives TARP search PDU, and Tar-ttg does not match its own node T ID. ^ Jun search Discard DU.

FIG. 9 is a diagram showing distribution of a type 2 T ARP search PDU. Since the TL1 response timer times out, the GNE 52 # 1 distributes the type 2 TAR P search PDU to the adjacent node 52 # 2 of the IS 2, as shown in (70). When GNE 52 # 2 receives the type 2 TARP search PDU, it receives type 2 and the source node GNE 52 # 1 is area # 1, which is different from area # 2 of its own node. As shown in (72) and (74), the TARP search PDU is delivered to the adjacent nodes NE 54 # 21 and 54 # 22 in the same area other than the transmission source. Since NE 5 4 # 21 matches Tar-ttg with its own node T ID, as shown in (76), it responds with TAR P reply PDU to GNE 5 2 # 1 of the transmission source. NE 5 4 # 22 is a search result because Tar-ttg does not match its own node T ID and is IS 1. Discard 011.

FIG. 10 compares the number of type 2 TAP search PDUs in the case of the prior art and the above case. The circle in Fig. 10 indicates distribution, and the Hai Phong indicates no distribution. As shown in FIG. 10, in the present embodiment, the number of T ARP search PDUs can be reduced by five compared to the conventional case.

(2) When NE 5 4 # 1 1 is the search source of TAR P search PDU

FIG. 11 is a diagram showing distribution of a type 1 TARP search PDU. If the NS AP address corresponding to the TID of NE 5 4 # 2 1 is not stored in the TAR P cache memory, the type of NE 5 4 # 11 will be used as shown in (80) and (82). After issuing a TAR P search PDU to NE 5 4 # 1 2 and GNE 5 2 # 1 of IS 1, Start the response timer. When the NE 54 # 12 receives the TARP search PDU, the NE-54 finds that the Tar-ttg does not match its own node TID and that its own node is IS1, so the NE 54 # 12 receives the TARP search PDU. Discard. When receiving the TAR P search PDU, GNE 5 2 # 1 discards the TAR P search PDU because Tar-ttg does not match its own node TID and Tar-tcd is type 1.

FIG. 12 is a diagram showing distribution of a type 2 TARP search PDU. When the T1 response timer times out, the NE 54 # 11 1 delivers the type 2 TAR P search PDU to the adjacent node 52 # 1 of the IS 2 as shown in (90). Upon receiving the type 2 TA RP search PDU, GNE 5 2 # 1 confirms that Tarttg does not match its own node TID, that its own node is IS 2, and that the source node NE 5 4 # 1 1 is the same. Since it is IS 1 in area # 1, the TA RP search PDU is delivered to different area adjacent node 52 # 2 other than the transmission source as shown in (92). When GNE 5 2 # 2 receives the type 2 TAR P search PDU, Tar-ttg does not match its own node TID, its own node is IS 2 and the source node GN E 5 2 # 1 is 荬: i because it is IS 2 in the rear area. As shown in (94) and (96), adjacent nodes in the same area other than the source NE 5 4 # 2 1, 5 4 Deliver the TAR P search P DU to # 22. Because NE-54 # 21 matches Tar-ttg with its own node TID, as shown in (98), it responds with a TAR P reply PDU to GNE 52 # 1 of the transmission source. NE54 # 22 discards the TARP search PDU because Tarttg does not match its own node TID and its own node is IS1.

Industrial applicability

According to the present invention described above, the number of address search PDUs delivered on the LAN by the address search function can be significantly reduced as compared with the number delivered by the conventional technology. When N IS1 nodes are connected on the same LAN segment, in the related art, the number of TARP search PDUs distributed on the LAN is (N-1) ² . According to the present invention, since the TARP search PDU is delivered to (N-1) adjacent nodes, the number of the TARP search PDUs delivered on the LAN is (N-1). Therefore, the number of TARP search PDUs to be delivered according to the present invention can be reduced to 1 / (N−1) as compared with the conventional case. This is the traffic on LAN The load can be greatly reduced, that is, the load can be significantly reduced, and the transfer efficiency on the LAN can be improved.

Claims

The scope of the claims

1. A transmission device connected to the LAN segment and set with the node ID, network address for routing, area address, and system type.

An address search PDU receiving unit for receiving an address search PDU from the RAN segment;

When the node ID of the own transmission device matches the node ID set in the address search PDU received by the address search PDU reception unit, an address reply PDU including the network address of the own transmission device is transmitted. An address reply PDU transmission unit to be transmitted to the original transmission device;

If the node ID of the own transmission device does not match the node ID set in the address search PDU received by the address search PDU reception unit, and the system type of the own transmission device is the first system type, the corresponding address. A first address search PDU discarding unit for discarding the search PDU,

The node ID of the own transmission device does not match the ID set in the address search PDU received by the address search PDU reception unit, and the type of the address search PDU is transmitted to the different adjacent transmission device. A second address search PDU discarding unit that discards the address search PDU when the first type prohibits distribution of the address search PDU and the system type of the own transmission device is the second system type;

A transmission device comprising:

2. The type set in the address search PDU is the second type that permits delivery to the different area adjacent transmission device, and the transmission device of the transmission source of the address search PDU is the same area address, and the system thereof is used. The method according to claim 1, further comprising, when the type is the first system type, a first address search PDU delivery unit that delivers an address search PDU to a different adjacent transmission device other than the transmission device of the transmission source. Transmission equipment.

3. The type set in the address search PDU is When the transmission device of the second type that permits distribution is the transmission device of the transmission source of the address search PDU is a different area address and the system type is the second system type, the transmission device of the transmission source 3. The transmission apparatus according to claim 2, further comprising a second address search PDU distribution unit that distributes an address search PDU to an adjacent transmission apparatus in the same area other than the above.

4. A transmission device connected to the LAN segment and configured with node ID, network address, area address and system type,

An adjacency database holding network addresses, system types, and area addresses of adjacent transmission devices connected to the LAN segment;

A first address search PDU transmission unit for transmitting an address search PDU including a target node ID and a first type prohibiting distribution to an adjacent transmission device in a different area to an adjacent transmission device;

If an address reply PDU to the address search PDU cannot be received within a certain period of time after the address search PDU has been delivered to the LAN segment, the evening node ID and the address node ID included in the addressless search PDU are not received. A second address search PDU transmitting unit that transmits an address search PDU that includes a second type permitting distribution to a different area adjacent transmission device to an adjacent transmission device of the second system type and that distributes a address search PDU;

An address search PDU receiving section for receiving an address search PDU from the LAN segment;

When the node ID of the own transmission device matches the FID set in the address search PDU received by the address search PDU receiving unit, an address reply PDU including the network address of the own transmission device is transmitted. An address reply PDU transmission unit to be transmitted to the original transmission device;

When the node ID of the own transmission device does not match the node ID set in the address search PDU received by the address search PDU reception unit and the system type of the own transmission device is the first system type, A first address search PDU discarding unit for discarding the address search PDU,

The address search PD ノ The node set in the address search PDU received by the receiving unit. — If the node ID of the own transmission device does not match the ID and the type of the address search PDU is the first type that prohibits delivery to another adjacent transmission device, and the system of the own transmission device When the type is the second system type, the second address search PD for discarding the address search PD U, the discard unit,

A transmission device comprising:

Summary Form

In a transmission device that is connected to the LAN segment and has a node ID, a network address for routing, an area address, and a system type, an address search PDU receiver that receives an address search PDU from the LAN segment When the node ID of the own transmission device matches the node ID set in the address search PDU received by the address search PDU receiving unit, the address reply PDU including the network address of the own transmission device is transmitted from the transmission source. The address reply PDU transmitting unit to be transmitted to the transmission device of the own device and the node ID set in the address search PDU received by the address search PDU receiving unit are not matched by the node I 3D of the own transmission device and the own transmission device. A first address search PDU discarding unit for discarding the address search PDU when the system type is the first system type; The node ID of its own transmission device does not match the node ID set in the address search PDU received by the address search PDU receiver, and the type of the address search PDU prohibits delivery to a different area adjacent transmission device. When the transmission type is the first type and the system type of the own transmission device is the second system type, a second address search PDU discarding unit for discarding the address search PDU is provided.