JP2000358042A - Routing method for network and packet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of times of generation of routing processing based on the destination address of a packet concerning connectionless(CL) type communication due to PVC on an ATM network or the like. SOLUTION: As for a CL packet containing a specified destination address, in input nodes IF1, R1 and VCH1, routing is executed by performing capsuling by using a Tadd (temporary address related to a connection with the adjacent node) consisting of VPI and VCI dedicated to the destination address. When a packet (ATM cell) S capsuled by the dedicated Tadd is received, in relay nodes TF2, R2 and VCH2 or the like, the dedicated Tadd thereof is replaced with a corresponding dedicated Tadd. Thus, routing is performed by using the dedicated Tadd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a network (for example, an ATM network) and a packet routing method.

[0002]

2. Description of the Related Art Generally, in a computer network, a source node of data forms a packet by adding a destination address and a source address to information to be transferred, and the packet is transmitted to the network so as to be transmitted from the source node. Information is transmitted to the destination node. This is basically the same in the Internet connected by an infinite number of routers (gateways). A source node is assigned by a rule for assigning an address to a node constituting a network and a packet is routed using the rule. Are transmitted to the destination node.

[0003] Internet Protocol (IP) such as the Internet
A col) based computer network is considered as a CL (Connectionless) type network because each packet includes a destination address and the connection is cut off when the transmission of one IP packet is completed. That is, a connection (communication path in the data link layer) is established and released in IP packet units.

On the other hand, the telephone network is basically regarded as a CO (Connection Oriented) type network. For example, in the routing of IP packets in an ATM (Asynchronous Transfer Mode) backbone, there is a method of performing address resolution in SVC (Switched Virtual Connection). SVC is a method of selecting and connecting a partner according to a call setting procedure every time communication is started, and it can be said that the existing telephone network functions as a CO type network even in the transmission of IP packets.

[0005]

In recent years, information communication services using a telephone network have been developed one after another, and the need to relay data packets such as IP packets in the telephone network has been increasing. In general, in data communication, it is known that packets are generated intermittently, and it is inefficient to perform a process of establishing / disconnecting a connection for a subscriber who transmits and receives a rarely generated packet.

In the conventional ATM backbone of a telephone network, each ATM exchange (Virtual Channel Handler) checks the destination IP address of an IP packet encapsulated in an ATM cell and stores the result in a conversion table between the IP address and the ATM address. When the number of IP packets to be routed increases, the overhead due to the routing process becomes a bottleneck, and the throughput of the entire telephone network may decrease.

On the other hand, in the ATM network, PVC (Perm
Anent Virtual Connection) is also specified. PVC is a fixed connection method in which a communication partner is fixedly set in advance, and communication is performed immediately after connection is made. That is, if PVC is used, CL-type communication can be realized in a CO-type ATM network. However, in CL-type communication using PVC, in each ATM exchange, VP (Virtual Path) and VC (Vi
rtual Connection) is assigned. That is,
PV from one ATM switch to the next ATM switch on the route
C is only assigned once per ATM switch, and ATM cells containing routed IP packets are (output)
It is transmitted to the next ATM switch by one PVC according to the route. Usually, a plurality of ATM cells having different destinations are multiplexed on one PVC, so that a routing process based on the IP address is performed hop-by-hop for each ATM switch. That is, there is the same drawback as when SVC is used.

The present invention has been made in view of the above-described circumstances, and in a CL-type communication using PVC in an ATM network or the like, it is possible to reduce the number of times of occurrence of routing processing based on a destination address of a packet and to increase traffic. It also aims to maintain high throughput.

[0009]

According to one aspect of the present invention, there is provided a network for routing a packet including a destination address. Is encapsulated in Tadd (temporary address regarding connection with an adjacent node) corresponding to the destination address of the packet,
The routing of the encapsulated packet is referred to as Tad.
receiving the packet encapsulated with the Tadd, replacing the Tadd of the encapsulated packet, and routing the encapsulated packet after the substitution to the Tadd after the substitution. And a relay node for receiving the packet encapsulated by the Tadd, decapsulating the encapsulated packet, and outputting the packet.
d includes a dedicated Tadd, and a packet including a specific destination address is encapsulated at the input node using the dedicated Tadd.

According to a second aspect of the present invention, in the network according to the first aspect, when the relay node receives a packet encapsulated in the dedicated Tadd, the relay node uses the exclusive packet for the encapsulated packet. It is characterized in that Tadd is replaced with a dedicated Tadd corresponding to the dedicated Tadd.

According to a third aspect of the present invention, in the network according to the first or second aspect, the input node comprises:
Encapsulation is performed on the basis of the Tadd additional information in which the correspondence information between the destination address and the dedicated Tadd is stored.
If the destination address of the input packet is stored in the dd additional information, the input packet is encapsulated with the corresponding dedicated Tadd stored in the Tadd additional information, and the relay node The replacement is performed based on the Tadd replacement information in which the correspondence information between the dedicated Tadd before replacement and the dedicated Tadd after replacement is stored, and the dedicated Tadd of the received encapsulated packet is replaced with the dedicated Tadd before the replacement. When stored as Tadd, the replacement of the dedicated Tadd of the received encapsulated packet is performed with the corresponding dedicated Tadd after replacement stored in the Tadd replacement information.

According to a fourth aspect of the present invention, in the network according to the third aspect, the input node is connected to the Ta node.
If there is no dedicated Tadd information corresponding to the destination address of the input packet in the dd additional information and the destination address is new, an output route is determined based on the destination address, and the output route is determined. And the Tadd additional information is updated to associate the destination address with the allocated dedicated Tadd. The relay node replaces the received encapsulated packet with the Tadd replacement information. If there is no Tadd information corresponding to the previous dedicated Tadd and the destination address of the received encapsulated packet is new, an output route is determined based on the destination address and replaced with the output route. After the dedicated Tadd is assigned, the Tadd
The replacement information is updated so that the dedicated Tadd before replacement is associated with the allocated dedicated Tadd after replacement.

According to a fifth aspect of the present invention, there is provided the network according to any one of the first to fourth aspects, wherein the Ta
dd includes a shared Tadd, the input node encapsulates the input packet with the dedicated Tadd or the shared Tadd, and the relay node performs the dedicated Tadd or the dedicated Tadd of the received encapsulated packet. The shared Tadd is replaced.

According to a sixth aspect of the present invention, in the network according to the fifth aspect, the input node has monitoring means for monitoring traffic of the input packet for each destination address, and the traffic is determined by a predetermined number. If the dedicated Tadd is assigned to a destination address that satisfies the condition, the dedicated Tadd is released, and the routing of the packet including the destination address is performed by the shared Tadd.
d.

According to a seventh aspect of the present invention, in the network according to the fifth or sixth aspect, the input node comprises:
Monitoring means for monitoring the traffic of the input packet for each destination address, allocating the dedicated Tadd to a destination address where the traffic satisfies a predetermined condition and the dedicated Tadd is not assigned, The routing of a packet including an address is performed by using the allocated dedicated Tadd.

[0016] According to an eighth aspect of the present invention, in the network according to the sixth or seventh aspect, the predetermined condition is:
The change is made based on the total amount of traffic of a packet input to the input node.

According to a ninth aspect of the present invention, in the network according to any one of the first to eighth aspects, the network is an ATM network, and the encapsulated packet is an ATM cell. .

According to a tenth aspect of the present invention, in the network according to the ninth aspect, the routing of the packet is performed after a routing path is set in advance by a call setting procedure, or the routing path is set in advance by a call setting procedure. The setting is performed using the Tadd without setting.

According to an eleventh aspect of the present invention, in the network of the ninth or tenth aspect, the Tadd comprises a VPI and a VCI.

According to a twelfth aspect of the present invention, in the network of the first aspect, the destination address of the packet is an IP address.

According to a thirteenth aspect of the present invention, there is provided an input node,
A method for routing a packet including a destination address in a network including a relay node and an output node, wherein the input node receives the input of the packet, and converts the packet with a Tadd corresponding to the destination address of the packet. Encapsulating and routing the encapsulated packet based on the Tadd; receiving, at the relay node, the packet encapsulated with the Tadd; replacing the Tadd of the encapsulated packet; Routing the subsequent encapsulated packet based on the replaced Tadd; receiving, at the output node, the packet encapsulated with the Tadd and decapsulating the encapsulated packet; Output step Wherein the Tadd includes a dedicated Tadd, the packet including a specific destination address,
The input node performs encapsulation using the dedicated Tadd.

According to the above configuration, in CL-type communication using PVC in an ATM network or the like, for example, a PVC is dedicated to a destination address with a high communication frequency, and a PVC is shared with a destination address with a low communication frequency. In addition, it is possible to reduce the number of occurrences of the routing processing of the packet using the destination address, and to maintain the high throughput even when the traffic increases.

In an ATM-SVC network, for example, an SVC using call processing according to a signaling procedure is not set for a destination address having a high communication frequency temporarily, and a PVC is fixedly set between nodes. High-speed communication can be realized without the need.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a network according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration example of a network (ATM network) according to one embodiment of the present invention. In the present embodiment, the network according to the present embodiment is used for receiving a packet supplied from a CL-type communication network (CL network CLN) and routing (relaying) the packet to the CL-type communication network. ing.

The network according to the present embodiment includes an input node, a relay node, and an output node (not shown). In FIG. 1, the interface IF1 and the router R
1 and the ATM switch VCH1 constitute an input node. The interface IF2, the router R2 and the ATM switch VCH2 constitute a relay node. Further, the interface IF3, the router R3, and the ATM
The exchange VCH3 forms another relay node.

In FIG. 1, a CL network CLN is a CL network on which an IP such as the Internet is mounted. Packet P is C
This is a packet (hereinafter, referred to as a “CL packet”) transmitted from the L network CLN to another network via the ATM network according to the present embodiment. The destination address (in this embodiment, the IP address) is stored in the header IH of the packet P, and the information to be transmitted is stored in the data section IM.

In the present embodiment, packet routing is performed using Tadd. Tadd is a temporary address related to a connection with an adjacent node.
In the present embodiment, Tadd includes dedicated Tadd and shared Tadd. The dedicated Tadd is a Tadd dedicated to one destination address. In contrast, the shared Tad
d is Tadd which is not dedicated to one destination address, and corresponds to, for example, the PVC in the above-described conventional ATM network. Therefore, a plurality of ATM cells having different destinations can be multiplexed on one shared Tadd. In the present embodiment, Tadd is composed of VPI and VCI (PVC).

The input node receives the input of the CL packet, encapsulates the packet with Tadd corresponding to the destination address of the packet, and generates an ATM cell. In the present embodiment, a CL packet including a destination address satisfying a predetermined condition is encapsulated using a dedicated Tadd. The input node performs routing of the encapsulated CL packet (ATM cell) based on Tadd. The ATM cell S includes a header AH, and the header AH includes VPI and VCI.

The interface IF1 of the input node is CL
An interface for converting a packet into an ATM cell for routing. The router R1 routes the CL packet based on the destination IP address of the CL packet.

The input node has a destination address and a dedicated Tad.
Tadd additional table (T
(additional information), and performs Tadd.
If the destination address of the CL packet input in the additional information is stored, the CL packet input in the corresponding dedicated Tadd stored in the Tadd additional information is encapsulated.

FIG. 2 is a diagram exemplifying the contents of the Tadd addition table of the input node, and FIG. 3 is a diagram exemplifying the contents of the vacancy management table (vacancy management information) of the input node and the relay node. . Interface IF1
Has a Tadd addition table illustrated in FIG. 2 and an empty / busy management table illustrated in FIG. The Tadd addition table is a table storing dedicated Tadd information for a destination IP address, and is used when a CL packet is encapsulated with a dedicated Tadd corresponding to the destination address. The vacancy management table is a table for managing vacancies of VPI and VCI.
This is used when Tadd (constituted by CI) is newly assigned.

The relay node receives the packet (ATM cell) encapsulated in Tadd, and
Replace add. That is, the input Tadd (Tadd before replacement) is replaced with the output Tadd (Tadd after replacement). Then, the replacement ATM cell is routed based on the output Tadd.

Interfaces IF2 and IF3 of the relay node are interfaces for routing ATM cells, and replace Tadd of ATM cells. Routers R2 and R3 route ATM cells based on the destination IP address of the CL packet.

The relay node has a dedicated input Tadd (Tadd before replacement) and a dedicated output Tadd (Tadd after replacement).
d) is replaced based on the Tadd replacement table (Tadd replacement information) storing the correspondence information with d), and the (input) Tadd of the received encapsulated packet is Tadd.
If stored in the replacement information, the corresponding output Tadd stored in the Tadd replacement information replaces the Tadd of the received encapsulated packet.

FIG. 4 is a diagram exemplifying the contents of the Tadd replacement table possessed by the relay node. Interface I
F2 and IF3 have a Tadd replacement table illustrated in FIG. 4 and an empty / busy management table illustrated in FIG.
The Tadd replacement table is a table storing information of a dedicated output Tadd for a dedicated input Tadd.
Used when replacing the dedicated Tadd of the TM cell.

In this embodiment, the relay node replaces the dedicated Tadd with the corresponding dedicated Tadd. That is, when a packet encapsulated by the dedicated Tad is received, the dedicated Tad of the encapsulated packet is received.
Replace d with a dedicated Tadd corresponding to the dedicated Tadd. However, a relay node that replaces the dedicated Tadd with the shared Tadd may be provided.

The output node receives the packet (ATM cell) encapsulated by Tadd, decapsulates the ATM cell, that is, extracts the CL packet from the ATM cell and transmits it to the outside. Since they are well known, detailed description is omitted.

FIG. 5 is a flowchart showing an example of a packet routing process at the input node.

The input node is connectionless (CL)
Provides interconnection between the network and a connection-oriented (CO) network. In addition, the vacant / busy management of a temporary address (Tadd) related to a connection with an adjacent node in the CO network is performed.

When the input node receives a CL packet from the CL network, it checks the Tadd addition table and determines whether or not a dedicated Tadd corresponding to the destination address of the CL packet has not been set (step SA1).

If the exclusive Tadd is not set, the CL packet is encapsulated with the exclusive Tadd and the ATM is added to the ATM.
A cell is generated (SA9), and the ATM cell is converted to its dedicated T
The signal is output to the output path indicated by add and transmitted to the next node (SA10).

If the dedicated Tadd has not been set, an adjacent node (next node of the routing destination) to be used for relaying the packet, that is, an output path is determined from the destination address of the CL packet (SA3). And that C
It is determined whether or not the L packet is a new packet, that is, whether or not the destination address of the CL packet is new (SA4).

If the destination address of the CL packet is not new, encapsulation is performed using the shared Tadd.
Therefore, the shared Tadd corresponding to the output path determined in step SA3 is obtained (SA5).

If the destination address of the CL packet is new, a dedicated Tadd is allocated, and encapsulation is performed with the dedicated Tadd. The dedicated Tadd is determined and assigned to the output path (SA6), the destination IP address and the dedicated T
is stored in the Tadd addition table (SA
7).

Regardless of whether the destination address of the CL packet is new or new, the CL packet is encapsulated with the acquired shared Tadd or dedicated Tadd (SA
8), output to the output path indicated by the shared Tadd or dedicated Tadd and transmit to the next node (SA9).

In this embodiment, as described above, when a CL packet including a new destination address is received, a dedicated Tadd is assigned to the output path.

FIG. 6 is a flowchart showing an example of routing processing of an ATM cell in the relay node.

The relay node manages the vacancy of a temporary address (Tadd) related to the connection with the adjacent node.

When the relay node receives the ATM cell,
The Tadd substitution table is checked, and the input T of the ATM cell is checked.
It is determined whether or not the output Tadd (dedicated Tadd) corresponding to add has not been set (SB1).

If the output Tadd is not set (S
B2), the input Tadd of the ATM cell is replaced with the corresponding (dedicated) output Tadd, output to the output path indicated by the output Tadd, and transmitted to the next node (SB10).

If the output Tadd is not set, the ATM
From the destination address of the CL packet encapsulated in the cell (SB3), an adjacent node to be used for relaying the packet, that is, an output path is determined (SB4). Then, it is determined whether or not the destination address is new (SB5).

If the destination address is not new, replacement is performed with the shared output Tadd. Therefore, the shared output T corresponding to the output path determined in step SB4
The add is acquired (SB6).

If the destination address is new, a dedicated output Tadd is assigned and replaced with the dedicated output Tadd. The dedicated output Tadd is determined and assigned to the output path (SB7), and the input Tadd and the dedicated output Ta
dd and dd are stored in the Tadd replacement table (SB8).

Regardless of whether the destination address is new or new, the input Tadd of the ATM cell is replaced with the acquired shared output Tadd or the dedicated output Tadd, and the ATM cell is output to the output path indicated by the output Tadd to the next node. Transmit (SB9).

In this embodiment, only the dedicated input Tadd is registered in the Tadd replacement table. This is because there is a possibility that the output Tadd corresponding to the common input Tadd becomes plural.

In this embodiment, as described above, when an ATM cell including a new destination address is received, a dedicated output Tadd is assigned to the output path. If the destination address is new, the A
The input Tadd is always the dedicated Tadd since the input node or the relay node of the TM cell transmission source should have assigned the dedicated Tadd to the output path. Therefore,
The input Tadd stored in the Tadd replacement table in step SB9 is always a dedicated Tadd.

The output Tadd corresponding to the input Tadd is T
When set in the add replacement table, the ATM cell can be routed as it is without terminating the CL packet. That is, even when the CL packet is divided into several ATM cells and encapsulated, if the output Tadd corresponding to the input Tadd is set, the CL packet is terminated (assembled) and the CL packet is terminated. No need to look up the destination address of the packet.

The processing at the output node is performed by the CO network and the CL.
This is to perform interconnection with the network, take out the encapsulated CL packet, and transmit it to the CL network.

FIG. 7 is a diagram showing a dedicated Tadd at an input node.
6 is a flowchart illustrating an example of a release process.

First, it is determined whether or not there is a destination IP address in which a dedicated Tadd is set, which satisfies a predetermined condition (SC1). The release of the dedicated Tadd corresponding to the destination IP address satisfying the predetermined condition is determined (SC2). The release is performed at the input node, and the release is notified to the relay node at the routing destination of the destination IP address (SC3).

FIGS. 2C to 2E show examples of releasing the dedicated Tadd.

For the packet containing the destination IP address from which the dedicated Tadd has been released, routing is performed using the shared Tadd.

For example, the following method can be considered as a method of notifying the release to the next node.

A) Release using the signaling procedure for release.

B) Create a Tadd release packet.

C) The release Tadd information is piggybacked on the new Tadd setting packet used when Tadd is newly assigned.

D) By making the value of Tadd newly assigned a function of the release Tadd, when the new Tadd is allocated at the next node, the release Tadd is also maintained.

When the notification is made by the method b), c) or d), the release Tadd is released, and the release Tadd generated by the release Tadd at the output side node is performed.
The release regarding the add is determined, and the next node is notified.

In the present embodiment, the input node monitors the traffic of the input packet for each destination address, and determines whether the traffic satisfies a predetermined condition. The predetermined condition may be, for example, a case where an input interval of a packet including the destination address is equal to or longer than a predetermined interval. The predetermined condition may be changed based on the total amount of traffic of the packet input to the input node.

The predetermined condition may be such that a user is determined for each destination IP address and service conditions, quality and the like of the user are considered.

FIG. 8 is a diagram showing a dedicated Tadd at an input node.
6 is a flowchart showing an example of an allocation process.

First, it is determined whether or not there is a destination IP address for which the dedicated Tadd is not set, which satisfies a predetermined condition (SD1). It is determined that a dedicated Tadd is assigned (set) to a destination IP address satisfying a predetermined condition (SD2). The assignment is performed at the input node, and the assignment is notified in order to perform the assignment at the relay node to which the destination IP address is routed (SD3).

When allocating the dedicated Tadd in step SD2, it may be determined whether or not there is a dedicated Tadd that can be used, and the dedicated Tadd may be allocated only when it exists.

The packet including the destination IP address to which the dedicated Tadd is assigned is thereafter routed using the dedicated Tadd.

The packet including the destination IP address to which the dedicated Tadd is assigned is thereafter routed using the shared Tadd.

As a method of notifying the assignment to the next node, for example, the following method can be considered.

A) Assignment using signaling procedure for assignment.

B) Create a packet for Tadd assignment.

When the notification is made by the method b), the allocation T
While performing the allocation process of add, by the allocation Tadd,
Further, an assignment related to an assignment Tadd occurring at the output side node is determined, and the next node is notified.

In the present embodiment, the input node monitors the traffic of the input packet for each destination address, and determines whether the traffic satisfies a predetermined condition. The predetermined condition may be, for example, a case where an input interval of a packet including the destination address becomes equal to or less than a predetermined interval. The predetermined condition may be changed based on the total amount of traffic of the packet input to the input node.

The predetermined condition may be such that a user is determined for each destination IP address and service conditions, quality and the like of the user are considered.

Hereinafter, a transmission example of a CL packet will be described.

First, the first transmission in which the destination address is new will be described.

Destination I, such as through ATM switch VCH2
When a new CL packet P having the P address IP1 is received by the interface IF1, the interface IF
For example, VP2 and VC1 are obtained based on the routing result of the router R1. This VP2 and V
C1 is stored in the Tadd addition table (FIG. 2A)
And (b)). Then, the ATM exchanges VCH1 to VCH1
ATM cells S (VP2 is contained in the header AH as VPI and VC1 as VCI) are transmitted by the PVC specified by P2 and VC1. Here, V
P2 is a path connected to the interface IF2.

At the interface IF2, for example, as shown in FIG. 4, the input Tadd (VP
2 and VC1) are output to Tadd (VP1 and VC1).
A record to be replaced in 1) is added. Then, an ATM cell in which the VPI in the header AH is replaced by VP1 and the VCI is replaced by VC1 is transmitted from the ATM switch VCH2.

Finally, at the output node, the ATM
A CL packet P is extracted from the cell and sent to an external network.

Next, the second transmission will be described.

CL having the above destination IP address IP1
When the packet P is received again by the interface IF1, the interface IF1 can obtain the ATM cell S without referring to the Tadd assignment table (FIG. 2B) and performing the routing by the router R1.

The interface IF2 is connected to Tadd
Referring to the replacement table (FIG. 4B), the VPI and the VCI in the header AH of the ATM cell S are replaced with VP1 and VC1,
Sends it to ATM switch VCH2.

That is, in the second and subsequent transmissions, the destination I
CL packets are transmitted without referring to the P address.

In the present embodiment, P
Although routing by VC, that is, packet routing using dedicated Tadd or shared Tadd is performed, it is also possible to select routing by SVC, that is, routing after setting a routing route in advance by a call setup procedure. it can. For example, the definition of information quality (delay, error loss rate, etc.) (Q
routing is performed by SVC which is suitable for QoS control when OSS is severe, and routing by PVC (routing of packets using dedicated Tadd or shared Tadd) is performed when the quality is loose (best effort traffic). Can be

Although the embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and various changes can be made within the scope of the technical idea.

[0094]

As described above, according to the present invention,
In CL-type communication using PVC in an ATM network or the like, for example, a PVC is dedicated to a destination address with a high communication frequency and a PVC is shared with a destination address with a low communication frequency, so that a packet routing process using the destination address is performed. Can be reduced, and high throughput can be maintained even when traffic increases.

According to the present invention, for example, ATM-SV
In the C network, the SVC using the call processing according to the signaling procedure is not set for the destination address having a high communication frequency temporarily, and the PV is fixedly set between the nodes.
High-speed communication can be realized without setting C.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a network according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating the contents of a Tadd addition table included in an input node;

FIG. 3 is a diagram exemplifying the contents of an idle / busy management table possessed by an input node and a relay node;

FIG. 4 is a diagram illustrating the contents of a Tadd replacement table possessed by a relay node;

FIG. 5 is a flowchart illustrating an example of a packet routing process in an input node;

FIG. 6 is a flowchart illustrating an example of an ATM cell routing process in a relay node;

FIG. 7 is a flowchart illustrating an example of release processing of a dedicated Tadd in an input node.

FIG. 8 is a flowchart illustrating an example of processing for assigning a dedicated Tadd in an input node.

[Explanation of symbols]

 CLN CL network IF1, IF2, IF3 Interface R1, R2, R3 Router VCH1, VCH2, VCH3 ATM switch PCL packet IH header IM data part S ATM cell AH header

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Motoi Tamura 2-10-1 Toranomon, Minato-ku, Tokyo NTT Mobile Communications Network Co., Ltd. F-term (reference) 5K030 GA01 GA13 HA10 HB14 HC01 HD09 JA06 JA11 JL07 KA05 KA15 LB05 LB18 LB20 LC11 5K051 AA03 DD05 FF03 FF14 FF16 GG02

Claims (13)

[Claims] 1. A network for routing a packet including a destination address, wherein the network receives the input of the packet, encapsulates the packet with Tadd corresponding to the destination address of the packet, and routes the encapsulated packet. The Tadd
Receiving the packet encapsulated with the Tadd, replacing the Tadd of the encapsulated packet, and performing routing of the encapsulated packet after the substitution based on the Tadd after the substitution. And an output node for receiving the packet encapsulated by the Tadd, decapsulating the encapsulated packet, and outputting the packet.
d. A network including d and encapsulating a packet including a specific destination address at the input node using the dedicated Tadd. 2. The network according to claim 1, wherein when the relay node receives a packet encapsulated with the dedicated Tadd, the relay node corresponds to the dedicated Tadd of the encapsulated packet with the dedicated Tadd. A network characterized by replacing with a dedicated Tadd. 3. The network according to claim 1, wherein the input node performs encapsulation based on Tadd additional information in which correspondence information between a destination address and a dedicated Tadd is stored, and the input node adds the Tadd additional information to the Tadd additional information. If the destination address of the input packet is stored, the T
The corresponding dedicated Tadd stored in the add additional information
Performs the encapsulation of the input packet, and the relay node performs the replacement based on the Tadd replacement information storing the correspondence information between the dedicated Tadd before replacement and the dedicated Tadd after replacement, and performs the received encapsulation. In the case where the dedicated Tadd of the replaced packet is stored in the Tadd replacement information as the dedicated Tadd before replacement,
A network, wherein the dedicated Tadd of the received encapsulated packet is replaced with the corresponding dedicated Tadd after replacement stored in the add replacement information. 4. The network according to claim 3, wherein the input node includes, in the Tadd additional information, a dedicated Tadd corresponding to a destination address of the input packet.
If there is no such information and the destination address is new, an output route is determined based on the destination address, a dedicated Tadd is assigned to the output route, the Tadd additional information is updated, and the destination address is updated. And the assigned dedicated Tadd, and the relay node includes, in the Tadd replacement information, a dedicated Tadd before replacement of the received encapsulated packet.
If there is no Tadd information corresponding to the received packet and the destination address of the received encapsulated packet is new, the output route is determined based on the destination address, and the dedicated Tadd after replacement is replaced in the output route. And assigning the Ta
A network characterized in that dd replacement information is updated so that the dedicated Tadd before replacement and the assigned dedicated Tadd after replacement correspond to each other. 5. The network according to claim 1, wherein the Tadd includes a shared Tadd, and the input node performs encapsulation of the input packet with the dedicated Tadd or the shared Tadd. Wherein the relay node replaces the dedicated Tadd or the shared Tadd of the received encapsulated packet. 6. The network according to claim 5, wherein the input node has a monitoring unit that monitors traffic of the input packet for each destination address.
If the dedicated Tadd is allocated to a destination address whose traffic satisfies a predetermined condition, the dedicated Tadd is released, and routing of a packet including the destination address is performed using the shared Tadd. Network. 7. The network according to claim 5, wherein the input node has monitoring means for monitoring the traffic of the input packet for each destination address, and the traffic satisfies a predetermined condition; The dedicated Tadd is assigned to a destination address to which the dedicated Tadd is not assigned, and routing of a packet including the destination address is assigned to the dedicated Tadd.
A network, wherein the network is performed using d. 8. The network according to claim 6, wherein the predetermined condition is changed based on a total amount of traffic of a packet input to the input node. 9. The network according to claim 1, wherein said network is an ATM network, and said encapsulated packet is an ATM cell. 10. The network according to claim 9, wherein the routing of the packet is performed after a routing path is set in advance by a call setting procedure, or the packet is routed without setting a routing path in advance by a call setting procedure.
A network, wherein the network is performed using add. 11. The network according to claim 9, wherein said Tadd comprises a VPI and a VCI. 12. The network according to claim 1, wherein a destination address of the packet is an IP address. 13. A method for routing a packet including a destination address in a network including an input node, a relay node, and an output node, the method comprising: receiving an input of the packet at the input node;
The packet is represented by a T corresponding to the destination address of the packet.
encapsulating with the add, performing routing of the encapsulated packet based on the Tadd, and receiving, at the relay node, the packet encapsulated with the Tadd and replacing Tadd of the encapsulated packet; Routing the encapsulated packet after the replacement based on the Tadd after the replacement; and receiving at the output node a packet encapsulated with the Tadd, encapsulating the encapsulated packet. Releasing the packet and outputting the packet, wherein the Tadd includes a dedicated Tadd, and for a packet including a specific destination address, the input node performs encapsulation using the dedicated Tadd at the input node. Routing method.