JPH10190694A - Transmission system for route control information of atm network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the understanding of the route control information in an ATM network and to attain the smooth communication in an entire IP network including the ATM network by calling an SVC to the router to which the IP and ATM addresses are notified from an ATM-ARP server and acquiring the router control information via the connection. SOLUTION: The routers and nodes belonging to an ATM-LAN 20 must have the same route control information. When a node that is newly added to the ATM-LAN 20 notifies an ATM-ARP server 21 of the correspondence between its IP and ATM addresses, the server 21 notifies this new node of the correspondence between the IP and ATM addresses of all routers. Also the IP and ATM addresses of a newly added router are notified to all nodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an ATM (Async).
The present invention relates to a route control information transmission system that transmits route control information between nodes when TCP / IP communication is performed on a (Transfer Mode) network.

[0002]

2. Description of the Related Art One conventional ATM-LAN method is L
I, one of the organizations that standardize ATM related to AN
ETF (Internet Engineering)
RFC1577 (Request), which is a standard recommendation document on TCP / IP created by Taskforce.
For Comments) "Classic IP and ARP (Address Resolution) in ATM
ion protocol, address resolution protocol). This is the IP (Internet Protocol) of the node (host or router)
Without changing the protocol stack basically,
A virtual channel (V
C: Virtual Channel), which defines an operation method of address resolution that associates an IP with an ATM address in ATM according to a classic paradigm.

[0003] The classical paradigm referred to here is a logical IP.
Subnet (LIS: Logical IP Subn
The connection configuration and settings of the hosts and routers in the network are individually determined by the administrator of the LIS. All the nodes in the LIS have the same IP subnet number and the same address mask. The communication with other LIS is performed via a router.

Here, the address resolution protocol (A
RP) will be described. In the case of a media sharing type LAN such as Ethernet, an information message (packet) sent from a node is transmitted to all nodes and broadcast can be performed. The receiving node determines whether the packet is addressed to itself by looking at the destination address added to the packet by the transmitting node.

[0005] In the case of a LAN such as the above-mentioned Ethernet of a shared medium type, when communication is performed with an address on a logical network as a destination, even if the hardware address for transmitting an actual signal is not known, the same subnetwork is used. Can be known by the above-mentioned broadcast function. That is, an ARP packet inquiring about a hardware address corresponding to a network address is transmitted to the network, and the hardware address can be received as a response from a node having the corresponding network address.

[0006] As described above, in the medium sharing type LAN, communication can be performed without connection by the destination network address. However, since the ATM network is a star type network and the establishment of a connection is premised, a virtual channel ( VC) is set and communication is performed using this VC. Therefore, the medium sharing type L
Unlike AN, broadcast cannot be performed, and address resolution by broadcast cannot be performed.

[0007] Therefore, a mechanism for obtaining information on the correspondence between the network address (IP address) and the hardware address (ATM address) is required, and an ATM-ARP server holding these address correspondence tables is installed in the network. Each node is made to know the ATM address of the ATM-ARP server. ATM-
Open a connection to the ARP server, send the network address (IP address) of the communication destination, and send the ATM
-The hard address obtained by querying the ARP server (A
A to the destination node using the
Communication can be performed by setting up a TM connection and flowing an IP packet thereover.

[0008]

SUMMARY OF THE INVENTION The conventional RFC1577
In an ATM network using, there is no function to broadcast (broadcast) in the network.
Originally, the route control information that should be broadcast periodically by a router is actually performed only from a corresponding router to a node on which a VC (virtual channel) has already been established. Therefore, when a node is newly set on the ATM network, VCs with routers must be secured by first performing PING (communication for arrival confirmation) with all routers in the LIS where the node exists. There was a problem that the routing table was not created above, and a solution was required.

In view of such a point, the present invention provides an RF
It is an object of the present invention to provide means for securing communication of route control information in an ATM network using C1577 and enabling smooth communication in all IP networks including an ATM network.

[0010]

The above object is achieved by an ATM network route control information transmission system constructed as follows.

FIG. 1 is a block diagram of the present invention. In FIG. 1, reference numeral 1 denotes a node (host or router) connected to the ATM network that notifies the ATM-ARP server of a correspondence between the IP address of the own node and the ATM address by adding a router identifier indicating whether the node is a router or not. Router identifier notifying means 2 for adding the notified router identifier and holding the node address correspondence in the ATM-ARP server, and 3 for the ATM-ARP server.
A router address notifying means for notifying a required node of an IP address and an ATM address of a node whose router identifier held by the server is a router, a router address holding means for holding the notified router address in its own node, Is route control information obtaining means for obtaining route control information from a required router based on the stored router address.

An ATM having an ATM-ARP server for holding correspondence between a node IP address and an ATM address
When performing TCP / IP communication on a network, it is necessary for a router to periodically notify each node of route control information so that the address of a gateway router corresponding to a destination network with which each node communicates can be known. is there.

When a node newly incorporated in the ATM network notifies the ATM-ARP server of the correspondence between its own IP address and the ATM address, the ATM-ARP server receives the ATM-ARP server.
The RP server sends the IP address and A of all routers in the LIS held by the ATM-ARP server to this node.
The correspondence of the TM address is notified.

When the newly incorporated node is a router, the IP address and ATM address of this router are notified to all nodes in the LIS. As described above, the ATM-ARP server sends the router IP address and AT
Each node notified of the M address sends an SVC (Switched Virtual) to the notified router.
Channel) to establish a connection and obtain route control information. With this connection, the router can periodically transmit route control information to necessary nodes.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is an explanatory view (part 1) of an embodiment of the present invention. The figure shows nodes belonging to the subnet of the ATM-LAN 20, their IP addresses and ATM.
The figure shows an ATM-ARP server 21 that manages an address comparison table. The node includes a host and a router. The router is a device that transfers communication packets with another subnet, and the host is a device such as a computer or a terminal that is connected to the ATM-LAN and processes and communicates information. The ATM-ARP server is also one of the nodes, but is distinguished as having a special function.

In order to describe the configuration and operation of the embodiment of the present invention, a new M
FIG. 2 shows a configuration of an initial state of the ATM network showing a process of sequentially incorporating the host 27 and the N router 26. In FIG. 2, a router (A router 22,
B router 23), host (X host 24, Y host 2)
5) mutually connect nodes and ATM-ARP
Solid lines such as 28 connecting the server 21 and each node are ATM
This shows a state where a connection is established between nodes of the network. The M host 27 is now ready for ATM-L
A node that is being incorporated into AN20, ATM-A
The RP server 21 and a dotted line 29 connecting the RP server 21 indicate a state in which a connection is to be established between them.
Although the N router 26 is installed in hardware,
The operation to incorporate into the M-LAN is not performed.

As described above, the ATM network is a connection-type network. In order to enable each node to exchange packets and communicate as an ATM-LAN, the ATM network is used to know the ATM address as a communication partner's hard address. It is necessary to register its own soft address (IP address) and hard address (ATM address) in the ARP server, and to establish a connection with a partner with a possibility of communication by VC (Virtual Channel).

First, the operation of the system when the M host 27 is incorporated into the ATM-LAN 20 will be described to explain the embodiment of the present invention. First, ATM-A at this time
FIG. 3 shows the state of the address comparison table of the RP server 21.
(A). This table is for each node to present a soft address, that is, an IP address, to search for and obtain a hard address, that is, an ATM address.
It is in the form of a comparison table between IP addresses and ATM addresses. A "router identifier", which is a feature of the present invention, is additionally provided in addition to the address comparison table of a normal ATM-ARP server. For example, ATM-LAN at the moment
The A router 22 incorporated in 20 has an IP address “a”, an ATM address “A”, and a router identifier “R” indicating a router. Similarly, for the host Y25, the IP address “y”, the ATM address “Y”,
It can be seen that the router identifier is “H” indicating the host.

FIG. 3B shows an M host 2 to be newly incorporated.
7 shows the contents registered in the address comparison table of the ATM-ARP server 21 as the first operation performed by the ATM-ARP server 21. A flowchart describing the detailed operation will be described later.
The node incorporated in the M-LAN 20 specifies the ATM address of the ATM-ARP server 21 set in advance, establishes a connection with the ATM-ARP server 21, and stores the above contents in the address comparison table of the ATM-ARP server 21. register. At this time, whether the new node is a host or a router is identified as a router identifier. FIG. 3C shows the N router 26 connected to the ATM later.
(D) shows the contents of the address comparison table of the ATM-ARP server 21 when the M host 27 and the N router 26 are registered when incorporated into the network configuration. FIG. 4 shows a message format to be transmitted and a registration frame to the ATM-ARP server.

FIG. 5 is an explanatory view (part 2) of the embodiment of the present invention. Here, the state in which the address of the M host 27 is registered in the ATM-ARP server 21 is shown, and the M host 27 and the ATM-ARP server 21 are newly
1 indicates that a connection has been established.
At this time, the ATM-ARP server 21 is a feature of the present invention.
For the newly registered M host 27 in FIG.
And extracts the address information of the router already registered in the address comparison table shown in FIG. The received M host 27 stores the address in its own address comparison table (similar to that of the ATM-ARP server 21) (not shown), and the router identifier of the node whose address has been notified is "R". Open connections to all routers and register their addresses in the router's address comparison table. Dotted lines 52 and 53 in FIG. 5 indicate a state in which connections are to be made to the existing routers, the A router 22 and the B router 23. In this way, the address (IP address and ATM address) of the M host 27 is changed to the existing router (A router 22, B router 22).
By notifying the router 23), it is possible to periodically transmit the route control information that is confirmed and held by each router. This makes it possible to send a communication packet to a node belonging to another subnet via an appropriate router.

FIG. 6 is an explanatory view (part 3) of the embodiment of the present invention. This is because the M host 27 establishes a connection to the A router 22 and the B router 23 and notifies the address, and the next new node, the N router 26 registers the address and the router identifier to the ATM-ARP server 21. , And subsequently the addresses of all the registered routers in the same subnet are notified from the ATM-ARP server 21.

Here, the ATM-ARP server 21 recognizes from the registered "router identifier" that the newly registered node is a router, and the address information of the newly registered router which is a feature of the present invention is The ATM-ARP server 21 notifies all the existing nodes belonging to the same subnet together with the router identifier. A dotted arrow indicates this. Also, each node notified of the address information of the new router recognizes that the other party is a router, and makes an SVC call to the new N router 26 to establish a connection. This state is indicated by a dotted line such as 64 in FIG. In this way, the routers are connected to all nodes in the same segment, and each router can periodically transmit route control information to these nodes.

How the above-described operation is performed in each node will be described with reference to a flowchart. FIG. 7 shows an operation flowchart of the ATM-ARP server. Here, only those relating to the incorporation of the node among the functions of the ATM-ARP server are shown. In step S71, it is determined whether or not a new node is to be registered. If new, the node and ATM-
Since no connection has been established with the ARP server, an InATM-ARP request (Inverts AT) is sent to the new node in step S76.
M-ARP) to inquire about the IP address.
Upon receiving this InATM-ARP request, the newly registered node returns its own IP address.
In step S72, it is determined whether or not this response is received. If the response is received, the address (IP address and ATM address) obtained as the response in step S73 and the router identifier which is a feature of the present invention are registered. . As a result, the connection between the ATM-ARP server and the newly incorporated node is established, and the comparison table is prepared.

Next, in steps S74 and S75, the router identifier is checked for the node already registered in the address comparison table, and the display is "router".
Is extracted and transmitted to the newly registered node. This is because when trying to communicate with nodes belonging to other subnets, each node communicates via a router, so it is necessary to know the addresses of all existing routers to establish a connection with the router. Is what you do.

Then, steps S77 and S78
In (2), when the newly registered node is a router, the address (IP, ATM) and router identifier of the new router are transmitted to all nodes to inform them. New router is ATM-LAN
When incorporated into a network, all existing nodes establish a connection with this router and provide an address to obtain route control information.

FIG. 8 shows an operation flowchart of the node (host, router). Here, of the functions of the node, the functions related to the present invention (incorporation of the node into the ATM-LAN and transmission of route control information) are shown for both the host and the router.

First, in step S80, it is determined whether or not the trigger for activation is a timer. If not a timer, step S
In step 83, it is checked whether there is an instruction to newly incorporate the ATM-LAN into the ATM-LAN (for example, turning on the power of the node).
An SVC call is made to the P server to establish a connection.
On the other hand, the ATM-ARP server sends InATM-A
When an RP request has been received, this is detected in step S84, and an IP address and a router identifier are sent to the ATM-ARP server as a response in step S89.

Subsequently, when the address of the existing router is notified from the ATM-ARP server, step S8 is performed.
5. The address of one or more routers received in step S86 is added to and held in the address comparison table of each node. Further, a connection is established to all the routers notified and added in step S87.

As described above, the connection with all the routers in the subnet is established and the route control information can be received from the router. The periodic notification of the route control information from the router is performed, for example, once every 30 seconds to all nodes in the subnet. That is, in the flowchart, if the activation cause is a timer, in step S80 to step S81, if the self is a router, in step S82, all nodes in the address comparison table of the router are notified as transmission of route control information which is the role of the router. . Although the step of receiving the notified route control information is not shown in the flowchart, both the host and the router are updated and stored in a route control information table (not shown).

[0030]

As is apparent from the above description, according to the present invention, by introducing the route identifier, the change of the configuration of the ATM-LAN by the ATM network can be performed without the need for static registration and operation by the network administrator. In addition, there is an industrial effect that a route control information transmission system of an ATM network capable of autonomously securing the communication of route control information can be configured, thereby facilitating system construction and increasing the efficiency of system operation.

[Brief description of the drawings]

FIG. 1 is a block diagram of the present invention.

FIG. 2 is an explanatory view of an embodiment of the present invention (part 1);

FIG. 3 is an address comparison table of an ATM-ARP server.

FIG. 4 Registration frame to ATM-ARP server

FIG. 5 is an explanatory view of an embodiment of the present invention (part 2);

FIG. 6 is an explanatory view of an embodiment of the present invention (part 3);

FIG. 7 is an operation flowchart of an ATM-ARP server.

FIG. 8 is an operation flowchart of a node (host, router).

[Explanation of symbols]

 1 router identifier notifying means 2 router identifier holding means 3 router address notifying means 4 router address holding means 5 route control information obtaining means

Claims (4)

[Claims] 1. The IP of a node (host or router)
ATM that holds the correspondence between addresses and ATM addresses
TCP / ATM on ATM network with ARP server
A route control information transmission system for transmitting route control information between nodes when performing IP communication, wherein a node connected to the ATM network is an ATM-
When notifying the ARP server of the correspondence between the IP address and the ATM address, a router identifier notifying unit for notifying by adding a router identifier indicating whether or not the own node is a router, and adding the notified router identifier. Router identifier holding means for holding a correspondence between an IP address and an ATM address in an ATM-ARP server, and a router address notification for notifying a required node of an address of a node whose router identifier held in the ATM-ARP server is a router Means, router address holding means for holding the notified router address in its own node, and route control information obtaining means for obtaining route control information from a required router based on the held router address. A routing control information transmission system for an ATM network, characterized in that: 2. IP of a node (host or router)
ATM that holds the correspondence between addresses and ATM addresses
TCP / ATM on ATM network with ARP server
A route control information transmission method for transmitting route control information between nodes when performing IP communication, wherein the node connected to the ATM network is an ATM-
When notifying the ARP server of the correspondence between the IP address and the ATM address, the ARP server notifies the ARP server by adding a router identifier indicating whether or not the own node is a router, and adds the notified router identifier to the IP address and the ATM. The correspondence with the address is held in the ATM-ARP server, and the router identifier held in the ATM-ARP server notifies the required node of the address of the node whose router is the router,
Hold the router address notified to the own node,
An ATM characterized by obtaining route control information from a required router based on the stored router address.
A method for transmitting network route control information. 3. The ATM network route control information transmission system according to claim 1, further comprising:
When a node connected to the network notifies the ATM-ARP server of the correspondence between the IP address and the ATM address, a router identifier notifying means for notifying by adding a router identifier indicating whether or not the own node is a router; −
Router address holding means for holding the router address notified from the ARP server in its own node, and route control information obtaining means for obtaining route control information from a required router based on the held router address. Medium on which program is recorded. 4. An ATM network route control information transmission system according to claim 1, further comprising:
Router identifier holding means for holding the correspondence between the IP address and the ATM address in the ATM-ARP server by adding the router identifier notified from the node connected to the network, and the router identifier held in the ATM-ARP server being a router A medium that stores a program for functioning as a router address notifying unit that notifies an address of a certain node to a required node.