JP2000032063A - Isdn router and communication path selection method using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a the ISDN router that can select an optimum path in terms of the communication cost. SOLUTION: The ISDN routers R1, R2, R3 interconnect plurality of networks. ISDN area code are added to a routing table that is referenced in the case of relaying data between networks, and in the case that an area code of an ISDN number of a destination connected newly is coincident with an area code of an existing network relay destination, a charge of a bypass that is a path connecting to a newly connected destination via an existing network is compared with a charge of a direct path that connects directly to the destination connected newly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISDN router for connecting a plurality of networks and selecting an inexpensive connection path at each time when selecting a connection path connecting the networks. The present invention relates to a communication path selection method used.

[0002]

2. Description of the Related Art In recent years, there has been an increasing number of cases in which an ISDN router is used to connect to a provider or the like that provides an access point for connecting between remote networks or to the Internet through a public line. At this time,
When trying to connect to the other party to communicate with, select a router to be connected to the other party to communicate using the routing table built in the ISDN router (routing table), The line is actually connected to establish a communication path. The routing table manages the correspondence between the destination (destination) to communicate with and the ISDN router (gateway) to be actually connected as a table. As shown in (Table 1) and (Table 2), each destination Each entry has a structure in which a value obtained by counting the number of routers that pass through to reach the destination as the number of hops is added to the entry for each nation.

[0003]

[Table 1]

[0004]

[Table 2]

[0005] When there are a plurality of entries to the same destination, a route having a small number of hops is preferentially selected. Further, even if the number of routes connecting to destinations already registered in the table further increases by connecting to a certain gateway, a route having a small number of hops is preferentially registered in the routing table.

[0006]

However, in the routing table of the conventional ISDN router, when a gateway to be connected is determined, or when an entry is dynamically added or changed in the routing table, the destination is reached. Only the number of routers that pass through, that is, the number of hops is the basis for selection, and a route with a small number of hops takes precedence, but in actuality, this route has a higher communication cost than other routes. Or
The throughput may be small.

In the ISDN router and the communication route selection method using the ISDN router, it is required to select an optimal route in terms of communication cost.

The present invention provides an ISDN router capable of selecting an optimal path in terms of communication cost, and a communication path selecting method using an ISDN router for selecting an optimal path in terms of communication cost. The purpose is to:

[0009]

In order to solve this problem, an ISDN router according to the present invention refers to a routing table which stores the number of hops and charges for each destination when relaying between a plurality of networks. ISDN router for connecting to the network, the ISDN area code is added to the routing table, and the area code of the newly connected ISDN number matches the area code of the existing network relay destination Has a configuration for comparing a fee for a detour route, which is a route connecting to a newly connected partner via an existing network, and a fee for a direct route, which is a route for directly connecting to a newly connected partner. .

[0010] Thus, an ISDN router capable of selecting an optimal route in terms of communication cost is obtained.

A communication path selection method using an ISDN router for connecting a plurality of networks by referring to a routing table storing the number of hops and charges for each destination when relaying between networks, the method comprising: If the area code of the newly connected partner's ISDN number matches the area code of the existing network relay destination, the new connection is made via the existing network. A configuration is provided for comparing the fee of a detour route that is a route connecting to a destination and a fee of a direct route that is a route directly connecting to a newly connected destination.

As a result, a communication path selection method using an ISDN router for selecting an optimum path in terms of communication cost can be obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS ISD according to claim 1 of the present invention
The N router is an ISDN router for connecting a plurality of networks by referring to a routing table that stores the number of hops and charges for each destination when relaying between networks, and includes an ISDN area code in the routing table. Is added, and if the area code of the newly connected destination's ISDN number matches the area code of the existing network relay destination, a route connecting to the newly connected destination via the existing network And the direct route, which is a route directly connected to the newly connected partner, is compared, and whether the route is the detour route or the direct route is determined based on the comparison result of the fees. It has the effect of determining.

An ISDN router according to a second aspect of the present invention is the ISDN router according to the first aspect, wherein the alternative path is selected when the charge of the alternative path is lower than the charge of the direct path. Even if a new connection is made, when the detour route is cheaper than the existing direct route, there is an effect that the detour route is connected through the detour route.

According to a third aspect of the present invention, in the communication path selecting method using the ISDN router, a plurality of networks are connected by referring to a routing table storing the number of hops and a charge for each destination when relaying between the networks. I for
A communication route selection method using an SDN router, in which an ISDN area code is added to a routing table, and an area code of an ISDN number of a newly connected partner matches an area code of an existing network relay destination. In this case, the fee of the detour route, which is a route connecting to the newly connected partner via the existing network, and the direct route, which is a route directly connecting to the newly connected partner, are compared. Even if a new connection is made, the detour route is connected via the detour route when the fee is lower than the existing direct route.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. (Embodiment 1) FIG.
FIG. 1 is a configuration diagram showing an ISDN line system using an SDN router.

In FIG. 1, reference numerals 1, 2, and 3 denote local area networks (hereinafter, referred to as "LANs") at points A, B, and C, which are physically distant points, respectively. ISDN which is the exchange equipment of No.3
This is an ISDN network to which routers R1, R2, and R3 are connected.

Table 3 shows that the ISDN routers R1, R2,
Shows the IP address, ISDN number, and ISDN subaddress for R3.

[0019]

[Table 3]

The above (Table 1) and the following (Table 4)
4 shows a configuration of a routing table of the SDN router R1.

[0021]

[Table 4]

(Table 1) shows a routing table of the conventional ISDN router R1, and (Table 4) shows a routing table of the ISDN router R1 when a route is dynamically changed after connecting the points AC.

The change of the routing system when connecting points AC will be described below. As shown in FIG. 1, A-
It is assumed that there is a route connecting B for 200 yen for 3 minutes. Here, it is assumed that point C is newly connected to point A.
Here, the ISDN router R1 searches the routing table to see whether there is a route that matches the area code of the point C (here, 092). Here, point B
Is applicable. Since the area code is the same, if the point BC is connected, it is clear that the fee is 10 yen for 3 minutes.
Here, the number of hops between points A and B is compared with the number of hops when connecting points A and C. The latter is 7, and the following holds: (hop number of newly connected route)> (hop number of existing route) +1. That is, (hop number of newly connected path) − (hop number of already existing path) ≧ 2. Therefore, when the route between the points A and C once connected is to be discarded and a new connection is made between the points A and C, the point is set using the ISDN router R2 as a gateway in addition to the route between the points A and B already existing. The route is set by directly connecting B and C.

Here, (Table 1) and (Table 4) will be described in detail. (Table 1) shows the conventional number of hops between points A and B of 5 and the number of hops between points A and C of 7, and the charges are 200 yen and 220 yen, respectively. (Table 4) shows the number of hops 5 between points A and B and the point A-
Shows the number of hops 6 between C, the fee is 200 yen each, 2
It is 10 yen. That is, in the conventional route selection, the fee is 220 yen for 7 hops between the points A and C, whereas in the route selection in the present embodiment, the point A-
The cost is 210 yen for 6 hops between Cs.

As described above, according to the present embodiment, the area code of the ISDN is added to the routing table to be referred to when relaying between networks, and the area code of the ISDN number of the newly connected partner is added. If the area code of the existing network relay destination matches, the detour route that connects to the newly connected destination via the existing network and the route that directly connects to the newly connected destination By comparing the fee with a certain direct route, it is possible to determine whether to use the detour route or the direct route based on the comparison result of the fee. If the fee is lower than the direct route, the connection is made by the detour route, and the route optimal for the communication cost can be selected. For example, in the case of (Table 1) and (Table 4), the fee is 10 yen (220 yen-210) for 3 minutes by selecting the point ABC.
Circle), and the number of hops can be reduced by one.

(Embodiment 2) FIG. 2 is a configuration diagram showing an ISDN line system using an ISDN router according to an embodiment of the present invention.

In FIG. 2, LAN1, 2, 3, ISD
The N line 4 and the ISDN routers R1, R2, R3 are the same as those in FIG.

Table 5 shows ISDN routers R1, R2,
Shows the IP address, ISDN number, and ISDN subaddress for R3.

[0029]

[Table 5]

(Table 5) shows a conventional R1 routing table, and (Table 6) shows a routing table of the ISDN router R1 when a route is dynamically changed after connecting points AC.

[0031]

[Table 6]

The change of the routing method when connecting points AC will be described below. As shown in FIG.
It is assumed that there is a route connecting B at 230 yen for 3 minutes. Here, it is assumed that point C is newly connected to point A.
Here, the ISDN router R1 searches the routing table to see whether there is a route that matches the area code of the point C (here, 092). Here, point B
Is applicable. Since the area code is the same, if the point BC is connected, the fee is 10 yen for 3 minutes. Where point AB
The number of hops between the points A and C is compared with the number of hops when connecting points A and C. The latter is 5, and the following holds: (hop number of existing route)> (hop number of newly connected route) +1. That is, (hop number of existing route) − (hop number of newly connected route) ≧ 2. Therefore, the existing route between the points A and B is discarded, and the point A-
When connecting between points B, in addition to the path between points A and C newly connected, the path is set by directly connecting points B and C using the ISDN router R3 as a gateway.

Here, (Table 5) and (Table 6) will be described in detail. (Table 5) shows the conventional number of hops 8 between points A and B and the number of hops 5 between points A and C, and shows that the charges are 230 yen and 200 yen, respectively. (Table 6) shows the number of hops 6 between the points A and B and the point A-
Shows the number of hops 5 between C, the fee is 210 yen each, 2
It shows that it is 00 yen. That is, in the conventional route selection, the fee is 230 yen for 8 hops between points A and B, whereas in the route selection in the present embodiment, the point A-
The fee is 210 yen for 6 hops between B.

As described above, according to the present embodiment, when the route between the points A and B (charge 230 yen) that has already existed is discarded and a new connection is made between the points A and B, a new connection is made. In addition to the route between points A and C, points A and B are directly connected to points B and C using ISDN router R3 as a gateway.
By setting the route between -B, the fee can be reduced to 20 yen (230 yen-210 yen) for 3 minutes, and the number of hops can be reduced by two.

(Embodiment 3) FIG. 3 is a configuration diagram showing an ISDN line system using an ISDN router according to Embodiment 3 of the present invention.

In FIG. 3, the LANs 1, 2, the ISDN line 4, and the ISDN routers R1, R2 are the same as those in FIG. 5 is ISDN
This is a LAN having a router R4. As shown in (Table 7), the ISDN router R4 has an ISDN subaddress of “K
urume ".

[0037]

[Table 7]

(Table 8) shows a set of an area code of an ISDN address and its subaddress, and (Table 9) shows an area code of an ISDN number of an area adjacent to the area of the area code shown in (Table 8). Shows a set of station number and its subaddress.

[0039]

[Table 8]

[0040]

[Table 9]

As shown in FIG. 3, it is assumed that there is already a route connecting A and B for 200 yen for 3 minutes. Here, it is assumed that point C is newly connected to point A. Where ISDN
The router R1 searches the routing table to see if there is a route that matches the area code of the point C (here, 092). Here, there is no corresponding existing route. Therefore, a database in the ISDN router is searched in order to check whether or not an area adjacent to the area code of the existing route exists. In this case, as shown in (Table 9), 0942 (Kurume) matches.

Therefore, when a new connection is made between the point A and the point C, the optimal route that has already been set is established by connecting the point B and the point C to the route between the points A and B that has already been set. Use to save as much connection fee as possible.

As described above, according to the present embodiment, the IS
The adjacent relationship between the area codes of DN numbers is registered in a database, and when connecting to a new destination having an unknown area code, a route to a network relay destination having an adjacent area code is added. Thus, even when connecting to a destination in an unknown area, an optimal route can be derived inductively from existing optimal route information.

[0044]

As described above, according to the ISDN router according to the first aspect of the present invention, an ISDN router for connecting a plurality of networks, the routing table being referred to when relaying between the networks. ISDN
Add the area code of the ISDN of the newly connected party
If the area code of the number matches the area code of the existing network relay destination, the detour route that connects to the newly connected destination via the existing network and the newly connected destination By comparing the fee with the direct route, which is the route directly connected, it is possible to determine whether to use the detour route or the direct route based on the comparison result of the fee, Also, when the detour route is lower in price than the direct route, there is obtained an advantageous effect that the route is connected by the detour route and the route optimal for communication cost can be selected.

According to the ISDN router of the second aspect, in the ISDN router of the first aspect, when the charge of the bypass route is lower than the charge of the direct route, the bypass route is newly selected by selecting the bypass route. Even if the connection is made, if the detour route is cheaper than the existing direct route, the detour route can be connected by the detour route, so that an advantageous effect that an optimal route in terms of communication cost can be selected can be obtained. Can be

According to the communication route selection method using the ISDN router according to the third aspect, a plurality of networks are referred to by referencing a routing table storing the number of hops and charges for each destination when relaying between the networks. A method of selecting a communication route using an ISDN router for connection, wherein an area code of an ISDN is added to a routing table, and an area code of an ISDN number of a newly connected partner and an area code of an existing network relay destination. If the station numbers match, compare the charges for the detour route, which is the route connecting to the newly connected partner via the existing network, and the direct route, which is the route connecting directly to the newly connected partner. By doing so, it is possible to determine whether to use the detour route or the direct route based on the comparison result of the charges, so that the existing network can be used. Advantageous effect that to communicate cost-optimal route to connect with detour route is selected if the lower rate than the direct path towards even detour path via.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an ISDN line system using an ISDN router according to a first embodiment of the present invention;

FIG. 2 is a configuration diagram showing an ISDN line system using an ISDN router according to a second embodiment of the present invention;

FIG. 3 is a configuration diagram showing an ISDN line system using an ISDN router according to a third embodiment of the present invention;

[Explanation of symbols]

 1, 2, 3, 5 LAN 4 ISDN line R1, R2, R3 ISDN router

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04M 3/00 H04L 11/02 F 15/16

Claims (3)

[Claims] 1. An ISDN router for connecting a plurality of networks by referring to a routing table for storing the number of hops and charges for each destination when relaying between networks, wherein the routing table includes an ISDN When an area code is added and the area code of the newly connected destination's ISDN number matches the area code of the existing network relay destination, the newly connected destination via the existing network And comparing a detour route which is a route connecting to the newly connected partner with a direct route which is a route directly connecting to the newly connected partner.
SDN router. 2. The ISDN router according to claim 1, wherein the alternative route is selected when the fee of the alternative route is lower than the fee of the direct route. 3. A communication path selection method using an ISDN router for connecting a plurality of networks by referring to a routing table storing the number of hops and charges for each destination when relaying between networks. The area code of ISDN is added to the routing table, and if the area code of the newly connected partner's ISDN number matches the area code of the existing network relay destination, the connection is made via the existing network. A communication route using an ISDN router, wherein a fee is compared between a detour route which is a route connecting to the newly connected partner and a direct route which is a route directly connecting to the newly connected partner. Selection method.