JP2003018205A - TCP profile setting method and program - Google Patents

Abstract

(57) [Problem] To provide a TCP profile setting method for setting a TCP parameter value according to a bearer characteristic between terminals as a profile. A first terminal and a second terminal are connected to each other via a plurality of networks connected via a plurality of routers.
When a connection is established before performing information communication by the CP / IP method, the first terminal and the second terminal are referred to by referring to communication characteristic information for each destination network stored in a routing table held by each router on a communication path. 2 refers to the communication information characteristic up to the nearest router stored in the terminal 2 and refers to the end-to-end communication characteristic information.
TC having procedure for determining parameters of P / IP communication
P profile setting method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a LAN-WAN-
In communication between terminals using TCP via a plurality of networks such as LAN connection, it is possible to improve the throughput of streaming transfer by setting TCP parameter values between both terminals according to bearer characteristics. Regarding profile setting method.

[0002]

2. Description of the Related Art WAN (wide area network)
ork) and diversification of connection form, and wireless LAN (l
With the diversification of LAN accommodating systems due to the popularization of local area networks, TCP / IP (tr
enmission control protoc
The properties of the lower layers carrying the ol / internet protocol have come into widespread use. Therefore, TCP communication is also increasingly affected by the characteristics of the bearer.

Regarding TCP communication parameter setting,
MTU (Maximum Transmissi) of the communication path
Japanese Patent Application Laid-Open No. 2000-124950 discloses an example in which the transmission / reception data size is optimized for each application based on the on-unit) and reflected in the MMS (TCP maximum segment length) and the sliding window. But,
It is a setting change according to the upper application type,
Since it does not reflect the bearer characteristics of the lower layer and the setting change is part of the parameter and is an indirect value change based on the causal relationship, each parameter value that is complicatedly related is optimal as a whole. There was a problem that it would not be realized. Japanese Patent Laid-Open No. 5-22345 shows an example of a method for determining an MTU by using route information, but the MTU does not necessarily reflect the bearer characteristic and is used for TCP parameter optimization based on the bearer characteristic. There was a problem that there was not enough information to do so.

[0004]

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a TCP profile setting method for setting a TCP parameter value according to a bearer characteristic between terminals as a profile.

[0005]

According to a TCP profile setting method of the present invention for solving the above problems, a first terminal and a second terminal are connected via a plurality of networks connected via a plurality of routers. And a procedure for establishing a connection before performing information communication by the TCP / IP method, a procedure for referring to communication characteristic information between the first terminal and the second terminal, and the communication characteristic information. It is characterized by having a procedure for determining the parameters of TCP / IP communication based on the above.

TCP is referred by referring not only to the communication characteristic information between routers but also to all the communication characteristic information between terminals.
Since the parameters of / IP communication are determined, it becomes possible to set the optimum TCP / IP profile for communication between terminals.
Efficient streaming transfer is possible.

Further, in the TCP profile setting method of the present invention for solving the above-mentioned problems, the procedure for referring to the communication characteristic between both terminals is further stored in a routing table held by each router of the communication path. Further, it is characterized by comprising a procedure for referring to the communication characteristic information for each destination network and a procedure for referring to the communication information characteristic up to the nearest router stored in the first terminal and the second terminal.

By managing the bearer characteristics for each route and setting the TCP communication parameters according to the connection destination network, efficient streaming transfer in consideration of the lower layer for each TCP connection is possible. In addition, by extending the communication characteristics that are present when a plurality of networks pass through to the end-to-end, the TCP lower layer between the end-to-end including the accommodating section where the versatile communication characteristics are assumed is included. It is possible to set the TCP communication parameter according to the setting.

Further, in the TCP profile setting method of the present invention for solving the above-mentioned problems, at least one of a band, an execution speed, a maximum transfer unit, a packet error rate, a packet size and a hop number is held as the communication characteristic information. It is characterized by doing.

By using the bandwidth, the execution speed, the maximum transfer unit, the packet error rate, the packet size, the number of hops, and the like as the communication characteristics, the TCP subordinate between the end including the accommodating section where the various communication characteristics are assumed is included. It is possible to set TCP communication parameters according to layers. Also,
By defining a set of TCP parameters as a TCP profile, the interrelated TCP parameters can be effectively adjusted.

In addition, in the TCP profile setting method of the present invention for solving the above-mentioned problems, each router further holds the procedure in which the first terminal and the second terminal refer to the communication characteristic information. Each router in the communication path has a procedure for updating the communication characteristic information in the routing table.

By updating the communication characteristic information, efficient streaming transfer becomes possible even in the form of wireless connection in which the communication characteristic changes.

Further, the program of the present invention for solving the above problems is stored in communication characteristic information between the first terminal and the router closest to the first terminal and a routing table held by each router of the communication path. A procedure for transmitting the communication characteristic information for each destination network to the second terminal simultaneously with the connection request, the communication characteristic information between the second terminal and the router closest to the second terminal, and each router of the communication path. A procedure for receiving the communication characteristic information for each destination network stored in the routing table held by the second terminal from the second terminal at the same time as the connection response, and between the first terminal and the router closest to the first terminal and the second terminal. A procedure for deciding TCP / IP communication parameters based on communication characteristic information between the terminal and the router closest to the second terminal and for each destination network of the communication path is implemented on the computer. Characterized in that to.

When this program is executed by the first terminal, TCP that is optimal for end-to-end communication characteristics is obtained.
It is possible to perform TCP communication according to the parameters of / IP communication, and it is possible to perform efficient streaming transfer considering the lower layer for each TCP connection.

Further, the program of the present invention for solving the above problems is stored in communication characteristic information between the first terminal and the router closest to the first terminal and a routing table held by each router of the communication path. A procedure for receiving the communication characteristic information for each destination network from the first terminal at the same time as the connection request, and between the first terminal and the router closest to the first terminal and between the second terminal and the second terminal. A procedure for determining the parameters of TCP / IP communication based on the communication characteristic information between the latest routers and each destination network of the communication path, the communication characteristic information between the second terminal and the routers closest to the second terminal, and The procedure for transmitting the communication characteristic information for each destination network stored in the routing table held by each router of the communication path to the first terminal at the same time as the connection response is implemented on the computer. Characterized in that to.

By executing this program by the second terminal, TCP that is optimal for end-to-end communication characteristics
It is possible to perform TCP communication according to the parameters of / IP communication, and it is possible to perform efficient streaming transfer considering the lower layer for each TCP connection.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention.

[0018]

First Embodiment FIG. 1 shows a case where a terminal device 1 accommodated in a LAN 5 performs communication using a TCP with a terminal 2 accommodated in a LAN 7 via a WAN 6.
The terminal 1 obtains the bearer quality for each route together with the route information from the accommodating router 2, and holds the bearer characteristic for each destination network on the routing table. When starting TCP communication with the terminal 2 on the other end, the terminal 1 notifies the terminal 4 on the other end of the bearer characteristics from the terminal 1 to the accommodating router 2 by the self-accommodation method when requesting a TCP connection.

The terminal 4 receives from the routing table the bearer characteristics between the LAN5 and LAN7 attached to the route information for the destination LAN5, the accommodating router 3 by the self-accommodation method between the terminal 4 and the terminal 1-router 2 received by the connection request. The bearer characteristic between the end-to-end, that is, the terminal 1 to the terminal 4 is determined in consideration of the bearer characteristic between the terminals. A TCP profile in the bearer characteristic category to which the bearer characteristic corresponds is selected, and the TCP profile is set as a TCP communication parameter value. When the terminal 4 responds to the connection,
The bearer characteristic according to the accommodation method of the LAN 7 is notified to the terminal 1.

Similarly, in the terminal 1, the inter-LAN bearer characteristic to the destination network 7, the accommodating router 2-the inter-terminal 1 bearer characteristic and the accommodating router 3-received in the connection response.
The bearer characteristic between the terminals 4 is added, the bearer characteristic between the end-to-end is determined, the TCP profile is selected, and the TC
Set as P communication parameter value. In this way, the end-to-end bearer characteristics are determined from the bearer characteristics managed for each destination network, and the TCP profile combining the TCP communication parameters is selected accordingly.

In FIG. 2, as an example of inter-terminal communication via a plurality of networks, a terminal device 1 in a LAN 5 is connected between LANs via a WAN 6 by accommodating routers (edge routers) 2 and 3, and is connected to a LAN 7. One terminal 4 and TC
An example of a TCP profile setting method for P communication will be described. The terminal device 1 includes the upper application 11 and T
Includes CP software 12, profile determination function 13 and route control 14. Further, the communication partner terminal 4 includes an upper application 41, TCP software 42, a profile determination function 43, and a route control 44.

The upper applications 11 and 41 notify the TCP software of the accommodation method selected by the user and activate the TCP connection. The TCP software 12 and 42 manage the TCP communication parameters set based on the TCP communication profile for each TCP connection. Profile determination functions 13 and 43
Determines the terminal-to-terminal bearer characteristics from the characteristics of the bearer accommodated by the terminal itself, the characteristics of the bearer accommodated by the partner notified at the time of connection, and the characteristics of the destination network bearer attached to the route information, and the TCP communication profile that matches the bearer characteristics. To set. The route controllers 14 and 44 obtain the route control information and the bearer characteristic associated with it from the accommodating routers 2 and 3, respectively, and manage the bearer characteristic for each route. The accommodating routers 2 and 3 exchange route information and bearer characteristic information attached thereto, respectively.

The operation of the embodiment will be described with reference to FIGS. The accommodating routers 2 and 3 and the other routers included in the LANs 5 and 7 add bearer characteristics according to the bearer method used for connection when exchanging the route control information. Here, as the bearer characteristics, in the present embodiment, (1) transmission rate, bandwidth, execution speed (2) transmission unit, MTU (3) transmission quality, error characteristic, packet error rate, bearer packet size delay characteristic -Specify the number of hops. Except for the number of hops, bearer characteristics are given in advance or have actual values.

Each router, when transmitting the route information and the bearer information, compares the bearer characteristic information received together with the route information with the bearer characteristic of the interface on the receiving side and the forwarding side or only the receiving side of the route information and the bearer characteristic information. However, when the bearer characteristic should be updated, each characteristic value is updated. In the present embodiment, for example, the following processing is performed to update the bearer characteristics. (1) Transmission rate: Since it is considered that the slowest part of the path determines the transmission rate, if the bandwidth / execution rate of the transmission / reception interface is smaller than the received value, the value is updated. (2) Transmission unit: Since it is necessary to match the minimum value through the route, when the MTU of the transmission interface is smaller than the received value, the value is updated with that value. (3) Transmission quality ... Using the packet error rate and bearer packet size as the error characteristics through the route, an index indicating the size at which retransmission does not occur when a TCP segment of a certain size is transmitted is created as follows. . The product of the error characteristics of each network is used as the error characteristic (retransmission avoidance characteristic) through the route. As the error characteristic of each network, (1-packet error rate) raised to the power of (1 / bearer packet size) ≈ (1- (1 / bearer packet size) * (packet error rate)) is used. A hop count is used as the delay characteristic through the route. Therefore, each router multiplies the error characteristic of the received network by the error characteristic of the transfer side network. As for the hop count, as in the case of normal route control, 1
Increment by one. By virtually setting the bearer characteristic via a plurality of networks in this way, each router and terminal can hold the bearer characteristic as an attribute of the destination route in the route control information.

When the terminal 1 performs the TCP communication with the terminal 4, the upper application 15 instructed to connect by the accommodation method selected by the user acquires the bearer characteristic of the accommodation method, and connects the TCP connection with the TCP software. 12 (FIG. 3A1). The TCP software 12 stores the bearer characteristics of the accommodation method and transmits a connection request to the TCP software 42 of the partner terminal 4. At that time, a bearer characteristic by the self-accommodation method is notified to the other party using the option header or the like (FIG. 3A).
2).

TCP of the partner terminal 4 which received the connection request
The software 42 has a TCP profile determination function 43.
In the received bearer characteristic between the terminal 1 and the accommodating router 2, the bearer characteristic between the accommodating router 3 and the terminal 4 by the self accommodating method, and the route information for the destination LAN 5 held in the routing table managed by the route information 44. In consideration of the bearer characteristics between the attached LAN5 and LAN7, end-
The bearer characteristic between the ends, that is, between the terminal 1 and the terminal 4 is determined. To add the bearer characteristics, the same processing as that performed by each router is performed. From this bearer characteristic, the corresponding TCP profile is determined (FIG. 3A3). The TCP profile divides the bearer characteristic into several categories, and selects the TCP profile of the category to which the end-to-end bearer characteristic belongs. FIG. 4 shows the relationship between the TCP profile and the bearer characteristic category when the bearer characteristic is expressed by three elements. The TCP communication parameters can be set by the TCP profile for each connection.

TCP software 42 of the terminal 4 on the other side
Returns a connection response to the TCP software of the terminal 1. At this time, the bearer characteristic between the terminal 4 and the accommodating router 3 by the self-accommodation method is notified (FIG. 3A4). In the TCP profile determination function 13, the TCP software 12 of the terminal 1 that has received the connection response sets the received router 2 according to the self-accommodation method to the received bearer characteristic between the terminal 4 and the accommodated router 3.
-From the bearer characteristic between the terminals 1 and the routing table managed by the route information 14, the bearer characteristic between the LAN5 and the LAN7 attached to the route information for the destination LAN7 is added, and the end-to-end, that is, the terminal 1 to the terminal 4 is considered. Determine bearer characteristics. To add the bearer characteristics, the same processing as that performed by each router is performed. A corresponding TCP profile is determined from this bearer characteristic (FIG. 3A5). T
The CP profile divides the bearer characteristic into several categories, and TC of the category to which the end-to-end bearer characteristic belongs.
Select a P profile. (See FIG. 4) The setting of TCP communication parameters by the TCP profile is possible for each connection.

In this way, the upper applications 11 and 41 are connected between the two terminals by using the TCP software in which the TCP parameters are set according to the bearer characteristics of the communication path.
Implements optimal TCP communication (FIGS. 3A6 and A).
7). In the present embodiment, TCP communication is performed by MMS (TCP maximum segment length), weighting coefficient for round trip time (RTT) update, round trip time deviation control coefficient with respect to timeout value, optimum reception window size, timer backoff multiplier, and the like. T as a parameter
It defines what is included in the CP communication profile. Actually, it depends on the TCP driver to be mounted.

[0029]

Second Embodiment Next, as a second embodiment of the present invention,
Parameter setting during connection will be described. Referring to FIG. 5, a bearer characteristic correction during TCP communication is added to the embodiment shown in FIG. 3, so that TCP communication parameters can be dynamically set during connection.

When the terminal 1 performs TCP communication with the terminal 4, the upper application 15 instructed to connect by the accommodation method selected by the user acquires the bearer characteristic of the accommodation method and connects the TCP connection by TCP software. 12 (FIG. 5A1). The TCP software 12 stores the bearer characteristics of the accommodation method and transmits a connection request to the TCP software 42 of the partner terminal 4. At that time, the bearer characteristic by the self-accommodation method is notified to the other party using the option header or the like (FIG. 5A).
2).

TCP of the other terminal 4 which has received the connection request
The software 42 has a TCP profile determination function 43.
In the received bearer characteristic between the terminal 1 and the accommodating router 2, the bearer characteristic between the accommodating router 3 and the terminal 4 by the self accommodating method, and the route information for the destination LAN 5 held in the routing table managed by the route information 44. In consideration of the bearer characteristics between the attached LAN5 and LAN7, end-
The bearer characteristic between the ends, that is, between the terminal 1 and the terminal 4 is determined. To add the bearer characteristics, the same processing as that performed by each router is performed. From this bearer characteristic, the corresponding TCP profile is determined (FIG. 5A3). The TCP profile divides the bearer characteristic into several categories and selects the TCP profile of the category to which the end-to-end bearer characteristic belongs (see FIG. 4). The TCP communication parameters can be set by the TCP profile for each connection.

TCP software 42 of the terminal 4 on the other side
Returns a connection response to the TCP software of the terminal 1. At this time, the bearer characteristic between the terminal 4 and the accommodating router 3 by the self-accommodation method is notified (FIG. 5A4). In the TCP profile determination function 13, the TCP software 12 of the terminal 1 that has received the connection response sets the received router 2 according to the self-accommodation method to the received bearer characteristic between the terminal 4 and the accommodated router 3.
-From the bearer characteristic between the terminals 1 and the routing table managed by the route information 14, the bearer characteristic between the LAN5 and the LAN7 attached to the route information for the destination LAN7 is added, and the end-to-end, that is, the terminal 1 to the terminal 4 is considered. Determine bearer characteristics. To add the bearer characteristics, the same processing as that performed by each router is performed. The corresponding TCP profile is determined from this bearer characteristic (FIG. 5A5). T
The CP profile divides the bearer characteristic into several categories, and TC of the category to which the end-to-end bearer characteristic belongs.
Select a P profile. (See FIG. 4) The setting of TCP communication parameters by the TCP profile is possible for each connection.

In this way, the upper applications 11 and 41 are used between the two terminals by using the TCP software in which the TCP parameters are set according to the bearer characteristics of the communication path.
Implements optimal TCP communication (FIGS. 5A6 and A).
7). The terminals 1 and 4 that have started the TCP communication regularly monitor and update the accommodated bearer characteristics. The LAN routers such as the accommodating routers 2 and 3 also regularly monitor and update the bearer characteristics of the connected interfaces. As an example, the execution speed and the packet error rate are dynamically monitored targets. The profile determination function 13 transmits the accommodated bearer characteristic updated by the monitoring to the partner terminal 4 as a bearer characteristic update request through the TCP software (FIG. 5A8). The bearer characteristic update request can also be piggybacked on the data during TCP communication by using the TCP header option or the like. Upon receiving the bearer characteristic update request, the partner terminal 4 receives the bearer characteristics on the partner terminal 4 side, LAN1-LA, which are respectively updated by the profile determination function 43.
The TCP communication profile is determined again from the bearer characteristic between N4 and the bearer characteristic accommodated in the own terminal 1. This processing is also performed in the same manner as that shown in the first embodiment (FIG. 5A9). The terminal 4 returns the updated self-accommodation bearer characteristic as a bearer characteristic update response (FIG. 5A10).

The terminal 1, which has received the bearer characteristic update response,
In the profile determination function 13, from the updated bearer characteristics of the partner terminal 4 side, the bearer characteristics between LAN1 and LAN4, and the bearer characteristics of the own terminal 1 that are respectively updated, TC is again set.
Determine the P communication profile. This processing is also performed in the same manner as that shown in the first embodiment (FIG. 5A11). In this way, TCP based on the updated TCP communication parameters
The upper applications 11 and 41 of both terminals continue to use the communication (FIG. 5A12).

[0035]

Third Embodiment Next, client-server communication by dial-up connection will be described as a third embodiment of the present invention. FIG. 6 shows an embodiment in which the client uses dial-up and communicates with the server by remote access. The terminal device 1 remotely accesses the access server 2 in the ISP network 8 through the access network 5 by dialing up. The terminal 1 makes a TCP connection to the server 4 on the LAN 7 through the communication path established by dial-up. The ISP network 8 and the network 7 accommodating the server are connected by the router 3, and the router 3
And routers in each network, access server 2
And the server 4 manages the bearer characteristic as an attribute of the route information, as in the previous embodiment.

The operation of this embodiment will be described with reference to FIGS. FIG. 7 shows an example of client-server communication by dial-up connection. The terminal device 1 includes a host application 11, TCP software 12, profile determination function 13, route control 14 and access function 1.
Including 5. In addition, the server 4 is the upper application 4
1, TCP software 42, profile determination function 4
3 and route control 44.

The upper applications 11 and 41 notify the TCP software of the accommodation method selected by the user and activate the TCP connection. The TCP software 12 and 42 manage the TCP communication parameters set based on the TCP communication profile for each TCP connection. Profile determination functions 13 and 43
Determines the terminal-to-terminal bearer characteristics from the characteristics of the bearer accommodated by the terminal itself, the characteristics of the bearer accommodated by the partner notified at the time of connection, and the characteristics of the destination network bearer attached to the route information, and the TCP communication profile that matches the bearer characteristics. To set. The route controllers 14 and 44 obtain the route control information and the bearer characteristic associated with it from the access server 2 and the router 3, respectively, and manage the bearer characteristic for each route. The access server 2 and the router 3 exchange route information and bearer characteristic information attached thereto, respectively.

In FIG. 8, the terminal 1 has an access function 1
5 via the access network 5,
Access the access server 2 in the network 8. When the terminal 1 performs TCP communication with the server 4,
The upper application 11 instructed to connect by the access method selected by the user activates the access function 15 and establishes a communication path with the access server 2 in the ISP network 8. At that time, the access server 2 notifies the route control 14 of the terminal 1 of the route information held by the access server 2 and the bearer characteristic between the access server 2 and the router 3 according to its accommodation method (FIGS. 8A1, A2 and A3). . Further, when the communication path is established, the access server 2 sends an establishment response to the higher-level application 11 (FIG. 8A4).

The upper-level application 11 which has established the access communication path, then communicates with the server 4, which is a communication partner,
Establish a TCP connection. The upper application 11 notifies the bearer characteristic of the access method and requests the TCP software 12 to connect the TCP connection (FIG. 8A5). The TCP software 12 stores the bearer characteristic of the access method, and the TCP software 42 of the server 4 receives the bearer characteristic of the access method in the connection request and the bearer characteristic between the access server 2 and the router 3 notified from the access server. The bearer characteristic between the terminal 1 and the router 3 is determined, and the bearer characteristic is attached and transmitted (FIG. 8A).
6).

The TCP software 42 of the server 4 which has received the connection request, in the TCP profile determination function 43, includes the received bearer characteristic between the terminal 1 and the router 3 and the bearer characteristic between the accommodating router 3 and the server 4 by the self-accommodation method, and From the routing table managed by the route information 44,
The bearer characteristic between the ISP network 8 and the LAN 7 attached to the route information for the destination LAN 6 is added, and the bearer characteristic between the end-to-end, that is, the terminal 1 to the server 4 is determined. The addition of the bearer characteristics is the same as in the first embodiment.
A corresponding TCP profile is determined from this bearer characteristic (FIG. 8A7). TCP software 4 on server 4
2 returns a connection response to the TCP software of the terminal 1. At this time, the bearer characteristic between the server 4 and the router 3 by the self-accommodation method is notified (FIG. 8A8).

The TCP software 12 of the terminal 1 which has received the connection response, in the TCP profile determination function 13, shows the received bearer characteristics between the server 4 and the accommodating router 3 as follows.
Bearer characteristics between the router and the terminal 1 notified to the server, and
From the route auxiliary information managed by the route information 14, the destination LAN
The bearer characteristic between the ISP network 8 for LAN 7 and the LAN 7 is added, the bearer characteristic between the end and the end is determined, and the corresponding TCP profile is set (FIG. 8A9). Or later,
The terminal 1 and the server 4 start TCP communication (FIGS. 8A10 and 11A).

[0042]

As described above, the present invention has the following effects. The first effect is that the bearer characteristic is managed for each route and the TCP communication parameters are set according to the connection destination network.
This is a point that efficient streaming transfer is possible in consideration of the lower layer for each CP connection. The second effect is to extend the bearer characteristics, which are present when a plurality of networks pass, to end-to-end, and
By exchanging the bearer characteristic of the accommodating part with the communication partner side, it is possible to set the TCP communication parameter according to the TCP lower layer between the end-to-end including the accommodating part in which various bearer characteristics are assumed. is there. The third effect is
By defining a set of TCP parameters as a TCP profile, it is possible to effectively adjust mutually related TCP parameters.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of TCP communication according to the first embodiment.

FIG. 2 is a diagram showing a device configuration for performing TCP communication according to the first embodiment.

FIG. 3 is a diagram showing a procedure for setting a TCP profile according to the first embodiment.

FIG. 4 is a conceptual diagram of category classification of TCP profile.

FIG. 5 is a diagram showing a procedure for setting a TCP profile according to the second embodiment.

FIG. 6 is a TCP by remote access according to the third embodiment.
Communication conceptual diagram

FIG. 7 is a diagram showing a device configuration for performing TCP communication according to the third embodiment.

FIG. 8 is a diagram showing a procedure for setting a TCP profile according to the third embodiment.

[Explanation of symbols]

1, 4 ... Terminal 2, 3 ... Accommodation router (edge router) 5, 7 ... LAN 6 ... WAN 8 ... ISP network 11, 41 ... Higher applications 12, 42 ... TCP software 13, 43 ... Decision function 14, 44 ... Route control 15 ... Access function

Claims (6)

[Claims] 1. A first terminal and a second terminal are connected via a plurality of networks connected via a plurality of routers, and T
A procedure for establishing a connection before performing information communication by the CP / IP method, a procedure for referring to communication characteristic information between the first terminal and the second terminal, and a TCP based on the communication characteristic information. / IP profile setting method having a procedure for determining parameters of IP communication. 2. The procedure for referring to the communication characteristic between the both terminals further includes a step for referring to communication characteristic information for each destination network stored in a routing table held by each router of the communication path, and The TCP profile setting method according to claim 1, comprising a procedure of referring to communication information characteristics up to the nearest router stored in the first terminal and the second terminal. 3. The method according to claim 1, wherein at least one of a band, an execution speed, a maximum transfer unit, a packet error rate, a packet size, and a hop count is held as the communication characteristic information. TCP profile setting method. 4. The procedure for the first terminal and the second terminal to refer to the communication characteristic information, further includes the communication characteristic information of the routing table held by each router as the router of the communication path. The method for updating a TCP profile according to claim 2 or 3, further comprising: 5. A connection request for communication characteristic information between a first terminal and a router closest to the first terminal, and communication characteristic information for each destination network stored in a routing table held by each router of a communication path. At the same time, the procedure for transmitting to the second terminal, the communication characteristic information between the second terminal and the router closest to the second terminal, and the destination network for each destination network stored in the routing table held by each router on the communication path Procedure for receiving communication characteristic information from the second terminal at the same time as the connection response, communication between the first terminal and the router closest to the first terminal, communication between the second terminal and the router closest to the second terminal, and communication Based on the communication characteristic information for each destination network of the route,
A program for causing a computer to execute a procedure for determining parameters of TCP / IP communication. 6. A connection request for communication characteristic information between a first terminal and a router closest to the first terminal, and communication characteristic information for each destination network stored in a routing table held by each router of a communication path. At the same time, the procedure for receiving from the first terminal, and communication between the first terminal and the router closest to the first terminal, between the second terminal and the router closest to the second terminal, and for each destination network of the communication path A procedure for determining parameters of TCP / IP communication based on the characteristic information,
At the same time as the connection response, the communication characteristic information between the second terminal and the router closest to the second terminal and the communication characteristic information for each destination network stored in the routing table held by each router on the communication path are set at the same time as the connection response. A program that causes a computer to execute the procedure of sending to a terminal.