JPH10327188A - Packet network and packet exchange method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packet network and an exchange method, with which new and former different service styles can mutually coexist with compatibility, by transmitting a packet for supporting the former service style as a packet to be sent again when a packet for supporting the new service style is abandoned. SOLUTION: A packet adding a user identifier as additional information for providing the new service style to an extension check sum adding a constant value to a conventional check sum is first transferred from a service resource 2 to a service resource 3. The user identifier is reported from an access control part 16 to an access control part 17 through a data transfer circuit 11. When this packet is abandoned without extending a protocol stack 19 at the access control part 17, the access control part 16 at the service resource 2 transfers the packet having the conventional check sum. This packet is accepted, processed at the process control part 17 in the service resource 3 and dispatched to an application 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is used to integrate a plurality of service types provided on a computer network. In particular, the present invention relates to a technology for extending a protocol for combining service types having different interfaces.

[0002]

2. Description of the Related Art In a computer network service for accessing service resources distributed in the same packet network, a plurality of service formats are integrated to realize a service format with a new common interface, and conversely. When matching an old service format with an interface supporting a new common service format, an unnecessary part of information exchanged between application programs (hereinafter abbreviated as an application) is ignored or missing information is supplemented. The application needs to be modified to add additional information above.

However, with the generalization of computer network services, it has become difficult to modify all related applications, and how to apply new service type applications on the same network without affecting old service type applications. Is an important issue.

An introduction form of a new service format in a conventional packet network will be described with reference to FIGS. When realizing a new service format in place of the old service format, a packet in which additional information for realizing the new service format is added to existing information used for realizing the old service format is exchanged. It is done by that.

[0005] Thus, a new service format can be realized without affecting existing applications that operate on the premise of the protocol stack of the old service format (the entire protocol hierarchy such as OSI is called a protocol stack). Can be transmitted and received.

FIG. 4 is a diagram showing a (A) system of a conventional example. In the method shown in FIG. 4, in the communication from the application 4 to the application 5, the unused area 32 or the available area 32 in the information format of the packet 30 exchanged on the data transfer path 50 between the access controllers 16 and 17 is used. Unused option value 3 in option area 31
3 is a method for exchanging additional information by using the third method.

FIG. 5 is a diagram showing a conventional (Otsu) system. The method shown in FIG. 5 is based on the data transfer path 5 for transmitting additional information corresponding to the data transfer path 50 for transmitting existing information between the access control units 16 and 17 in the communication from the application 4 to the application 5.
1, the data transfer path 50 exchanges the packet 60 including the existing information, and the data transfer path 51 exchanges the packet 41 including the additional information.
And 51 correspond to the data transfer path correspondence management unit 13 in the protocol stack 18 and the protocol
This is a system associated by the data transfer path correspondence management unit 14 in the stack 19.

In the above (A) system, the unused area 32, which is an area used for transferring additional information, and the unused option value 33 of the option area 31 are set so that the protocol stack 19 corresponds to the new service format. The existing protocol and the additional information are passed to the new service format application stack that operates on the new service format protocol stack. If it is present, it is ignored, and only the existing information is passed to the application of the old service format operating on the protocol stack of the old service format, and compatibility is maintained.

In the above (Otsu) system, the protocol
If the stack 19 is a protocol stack extended to support the new service format, the data transfer path 5
0 along with the existing information to be transferred,
The additional information transferred is accepted, and the existing information and additional information are passed to the new service type application running on the new service type protocol stack. Since the existence of the data transfer path 51 for transferring the additional information is not known, the additional information is not accepted, and the data transfer path 50 is transmitted to the old service format application operating on the old service format protocol stack. Only existing information to be transferred is delivered and compatibility is maintained.

The above (A) method is generally used when a provisional measure is required independently in a closed environment.
In addition, the above (Otsu) method is Internet standard IDE
Used for the NT protocol (RFC1413).

[0011]

However, in the above-mentioned (A) method, the unused area 32 and the unused option value 33 of the option area 31 shown in FIG. There is no guarantee that the protocol stack that relays the packets will always relay correctly as expected. Further, there may be a case where a sufficient area for mapping desired additional information to the unused area 32 and the unused option value 33 of the option area 31 cannot always be found.

Further, in the above-mentioned method (B), if a security filter or the like which is not expected to exist in the data transfer path 51 shown in FIG. There is a case where data transfer by the network 51 cannot be performed and additional information cannot be transmitted.

Therefore, it is possible to transfer additional information that was not originally planned for an existing protocol without disturbing the consistency of the protocol, and to integrate the old service format and the new service format organically. Realization of services is desired.

The present invention has been made in such a background. When new and old different service types are mixed in the same network, the new and old different service types can coexist with each other with compatibility. It is an object to provide a packet network and a packet switching method. The present invention
It is an object of the present invention to provide a packet network and a packet switching method in which a service resource supporting a new service format and a service resource supporting an old service format can mutually perform packet switching.

[0015]

SUMMARY OF THE INVENTION The present invention utilizes the fact that discarded packets are retransmitted when data is exchanged using packets, and when a packet supporting a new service format is discarded, The most important feature of the retransmitted packet is to enable the mixture of the new and old different service formats by transmitting the packet supporting the old service format.

For example, a packet with an abnormal checksum is discarded by a layer completely unrelated to the upper application and is retransmitted, using a general condition to add a packet with additional information used for realizing a new service format. Changes the checksum calculation method so that protocol stacks that do not support the extension simply discard them, and protocol stacks that support the extension allow additional information to be passed to the upper layer so that new and old service types can be mixed. .

As a result, as in the case of the above-mentioned (A) system, there is no influence on the legitimate protocol,
Unlike the (B) method, it does not have a separate data transfer path, so it is not affected by environmental conditions such as security filters.

That is, a first aspect of the present invention relates to a plurality of services for mutually exchanging packets and transmitting and receiving information.
The transmission-side service resource is a packet network provided with resources and means for retransmitting a packet discarded without being received by the reception-side service resource. A feature of the present invention is that different old and new service formats are mixed in the same network, the service resource on the transmitting side transmits a packet supporting the new service format, and the means for retransmitting the packet includes: When the packet supporting the new service format is discarded by the service resource on the receiving side, the method includes means for transmitting a packet supporting the old service format as a retransmission packet.

A second aspect of the present invention is that a plurality of services
This is a packet switching method in which resources exchange packets with each other to transmit and receive information, and a service resource on the transmitting side is a packet switching method for retransmitting a packet discarded without being received by the service resource on the receiving side. A feature of the present invention is that different service formats, old and new, are mixed in the same network, the service resource on the transmitting side transmits a packet supporting the new service format, and the packet supporting the new service format is transmitted. When discarded by the service resource of the receiving side, the service resource of the transmitting side is to transmit a packet supporting the old service format as a retransmission packet.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a conceptual diagram of a packet network according to an embodiment of the present invention.

The present invention comprises service resources 2 and 3 for mutually exchanging packets and transmitting and receiving information. The service resource 2 on the transmitting side is discarded without being received by the service resource 3 on the receiving side. This packet is a packet network that retransmits this packet.

Here, a feature of the present invention is that different old and new service formats are mixed in the same network, and the service resource 2 on the transmitting side transmits a packet supporting the new service format, and The resource 2 is to transmit a packet supporting the old service format as a retransmission packet when the packet supporting the new service format is discarded by the service resource 3 on the receiving side.

FIG. 1 shows that a user 15 uses a service resource 2 application 4 to transmit a service resource 3
Of the application 5 is accessed.

Here, in the case of the old service format, the user 15 can unconditionally access the application 5 of the service resource 3 via the application 4 of the service resource 2.

However, in the new service format, the user 15
First transfers the user code and the password of the user 15 to the service / resource management unit 60 in the server 1. The service resource management unit 13 transfers the user identifier to the access control unit 16 of the service resource 2. The access control unit 16 transfers the user identifier to the access control unit 17 of the service resource 3 as additional information. The access control unit 17 authenticates the user 15 based on the user identifier, and transfers the result to the service / resource management unit 60. This allows
When the authentication of the user 15 is completed, the application 5 can be used by the user 15 via the application 4.

Therefore, in the embodiment of the present invention, a case where the service resource 2 transfers the user identifier to the service resource 3 as additional information for realizing the new service format will be described. The protocol stack 18 of the access control unit 16 of the service resource 2 has been expanded to support the new service format.

The user 15 transfers the user code and the corresponding personal identification code to the service / resource management unit 60 in the server 1 via the data transfer path 8 different from the application 4 to be used, and authenticates the registered user. receive. The service resource management unit 13 notifies the access control unit 16 of the service resource 2 of the user identifier via the data transfer path 9.

When the user 15 needs to access the application 5 that provides the service when using the application 4, the user identifier is changed via the data transfer path 11 without the application 4 or 5 being concerned. The information is transmitted from the access control unit 16 to the access control unit 17.

The access control unit 17 provides services via the data transfer path 10 which the application 5 is not aware of.
The overall access control is performed by confirming the validity of the user identifier to the resource management unit 60 and connecting to the application 5 if the user identifier is valid, and not connecting to the application 5 if invalid. .

Here, the transfer of the additional information performed by the data transfer path 11 operates differently depending on whether the protocol stack 19 of the access control unit 17 has been expanded or expanded. This operation will be described with reference to FIGS. FIG. 2 is a diagram showing an operation when the protocol stack 19 of the access control unit 17 is not expanded. FIG. 3 is a diagram showing the operation when the protocol stack 19 of the access control unit 17 has been extended. Each shows a case where the access control unit 16 attempts to send a packet to the access control unit 17.

From the access control unit 16 relating to the application 4, regardless of whether the access control unit 17 relating to the application 5 has not been expanded or has been expanded for the new service format, the check calculated by the conventional calculation method is initially performed. A packet 20 having an extended checksum 23 obtained by adding a certain value to the sum and additional information 22 is transferred.

As shown in FIG. 2, when the protocol stack 19 of the access control unit 17 is not extended, the packet 20 is discarded because the extension checksum 23 is not understood. However, as shown in FIG.
If the protocol stack 19 has been extended, the extended checksum 23 is authenticated as a valid checksum, and the packet 20 is received by the access control unit 17 and processed, and then passed to the application 5.

As shown in FIG. 2, when the protocol stack 19 of the access control unit 17 is not expanded and the packet 20 is discarded, the access control unit 16 performs the normal packet discarding due to congestion or collision. As before, retransmit the same packet.

At this time, the access control unit 16 transfers the packet 21 having the conventional checksum 24. Since this is a packet that supports the old service format,
The access control unit 17 operated by the unextended protocol stack normally receives the packet 21. The packet 21 is passed to the application 5 after being processed by the access control unit 17.

As described above, according to the present invention, even if the protocol stack 19 of the access control unit 17 has not been expanded or has been expanded, the user 15 can use the service 4 through the application 4 of the service resource 2. -The application 5 of the resource 3 can be used. At this time, if the protocol stack 19 of the access control unit 17 has been extended, the user 15 cannot use the application 5 until the user 15 is authenticated.

(Summary of Embodiment) In the embodiment of the present invention,
Whether the discard of the packet is due to the unexpanded protocol stack of the access control unit on the receiving side,
Alternatively, it is difficult for the transmission source to determine whether the packet has been discarded due to congestion, collision, or the like even if the packet has been extended. Therefore, it cannot be denied that a packet supporting the old service format is retransmitted to the access control unit of the service resource having the extended protocol stack.

However, it is rare that packets are discarded due to congestion or collisions due to recent high communication quality or link-level error correction. Even though there is a possibility that packets supporting the old service format can be accepted, the difficulty in determining the cause of discard is negligible compared to the advantage of the present invention.

[0039]

As described above, according to the present invention,
When new and old different service types are mixed in the same network,
The new and old different service types can coexist with each other with compatibility. That is, the service resources that support the new service format and the service resources that support the old service format can mutually exchange packets.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a packet network according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an operation when a protocol stack of an access control unit is not extended;

FIG. 3 is a diagram showing an operation when a protocol stack of an access control unit has been extended.

FIG. 4 is a diagram showing a (A) system of a conventional example.

FIG. 5 is a diagram showing an (Otsu) system of a conventional example.

[Explanation of symbols]

1 server 2, 3 service resource 4, 5 application 8, 9, 10, 11, 12, 50, 51 data transfer path 13, 14 data transfer path correspondence management unit 15 user 16, 17 access control unit 18, 19 protocol Stack 20, 21, 30, 40, 41 Packet 22 Additional Information 23 Extended Checksum 24 Conventional Checksum 31 Optional Area 32 Unused Area 33 Unused Option Value 60 Service / Resource Management Unit

Claims (2)

[Claims] A plurality of service resources for mutually exchanging packets and transmitting and receiving information are provided, and a service resource on a transmission side is used for a packet discarded without being received by a service resource on a reception side. A packet network comprising means for retransmitting a packet, wherein different new and old service formats are mixed in the same network, wherein the service resource on the transmitting side transmits a packet supporting the new service format, and retransmits the packet. Means for transmitting a packet supporting the old service format as a retransmission packet when the packet supporting the new service format is discarded by the service resource on the receiving side. 2. A plurality of service resources exchange packets with each other to transmit and receive information, and a service
The resource is a packet switching method for retransmitting a packet discarded without being received by the service resource on the receiving side, wherein different old and new service types are mixed in the same network, The resource transmits a packet supporting the new service type, and when the packet supporting the new service type is discarded by the service resource of the receiving side, the service resource of the transmitting side transmits the old service as a retransmission packet. A packet switching method comprising transmitting a packet supporting a format.