Gateway device

Abstract

The invention provides a gateway apparatus. Even when all of usable sessions are in use, a communication can be established for a new session and the interrupted session is automatically restored. Information on degrees of importance of communication sessions and information of restoration requirement are set in advance and stored in a session importance table (130) in association with identifier(URI) of communication initiating terminals and identifier of destinations of communication. When a connection request for a session having a high degree of importance such as an emergency session isreceived, the session having the lowest degree of importance is selected and interrupted. Information of the interrupted session such as the communication initiator identifier and the communication destination identifier is stored in a session restoration table (140). The session is automatically restored as soon as a session resource becomes unoccupied according to the communication initiator identifier and the communication destination identifier stored in the session restoration table (140).

Description

technical field [0001] The present invention relates to a gateway device, and more particularly to a gateway device for connecting a specific new session when all available sessions are used. Background technique [0002] Patent Document 1 discloses a technique for disconnecting a physical line in order to enable a new important call when line resources are exhausted (both B channels are used) in an ISDN network. For example, Patent Document 1 discloses a technique of opening a relay contact to disconnect an I-interface line connected from a line termination device to a plurality of ISDN communication terminals when it is determined that the call is a priority call. [0003] Also, for example, a technique of disconnecting another session with a lower priority from a connection request from a user terminal with a higher priority is known (for example, refer to Patent Documents 2 to 5). [0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 11-266324 [0005]...

AI Technical Summary

Problems solved by technology

[0010] Furthermore, when a user terminal with a high priority is still connected, even if a user with a low priority tries to reconnect, the connection of the user with a low priority whose communication is cut off may not be permitted, and the user repeatedly tries to connect. time to reconnect

On the other hand, since the timing of the user's reconnection attempt has nothing to do with the disconnection and opening of the session, there may be idle time between the disconnection and release of the session of another user terminal with high priority and the user's reconnection attempt.

Therefore, the utilization efficiency of the line is reduced

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