Communication system, communication method, and call control server

摘要

A first call control server transmits line information of a line to be used by a terminal device calls of which are controlled by the first call control server to a second call control server when congestion is detected. The first call control server receives the line information to be used in call control from the second call control server, and establishes a connection with the terminal device using the received line information. The second call control server receives the line information from the first call control server, and receives a call control request for the terminal device, the call control request being addressed to the first call control server. The second call control server responds to the first call control server with the received line information, when the call control request is received.

主权项

1. A communication system comprising:
a first call control server; a second call control server, and a load balancing server that distributes call control requests to each of call control servers, the first call control server comprising:
a transmitting unit that transmits station data which is stored as an objective of call control by the first call control server to the second call control server when congestion is detected, the station data including called telephone information which identifies a destination terminal device of the call control and line information related to a communication line to be used by the destination terminal device; anda connecting unit that receives a result of C-PLANE control which specifies called information which is used to call connection from the second call control server, and establishes, by executing U-PLANE control which establishes the call connection using the result of C-PLANE control, the call connection with the destination terminal device, the second call control server comprising:
a first receiving unit that receives the station data from the first call control server;a second receiving unit that receives a call control request for the destination terminal device, the call control request being addressed to the first call control server; anda responding unit that executes the C-PLANE control based on the received station data when the second receiving unit receives the call control request, and responds the first call control server with the result of the C-PLANE control, and the load balancing server comprising:
a predicting unit that predicts a change in load based on load information from each of the call control servers; andan instruction transmitting unit that transmits an instruction the first call control server, the instruction for transmitting the station data to the second call control server, when the predicting unit predicts that the load on the first call control server is to exceed a threshold in a predetermined time period.