Server

Abstract

A server capable of reducing an overloaded state even if a refreshing message is frequently generated. A central processing unit receives a first message transmitted from a terminal to establish a session. The central processing unit, when receiving the first message from the terminal, allocates to itself and the other plural central processing units the subsequent message transmission and reception between the terminal and a terminal as a communication partner. The central processing unit allocates to itself and the other plural central processing units the message transmission and reception between the terminals, for example, in a round robin fashion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an outline of a server.

FIG. 2 shows a system configuration example of a SIP server according to a first embodiment.

FIG. 3 illustrates a port of the SIP server.

FIG. 4 illustrates allocation of CPUs to ports.

FIG. 5 is a functional block diagram of the SIP server.

FIG. 6 is a sequence diagram showing operations of the session establishment between terminals.

FIG. 7 shows an example of an initial INVITE message transmitted to the SIP server from the terminal.

FIG. 8 shows an example of the initial INVITE message transmitted to the terminal from the SIP server.

FIG. 9 shows an example of a 200OK message transmitted to the SIP server from the terminal.

FIG. 10 shows an example of the 200OK message transmitted to the terminal from the SIP server.

FIG. 11 shows an example of an ACK message transmitted to the SIP server from the terminal.

FIG. 12 shows an example of the ACK message transmitted to the terminal from the SIP server.

FIG. 13 is a sequence diagram showing operations of an existence check on the session between terminals.

FIG. 14 shows an example of a refresh INVITE message transmitted to the SIP server from the terminal.

FIG. 15 shows an example of the refresh INVITE message transmitted to the terminal from the SIP server.

FIG. 16 shows an example of the 200OK message transmitted to the SIP server from the terminal.

FIG. 17 shows an example of the 200OK message transmitted to the terminal from the SIP server.

FIG. 18 shows an example of the ACK message transmitted to the SIP server from the terminal.

FIG. 19 shows an example of the ACK message transmitted to the terminal from the SIP server.

FIG. 20 illustrates a port allocation in the SIP server according to a second embodiment.

FIG. 21 is a functional block diagram of the SIP server.

FIG. 22 is a flowchart showing operations of a port distribution in the SIP server.

FIG. 23 illustrates a port allocation in the SIP server according to a third embodiment.

FIG. 24 is a functional block diagram of the SIP server.

FIG. 25 is a flowchart showing operations of a port distribution in the SIP server.

FIG. 26 is a sequence diagram for illustrating the existence check on the session.

Claims

1. A server for establishing and maintaining a session between terminals, comprising: a central processing unit for receiving a first message transmitted from a terminal to establish the session and for allocating, to one of the central processing unit and other plural central processing units, subsequent message transmission and reception between the terminal and a terminal as a communication partner.

2. The server according to claim 1, wherein: the central processing unit allocates the message transmission and reception in a round-robin fashion.

3. The server according to claim 1, wherein: the central processing unit allocates the message transmission and reception based on a reception amount of the message per unit time.

4. The server according to claim 3, wherein: the central processing unit, when the reception amount is less than a threshold, allocates to the central processing unit the message transmission and reception.

5. The server according to claim 3, wherein: the central processing unit, when the reception amount exceeds a threshold, allocates the message transmission and reception to one of the other plural central processing units.

6. The server according to claim 1, wherein: the central processing unit allocates the message transmission and reception based on its own usage rate.

7. The server according to claim 6, wherein: the central processing unit, when the usage rate is less than a threshold, allocates to the central processing unit the message transmission and reception.

8. The server according to claim 6, wherein: the central processing unit, when the usage rate exceeds a threshold, allocates the message transmission and reception to one of the other plural central processing units.

9. The server according to claim 1, wherein: one port number is allocated to each of the central processing unit and the other plural central processing units, and the central processing unit controls such that the message transmission and reception is allocated based on the port number.