Chapter 8. SIP Services
SIP(Session Initiation Protocol) is a protocol for creating and terminating various media stream sessions over an IP
network.It is for example used for Internet telephone calls and distribution of video streams.
SIPtakes care of the initiation, modification and termination of a session with one or more participants. The
protocolmakes it possible for the participants to agree on what media types they should share. You can find more
informationabout SIP in appendix A, More About SIP, and in RFC 3261.
Youfind examples on how to configure your 3Com VCX IP Telecommuting Module for SIP in chapter 4, How To
ConfigureSIP.
TheSIP module in 3Com VCX IP Telecommuting Module handles SIP requests for users who have registered on a
machineconnected to the Telecommuting Module. The module forwards the request through the Telecommuting
Module,which enables users behind different network interfaces to make contact. The SIP module controls the
securityrules to temporarily let through the media streams that the users agree on, on their assigned ports.
Youmust enter a DNS server and a Default gateway on the Basic Configuration page to make the SIP module
worksatisfactorily.

Administration of SIP

Toenable the SIP function of the Telecommuting Module, you must at least configure on the Basic page.
TheseSIP functions are configured in the SIP Services section:
•SIPmodule on/off.
•SIPlogging.
•Portrange for SIP media.
•Interoperabilitysettings.
•SIPtimeouts.
•RemoteSIP Connectivity (requires a Remote SIP Connectivity Module).

Basic

Here,you make basic settings for the Telecommuting Module SIP management.
General
Here,select whether the SIP module should be activated or not. If you select to turn the SIP module Off, no other
SIPsettings will have any effect.

SIP media port range

Statea port interval which the Telecommuting Module should use for SIP media streams. You can use any high
portsexcept 4500 (reserved for NAT-T)and 65097-65200 (reserved for RADIUS).
Enterthe lower and upper limit of the port range that the Telecommuting Module should use for media streams. The
upperlimit must be at least as high as the lower limit.
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