2006-09-21: New module SIP Session Timer (sst) uploaded to CVS

The module was provided by Ron Winacott. The new module gives OpenSER basic SIP Session Timer support. See rfc4028 for more information on SST. This new module uses the new dialog module to track the creation, updating and termination of SIP dialogs. The dialog module supports timed out termination of the dialog but at this time the timeout value is hardcoded (avp accessable and modparam() settable).

What the sst module does is uses the dialogs own callbacks to update the dialog timeout value based on the current expire: header value. There is also a script function called sstCheckMin(min_se_value) that can be used in a proxy configuration to reply with a 422 "Session Interval Too Small" to a INVITE with a small MIN_SE value.