I'm trying to find out if there's a configuration option within 3.2.X or 4.0.X to force regeneration of call-id upon REGISTER. I have combed through the admin guides and Polycom site for information but I have not been able to find anything on the topic so far. RFC 3261 states this is possible :
The Call-ID header field acts as a unique identifier to group together a series of messages. It MUST be the same for all requests and responses sent by either UA in a dialog. It SHOULD be the same in each registration from a UA.
SHOULD != MUST but I'm thinking it may not be supported by Polycom. I did find an explination of why it "SHOULD" be the same here :
( https://lists.cs.columbia.edu/pipermail/sip-implementors/2002-October/003963.html ) The requirement that an UA SHOULD use the same call-id for all registration during a single boot cycle is to ensure sequencing of the Register requests. It ensures that an out-of-order REGISTER request doesnot do any harm. (change or remove a binding registered by a REGISTER request sent after it). Section 10.3, step 8 explains the processing of the Registrar w.r.t to callids.