#1 Call-ID Header generation

[Georgi Dimitrov]

The Call-ID header generated is not optimal, since it is of the form:

Call-ID: 9b25ccf8570a7bc7c315c60363970b47@192.168.1.144

This is a problem, since RFC 3261 states:

"All SIP UAs must have a means to guarantee that the Call-
ID header fields they produce will not be inadvertently generated by
any other UA."

An example of a more-unique Call-ID would be:

Call-ID: f81d4fae-7dec-11d0-a765-00a0c91e6bf6@foo.bar.com

RFC 3261 does not specify how exactly the uniqie value for Call-ID header is to be generated, but it has to be an globally unique
identifier over space and time unless overridden by method-specific behavior.