[asterisk-dev] UAC leg cancel on early media / MoH.

Raj Jain rj2807 at gmail.com
Fri Nov 2 17:38:12 CDT 2007

Quoting from section of RFC 3261:

   If the UAS desires an extended period of time to answer the INVITE,
   it will need to ask for an "extension" in order to prevent proxies
   from canceling the transaction.  A proxy has the option of canceling
   a transaction when there is a gap of 3 minutes between responses in a
   transaction.  To prevent cancellation, the UAS MUST send a non-100
   provisional response at every minute, to handle the possibility of
   lost provisional responses.

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