> On 2/24/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
[snip]
>> If both series of REGISTER messages used the same Call-Id, then they
>> would form only one pseudo-dialog, and only the contact in the most
>> recent REGISTER would be registered. In that case, an incoming
>> request would be sent to only one UA.
This is an odd case. Its really erroneous for the two UAs to be using
the same Call-Id for their registrations.
But if it does happen, I disagree with the conclusion above.
Based on the description in 3261, there really is no unique
"pseudo-dialog" state. Rather, each contact in the location service
carries the Call-Id and CSeq of the last registration to affect it. So
the fact that there are two (possibly conflicting) sequences of sequence
numbers in use, this will not be detected unless both UAs attempted to
register the same contact address.
The first registration for each unique contact will succeed, and stamp
the contact with the Call-Id and CSeq value.
In subsequent refreshes of the registration by the two UAs, as long as
each only refreshes its own contact, and as long as each keeps
incrementing its own CSeq value, then both contacts will remain actively
registered and available for dispatching.
Paul
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