#22 Dialog should stick to one remote transport address

[Mikhail Zabaluev]

In some cases there are several request destination addresses available for a target URL, such as when an SRV lookup returns entries of the same priority. Requests in a dialog should stick to one transport address chosen for the initial request. This prevents confusion on the server side, where the alternative proxies often know nothing about each other's dialogs.

This also applies to resubmissions of INVITE requests after an authentication challenge. If authentication responses are fanned around multiple proxies which know nothing of each other's challenges, the number of steps needed to make the authentication succeed is not deterministic.

[Mikhail Zabaluev]

See
https://bugs.maemo.org/show_bug.cgi?id=3824
for a case where usage of SRV results exhibits the problem.