[OpenSER-Devel] SF.net SVN: openser: [4242] trunk

[Dan Pascu]

On Sunday 25 May 2008, Juha Heinanen wrote:
> dan,
>
> i'm reading README of nat_traversal module and started to wonder why
> the module needs to distinguish subscribe and invite dialogs as
> keepalive conditions?  why not just have registrations and UA initiated
> dialogs?

Because they have a very different behavior regarding how they setup the 
dialog. SUBSCRIBE starts a timed session, where you know how long the 
session will last by the Expire header. The INVITE dialog however has a 
duration that is not known in advance and a BYE must end the dialog.

The distinction however is just a concept to explain things and as you can 
see in the use cases, handling a subscription is different from a call 
setup which justifies it.

-- 
Dan