[Serusers] Some questions on "loose_route"

Jan Janak jan at iptel.org
Sat Jan 3 18:14:55 CET 2004


On 03-01 18:59, Juha Heinanen wrote:
> Greg Fausak writes:
> 
>  > Well, that is my question.  Shouldn't all other messages
>  > be record routed if the invite was record routed?
> 
> no, because the route recorded for initial transaction that established
> the dialog will be used for all subsequent requests of that dialog.  i
> was just referring to your script that asked if it is an error if you
> end up there.  so you only need record route the initial request
> (the one without to tag).

  Basically you need to record route all target refreshing requests (as
  far as I know currently only INVITE and SUBSCRIBE) are target
  refreshers.

  Generally you don't know if a message is target refresher because some
  other may be created in the future. That's the reason why it is
  recommended to record-route all requests.

  So it is a tradeoff between efficiency and compatibility with future
  (or proprietary) extensions. If you want shorter messages
  (Record-Route headers can significantly bloat SIP messages, especially
  when proxy chains are involved, not even speaking of IPv6 addresses),
  record route INVITE and SUBSCRIBE requests only.

  If you don't care about efficiency and huge messages, record-route
  everything.

    Jan.




More information about the sr-users mailing list