[SR-Users] branches usage

[Uri Shacked]

OK...
It worked great... and, no append_branch() was needed... only t_on_branch
with the main branch route.
When will i need to use the append_branch?
BR,
Uri

On Wed, Mar 28, 2012 at 4:00 PM, Uri Shacked <ushacked at gmail.com> wrote:

>  Hi,
>
> Thanks, this was very helpful for understanding.
>
> Still let’s see if i got it right:
>
> I get the INVITE.
>
> Do whatever I do on the main route.
>
> Then do:
>
> “append_branch();”
>
> “changes….changes…..;”
>
>  Now before the t_relay do t_on_branch(name of branch).
>
> Get the reply (301 in my case)
>
> And from here I am back to the original request?
>
> maybe a stupid question now but - I must use the append_branch()  right
> :-)?
>
> BR,
>
> Uri
>
>
> Hi,
>
> On 03/27/2012 04:46 PM, Uri Shacked wrote:
> >* In my case i need to change the header and then send it.
> *>*
> *>* Here the case works if i make the changes after i sent the invite and
> *>* got the reply. As i know the t_on_branch will work after the invite is
> *
> >* sent... am i wrong?
> *>*
> *>* There are many questions to ask about the branches... when do they
> work *>* in a serial manner, when parallel... where can i find it
> documented best?
> *
> Actually it's quite simple. If a request comes in and you modify it in a
> normal route (e.g. calling rtpproxy_offer(), uac_replace_from(), adding
> additional headers and stuff like that) and you send it out using e.g.
> t_relay(), then in a serial scenario when you re-enter via a
> failure-route, these changes will still be there (which is not always
> what you want).
>
> On the other hand, if you register a branch route via t_on_branch() and
> do your changes there instead of prior to calling t_relay(), then these
> changes from branch route will be rolled back, and you can do your
> changes easily again in the same or another branch route starting with
> your original message. This is important for example in serial call
> forward scenarios, where the first destination might require an
> rtpproxy, but the second doesn't, or when the first destination requires
> different custom headers compare to the second.
>
> Basically the same applies to parallel scenarios. If you modify your
> message before calling lookup() and you've multiple contacts registered
> for your destination, then your changes will apply for all branches
> which are created by that. However if you move your modifications to a
> branch route, then you can work on your messages individually, depending
> on the branch.
>
> Hope this clarifies it a bit.
>
> Andreas
>
>
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