[OpenSIPS-Devel] loose routing params embedded in username

[Bogdan-Andrei Iancu]

Hi Phil,

Indeed, that is an interesting idea I would say - so far we did a lot of 
testing at SIPit this week and all the clients were compliant with the 
RR params - we found only some clients that have problems with too long 
RR headers :) - but even with the new approach, it will be the same.

upload a feature request on this, please.

Regards,
Bogdan

Phil Vandry wrote:
> Hello,
>
> OpenSIPS (via the rr module) provides a framework for placing parameters
> in Record-Route URIs for later retrieval during loose-routing. Several
> modules make use of this functionality:
>
> - rr stuffs the From tag into a parameter and uses is for is_direction()
> - dialog uses it to match subsequent requests to an existing dialog
> - uac uses it to remember the original From: URI that needs to be
>   restored later
> - the user may add custom parameters in the script and retrieve them
>   using loose routing.
> - etc...
>
> Unfortunately, in integration testing, I found that storing these
> parameters in URI parameters was not reliable. I found two devices
> that mangle the parameters from a Record-Route header that passes
> through them. One is a high-end desktop SIP (hard) phone and the
> other is the application server SIP container from a major commercial
> IMS vendor. Interestingly, they both seem to have the same problem:
> the first parameter from the top route is transposed to the RURI and
> subsequent parameters are discarded. Visually:
>
> METHOD ruri SIP/2.0
> Route: uri;lr;p1;p2
>
> becomes:
>
> METHOD ruri;p1 SIP/2.0
> Route: uri;lr
>
> I did not spend much time trying to fix the broken devices. Instead, I
> chose to change the way OpenSIPS's rr works for increased robustness.
>
> There is another place besides URI parameters where private data like this
> can be stored: the SIP username, which is otherwise not very useful in a
> lr URI. Storing opaque data in the URI username is a common technique
> and I can quickly think of at least two implementations that I work with
> that use it (an SBC and a CSCF, both commercial products).
>
> Instead of:
>
> sip:opensips.server;lr;p1=value1;p2=value2;p3=value3
>
> I use:
>
> sip:p1=value1.p2=value2.p3=value3 at opensips.server;lr
>
> I have a patch to the rr module which implements this as a configurable
> option:
>
> modparam("rr", "param_in_username", ".")
>
> (the value of the parameter is the delimiter that should be used.)
>
> I would like to know if a patch like this would be considered for inclusion
> in OpenSIPS.
>
> -Phil
>
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