Subject: [sipcore] ue-addr parameter in SIP Contact header

From: Ranjit Avasarala <[email-masked]>
Date: Thu, 3 Oct 2019 10:16:42 -0500

Hello SIP experts

I have a scenario where, the S-CSCF is ignoring
ue-addr=x.y.z.a;transport=udp parameter in INVITE request.  Ignoring in the
sense that it is not adding the "ue-addr" parameter in the INVITE it
forwards to next hop

but in another scenario, when the "ue-addr" is of the format
ue-addr=x.y.z.x>  i.e there is no transport=udp parameter added, then the
S-CSCF is adding the "ue-addr" in the INVITE it forwards to next hop.

So what could be the issue - is it presence of transport=udp next to
ue-addr parameter that S-CSCF is not liking and ignoring?

Thank you
Ranjit

---

From: Paul Kyzivat <[email-masked]>
Date: Thu, 3 Oct 2019 13:31:36 -0400

Ranjit,

On 10/3/19 11:16 AM, Ranjit Avasarala wrote:
> ue-addr=x.y.z.a;transport=udp parameter in INVITE request.  Ignoring in 
> the sense that it is not adding the "ue-addr" parameter in the INVITE it 
> forwards to next hop
> 
> ue-addr=x.y.z.x>  i.e there is no transport=udp parameter added, then 
> the S-CSCF is adding the "ue-addr" in the INVITE it forwards to next hop.
> 

Yesterday you asked a similar question on the dispatch list. I replied 
to you and suggested that <[email-masked]> is a 
more appropriate place to ask this kind of question. Today you are 
trying sipcore. I still say that sip-implementors is a better place. Now 
that you identify an S-CSCF it is obvious that this pertains to 3GPP 
IMS. You may have better luck asking some IMS forum.

Also, if you expect to get an answer anywhere you need to provide better 
information. What you provided today is marginally more helpful than 
what you said yesterday, but is still very unclear. Please provide the 
context (in the form of a call flow), and copies of the sip message(s) 
of concern.

Based on the little you provide above, I *guess* that you are using 
"ue-addr" as a SIP URI parameter in a sip header field - perhaps the 
Request-URI. If so, please note that "ue-addr" is *not* registered as a 
SIP URI parameter in the iana registry. See:

https://www.iana.org/assignments/sip-parameters/sip-parameters.xhtml#sip-parameters-11

Note that Standards Action is required to define new SIP URI parameters. 
3GPP is pretty good about following IETF rules for SIP and registering 
their unique parameters in appropriate IANA registries. So I am guessing 
that "ue-addr" is proprietary to one 3GPP vendor's implementation.

If you send a request containing a URI parameter to a server that 
doesn't know about that parameter, then it is quite plausible that the 
parameter will be ignored and not passed along on the next hop.

If you have more questions, please provide sufficient detail so that 
they may be answered.

	Good luck,
	Paul

---

From: Christer Holmberg <[email-masked]>
Date: Fri, 4 Oct 2019 06:13:58 +0000

Hi,

...

> that "ue-addr" is proprietary to one 3GPP vendor's implementation.

I think so too. My 3GPP colleague told me that, as far as he knows, 3GPP does not define such parameter.

Regards,

Christer