Subject: RE: [Sip] Re: [Enum] SIP AoR, tel and ENUM - Second Try

From: "Tolga Tarhan" <[email-masked]>
Date: Fri, 9 Dec 2005 10:35:48 -0800

All,

Just to be clear, let me define my understanding of Juha's scenario:

1) UserA@provA sends an invite to his local proxy (provA) for
UserB@provB.

2) UserB has told his provider that he wants all of his calls redirected
to his PSTN number.  Clearly, userB's intent is that the call be
completed through a media gateway to the PSTN.  For this example, let's
say the number was +17205551212.

3) provB receives the request from provA and now needs to send a
redirect to the PSTN number.  Assume for this example that provA and
provB have no business relationship, and therefore, provB will not
accept a call to the PSTN from provA.

That being said, probably the simplest thing that provB can do is use a
tel: URI in the redirect.  That avoids all ambiguity and logically
requests that provA use a local media gateway to complete the call to
the PSTN.

If the tel: URI is not an option for some reason, then provB should send
the redirect to sip:+17205551212@provA;user=phone.  Notice the use of
provA, which the proxy at provB would have to derive, presumably using
the "From" header.  I don't think this is a good option, because there
may be no reliable way to consistently derive the correct URI.

I have to side with Paul, however, in saying that IF the redirect from
provB actually refers to sip:+17205551212@provB (regardless of the
presence of a user attribute), then the RFC is fairly clear -- the
request that results from the redirect must be sent to provB, which will
almost certainly fail.

--
Tolga Tarhan

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
Juha Heinanen
Sent: Friday, December 09, 2005 8:59 AM
To: Stastny Richard
Cc: Sip
Subject: Re: [Sip] Re: [Enum] SIP AoR, tel and ENUM - Second Try

Stastny Richard writes:

 > A user enters a phone number, the UA sends it by default
 > to his provider A with
 > sip:[email-masked];user=phone

that is fine if the user is placing the call, but how about when the
user wants to refer the calling party with 302 to his number on pstn
network?  

last time i checked, phones from paul's company use sip uri format,
which according to paul's interpretation must be routed to whatever host
part is listed there, which for sure get blocked by the proxy if the
caller belongs to a different domain.

-- juha

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Use [email-masked] for questions on current sip
Use [email-masked] for new developments on the application of sip

_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [email-masked] for questions on current sip
Use [email-masked] for new developments on the application of sip

---

From: Paul Kyzivat <[email-masked]>
Date: Mon, 12 Dec 2005 09:13:06 -0500

Tolga Tarhan wrote:
> the redirect to sip:+17205551212@provA;user=phone. 

If provA and provB have no business relationship, then it is 
inappropriate for provB to create a uri in the domain of provA.

This is different from the case Richard gave, where a uri is rewritten 
to the domain of the target when forwarding, because that presumes a 
business relationship.

> Notice the use of

Right!

> request that results from the redirect must be sent to provB, which will

	Paul