Yes because it's telling one of the parties that the other party is
someone else.
Say you have this...
SIP UA
Alice------------->Proxy--------------->SIP gateway------------>some
network------>Bob
The call gets established. Alice talks to Bob.
Then Bob transfers the call to Carol.
You would then expect something like an UPDATE or re-INVITE with a new
P-Preferred-Identity going from SIP gateway to proxy.
Incidentally, RFC 4916 (which is maybe a better solution) also tries to
solve the same problem.
The scenario I have described above is the same kind of problem as
described
in RFC 4916's introduction:
o the identity of a user that replaces the caller or callee
following a call rearrangement such as call transfer carried out
within the PSTN or within a back-to-back user agent (B2BUA) using
third party call control techniques.
________________________________
From: Jyoti Singhal [mailto:[email protected]]
Sent: 10 March 2011 08:58
To: Attila Sipos
Cc: [email protected]
Subject: Re: [Sip-implementors] Significance of different PAID header
inRe-INVITE
But once a dialog is established between two parties, does a change in
its PAID header has any significant for the other party?
With Regards,
Jyoti
On Thu, Mar 10, 2011 at 11:49 AM, Attila Sipos
<[email protected]> wrote:
I my experience it means that the identity of the connected
party has changed.
say you have a SIP gateway to some non-SIP network.
If a transfer occurs inside the network then the SIP
endpoint could become connected to a different user.
The SIP UA will update the P-Preferred-Identity
from RFC 3325:
9.2 The P-Preferred-Identity Header
The P-Preferred-Identity header field is used from a user
agent to a
trusted proxy to carry the identity the user sending the SIP
message
wishes to be used for the P-Asserted-Header field value that
the
trusted element will insert.
LATER IN THE SAME SECTION...
It is worth noting that proxies can (and
will) remove this header field.
Then I think the proxy will remove P-Preferred-Identity and
replace it with a P-Asserted-Identity to propagate the new
identity.
From RFC 3325:
9.1 The P-Asserted-Identity Header
The P-Asserted-Identity header field is used among trusted
SIP
entities (typically intermediaries) to carry the identity of
the user
sending a SIP message as it was verified by authentication.
LATER IN THE SAME SECTION...
It is worth noting that proxies can (and
will) add and remove this header field.
regards
Attila
-----Original Message-----
From: [email protected] on behalf
of Jyoti Singhal
Sent: Thu 10/03/2011 05:29
To: [email protected]
Subject: [Sip-implementors] Significance of different PAID
header inRe-INVITE
Hi All,
I need to know is there any significance of a modified PAID
header in
Re-INVITE.
With Regards,
Jyoti
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