Hi Vishai,

I made some commercial IP phone, and did a lot of interoperation tests with 
CSCFs in view of a UE
In those situations, always transition between UDP and TCP was an issue.
Because depends on a services, SIP message could have various size over MTU. 
But if an entity sends the sip message which size is over MTU without changing 
transport from UDP to TCP between a UE and CSCF, it will be fragmented and the 
message won't be serviced by UE or CSCF. This is a real-case and it's 
inevitable within real-services. I know that there are some ambiguous aspects 
in 3261 about that.
Lastly there is an effort about this, please refer to this
draft-gurbani-sip-large-udp-response-00.txt
I'm not sure this one is the latest :) 

Regards,

----------------------------------------------------------------------
Young-Joon Ryu (Alex) Team Manager

IMS Platform Team Nable Communications, Inc. 
Tel : +82-2-3288-4334 (Ext:236)
Mobile: +82-10-7701-8853
Fax: +82-2-558-8325 
Email : [EMAIL PROTECTED] 
http://www.nablecomm.com 
-----------------------------------------------------------

 

-----Original Message-----
From: Vishal Mathur [mailto:[EMAIL PROTECTED] 
Sent: Thursday, November 15, 2007 7:07 PM
To: 류 영준; [EMAIL PROTECTED]; [email protected]
Subject: RE: [Sip-implementors] How to determine transport to use from 
Routeheader

Hi Alex,

I am not sure that approach of send sip messages our TCP is correct if the 
original transport was UDP. This is because sender might not be having any 
connection open on TCP at all. That means sender has only connection open for 
UDP transport.

I think SIP RFC allow use to implement SIP stack only on UDP or TCP or even 
both. So if the implementation is only with UDP the above approach will fail.

Have any body tried sending reply to TCP port for Cisco ATA or IP phone when 
original message was generated on UDP?
Does it work?

Regards,

Vishal Mathur 
Jabber ID: [EMAIL PROTECTED]
Symantec Corporation
www.symantec.com
_________________________________
Office: +91-20-66067655

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of ? ??
Sent: Thursday, November 15, 2007 2:15 PM
To: [EMAIL PROTECTED]; [email protected]
Subject: Re: [Sip-implementors] How to determine transport to use from 
Routeheader

Hi all.
In addition to below, if the total size of sip message is over a MTU in 
constructing, you have to change the transport to TCP even though the original 
transport was UDP.

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of 라스토기
Sent: Thursday, November 15, 2007 10:33 AM
To: [email protected]
Subject: Re: [Sip-implementors] How to determine transport to use from Route 
header

Hi,
if route has sip then it is UDP, if sips then TLS and sip with transport as TCp 
then TCP.
I hope it helps...
Vipul Rastogi
Engineer, Business Management Team
Telecommunication Network Business
Samsung Electronics CO, LTD
Suwon P.O.BOX 105, 416
Korea 442-600
MO 010-9530-0354

Hi,

 

Can anyone please tell me How to find out the transport protocol to send
the request, when we have to use the 

 

Route header for determining next hop. 

 

Suppose we have a Route header with the value

 

Route: <sip:10.58.2.21:5060;lr>, <sip:10.48.2.40:5061;lr>

 

Now because the first route value contains the lr parameter so the IP
and Port of the next hop will be 10.58.2.21 and 5060 respectively, But

 

How to find out the transport to be used in this case.

 

Regards,

Jitendra.


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