RE: [rohc] Constant IP-ID in the RTP Profile(0x0001)

Biplab,

I would not recommend such a behavior since that break compression
transparency, which is bad. You can't just assume that the endpoint
does ignore the IP-ID although that is the likely behavior.
For 3095-based profiles, a zero IP-ID should be compressed using RND=1.

/Kristofer

Biplab Sarkar <mailto:bsarkar@starentnetworks.com> wrote on den 3
januari 2008 12:48 :

> * PGP Signed by an unknown key: 01/03/2008 at 12:47:59 PM
> 
> Hi Gangadharan,
> 
> IP-ID can be over-written with the value of RTP-SN at the
> compressor before compression for all "un-fragmented" IPv4
> packets. This will enhance the compression.  Since IP-ID is
> used in IP fragmentation, we can basically ignore its real
> value for "un-fragmented" IP packets.
> 
> Thanks & Regards,
> Biplab Sarkar
> 
> On Thu, 2008-01-03 at 17:07 +0530, Gangadharan G, TLS-Chennai wrote:
> 
> 	Hi All,
> 
> 
> 
> 	In the Linux Suse 10.1 machine, the value of the IP-ID
> in the IPv4 header is always zero (i.e., constant) in the
> entire IP datagrams.
> 
> 	The IP-ID Encoding, as per RFC 3095, of the RTP profile
> doesn't handle this case (constant IP-ID).
> 
> 
> 
> 	Also this issue had been discussed in the mailing list.
> 
> 	http://www1.ietf.org/mail-archive/web/rohc/current/msg01502.html
> 
> 
> 
> 	When I searched in the Internet, I found few proposed
> solutions (yet to read them).
> 
> 
> (draft-ietf-rohc-rfc3095bis-improvements-03.txt,
> draft-kapoor-rohc-rtp-new-requirements-00.txt
> <http://www.potaroo.net/ietf/idref/draft-kapoor-rohc-rtp-new-r
equirements/rfcmarkup?repository=/away/ietf&url=/away/ietf/all-ids/draft
->
kapoor-rohc-rtp-new-requirements-00.txt> , 
> 
> 	 RFC 3643 -- A Compression Profile for IP)
> 
> 
> 
> 	Please let me know the solution/standard that everyone
> is following for this issue in the RTP Profile.
> 
> 
> 
> 	Thanks,
> 
> 	Gangadharan
> 
> 
> 
> 
> DISCLAIMER:
> --------------------------------------------------------------
> ---------------------------------------------------------
> 
> The contents of this e-mail and any attachment(s) are
> confidential and intended for the named recipient(s) only.
> It shall not attach any liability on the originator or HCL or
> its affiliates. Any views or opinions presented in
> this email are solely those of the author and may not
> necessarily reflect the opinions of HCL or its affiliates.
> Any form of reproduction, dissemination, copying, disclosure,
> modification, distribution and / or publication of
> this message without the prior written consent of the author
> of this e-mail is strictly prohibited. If you have
> received this email in error please delete it and notify the
> sender immediately. Before opening any mail and
> attachments please check them for viruses and defect.
> 
> --------------------------------------------------------------
> ---------------------------------------------------------
> 
> 
> 
> 	_______________________________________________
> 	Rohc mailing list
> 	Rohc@ietf.org
> 	https://www1.ietf.org/mailman/listinfo/rohc
> 
> * Unknown Key
> * 0x6D543EEE (L)

_______________________________________________
Rohc mailing list
Rohc@ietf.org
https://www1.ietf.org/mailman/listinfo/rohc