Subject: [rohc] Rohc over IP tunnel

From: [email-masked]
Date: Mon, 06 Apr 2009 01:25:35 +0200

Hello All

We have submitted a new draft to IETF. This document proposes a method  
to use ROHC over IP tunnel.

The draft is available at
http://tools.ietf.org/search/draft-rawat-hc-tunneling-00

Since we would like to continue this work further, it will be  
interesting for us to receive feedback on the draft and initiate  
discussion at IETF.

Please let us know your opinion.

Regards
Priyanka Rawat

IT/TELECOM Bretagne

---

From: "Lars-Erik Jonsson" <[email-masked]>
Date: Mon, 6 Apr 2009 09:25:14 +0200

This submission does not make much sense to me, as ROHC already provides 
mechanisms for compression of tunneling headers (outer headers). To support 
tunneling was a requirement stated already by RFC 3096, and thus addressed 
by RFC 3095. Since then, compression of IP tunneling headers has been 
provided by all ROHC profiles.

Can you explain what you mean ROHC is missing, not doing correcty or 
efficiently, or by which other means you think ROHC is not sufficient in 
terms of IP tunnel compression?

BR
/L-E

----- Original Message ----- 
From: <[email-masked]>
To: <[email-masked]>
Cc: <[email-masked]>
Sent: Monday, April 06, 2009 1:25 AM
Subject: [rohc] Rohc over IP tunnel

> Hello All
>
> We have submitted a new draft to IETF. This document proposes a method  to 
> use ROHC over IP tunnel.
>
> Since we would like to continue this work further, it will be  interesting 
> for us to receive feedback on the draft and initiate  discussion at IETF.
>
> _______________________________________________
> Rohc mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/rohc

---

From: [email-masked]
Date: Tue, 07 Apr 2009 01:15:02 +0200

Hello Lars-Erik

The main differences are that the proposed solution, TuCP does not  
compress outermost IP header (IPout) and it focuses on packet  
reordering problem as there can be many routers between the compressor  
and decompressor.

The proposed draft defines header compression profiles for general  
tunneling mechanisms. For example, in case of L2TP tunnel, ROHC does  
not define a profile for compressing, IP/UDP/L2TP/PPP headers.  
Moreover, in this example, IP is not to be compressed as it is  
required for routing the packet to the final destination.

If we consider both the inner and outer encapsulation which is

IPout/UDP/L2TP/PPP/IPin/UDP/RTP,

currently, there is no profile defined in ROHC to compress this entire  
encapsulation. The ROHC RTP profile can be used to compress part of  
the encapsulation which is IPin/UDP/RTP. However, there is a problem  
of packet reordering in IP tunnels which needs to be addressed when  
ROHC (RFC 3095) is used over IP tunnels.

The proposed mechanism, TuCP, manages out of order packets, and thus  
it enables the use of ROHC for inner IP packet headers efficiently.

Hope that answers your queries.

Regards

Priyanka Rawat
IT/TELECOM Bretagne

Lars-Erik Jonsson <[email-masked]> a écrit :

> This submission does not make much sense to me, as ROHC already  
> provides mechanisms for compression of tunneling headers (outer  
> headers). To support tunneling was a requirement stated already by  
> RFC 3096, and thus addressed by RFC 3095. Since then, compression of  
> IP tunneling headers has been provided by all ROHC profiles.
>
> efficiently, or by which other means you think ROHC is not  
> sufficient in terms of IP tunnel compression?
>
> BR
> /L-E
>
>
> ----- Original Message ----- From: <[email-masked]>
> To: <[email-masked]>
>> We have submitted a new draft to IETF. This document proposes a  
>> method  to use ROHC over IP tunnel.
>>