Subject: RE: [rohc] RE: sigcomp issue zliu-3: cannot recovery from decompr ession failure ?

From: "Price, Richard" <[email-masked]>
Date: Thu, 25 Apr 2002 13:41:55 +0100

Hi,

RESET messages are possible within the current SigComp-06 draft:
just send a message that sets the state_memory_size to 0 and the
receiver will know that all of the dynamic states have been lost.

A RESET message will normally need to be sent piggybacked onto an
application message, otherwise the receiving endpoint will simply
discard it. However if security is provided by the lower layer
then standalone RESET messages are currently allowed by SigComp
(although the issue of standalone messages is still being discussed
as part of cabo-11).

Regards,

Richard

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]]
> Sent: Wednesday, April 24, 2002 8:32 PM
> To: [email-masked]; Price, Richard
> Cc: [email-masked]; [email-masked]
> Subject: RE: [rohc] RE: sigcomp issue zliu-3: cannot recovery from
> decompression failure ?
> 
> 
> Hi,
> 
> Can we allow a standalone RESET message from a decompressor
> to its peer compressor indicating that it has lost the
> dynamic states during a crash, and thus ask the compressor
> to restart with only static states? Since security is
> an obvious concern, let's assume the question is about 
> an environment that you have secure channel under SigComp.
> 
> Of course, one solution is to let the application to signal 
> the crash. But what if implementer does not want to change
> the existing signalling (say SIP) message flow? Then it seems
> that sending this signal at SigComp level will make the 
> addition of SigComp much simpler and easier.
> 
> (This is actually a feedback I received from my colleague in 
> 3GPP even after I had explained the current thinking in IETF).
> 
> RB,
> Zhigang
>