Subject: [rohc] context update in case of packet loss

From: [email-masked]
Date: Tue, 11 Feb 2003 11:43:42 +0530

Hi
Can some one tell me how the packet is updated on the decompressor side
when there is packet loss in the transit. I would really appreciate some
pointers in this regard.

thanks
alphonse

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From: "Ashok Kumar" <[email-masked]>
Date: Tue, 11 Feb 2003 11:56:35 +0530

Hi Alphonse,

When a packet is lost in transit, decompressor will not receive the
packet. So nothing needs to be done at decompressor. The subsequent
packets received by decompressor will indicate how the context should be
updated at decompressor.

-Ashok

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] 
Sent: Tuesday, February 11, 2003 11:44 AM
To: [email-masked]
Subject: [rohc] context update in case of packet loss

Hi

thanks
alphonse

This message is proprietary to Hughes Software Systems Limited (HSS) and
is
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It
may contain privileged or confidential information and should not be
circulated or used for any purpose other than for what it is intended.
If
you have received this message in error, please notify the originator
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From: [email-masked]
Date: Tue, 11 Feb 2003 16:11:48 +0530

Hi Ashok
Please can you tell me where exactly does the compressor and decompressor
fit in a traditional layer 7 model. My understanding is that it fits
between layer 2 (data link layer) and layer 3 (network layer or IP). If
that is the case, if a solution has to be implemented then dont we have to
tweak into layer2, layer3 implementation of the stacks on respective
platforms??
This doubt is specific to wireline implementatio of ROHC.
since IP packet is also compressed. how is the data transmission done
incase there is a router or some entity in between which doesnt support
ROHC. Basically the question is should all the entities in the route
support ROHC or is it suffcient if ROHC is implemented just on the
endpoints??

i would be really glad to hear back from you

thanks
alphonse

"Ashok Kumar" <[email-masked]> on 02/11/2003 11:56:35 AM

To:   alreddy, [email-masked]
cc:

Subject:  RE: [rohc] context update in case of packet loss

Hi Alphonse,

-Ashok

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Tuesday, February 11, 2003 11:44 AM
To: [email-masked]
Subject: [rohc] context update in case of packet loss

Hi

thanks
alphonse

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From: "kamaldeep dham" <[email-masked]>
Date: Tue, 11 Feb 2003 16:29:45 +0530

I guess, RFC 3095 does not specify, whether ROHC is a layer concept
between L2 and L3 or 
It's a sub layer in side L2 (data link). With respect to PDCP, ROHC
should be a part
of PDCP implementation. Basically your ROHC implementation will provide
rcv and snd
iinterfaces to the PDCP where it receives & sends IP packets. 

In my understanding ROHC is designed for point to point links only.
That's why you can have redundant information in the IP header.

-Kamal

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] 
Sent: Tuesday, February 11, 2003 4:12 PM
To: Ashok Kumar; [email-masked]
Subject: RE: [rohc] context update in case of packet loss

Hi Ashok
Please can you tell me where exactly does the compressor and
decompressor fit in a traditional layer 7 model. My understanding is
that it fits between layer 2 (data link layer) and layer 3 (network
layer or IP). If that is the case, if a solution has to be implemented
then dont we have to tweak into layer2, layer3 implementation of the
stacks on respective platforms?? This doubt is specific to wireline
implementatio of ROHC. since IP packet is also compressed. how is the
data transmission done incase there is a router or some entity in
between which doesnt support ROHC. Basically the question is should all
the entities in the route support ROHC or is it suffcient if ROHC is
implemented just on the endpoints??

thanks
alphonse

Hi Alphonse,

-Ashok

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Tuesday, February 11, 2003 11:44 AM
To: [email-masked]
Subject: [rohc] context update in case of packet loss

Hi

thanks
alphonse

This message is proprietary to Hughes Software Systems Limited (HSS) and
is intended solely for the use of the individual to whom it is
addressed. It may contain privileged or confidential information and
should not be circulated or used for any purpose other than for what it
is intended. If you have received this message in error, please notify
the originator immediately.  If you are not the intended recipient, you
are notified that you are strictly prohibited from using, copying,
altering, or disclosing the contents of this message.  HSS accepts no
responsibility for loss or damage arising from the use of the
information transmitted by this email including damage from virus.

Information contained in this E-MAIL being proprietary to Wipro Limited
is 'privileged' and 'confidential' and intended for use only by the
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From: "Ashok Kumar" <[email-masked]>
Date: Tue, 11 Feb 2003 16:35:58 +0530

Hi Alphanso,

Please see the comments inline.

Regards,
Ashok

Hi Ashok
decompressor
that is the case, if a solution has to be implemented then dont we have
to

Ashok >>  Since ROHC involves compression of Network Level PDU, so
certainly the compression can only be done once you have got network
level PDU from the upper layer. ROHC can be implemented as part of Data
Link Layer. How you implement ROHC to fit in a particular stack is
responsibility of the specific implementaion. >>

Ashok >> ROHC is primarily aimed for Point to Point Links. Both ends of
link should support ROHC. >>

thanks
alphonse

Hi Alphonse,

-Ashok

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Tuesday, February 11, 2003 11:44 AM
To: [email-masked]
Subject: [rohc] context update in case of packet loss

Hi

thanks
alphonse

Information contained in this E-MAIL being proprietary to Wipro Limited
is
'privileged' and 'confidential' and intended for use only by the
individual
 or entity to which it is addressed. You are notified that any use,
copying
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manner
whatsoever is strictly prohibited.

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From: "Lars-Erik Jonsson (EAB)" <[email-masked]>
Date: Tue, 11 Feb 2003 12:38:39 +0100

> decompressor fit in a traditional layer 7 model. My understanding
> is that it fits between layer 2 (data link layer) and layer 3
> (network layer or IP). If that is the case, if a solution has to
> be implemented then dont we have to tweak into layer2, layer3
> implementation of the stacks on respective platforms??

I would say that ROHC is "on top of" layer 2, i.e. the layer 2
technology must provide means to support ROHC. In the ROHC WG, we
have defined this for PPP as L2, see RFC 3241, which is the only
L2 protocol we have considered us (the IETF) responsible for. Take
a look at RFC 3241, it is a good example of L2 support for ROHC.

BR
/L-E