Subject: draft-martini-l2circuit-encap-mpls

From: "Yi Chu" <[email-masked]>
Date: Wed, 14 Mar 2001 09:31:34 -0500

Hi, Martini gangs:
What is your take on getting rid of padding with AAL5 PDU?  In frame mode
encap for AAL5, we can get rid of padding bytes to the extent that the
resulted packet aligns with 32-bit word, and keep the AAL5 trailer at the
end.  There is no need to pad to multiple of 48 bytes.  Is this an option in
the consideration?

yi

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From: "Yi Chu" <[email-masked]>
Date: Wed, 14 Mar 2001 10:29:06 -0500

I interpret AAL5 CPCS-PDU to be CPCS-SDU plus padding according to I.363.5.
The term CPCS-PDU payload is what probably should be used instead of
CPCS-PDU, to mean user data without padding.  Here is a quote from I.363.5
(5/96) section  9.2.1.2

'The CPCS-PDU trailer together with the padding field and the CPCS-PDU
payload comprise the CPCS-PDU.'

AAL5 trailer is needed IMO mainly to transport CPCS-UU octet.

yi

-----Original Message-----
From: Dan Tappan [mailto:[email-masked]]
Sent: Wednesday, March 14, 2001 9:42 AM
To: [email-masked]
Cc: [email-masked]; [email-masked]; [email-masked]; [email-masked]
Subject: Re: draft-martini-l2circuit-encap-mpls

>end.  There is no need to pad to multiple of 48 bytes.  Is this an option
in

To tell you the truth, my interpretation of the draft was that the padding
should _not_ be transported. section 4.2.1 says "No AAL5 trailer is
transported.", which means that you lose the AAL5 length word, and so
should probably remove the AAL5 padding.  I certainly don't see the draft
as requiring carrying the AAL5 padding.. I'm pretty sure our implementation
removes it.

But, I don't have a problem with changing the draft to either say that AAL5
padding MUST be removed, or that it MAY/SHOULD be removed.

I don't see any benefit to carrying the AAL5 trailer.

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From: Dan Tappan <[email-masked]>
Date: Wed, 14 Mar 2001 09:41:59 -0500