Subject: [Fwd: Re: AD review of draft-ietf-pwe3-cw-01.txt - comment 5]

From: Stewart Bryant <[email-masked]>
Date: Mon, 21 Feb 2005 07:52:27 +0000

Should have been sent to list as well

Stewart

-------- Original Message --------
Subject: Re: [PWE3] AD review of draft-ietf-pwe3-cw-01.txt - comment 5
Date: Sun, 20 Feb 2005 21:56:31 +0000
From: Stewart Bryant <[email-masked]>
To: Sasha Vainshtein <[email-masked]>
References: <AF5018AC03D1D411ABB70002A5091326015E1BA6@TLV1>

Sasha Vainshtein wrote:

> Stewart and all,
> Please note that TDM PWs do not require this mechanism
> because the size of the PW packet is defined during the
> setup.
> 
> So I suggest to change MUST to SHOULD and add the appropriate qualifier
> e.g. "TDM PWs represent a known exception becaues their packets all have 
> the same size defined at the PW setup". A reference to Section 6.1
> of the TDM Requirements document (which states that the common PWE3
> requirement to support variable length PDUs does not apply to TDM
> PWs) would be also in place ere.

Perhaps something like:

"If the PW payload size could be less than 64 bytes, and is
either variable or unknown to the CE-bound PE, the length field
is used to indicate the size of a PW payload that might have been
padded to the minimum Ethernet MAC frame size during its transit
across the PSN. If the MPLS payload (defined as the PW-CW + the
PW payload + any additional PW headers) is less than 63 bytes,
the length MUST be set to the length of the MPLS payload.
Otherwise the length MUST be set to 0."

I think that covers both TDM and ATM.

Stewart