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Re: [STDS-802-16] Clarification on the CRC in the MAC PDU



John,

According to my understanding, and according to the change we
made in the PDU construction SDL, if CRC is present, the
length will include the CRC, and therefore will be calculated
by the CRC.

Regards,
Itzik.

> -----Original Message-----
> From: owner-stds-802-16@LISTSERV.IEEE.ORG
> [mailto:owner-stds-802-16@LISTSERV.IEEE.ORG]On Behalf Of
Jonathan Labs
> Sent: Thursday, March 25, 2004 19:29
> To: STDS-802-16@LISTSERV.IEEE.ORG
> Subject: [STDS-802-16] Clarification on the CRC in the MAC
PDU
>
>
> Could someone please clarify an ambiguity I am seeing
regarding
> the MAC PDU
> and the CRC?  When present, is the CRC considered part of
the MAC
> PDU or is
> it like and appendix?
>
> Here are the sections in P802.16-REVd/D3, that suggest on
or the other
> interpretation:
> --Section 6.4.2, page 53, line 15, "A MAC PDU may contain a
CRC, as
> described in 6.4.3.5.".
> --Page 54, Table 5, Row 1: CI Description: "1 = CRC is
appended
> to the PDU."
> --Section 6.4.3.5 CRC calculation: "A service flow may
require
> that a CRC be
> appended to each MAC PDU carrying data for that service
flow
> (11.13.14). In
> this case, a CRC, as defined in IEEE 802.3, shall be
included in each MAC
> PDU..."
>
> The reason for differentiating is because the LEN field in
the MAC header
> (Table 5) is "The length in bytes of the MAC PDU including
the
> MAC header."
>
> So I guess the real question is, does the LEN field include
the length of
> the CRC when present?
>
> Thanks for your help.
>
> Jon
>