Cell Relay Archive

[heard@vvnet.com (C. M. Heard/VVNET, Inc.)]

On Mon, 28 Jul 1997 12:51:53 EDT Hui Wang <hwang@akira.hitel.com> wrote:
>
> I am trying to get specs on DS1 over ATM using PLCP. I want to
> get explicit PLCP format as I have to generate the byte stream
> myself. The Bellcore specs (GR-1110-CORE, TR-NWT-001112) direct me to
> IEEE P802.6_DS1_PLCP/D4, which published in 1991. I am wondering
> if new version is availiable and what's the corresponding
> ATM Forum standards.

The IEEE spec for the DS1 PLCP is IEEE Std 802.6c-1993.  It was published in
an 802.6 supplement in March 1994 (ISBN 1-55937-344-X).  Note, however, that
the ATM Forum DS1 Physical Layer Specification Version 1.0 (af-phy-0016.000,
September, 1994) does not call for using the SMDS/802.6 DS1 PLCP to which
you refer.  Instead a contiguous 1.536 Mbps stream of cells is mapped
directly into the DS1 payload.  This is done in such a way that octet
boundaries are preserved, that is, the first payload bit following each
DS1 framing bit is the first bit of an octet of some cell.

The ATM Forum recently started keeping approved specs on-line on their
public ftp server.  The URLs for this spec are:

ftp://ftp.atmforum.com/pub/approved-specs/af-phy-0016.000.doc  MS Word
ftp://ftp.atmforum.com/pub/approved-specs/af-phy-0016.000.pdf  Adobe Acrobat

Additional formats (ps, rtf, txt) may also be available.

I do know that some vendors (e.g., ADC-Kentrox, in their AAC-1) did support
PLCP-mapped DS1 ATM at one time, but I don't know if this is still the case.
Perhaps someone familiar with current products will comment on this.

Mike
--
C. M. Heard/VVNET, Inc.
heard@vvnet.com