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RE: [802.3ae] Wan Interface Sublayer




Ben,

The EoS you are talking about is the LAPS version of EoS. There is also a
GFP (Generic Frame Protocol) version of EoS which was developed in T1X1.5
and is moving into ITU. That uses a frame based encoding with a header
containing a length and a CRC check on the header and the x43+1 scrambler.
This method of framing was proposed to 802.3ae but the 64B/66B was chosen
instead.

GFP provides two methods for mapping Ethernet frames.
 In the frame mapping, an Ethernet frame is mapped into a GFP frame.
 In the transparent mapping, the GFP frame contains groups of 8B/10B
code-groups mapped into a 64B/65B code with a CRC. The transparent mapping
is defined for use with 1 Gbit/s Ethernet and with Fibre Channel. It is not
intended for use at 10 Gbit/s because the WIS provides similar
functionality. There is discussion of extending transparent mapping to cover
4B/5B for 100 Mbit/s operataion.

Regards,
Pat


-----Original Message-----
From: Ben Brown [mailto:bbrown@xxxxxxxx]
Sent: Thursday, August 16, 2001 4:52 AM
To: Ayers Mike
Cc: 'stds-802-3-hssg@xxxxxxxx'
Subject: Re: [802.3ae] Wan Interface Sublayer

Mike,

The major differences are:
  EoS uses byte stuffing and x43+1 scrambling just
  like HDLC/POS.

  802.3ae uses 64B/66B encoding and 1+x39+x58 scrambler.

Both fill the payload area of a SONET frame.

Regards,
Ben

"Ayers, Mike" wrote:
> 
>         Hello all,
> 
>         I'm still a little confused.  Could someone kindly tell me what
the
> differences are between the 10Gb/s Wan Interface Sublayer and a
> (hypothetical) Ethernet-over-10 Gb/s SONET implementation?
> 
>         Thanks,
> 
> /|/|ike /+yers
> Editor
> IETF Wan Interface Sublayer MIB


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