Ethernet over SDH tutorial/concepts.

Vinay Bannai bannai at pacbell.net
Tue Dec 6 07:28:43 UTC 2005


Sorry for the delay in posting, but I thought I would add couple of
comments here. 

Ethernet transport over SONET/SDH can be done in several ways. 

- Frame mapped GFP encapsulation (ITU-T G.7041). Here is a white paper
that is pretty detailed
(http://www.pmc-sierra.com/cgi-bin/document.pl?docnum=2020296)

- You can also do it using X.86 (LAPS)
(http://www.ieee802.org/3/ad_hoc/etholaps/public/docs/opening_report_030
1.pdf)

As far RPR goes, RPR is a MAC (802.17) and it is pretty much agnostic of
the PHY layer. RPR can run on dark fiber or on a SONET/SDH path layer.
RPR is not an encapsulation mechanism for Ethernet packets over SONET.
It is at the MAC layer and provides additional functionality like
running the nodes in a ring, oversubscription, fairness, QoS and
resiliency against node and fiber failures. Here is a tutorial about
RPR.
(http://www.simula.no/departments/networks/.artifacts/commagMarch04)  

Regards,
Vinay Bannai

-----Original Message-----
From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu] On Behalf Of
Michael K. Smith
Sent: Wednesday, November 30, 2005 3:29 PM
To: Paul Khavkine; MARLON BORBA
Cc: nanog at merit.edu
Subject: RE: Ethernet over SDH tutorial/concepts.


Hello:

It could also just be a direct Ethernet path over a SONET circuit
without the inherent 802.17 resiliency.  You should ask them for more
information about their infrastructure.  Are they using 802.17?  Is it
path-protected on the SONET side?

Mike

-----Original Message-----
From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu] On Behalf Of
Paul Khavkine
Sent: Wednesday, November 30, 2005 12:05 PM
To: MARLON BORBA
Cc: nanog at merit.edu
Subject: Re: Ethernet over SDH tutorial/concepts.



This is most likely something like RPR/802.17 which is Ethernet over
Sonet/SDH.


Cheers
Paul

On Wed, 30 Nov 2005, MARLON BORBA wrote:

>
>Dear NANOGers,
>
>We are in process of choosing a new corporate ISP for our company. One
of them offered us connection to their backbone using Ethernet over SDH.
I'd like to find some introductory texts or prospects about that
technology and some advice about its pros/cons when compared to
traditional data circuits.
>
>
>
>Abraços,
>Marlon Borba, CISSP.
>--
>GTER 20/GTS 02.05 - Participe!
>http://eng.registro.br/gter20/prog.html
>--
>
>

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Paul Khavkine
Networks/Systems Planning and Engineering
DISTRIBUTEL Communications.
740 Notre Dame West, Suite 1135
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