@John

Remember that of the 270 columns, 9 columns are section overheads. So if we use the calculation below;

9*261*8*8000=150336000, this is only with the RS and MS section removed if you remove the VC4 overhead then it will be lower.

David

From: skunkworks-bounces@lists.my.co.ke [mailto:skunkworks-bounces@lists.my.co.ke] On Behalf Of John Doe
Sent: Thursday, October 01, 2009 2:46 AM
To: Skunkworks Forum
Subject: Re: [Skunkworks] For all Transmission Network Ethusiasts - 100 Petabits/second.kilometer

@ David,

An SDH frame is transmitted byte-serially i.e 8 bits at a time.

One frame lasts for 125 microseconds hence there are 8000 frames per second.

The frame structure consists of 9 rows and 270 columns.

Doing the maths we get 9x7x8x8000=155520000 bits per sec.

i.e 155.52 Mb/s. This is an ITU-T standard (G.707 i think) so anything else is just noise :-)!!!

Probably the confusion comes from Mapping the PDH signals; American ANSI standard 1.5,6,45 (T1,T2,T3) or the European ETSI standard 2,34,140 (E1,E3,E4) or the SONET STS signal to the SDH containers.

On Thu, Oct 1, 2009 at 12:05 AM, David Kariuki <david.kariuki@kdn.co.ke> wrote:

Speaking of which, can anyone here clarify the exact capacity of an STM1. We
usually have these three 155, 145 or 126Mb used in alternating contexts

David

-----Original Message-----
From: skunkworks-bounces@lists.my.co.ke
[mailto:skunkworks-bounces@lists.my.co.ke] On Behalf Of John Gitau
Sent: Wednesday, September 30, 2009 8:49 PM
To: Skunkworks Forum
Subject: Re: [Skunkworks] For all Transmission Network Ethusiasts - 100
Petabits/second.kilometer

:-)) 155 lasers:- think someone wanted a rhyme with STM-1's
capacity..incidentallly the same lab was very instrumental here as
well...
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