@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... _______________________________________________ Skunkworks mailing list Skunkworks@lists.my.co.ke http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks Other services @ http://my.co.ke <http://my.co.ke/> Other lists ------------- Announce: http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks-announce Science: http://lists.my.co.ke/cgi-bin/mailman/listinfo/science kazi: http://lists.my.co.ke/cgi-bin/mailman/admin/kazi/general _______________________________________________ Skunkworks mailing list Skunkworks@lists.my.co.ke http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks Other services @ http://my.co.ke <http://my.co.ke/> Other lists ------------- Announce: http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks-announce Science: http://lists.my.co.ke/cgi-bin/mailman/listinfo/science kazi: http://lists.my.co.ke/cgi-bin/mailman/admin/kazi/general