You may want to get a hold of the Bellcore GR 253 SONET generic standards doc or other SONET Bellcore GR docs relating to switching times and the equivalent SDH ITU-T standards (which I am not sure what it is). On the SDH side you may want to start with ITU-T G.783.
Hope this helps pb --- bergenpeak wrote: > Sorry for the OT post. Figured I'd float this here > and see if > any one might be able to help. > > Does anyone really know where the 50 ms SONET > detect/fail-over time > comes from? > I've heard many answers, but none seem to be > verifiable. I'm looking > for pointers to docs which explain where or what > drove the 50 ms number. > > I've heard that: > > * 50 ms was a requirement to support voice. The > way this one is told > is that > more than 50 ms of noise/nothingness seriously > impacts MOS. Not sure > I buy that. > > > * Old telco switches would go bonkers if many T1's > started to flap > a the same time. 50ms at the SONET level > prevented the T1s from > flapping. > > * others, etc. > > Again, looking for docs / pointers which details the > answer. > > Thanks [EMAIL PROTECTED] __________________________________________________ Do you Yahoo!? Faith Hill - Exclusive Performances, Videos & More http://faith.yahoo.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=55708&t=55700 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]