Doug, I asked a couple of our transmission engineers about this, and neither could think of a specific Bellcore spec. for this. However, if you think it through, the yellow alarms should _always_ be propagated in both directions, as a T1 (DS1) connection is in reality a connection from one single endpoint to another single endpoint, often referred to "near-end" and "far-end" (depending on which end you are sitting at, of course!).
Let's consider the case of a pair of DS1 channel banks, which are _not_ directly connected together--the line goes through a DS3 mux. If the mux is simply connecting the two DS1 channel banks together, it _should_ pass the yellow alarms through transparently, as if the channel banks were connected directly with copper cable. If the mux is doing elaborate "drop & insert" manipulation of DS0 channels for multiple DS1 feeds, there may not _be_ a physical DS1 channel bank at the "far end" for a given "near-end" DS1 channel bank! In this case, the DS3 mux _itself_ will essentially be the "other end" for the DS1 channel bank, and the DS3 mux would have no need to pass the yellow alarms on to another device. - John -------------------------------------- At 11:29 AM 11/20/96 -0500, you wrote: >Does anyone know a Bellcore standard that states how far >an alarm is sent up and downstream? > >The basic question is: > >Does a yellow alarm propagate through a telephone network? > >******************************************************* >Doug McKean >[email protected] >------------------------------------------------------- >The comments and opinions stated herein are mine alone, >and do not reflect those of my employer. >------------------------------------------------------- >******************************************************* > ------------------------------------------------------------------ John Combs, Senior Project Engineer, ITS/TestMark Laboratories Email: [email protected] URL: http://www.testmark.com ------------------------------------------------------------------
