On Mon, 2003-06-30 at 13:07, Don Pobanz wrote: > Just some clarification here.
Thank you for the corrections. > On Monday, June 30, 2003 12:04 AM, Steven Critchfield > [SMTP:[EMAIL PROTECTED] wrote: > > > > As for slips and bipolar violations... > > T1s are just high speed serial lines. A sleep is when you loose sync > > with the far side and when you see a 1 come across the line, you may > > not > > know which bit it was for. > > A slip is when one end of the circuit is running according to a clock > that is faster than the other end. Once the capacity of the buffer > overflows a frame (193 bits) is discarded if the far end clock is > running faster or a frame is repeated if the far end clock is running > slower. > > It is called OOF (out of Frame) if sync is lost with the far end and > the system must retrain to find the framing bits. > > > > > This would be a slip. Bipolar violations are > > a part of the signaling, but can also be errors. > > I believe the word 'signaling' was used here by mistake. Bipolar > violations are not related to signaling. In the B8ZS case they are > intentionally used as part of the line coding. > > > A T1 alternates the > > polarity of the 1 pulse to allow the line to run farther on lower > > voltage. Just doing alternating polarity is AMI or Alternate Mark > > Inversion. A bipolar violation is when a bit is received as the same > > polarity as the last bit received. On an AMI line a bipolar violation > > is > > an error. On a B8ZS, bipolar violations are intentionally inserted > > into > > the line to keep the line from transmitting too many 0's in a row and > > contributing to a slip. > > Too many 0's don't contribute to a slip but contribute to a LOF (loss > of frame). > > > When set for B8ZS the "error" is somewhat > > expected and ignored. > > Some errors are expected and the expected errors do not count as a > bipolar violation. There can also be bipolar violations on a B8ZS line > coded T1. > > Don Pobanz > _______________________________________________ > Asterisk-Users mailing list > [EMAIL PROTECTED] > http://lists.digium.com/mailman/listinfo/asterisk-users -- Steven Critchfield <[EMAIL PROTECTED]> _______________________________________________ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
