Hi group. I am using the CISCO CIM for ISDN. There is talk about line transition and line-level changes and how the linecode command prvent the loss of synchronization. Can some one explain this better. I have pasted an excerpt from CIM (Cisco Interactive Mentor) Thanks Omer "Communications devices use various methods for encoding the stream of ones and zeros on a communication line. The major differences are in how often the different methods force a line transition from a low voltage to a high voltage and vice versa, and how this is done. Because continuous ones or zeros may be represented on the line by non-varying signals, and the clocking at both ends may have some slight variation, there is a danger that a loss of synchronization will occur at the bit level on the line. In order to make it easier for the destination machine to be sure that it is sampling the line for bits at the correct time, the sending machine will force line-level changes every time there are some number of bits that flow without causing a line transition. This allows the receiving machine to stay in sync by reducing the likelihood that clock drift from end to end will cause the receiver to incorrectly sample the line at the wrong time. Using the linecode command, you can define the linecode as either alternate mark inversion (AMI) or binary 8-zero substitution (B8ZS). AMI is the default. In this lab, use the linecode b8zs command. When configuring an actual router, you will need to contact your local telephone service provider to determine the line code requirements of the physical T1 line. The T1 controller values must match the service provided by the telephone company. Exit to privileged EXEC mode and use the show controller t1 0 command to view the controller configuration. Note that the linecode has changed to B8ZS. Also notice that there is a field titled "Line Code Violations." The show controller t1 0 command logs errors in 15-minute intervals, with the current interval at the top. Tip: If line code violations are incrementing in the current interval, check to see that you have correctly configured the line code at both ends. Don't forget that a bad line or bad equipment can cause various fields to increment spuriously because the bit stream is corrupted." Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=5353&t=5353 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
