Incorrect Line Configuration

If you are receiving lots of Abort frames and frames with CRC errors, this is an indication of a missmatched line configuration.

If this is a back-to-back connection for local testing:

Make sure that you are using the correct back-to-back cable and that the electrical interface is set correctly. For RS232 back-to-back, you should be using the 602 cable. For V.35 back-to-back, you should be using the 610 or 622 cable.One end of the back-to-back system must be configured for Internal Clocking and the other for External Clocking. The back-to-back cable is NOT symetrical, the end marked "CLOCKED END" Must be used on the Internally Clocked side. Check that both ends of the system are set for the same electrical interface, either RS232 or V.35.

If this is  a system with an external DSU/CSU unit:

• Make sure that your DSU/CSU configuration exactly matches the Telco line configuration. A common problem is to have missmatching numbers of DS0s configured.
• Have the Telco to do a round trip test on the system, including the DSU/CSU.

If this is a system with an integral DSU/CSU (S514/FT1 or S508/FT1 card):

• If this is a full T1 line, the card default configuration should be OK. Otherwise use the cfgft1 or monitor program to make sure that your DSU/CSU configuration exactly matches the Telco line configuration. A common problem is to have missmatching numbers of DS0s configured.
• Have the Telco to do a round trip test on the system, including the DSU/CSU.