Accepted Solutions
Hello ,
Look like it is clocking issue.
can you go through below details:
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Detecting Clocking Problems
To detect clocking conflicts on a serial interface, look for input errors as follows:
Step 1 
Use the show interfaces serial exec command on the routers at both ends of the link.
Step 2 Examine the command output for CRC, framing errors, and aborts.
Step 3 If either of these steps indicates errors exceeding an approximate range of 0.5 percent to 2.0 percent of traffic on the interface, clocking problems are likely to exist somewhere in the WAN.
Step 4 Isolate the source of the clocking conflicts, as outlined in the following section, “Isolating Clocking Problems.”
Step 5 Bypass or repair any faulty patch panels.
Isolating Clocking Problems
After you determine that clocking conflicts are the most likely cause of input errors, use the following procedure to isolate the source of those errors:
Step 1 Perform a series of ping tests and loopback tests (both local and remote), as described in the section “CSU and DSU Loopback Tests,” earlier in this chapter.
Step 2 Determine which end of the connection is the source of the problem, or whether the problem is in the line. In local loopback mode, run different patterns and sizes in the ping tests (for example, use 1500-byte datagrams). Using a single pattern and packet size may not force errors to materialize, particularly when a serial cable to the router or CSU/DSU is the problem.
Step 3 Use the show interfaces serial exec command, and determine whether input errors counts are increasing and where they are accumulating.
If input errors are accumulating on both ends of the connection, clocking of the CSU is the most likely problem.
If only one end is experiencing input errors, there is probably a DSU clocking or cabling problem.
Aborts on one end suggest that the other end is sending bad information or that there is a line problem.
Regards
mahesh
Hello ,
Look like it is clocking issue.
can you go through below details:
-------------------------------------------------------------------------------------------------------------
Detecting Clocking Problems
To detect clocking conflicts on a serial interface, look for input errors as follows:
Step 1 Use the show interfaces serial exec command on the routers at both ends of the link.
Step 2 Examine the command output for CRC, framing errors, and aborts.
Step 3 If either of these steps indicates errors exceeding an approximate range of 0.5 percent to 2.0 percent of traffic on the interface, clocking problems are likely to exist somewhere in the WAN.
Step 4 Isolate the source of the clocking conflicts, as outlined in the following section, “Isolating Clocking Problems.”
Step 5 Bypass or repair any faulty patch panels.
Isolating Clocking Problems
After you determine that clocking conflicts are the most likely cause of input errors, use the following procedure to isolate the source of those errors:
Step 1 Perform a series of ping tests and loopback tests (both local and remote), as described in the section “CSU and DSU Loopback Tests,” earlier in this chapter.
Step 2 Determine which end of the connection is the source of the problem, or whether the problem is in the line. In local loopback mode, run different patterns and sizes in the ping tests (for example, use 1500-byte datagrams). Using a single pattern and packet size may not force errors to materialize, particularly when a serial cable to the router or CSU/DSU is the problem.
Step 3 Use the show interfaces serial exec command, and determine whether input errors counts are increasing and where they are accumulating.
If input errors are accumulating on both ends of the connection, clocking of the CSU is the most likely problem.
If only one end is experiencing input errors, there is probably a DSU clocking or cabling problem.
Aborts on one end suggest that the other end is sending bad information or that there is a line problem.
Regards
mahesh
