Link up-down (flapping) quite often .,,E1-link... and many runts

[sirisak.c]

The network that I have configured...,

center-->7206 VXR 8 E1 ports connect to 3640 with E1 port.

The problem is link is up-down easily 40 times for a day.

I found the error,all are input error and almost of all are runts,and the other are abort and CRC.

I know the meaning of runts ,but I never known from cisco ,how to solve runts problem......???????

The service provider confirms that the quality of link is ok also.,,,

Anyway ,I don't really believe in the quality of link of this service provider,cause I can copare it to another link from the other service provider..,,,

My really serious problem is how to solve runts problem.(it occurs at 7200 ,no any error at 3640).

Hope somebody can help me for this problem .., and

Thanks in advance.

[doug.lockwood]

If your interface is up-down 40 times per day, you should concentrate on that. The runts will probably disappear if you fix the problem.

The first thing to examine is timing on the e-1.

If more than one device clocks the e-1, drifting clocks would take the line up and down many times, and corrupt many packets in the process.

It sounds like both the telco and the 7200 are providing clock. Changing the 7200 to external clocking would be the probable fix.

Regards;

Doug