Hello all;

I have seen this a few time and need help explaining it:

I have two 2500 routers, separated by 2 T1-lines. Each router is attached by a single serial line to a multiplexer that connects to the 2 T1 lines.

Now, everything works fine, the throughput is exactly as it should be, but one of the interfaces sometimes shows double the outgoing bandwidth and does not match the incoming rate at far end.

Here are some examples:

First, what I would call Normal:

Near router:

5 minute input rate 1736000 bits/sec, 210 packets/sec

5 minute output rate 2650000 bits/sec, 267 packets/sec

Far Router:

5 minute input rate 1394000 bits/sec, 133 packets/sec

5 minute output rate 2891000 bits/sec, 340 packets/sec

Then I have the rates I do not understand:

Near router:

5 minute input rate 24000 bits/sec, 46 packets/sec

5 minute output rate 4741000 bits/sec, 395 packets/sec

Far Router:

5 minute input rate 2041000 bits/sec, 159 packets/sec

5 minute output rate 17000 bits/sec, 35 packets/sec

The rate discrepancy between the outgoing data and the received data is 2070000 bit/sec! And there are only 2 T1s, does that not make the absolute max throughput 3088000 bits/sec?

And I have looked at the logs on the MUXs and there are not 1000s of drops, or any errors.

Thanks to anyone who takes the time to reply.