PTP T1 circuits clocking issue
Posted on 2004-04-21
I have a 3725 core router with three PTP T1 circuits to three 1721 routers. We are using the new v2.0 T1 cards. The ISP indicates there is no line clocking. Two CCIEs and Cisco have tried to solve my problem for over 40 hours with no luck. I am not very technical so I will do my best to describe the symptoms. Currently each branch router is providing clocking although we have also tried having the core router provide the clocking. Each T1 has been tested with hard loopback plugs several times and the ISP indicates lines are fine. Here are the symptoms:
The most common symptom is a reload of the core router results in not all three T1 circuits coming back up. Sometimes all three come up , most often a random two do, and sometimes only one does. The core router interface that does not come back up is in a down down state and the branch router is in an up down state. Issuing a clear service-module command on the down down interface brings the circuit back up.
Second and rare symptom has happened twice in one week on separate circuits: after several core router reloads the core router interface and branch router both come back with an Up Down state and CRCs start building on both sides. After about 40 minutes and simultaneous power recycles on both sides the circuit comes back up.
Third symptom is occasionally about 30 CRCs per night build up on the core router interfaces. There are no data loads on the circuits. They are not yet in production. Massive ping tests produce no CRCs.
ISP testing on one T1 circuit this afternoon showed the following results: testing back to the core router was clean. Testing to the branch router resulted in errors. Hard loop back on branch side circuit tested clean. When ISP puts branch router in loopback they see framing errors.
CCIEs now suspect a compatibility problem with the 1721 and v2.0 cards. The 3725 and all three T1 cards were chnaged out at the beginning becuase of suspected faulty hardware.