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Community Member

T1 Problems

I am having problems between 2 sites. The connection is intermittent. My main side is a 7513 with a ds3 card. The interface for the site that is the problem (s1/0/0/24:1) is throwing up input, crc and frame errors. The remote site is a 2500 with an external csu/dsu. I have had the line tested several times by our provider, and they say the line is clean, and they feel that the problem is on the 7513 side.

Any ideas?

Community Member

Re: T1 Problems

Does the csu/dsu at the remote site have any menu options? like showing you errors?

1.check timing. I assume this is a point to point t1. where you as the customer are providing timing from one side and recieving it on the other.

2. misconfigured port for framing or linecode. Check your config on the 7413 and the csu/dsu for frameing and linecode settings.

If they are correct I have seen a misconfigured port on the provider end. The circuit crossed 3 switches and one port on one switch was set to ami instead of b8zs. I was getting crc and framing errors with intermitant drops of the circuit.


Community Member

Re: T1 Problems

I would check the linecode also. It should be ANSI or B8ZS on both ends. The next thing you might check is if the timing on the external CSU is set to internal or external.

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