Frame Relay Intermitten Disconnects

[baboyd]

One of our remote sites keeps dropping a couple of times a day. 256k with 128 cir. It has an extended demarc and that was moved about the same time of when the problems started. How long and an Extend Dmarc be and is it straight CAT 5 connection.

 

[svermill]

You didn't mention what type of interface you are using. If it is an integrated csu, you may need to adjust your cable length setting. If it is an external CSU, you probably just need to adjust the Line Build Out (essentially the same thing as cable lenght). If it is none of these, you may have just exceded the spec.

 

[baboyd]

It is an integrated csu/dsu in a Cisco2620. So the cable length setting would be on the S0/0 interface setting...? What is the limit on a Extended demarc?

 

[svermill]

I believe that it is a controller command. Don't know that it is supported by all internal CSUs. I have never needed it but recently ran across it in a troubleshooting document on CCO.

Typically, 655 feet is the max cable run for a T1. That can be shortened or lengthened by variable factors such as cross talk on DSX panels, etc. I don't really know what an "extended demarc" is to be honest. Sounds like something I might want to run 22 gauge cable for as opposed to Cat5. Is this a term used by your telco? Are you pushing beyond 655 feet?

You may need to do some more in-depth troubleshooting. 'sh int' might give you some insight as to the types of errors that you are up against. There are some good troubleshooting guides on CCO that will help you to interpret the output.

 

[jeter]

Svermill is correct with a port adaptor card however I do believe that you need to have the provider come out and reset/build the LBO on the NIU. Cat 5 typically 300 ft is are limit. Let us know. Jeter@LasVegas.com
Fisher CCNA
Sprint-Data

 

[svermill]

Jeter,

Thanks. I am still of the old school where 22 guage two pair cable is what you use for long runs. I have joined the modern world and started using Cat5 for short runs. I was always concerned that the smaller guage wire of a Cat5 could be a problem. I also like the fact that if you buy the right T1 cable and DSX panels, you get a shield and a drain wire to tie down.

Is 300 feet your experience or is there some spec that warns against exceeding that number?

Regards,

Scott

 

[jeter]

300 ft is the standard however standards are just that. We perfer to stay within the limits only to avoid finger pointing. Its always the Telco problem right ( not on my watch ) haha Jeter@LasVegas.com
Fisher CCNA
Sprint-Data

 

[Guest_imported]

Who extended the dmarc? Did you do it yourself?

 

[OmiDimo]

open a ticket with your provider and have them STRESS TEST the line. they do this for physical layer. if they see problems they will let you know. sometimes (most times) they only test upto their demarcation point. request that they test to your CSU (through the extended wiring) they might not do it, but give it a try.

if they dont find any problems, have telco run a bi-directional NNI test to a loop (prolly to the smartjack).
its most probably a physical issue, somewhere out there, a line is exposed to some water (when it rains) or wind is blowing at a cable thats making your connection bounce. or it could be that you screwd up the inside wiring.