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T3 Errors on Serial

We recently installed a P2P T3 circuit between two offices. We are getting a large number of input errors, CRC, overruns and carrier transitions INTO one of the sites. At the site the connection is coming from, our provider is testing clean to the handoff to the LEC. The LEC claims their network is clean and that there is an issue between the demarc and CPE.

Our extension is RG59 Coax with a length of 478 feet from demarc to router.

My question is: I have read teh limits for this cable for T3 is 450 feet. Is this true? Could this be the problem? Does anyone have any insight into what direction to go with this?

Will rate.


Community Member

Re: T3 Errors on Serial

It could be a number of things, but the very first that I would look at based on previous experiences is the clocking.

If it's a P2P you will likely need to specify your own clocking, and are probably seeing slips on your t3 controller interface. If this is the case, try setting a clock source on one side as Internal, and on the other side as Line.

Good luck.

Community Member

Re: T3 Errors on Serial

Thanks. Verified this and that looks to be set right. Is it possible if the demarc extension is too long on one end and that we would receive these kinds of errors on the other?


Hall of Fame Super Gold

Re: T3 Errors on Serial

Yes, you are exceeding the supported distance. You could try low loss cable, but that may not be enough anyway.

Community Member

Re: T3 Errors on Serial

Thanks again. I had read somewhere 450 feet for this setup? Does this sound right? We are looking at our distance at around 480 feet. What would you think the best option be at the point? Repeater/booster, low loss cable, fiber converter?

Thanks again!

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