26xx Router Internal CSU/DSU?

[abe_froman]

I have looked everywhere and cannot find the distance limitations on the DS1 signal right off of the CSU module.

I am connecting two 2600's together, and they are not that far apart, hundreds, not thousands of feet. If the signal is strong enough, I won't have to come up with a "home made" DS1.

[scottmac]

Usually, the limit between a SmartJack (DS1 demarc from the Telco) and the CSU/DSU is ~655 feet over premises cabling (individually shielded pairs inside a shielded jacket).

Category-rated cabling has more loss and a different impedence than premises cabling and is not, "by spec," rated for carrying T1/DS1 traffic. However, many / most / all manufacturers of T1/DS1 equipment compensate for, and allow for, use of Category-rated cabling.

You should be able to use Category-rated UTP for at least a couple hundred feet successfully. If it doesn't work initially, try adjusting the Line Build Out (LBO) for a stronger signal.

If you connect them and see errors on the interface (crcs errors mostly), then you may need an active device in the middle (like an Adtran Atlas or similar).

Don't forget to set up one of the routers as a clock source (DCE) if they're back-to-back.

Good Luck

Scott