ISDN PRI cable length on a ISDN gateway MSE 8321 or GWY3201

[gfolens]

Hello,

I could not find in the available documentation what is the maximum cable length between the ISDN PRI port of a MSE 8321 (or GWY3201).

I see it should be a STP cable.

I also see in the advanced ISDN settings Line lenght = short/long but in the help no more explanation ("Do not change these settings unless advised to do so by Cisco Support...")

rgds, Geert.

[juriss]

Not always a simple direct answer..... its all about signal levels and dbs

Are you using an External CSU that is close to the MSE 8321?

We have an MSE8000 with a PRI blade and the CSUs are connected to the 8321 port with 5' patch cables

The Network side of the CSU is designed for longer length cables to go back to the PRI providers NIU or Smartjack

The below link is for the manual of the Adtran ACE T1CSU.... on page 26 it describes the switch settings for the NET and Equipment side Line Build Out or LBO.

www.adtran.com/pub/.../T1_CSU_ACE__3rd_Gen__Manual.pdf

With a CSU between the Smartjack and the 8321.... you should be able to set the LBO for almost any config and long as the Smartjack in not many thousand of feet away.....

I see lots of folks trying to not use CSU..... I think its needed for thing like this and for loopback testing and compared to the cost of the PRI and the 8321... T1 CSU are dirt cheap

SCJ

[t.svatek]

Hi Geert,

You should use a shielded 4-wire 120 Ohm twisted Pair Cable (often called PCM-Cable) instead of using common "Ethernet"-Cables with 100 Ohm impedance. A .

I recommend to use a cable with massive wires for the long distance (e.g. PCM 2 X 2 X 0.4) and a 120 Ohm Patch Cable with flex wires to connect the devices to a RJ45 jack (e.g. PCM 4x2xAWG26/7). Do not crimp massive wires directly on a RJ45 plug, because of potential reflections and bad connection. Always use a RJ45 Jack in beetween.

Tino