2 Replies Latest reply on Sep 4, 2012 12:58 PM by b124jr

    Maximum Dsitance between 908e and service provider smart jack

    b124jr New Member

      I have searched around and found several different distances allowed between the smart jack and the router's T1 port. The maximum distances i have found have ranged from 655 feet to 6000 feet.

      What is the actual distance allowed from the 908e to the service provider smart jack?

       

      Thanks

        • Re: Maximum Dsitance between 908e and service provider smart jack
          geo Employee

          Hello and thank you for posting to our forum.

           

          Any distance limitation is dictated by the type of T1 receiver interface on a unit or smart jack.  Typically smart jacks are DSX interfaces and T1 network interfaces on routers/CSUs are DS1 interfaces.

           

          T1 DSX interface - Tx level - 0dB / 6Vpp     Rx level - 0dBm                   Length - up to 655ft

          T1 DS1 interface - Tx level - 0dB / 6Vpp     Rx level - down to -36dBm    Length - 3000 ft w/loopback or 6000ft w/out loopback

           

          The DS1 receiver is more sensitive and can frame up on a T1 signal over a longer distance than the DSX interface.  DSX to DS1 connections require a straight through T1 cable where DSX to DSX or DS1 to DS1 connections require a T1 crossover cable (pins 1-4, 2-5).

           

          Note that on a TA 900, there is a NET (DS1) 0/1 and DSX interface 0/2.  On a TA 900e, all 4 T1s are labeled NET although T1s 0/3 and 0/4 can be configured for PRI or E&M like T1 0/2 on a TA 900.  A TA 900 T1 0/2 to a PBX would use a straight through T1 cable while a TA 900e T1 0/3 or 0/4 to a PBX would require a T1 crossover cable.

           

          Let me know if you have any questions.

           

          Regards.

          Geoff

          • Re: Maximum Dsitance between 908e and service provider smart jack
            b124jr New Member

            Thanks for the information. This clears it up for me.