PTP820G T1 Traffic

We have several 11820G links, in public safety service, passing (attempting) several T1 circuits. We are using Tenser Channel Banks (Motorola), and moving these circuits from PTP49600 radios, that have worked for over 8 yrs. We have FW ver 9.7 in all of the radios, all are set for ANSI. We move the circuits from the 49600 radios to the 820G radios, and the CB show they are happy, pass most traffic, but "M" lead in one direction doesn't work on all circuits. We have put test units on the radios, and all passes but pattern, but the CB report happy. When we put the CB back on the 49600 links, all works fine. We have worked with support on this, and they have told us to run the source radio in "loop timing" and the destination side in "Clock recovery", but the CB unlock and pass no traffic. Putting both ends in "clock recovery" gets the CB to lock. Question is, has anyone tried this before using the Tenser CB, and if so, what was the successful configuration? Thanks in advance.


I am not aware of any issue with Tnsr CB integration. I think your clock configuration nailed the problem. It looks like your CB are all configured to generate clock, so you need to configure the radios to use loop timing (taking clock from the front pannel T1 input).

Hope it help.



When the radios are in "clock recovery" the CB are satisfied, with no errors, in loop, they fail. When we move the T1 traffic from the 820G radios, and put them back on the PTP600 radios, the T1 traffic passes correctly. Clearly something is missing on the 820G links. Thoughts?

To configure the clocking properly on the radio, we need to know where the clock source is coming from.

If you channel back is generating clock, you need to configure the radio as loopback, see below

CB1--->Radio[loopback]--------------Radio[Recovery]------>CB2, in this case CB1 generate clock and CB2 is receiving clock.

You can also do this

CB1--->Radio[loopback]-----------Radio[Loopback]<--------CB2, in this case, both the CBs are generating clock, all derived from the same global source.

I don't know how you would be able to get it to work with both the radio using "Recovery". If you could tell me where the clock is comming from, I may be able to give you some suggestion.



Hoping this makes sense to you.

The prime channel bank get clock from a Trak GPS/ribidium clock, via sync port. They send clock on all T1's. Remote sites are set to Wans that come from prime and recover clock that way. 

Tell me the name of the T1 clock setting and it’s associated configuration in both channel banks in question.

For example:

TENSR #1 = Internal

TENSR # 2 = Loop

T1 clocking configurations are a bit tricky on the 820 radios but I have documented experience and can help you if you can provide me more information about how your multiplexers are configured.