Configuration required on PTP 820G to test the TDM service using a loopback plug

Configuration required on PTP 820G to test the TDM service using a loopback plug


T1 tester > IDU-Near > ODU-Near > ODU-Far > IDU-Far > Loop plug (physical plug looping the TX and RX)


To start with make sure the PTP 820G is set to ANSI Standard.

By default, the TDM interfaces in a PTP 820G unit are set to operate according to the ETSI standard, in E1 mode. This will not allow the T1 traffic to pass through, so we need to change the ETSI to ANSI using command line interface (CLI).

To change the TDM interfaces to operate according to the ANSI (FCC) standard (DS1), enter the following command in root view.

  • root> platform management set tdm-interfaces-standard ansi

Warning: This command results in system reset and restores the default configuration. However, the modem IP address never resets. 

Once the Standard has changed to ANSI then the Default TDM interface will change from E1 to T1.

Follow the below steps to configure the TDM Services and other parameters to test the T1 line:

  1. On the end where the T1 Tester is connected follow the below steps:-

Before configuring the TDM services, first we have to create any Eth. service for Radio port, because we need specify which type of traffic will be carried by the Radio.

Create any service point which is connected to the radio port in Ethernet/Services, this can be done under Ethernet > Services> Click on ADD and configure P2P service for Ethernet and Radio port.

Step 1:

You can configure the E1/DS1 interface in the E1/DS1 Interfaces page. To configure the E1/DS1 interface:

  • Select TDM > Interfaces > E1/DS1. The E1/DS1 Interfaces page opens.
  • Select an interface and click Edit. The E1/DS1 Interfaces – Edit page opens. Make sure, timing mode is set to “Loop”.

 Step 1.jpg

Loop: The output signal uses the clock of the incoming E1/DS1 lines. If you select Loop, you must select the clock source reference in the Recovery Clock Source Reference Port field. By default, each port will take itself as a reference.

Step 2:  Create the TDM Services for Port 1

Step 2.jpg 

Step 3: Select Required TDM Card and Timing as per below screen shot and then click on “Next”

Note: On the Remote end where loop plug is connected, select “Clock Recovery” as the timing mode

Step 3.jpg

Step 4: Select the Radio Slot 1-Port 1 or Radio protection-Group if the radio ports are grouped, then click on “Next”

Step 4.jpg

Step 5:  Select the local ID=1 and Remote ID=2 on the near end and vice versa on the Remote end.

Step 5.jpg

Step 6: Click on Submit to finish the complete configuration

Step 6.jpg 

  1. Follow the same steps above for the Remote radio but we need to make sure below two things are changed.

“Timing Mode” should be set to “Clock Recovery” (as per Step 2) and Under the Trail selection “Local ID and Remote ID” (Step 5) should be opposite value compare to near end radio.

Having the above setup with complete configuration should help us to test the T1 connection using a loopback plug on the remote end.