Back to Back connecting ATM Modules

Unanswered Question
May 15th, 2009


How can We Back to back connect two 7200 series Router via PA-POS-OC3.

Also can we connect two 3800 series Router via NM-1A-OC3-POM.

Thanks is advance.

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Paolo Bevilacqua Sat, 05/16/2009 - 13:56

Yes, absolutely in both cases or a mix of them. Just configure internal clock into one side only.

seekhpar121 Sun, 05/17/2009 - 01:28

Thanks for reply,but for mix,how can we connect PA-POS-OC3 and NM-1A-OC3-POM with each other since NM-1A-OC3-POM doesnot support sonet.

Any documentation for interconnecting either PA-POS-OC3,or NM-1A-OC3-POM or mix will be appreciated.

Tom Randstrom Sun, 05/17/2009 - 06:23

According to the following document for the NM-1A-OC3-POM, it identifies a step in the procedure to set it for SONET or SDH framing.


The PA-POS-OC3 also indicates SONET or SDH POS framing in the following document:


Hope this helps!

viyuan700 Sun, 05/17/2009 - 14:27

Link has example to configure PA-POS-OC3 back to back connection.

Both PA-POS-OC3 and NM-1A-OC3-POM have 3 type of cards

one Multimode (MM)

2 Single mode(SM)

When you mix these cards just see you have to connect MM to MM and SM to SM. Cannot mix MM with SM.

both support STS 3c rate so will not have problem in connecting

Paolo Bevilacqua Sun, 05/17/2009 - 21:59

In most cases you can even mix SM with MM. Just use an attenuator inline with SM TX to MM RX.

In any case, remember to rate useful posts with the scrollbox below.

viyuan700 Mon, 05/18/2009 - 05:27

Hi Paolo,

We cannot mix MM with SM as the lot of difference between core size of MM & SM fiber.

We can certainly mix SM sHort haul with SM long Haul card working on same wavelngth using inline attenuator.


This Discussion