(looped) display in ATM interface

Unanswered Question
Sep 9th, 2008
User Badges:

As far as we know, when the Telco provided a loop in our interface we are able to see the word(looped) in the interface. It means the conneection is being looped and testing are going on. However, I was informed by telco staf that we are unable to see this word while troubleshoooting for ATM interface. in fact, today, I faced the same issue when the Telco requested me to check for a loop and I were not able at all to see them. They only informed me that you wont be able to see it if ATM interface. The main thing I want to know is WHY. Is it something to do with Cells as ATM uses celss for transmission and not packets or due to Virtual Circuit Identifier (VCI)/VPI ? If anyone have the info, please let me know. Thanks in advanced.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Giuseppe Larosa Tue, 09/09/2008 - 01:36
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

Hello Karmesh,

you are in the right direction ATM cells use vpi/vci.

However, ATM framework provides for special purpose ATM cells that are called OAM cells: some type of OAM cells can be used to perform logical loopback tests I think OAM F4 or OAM F5.

What you need is to enable OAM management on the atm interface

see the following link to oam


or the ATM OAM ping


Hope to help



This Discussion