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Knowledge Base > ATM > How can I connect a ATM multimode OC-3 card to a singlemode OC-3 interface?

How can I connect a ATM multimode OC-3 card to a singlemode OC-3 interface?

If you have an ATM multimode OC-3 card installed in a Linux host and you need to connect to a singlemode OC-3 interface on a DSLAM or ATM switch, there are a couple techniques that can be used.

Option 1

    You can use a multimode to singlemode convertor/repeater device. These devices are normally used to convert multimode fiber to singlemode fiber in order to transmit over longer distances. However, these devices are relativly expensive compared to the second option.

Option 2

    The second option is to use a singlemode 10db attenuator such as a SC connector with UPC polish.

    The attenuator should be connected to the singlemode transmission cable or the multimode receiver. The OC-3 interfaces should be connected using multimode fiber patch cables.

    The attenuator prevents the singlemode transmitter from flooding the multimode receiver. This technique works for short distances that you would normally find in a test environment.

    The attenuators are usually available for under $50 US from a several distributors including L-Com and Sys Concept.