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Community Member

WAN Serial Link in the UK

Can someone confirm the following setup is correct?

An E1 circuit has been provided by the carrier to a remote site in the UK terminated on a "NTE52D", then connected to a Metrodata DC3000 X.121 DSU. The DC3000 is cabled to a WIC-1T on the router with a 72-0789-01 DTE cable. The symptoms are an UP/Down condition on the serial line, and currently there are no input packets being seen at the router interface. The carrier claims that loopback tests run clean to the DSU. When the DSU is set to loopback mode, the serial interface comes up.

Not being familiar with circuits in the UK ... Why the two boxes?

Is a WIC-1T serial port correct for the installation?


Re: WAN Serial Link in the UK

What type of E-1 is this? Is it a point-to-point, Frame Relay, ATM, other...

The Up/Down status tells you that you are good on a layer 1 level. You are seeing good DCE signals from the DCE equipment. In this case your DC3000 X.121 DSU. The down portion is telling you that your protocols are not talking to the remote side or switch correclty. It could mean various things.

1)The remote side router is shut down.

2) The LMI is down on a frame relay ckt.

3) No rcv on ATM cells.

4) Incorrect encapsulation on the serial interface.

You need to verify your config and make sure it is catered to your line correctly...Please rate..Good Luck...

Community Member

Re: WAN Serial Link in the UK

The link is a point to point IP and I am configured for HDLC, but the carrier was originally configured from Frame-Relay. They told me the other end was a Cisco router not a Frame-Relay switch so I had them change to HDLC encapsualtion. I have never heard of a point to point link configured as Frame-Relay.

The symptoms have changed since ealier. I am now seeing the line protocol go up and down. They must be working the issue.....

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