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New Member

WAN Loopback Testing Adapters DIY?

I'm looking for the pinout or whatever is needed to test certain devices like WIC-1DSU-T1, and how to do so. I found a pinout before for a WIC-1DSU-T1 loopback tester, but I still wasn't able to run the test. I'm wondering what the proper pinout or wiring config is for the loopback adapter, and what command I should be running on a Ciscl 2621 router to initiate this loopback test, or if I should just use the button, and what I should be expecting as output. So far, every time I've tried, it just looks like it's doing nothing and not working properly.

Also, if there is a pinout for testing any other WICS of VWICS etc. that is different from this one, it would be great to know those as well (like WIC-1ADSL, or VWIC-2MFT-E1).

Also also, not to drag on, but if there is a different pinout for standard RJ45 networking to test ports on a switch, it would be great to know that one :).

I'm really hoping someone just has a site I couldn't find with all these on it :).

Thanks in advance for any help.


Re: WAN Loopback Testing Adapters DIY?

Take a regular cat 5 cable, cut the cable may be 2 or 6 inches is more than enough. One end will have the Rj45 connector. The other end will have 8 wires. Only 4 are going to be used.

Twist wires 1 and 4 together.

Twist wires 2 and 5 together.

The rest of the pins can be left untouched.

Now you have a T1 loop.

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New Member

Re: WAN Loopback Testing Adapters DIY?

Well I've done that and all, but as soon as I go to run the loopback test, it just sits there. Doesn't show any error messages or say that it's complete. Maybe I'm running it wrong? What would be the proper command set on a router that has no previous configuration?

Re: WAN Loopback Testing Adapters DIY?


Once you are done with looping the physical wires you can check the status of the loop and the reliability of the link by issuing the following commands in ur router.

1.You need to make sure that all the counters i.e., ur CRC,Input errors etc., cleared before starting the can do the same using clear counters command.

2.once you are done with that you can check wehther you are recieving the loop on ur interface using show interface serial x/x.

this will show that ur serial is up and ur protocol is also up with (looped) condition.

3.Also you can issue extended ping command pinging ur local interface ip with more no of packets when compared to normal standard 5 packets.

4.monitor the ping for any drops as well as once its over you can issue show interface serial x/x to check for the reliability as well as for the errors.

But the loopback test which ur mentioning here are u setting something in the extenal csu/dsu device or how is it ?

in router you can use up show running interface serial x/x to view whether you have got any loopback related commands under it.

if its there u can very well remove the same prefixing no before the command under the interface config mode..


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