pin order of CAB-E1-PRI

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Jan 12th, 2007
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I fill annoyed by the cable CAB-E1-PRI (if I am not wrong, this cable is used for ISDN connection. One end is a RJ-45 connector to plug into Telecom's CPE. The other end is a DB-15 connector to match the PRI port on my NM-1CE1B module of the 2621 router.)

My quetion is: what is the signal definition on the pins of the RJ-45 and the DB15 connectors? I found two documents in CISCO's web site about the RJ-45 connector. One said that pin 1 is for Receive Tip, and pin 2 for Receive ring, and pin 3 for Transimit Tip, and pin 4 for Tx ring. The other said that pin 1 is for Transmit tip, and pin 2 for Tx ring, and pin3 for Receive tip, and pin 4 for Rx ring. Which one is right?

By the way, what is the meaing of "ring" and "tip"? And what is the difference between E1 and ISDN PRI?

Thank you!

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Overall Rating: 5 (2 ratings)
andrew.burns Fri, 01/12/2007 - 03:25
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Regarding pinouts - best bet is to confirm with your network provider as there are a couple of options depending on service and location.

If you're interesting in the signalling (tip/ring/etc.) then Cisco has a good paper on this here:

Also, E1 and ISDN PRI are different standards for different applications.



william_ccie Fri, 01/12/2007 - 03:59
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Hi, Andrew

Thank you for your quick response and the useful link. I am reading this article carefully.

My trouble is: I don't know the signal deffinition on the RJ-45 end, so I don't know how to match the connector that the telecom left for me. If I know what each pin means, I will order him to make a connector in a right pin sequence.

By the way, what does HTH mean?


william_ccie Fri, 01/12/2007 - 18:36
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As you Hope, That answer is extremely Helpful.

Thank you very much!


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