Split RJ45 IP Phone Line for RJ11 to utilize DID

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 Question by chad ellis posted 12 Dec 2003
 Split RJ45 IP Phone Line for RJ11 to utilize DID
I am an IT Technician but have never done this before so please don't harass me for not knowing! Our company utilizes an IP Phone system. I have DID's on some extensions. Before I was hired, one of the IP LAN lines was split into an RJ45 and an RJ11 so that a fax machine could utilize the DID. I would like to do this with another extension. Does anyone know how to do this; or could anyone direct me to this information?
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 Answer by Dmitri Abaimov posted 15 Dec 2003
Dear Chad,

When splitting the cable pairs like this you need to keep pairs 2 and 3 (orange and green) on their original locations, and take pair 1 (blue) into another jack, on both sides of the cable.

I assume, by DID you mean analog extensions because your IP Phones can also have Direct Inward Dialing. Also, if your phone system utilizes a mixture of IP phones, digital phones and analog devices (like faxes), contact the phone vendor before you do anything because the digital phones may use two pairs.

Another caveat: the IP phones may receive power from the switches. In this case you cannot split the cable as all pairs are already being used.

Sincerely,
Dmitri Abaimov, RCDD

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