Connecting a Phone to a RJ45 Jack FREE cabling and networking Helpdesk
 Question by Dan Woods posted 27 Aug 2003
 Connecting a Phone to a RJ45 Jack
I was reading your response to another reader's questions, but you forgot to answer the following question:

"I've read that one should use cat 5e cable for telephone wiring, and I've seen RJ45 outlets pictured as the outlet of choice for telephones. The 4-pair makes good sense to me, but I don't understand how one connects a telephone to the RJ45 outlet. Is this as simple as using a cable with a RJ45 jack at one end (wall outlet) and a RJ11 jack at the other end (phone input)? I feel stupid asking this, but everything I've read seems to assume that the reader already somehow knows this"


 Answer by Dmitri Abaimov posted 29 Aug 2003
Dear Dan,

Sorry, I really forgot to answer that one. It is really an easy one: RJ-11 plug fits right into RJ-45 jack, with pairs #1 converging.

Note: NONE of the other pairs converge in such connection unless RJ45 is terminated using USOC pinout.

However, connection pair #1 of the RJ11 to pair #1 of the RJ45 makes analog phones work.

Dmitri Abaimov, RCDD

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