Converting RJ-11 to RJ-45 FREE cabling and networking Helpdesk
 Question by Joe L posted 09 Jan 2006
 Converting RJ-11 to RJ-45

I'm in search of a reliable way to convert an RJ-11 cord into an RJ-45.

I purchased a VoIP system (Aastra 480i) to use with Vonage's service. After realizing my mistake, and experiencing Vonage's terrible call quality, I switched back to Verizon.

I'm hoping for a way to keep my Aastra phone hardware and purchase or build a box to convert and then disburse it to 4 or more handsets via a router. The hardware will only accept an incoming RJ-45.

Is this possible?

 Answer by Joseph Golan posted 10 Jan 2006
Dear Joe,
I am not familiar with Aastra 480i and there is limited information from their web site on this product.

I think your biggest issue is if your are getting VoIP from Verizon or POTS service and if the 480i can accept POTS service or only VoIP signals. As far as your question of an RJ-45 to RJ-11 cord, this will depend on the signal expected by the 480i, if it is POTS then you can just plug is the RJ-11 to your RJ-45 jack on the set, the 1st pair (typically used for POTS) will correctly align even though these are two different connectors.
My understanding of Vonage is they supply typically a VoIP modem so that the outbound signal (to the telephone equipment is equal to POTS service, but this doesn't appear to be your case by your wording. I would need to know more about the 480i to see if there is anyway to work this out.

Joseph Golan, RCDD

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