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How many wire pairs does my VOIP phone use?

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Oct 3rd, 2011
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my office has the Linksys SPA942 phones. We need to find out how many pairs of wires in a CAT5 cable it uses and which terminals (not sure if thats the right word) on the jack it uses.


I've looked through the documentation and cannot find anything. Anyone know where i can find this information?


thanks

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John Platts Mon, 10/03/2011 - 13:13
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Non-gigabit Ethernet over twisted pair cables with RJ-45 connectors (either 10BaseT or 100BaseTX) uses pairs 1, 2, 3, and 6, whereas gigabit Ethernet (1000BaseT) always uses all 8 pairs. Some PoE switches transmit the power using pairs 4, 5, 7, and 8, whereas other PoE switches transmit power using pairs 1, 2, 3, and 6. The 802.3af PoE standard requires devices to support both modes. I always wire all 8 pairs whenever I do Ethernet cabling, since we need to connect these cables to a PoE or Gigabit Ethernet port.

Troy Mon, 06/12/2017 - 10:18
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Know this post is a little old, but, without needing POE, can you have a gig VoIP phone work on just the 1,2,3 & 6?

I want to split up one jack with orange and green working for the phone and blue and brown working with the comp, all transmitting on 1,2,3 & 6, on separate jacks. Thoughts?

Dan Lukes Mon, 06/12/2017 - 10:35
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can you have a gig VoIP phone work on just the 1,2,3 & 6

No, gigabit ethernet use all eight wires for data. Use ethernet switch to connect two or more gigabit ethernet devices. Or use just fast ethernet phone - it's cheaper and you can split cable (although it's not recommended practice).

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