I am trying to switch two of three phone lines in a very large, very
> old house over to VoIP. The house has quite literally twenty
> extensions split between the three lines -- I think I need at least 4
> or 5 REN per line, plus the ability to drive all the wire leading to
> those handsets (over 100' in some cases) without exploding the audio
> output circuit in the ATA.
The Linksys PAP2 supports 5 REN and seems pretty robust for such a small unit. The PAP2-NA version can be purchased separately and used on any VoIP provider that allows outside equipment, or you can get a Vonage-locked version at retail stores for around $50, usually free after mail-in rebate.
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