Here's why I like it:
I have used it with several different ATA's such as Handy tone 496 and 486,HT 502 Linksys PAP2T,spa 2102 and Wrtp 54g with 2 VOIP line.
*All used behind the router.
*Sometimes more than two ATA's connected to router simultaneously, connected to two different VoIP providers.
*NEVER any problems.
*Used with various VoIP providers such as voip buster, CallCentric, FPL , Inphonex, Vbuzzer and BrainTel.
*I have NEVER had to do ANY port forwarding, DMZ, or any other contortions.

When I read about people needing to do these things, I scratch my head in wonderment.
(Please Note that I am not a sale agent or work for D-link )