EDIT: Turned out they had two routers chained together - that was the problem (see my next message). We have a home based Elastix/FreePBX box and recently a friend that has an extension off our system, using a Linksys PAP2 as the endpoint, asked if there was any way he could use it to connect to a friend's daughter currently residing in the Netherlands. I suggested that maybe if my friend's friend's daughter had a PAP2 she could connect to the sever as well. So he got another unit and configured it exactly the same as the one he uses (which works great) except on different extensions. We tested it, made calls back and forth, and it still worked great. He took it to his friend's home (the father of said daughter) and it worked great from there as well. The father then took the adapter to the Netherlands, and that's where the trouble started. It connects to the server just fine, the adapter shows up when you do "sip show peers" from the CLI, and has low ping time, you can pick up the phone and get dial tone and make another extension ring, or you can call her extension and it will ring. What we don't get is audio in either direction. Bear in mind, this is the same unit that worked great here in the U.S. with the same settings. So I began asking some questions and discovered that the young lady subscribes to some kind of triple play service, and I believe the company is called Tele2. Her IP address (in the range 18.104.22.168 - 22.214.171.124) resolves to "Versatel Consumer", which according to their whois, "is one of the largest ISP's in the Netherlands", and if you try to go to their web site you are redirected to a Tele2 page. The DSL modem is a Davolink DV2020, a Korean-made unit that appears designed for triple-play service. And I'm told that she does in fact get her television, telephone, and Internet from this company. I'm just wondering if anyone else has run into this and if so, were you able to resolve the problem? I've tried a couple obvious things (like having them set the the PAP2 to use sip ports 5061 and 5062 instead of 5060, just in case this company's phone service used 5060 - and yes I did also make that change in the extension configuration in FreePBX) and also tinkered with the RTP port min and max settings in the adapter (within the 10000-20000 range) but none of that helped. I'm just wondering if anyone else has ever tried to set up a remote extension with this particular provider and might have any hints, or in particular, might know what ports that device reserves for its own phone service. Skype calls get through just fine, so I'm not really sure why we can't get audio to or from the PAP2, but I suspect it has to do with the DV2020 (or maybe the company itself?) interfering with the audio packet stream in some way. I'm really at a bit of a loss here, and it doesn't help that I don't speak a word of Dutch and that the Tele2 web site is entirely in Dutch. If anyone has any suggestions on how to get the audio to work, I'd be very appreciative! The daughter's father (i.e. the friend of my friend) is visiting her today, so I'm hoping someone can tell me something useful today.