I'm testing out 3CX a little bit. So far I'm using a GXW-4104 and Aastra 9133i. My 3CX server is located at my office where I have a dynamic IP. I use dyndns.org. I had ultimately wanted to be able to use the hard phone on a portable remote basis. For example, when I am working on-site for a couple of days it would be nice to drag a hard phone with me. However, it seems like this 9133i phone isn't up to the task. While the manual says you can use a FQDN instead of an IP address for many settings, when I try to use mydomain.dyndns.org for proxy or registrar I get a "no service" from the phone but when I use the actual IP address that mydomain.dyndns.org points to, it works fine. Also, no STUN client. I was able to workaround that (for testing) by setting the IP address of my home router in the NAT IP settings. It would be so nice if this also support dyndns.org names (it doesn't) as I would be able to actually use these phones as remote phones pretty nicely. The brochure for the 9143i says it supports STUN and is really a 5-series stuff into the 9133i box (I like the 9133i box, it looks nice to me). But I'm hesitant to try one. I looked at the manual online and it doesn't say much about STUN. Hmmm... So basically, have you guys found any good phones for remote use behind a NAT to a 3CX server also behind a NAT? Is Cisco the best way to go?