Summary: Once set up (which was a pain in the ass), it works completely flawlessly with asterisk. I have one that currently is reporting that it is in it's 482 day of system up time. We've had no echo problems.
Summary: The Grandstream 4FXO seems to be a good gateway for the price; however set it up and get it to work with the minimum documentation is a real challenge not everybody is willing to take. To setup the box, it needs to be plugged to a LAN with DHCP and then find out what IP received.
Summary: just followed the instructions on line and have it running with 4 time warner digital lines. only issue is that i can't get it to work with 4 trunks and have to use all 4 DID on one trunk. only 1 trunk would ring.
Summary: I was able to to configure the unit to work with my POTS line as well as 2 magic jack lines. The web interface is similar to other Grandstream adapters (e.g. HT503). I haven't had to reboot the unit due to hang ups or other malfunctions and the price is good compare to other similar products.
Great way to add support for regular phone lines to an IP PBX
M. Anderson, Amazon
16 August 2011
Summary: This is a 4-port FXO SIP device. It allows you to add up to 4 regular telephone lines to an IP PBX, such as PBX in A Flash or the FreePBX Distro. It is relatively easy to configure, and Grandstream includes configuration instructions on its web-site.