"If it DID work, but isn't working now" says to me that, in principle, your configuration is right. "If it never worked properly" is different, and would indeed indicate a setup issue.
You said "This has been successful so far, but today I can hear the person on the other end, but they cannot hear me.", so sounds like the first of the above... so probably not a config issue.
- Always start by "power it off, take a few breaths, then power it back on again". It may take a couple of minutes to reboot. (I'm talking about your VOIP adapter here). Like so many other tech items, this so often fixes the problem!
- If you rebooted your broadband, or it went off by itself, then you may need to do a reboot of the voip adapter (mine was completely dead after I reset my broadband recently, a reboot of the VIOP adapter fixed it)
- If the reboot didn't fix it, then take a look at any logs, they may give a hint.
- What has changed from "it used to work" and "it stopped working"? Sometimes someone else did something, and you have to start from scratch to fix it!
(I should cut & keep that, it's relevant to so many issues!)
