What would cause some calls to get a busy signal and others to go through fine? I have a FreePBX system set up and have 4 SIPStation trunks and all was working just fine until I started getting a busy signal when calling in using my cell phone. Things got even stranger when I discovered that other phones call in just fine. When calls get a busy signal, nothing shows up on my internal server logs.
While troubleshooting this I bought a second DID and set it up the same as the first. All calls go through fine to this new number.
I also completely removed my SIPStation key and deleted trunks and then reinstalled them but the calls still get a busy signal from my cell phone.
Although not thoroughly tested, it appears that most land lines come through fine and cell phones (at least verizon) yield a busy signal. To add another wrinkle, a friends cell phone was giving me a busy signal last night while he was in the area but when he went home (about 40 miles away) his cell phone now works.
Any help with this would be appreciated.