(continued)
A.Use winmtr
https://sourceforge.net/projects/winmtr/
B. For Freephoneline.ca (based in Ontario), test to voip.freephoneline.ca (let winmtr ping about 100 times), voip2.freephoneline.ca, and voip4.freephoneline.ca. You can copy text to clipboard and paste your results (do not post your own IP public address though) and post them for others to examine if you want.
C. Look at the very last hop or line. Take a look at your average ping--and your maximum. You want those values to be relatively close.
You do not want high pings and lots of jitter (you do not want a lot of variation between each ping). If you get horrible results (pings over 200ms), you should probably avoid FPL.
I get between 11 (voip.freephoneline.ca and voip2.freephoneline.ca)-24ms (voip4.freephonline.ca) on average, depending on the server I'm testing to. Preferably, you want pings below 100ms.
Anything over 200ms is unacceptable.
What you don't want to see is 40, 45, 50, 35,
500, 40, 30, 45,
700. That's bad jitter.
You want relatively consistent pings without a lot of variation.
Try the free FPL desktop app first:
https://www.fongo.com/app/desktop/
Make sure that you're not muting anything (microphone/speakers), and that you tested to ensure your mic is working before fiddling around with the app:
http://win10faq.com/fix-microphone-settings/
And make sure you test incoming calls for 1-way audio issues. Test on a computer that's connected to your router (without DMZ or port forwarding enabled). Should you encounter 1-way audio issues, look for a feature called SIP ALG in your router (you may need to call your ISP if you're using a modem/router combo) and disable that feature. You should not need to do so with Asus routers or those running Asuswrt-Merlin, but you do need to in the ISP's device (better still to put it in bridge mode).
i. Typically it's better to have your own router and to stick whatever modem/router combo your ISP gives you into bridge mode.
ii. Disable SIP ALG in your own router. Many modem/router combos that are issued by ISPs have faulty SIP ALG/SPI functions enabled, with no way to disable them. These features can mangle SIP headers. If you don't know how to disable SIP ALG, contact your router's brand or contact your ISP.
To understand why SIP ALG is often a serious headache visit
https://www.voip-info.org/routers-sip-alg/ (scroll down to "SIP ALG Problems")
iii. Properly enable QoS in your router for your computer that's running the Freephoneline desktop app (and ensure no other programs are running on your computer that are hogging bandwidth while using the Freephoneline desktop app). Refer to your router's manual or contact your ISP if you were issued a modem/router combo from them (typically those routers suck and have horrible or absent QoS functions).
I'm not a huge fan of this website, but it suffices for an explanation of QoS:
http://www.voipmechanic.com/qos-for-voip.htm
Avoid anything it says about the G.729
iv. If you still get one-way audio issues with the Freephoneline desktop app, you may need to port forward, which is a security risk (and not advisable).
The FPL desktop app uses ports 5060-5061,6060-6061,13000-13001 if you're going to port forward for the desktop app (you need to port forward to the LAN IP of the computer you're using. For most home networks the IP will begin 192.168.xxx.x). Refer to your router's manual to learn how to port forward (if your router came from your ISP, contact your ISP).
I would start just by port forwarding 13000-13001 only, which is for RTP (audio packets). If that still doesn't work, you can try adding 6060 or 6061. The most dangerous ports to forward are 5060-5061 and really shouldn't be necessary if you're forwarding 6060 or 6061 anyway. I guess if all else fails, forward all of them: 5060, 5061,6060, 6061,13000, and 13001.
These are all UDP ports.
5060, 5061, 6060, and 6061 should be alternate SIP ports.
Only port forward if all else fails (and only do it temporarily, since it's a security risk). If your router was issued by your ISP, contact your ISP for guidance.
Note that only one registration per FPL account is allowed at any time. When there are multiple devices/softphones using the same account, only the most recent registration is valid. The previous device will lose registration, and, consequently, incoming calls will not work on it. This is especially important to consider if someone else is using your SIP credentials (username and password) that are found after logging in at
https://www.freephoneline.ca/showSipSettings or if you're trying to register your FPL account with a smartphone SIP app, the FPL desktop application, or with another device. Registration is required for incoming calls. It is not required for outgoing calls. A more significant concern, though, is that multiple registration attempts can lead to temporary IP bans. The more devices being used can make the temporary ban happen more quickly. Note that each time you reboot or restart your ATA or FPL desktop application, it's attempting to register with Freephoneline again. Multiple registration attempts within a short period can result in a temporary IP ban. Each time you reboot your ATA it's attempting to register with FPL's proxy server.
Do not test the ATA while the FPL desktop app is running and vice versa when using both with the same FPL account. Unplug your ATA while using the FPL desktop application. Exit the FPL desktop application when using the ATA.
8. If you get the same static while also using the Freephoneline desktop app, then I believe there's an inter-connect carrier issue or problem with call routes involving your account on FPL's end.
Submit a ticket:
https://support.fongo.com/hc/en-us/requests/new. Choose "my account inquiry" for the final issue type.
Let them know that you can reproduce the issue with the Freephoneline desktop application and let them know what other troubleshooting steps you've done.
Note that responses are delayed due to the pandemic. If there's a problem on FPL's end, then the fix has to come from support, and they are not obliged to read
nor respond on these forums.
9. If you can't reproduce the problem with FPL's desktop app, then there's an issue with your phone cord, ATA, or interference caused by devices nearby. If there's been a lightning storm or a brief power outage recently, it may have caused damage.
I would try testing with (and checking) new phone cords (static can be produced by faulty cords running to the ATA and to the phone handset), testing with a completely different corded (not cordless) phone, ensuring that you are not plugging the ATA into wall jacks in your home (which could fry your ATA if the phone company's line has not been disconnected at the demarc), and moving the ATA away from electrical sources of interference, which can also cause static. Ensure all cords are seated securely into ports (make sure none are loose). You may also want to test with another power supply if you have one available. If you're going to ask me why static doesn't also occur with outgoing calls, my suggestion is to check to see whether you aren't simply moving a defective cord into a temporary position that works. While I don't approve of all information at this site, you can visit
https://www.voipmechanic.com/how-to-tro ... static.htm for some other suggestions concerning static. Also, take a look at
https://www.voipmechanic.com/voip-voice-quality.htm