Follow the following steps, don't go any further if you fail in a step. For example, if call to 1 (800) 444-4444 won't go through, figure out the problem first.
Get a KoT VOIP account
do the initial configurations, register your device or softphone to your line. Make some test calls to 1 (800) 444-4444. Let's assume your KoT line # is 12345678831.
Get an ipkall (or CallCentric) #
username: gv12345678831 (your KoT VOIP line # after "gv")
hostname or IP address: sip.kots.us:5080
The entire SIP URI: email@example.com:5080
Note: If you want more codec support than g729, or if you have no ideal what is g729, then change 5080 to 5082 or 5081 in the above and following examples, and use G711 (PCM) as the preferred codec and use port 5062 or 5061 in your devices and soft phones.
If you use CallCentric, then configure its DID forwarding like this:
Use another phone to call your ipkall or CC # (assuming it is 15558887777), your KoT VOIP phone should ring. Pick it up.
Apply for a Google Voice account
if you don't have one yet. Don't use your primary email for this account, apply for a new Gmail account just for GV. This way, you can feel comfortable to add this account to your KoT VOIP configuration.
If you already have a GV# and it is bond to your primary email address, you may transfer it to another unimportant email address or a new Gmail dedicated for GV. Then you have nothing to worry about giving out your GV account info. Also make sure you have selected one of the recovery methods so you can recover your GV account in case of stolen.
Add your ipkall or CC # to your GV
as one of the forwarding numbers. Name it "ipkall" or anything. Google will call this # to verify, pick up the call and enter the two-digit verification code. Your ipkall # is now added to GV.
If you only need to receive calls to your GV #, you're done and no need to continue to the next steps. When someone calls your GV #, your KoT VOIP phones will ring.
Make your 1st GV call
Still in your GV login page, click the red "CALL" button, Number to call: 800-437-7950 (or any #), Phone to call with: ipkall, then click on the Connect button.
After 1 second or 2, your phone will ring, pick it up. You can dial any # to make your calls this way and you are done.
Direct GV dialing through KoT VOIP
If you want convenience so you can dial directly to any # on your KoT VOIP phones, then fill in your GV account info into your KoT VOIP account. The ipkall or CallCentric # is your GV forward #. Don't use symbols in your phone numbers, e.g., don't write (555) 888-7777; write 5558887777 instead.
Click the "Send" button. Dial 1-909-390-0003 or any 11-digit, voila, free calls to US and Canada, easy and totally convenient!
If the call still does not go through after each and every above steps being successful, usually it is because Google saw the access from a new location (where sip.kots.us is located) and blocked the access. You need to login to your GV account and then open this link in the same web browser:
Then make a call again right after.
If your Google account has 2-step verification enabled, you might need to add "sip.kots.us", "server2.kots.us" and/or "Google Voice" as your authorized site and/or application/service. For your reference:
If still no go, then disable 2-step verification.
You may also use GV for International calls, just put in "yes" in the "GV for International calls?" field. You need some credit in your GV account and Google charges about $0.02 per minute.
Ipkall or Callcentric?
Ipkall sometimes won't show caller ID correctly. This is a known issue between GV and ipkall, it has nothing to do with KoT VOIP. When GV sees a call going to an ipkall #, it changes the CID with a Washington area code so the call will be local to ipkall and thus save Google a penny or two.