Problem: Outbound calls placed over cell service result in a busy signal or fast busy every time.
Cause: Phone number wasn’t dialed with 10 digits.
Solution: All outbound calls must be dialed with 10 digits to insure completion.
Problem: Outbound calls placed over cell service won’t complete.
Cause: Mobile data and/or roaming data are not enabled.
Solution: Enable both checkboxes for data under Settings / Wireless & networks / Mobile networks. Don’t worry about the warning for roaming charges, there aren’t any.
Problem: Outbound Wi-Fi call rings once, then disconnects. Phone doesn’t usually try to re-dial this failure on cell.
Cause: Unknown. Experienced by a lot of members on the first call of the day or the first call after the phone’s screen has been off for a while.
Solution: Redial the call. The redial is almost always successful.
Problem: A Wi-Fi call in progress seems to drop, or one party can’t hear the other in the 15 seconds to 2 minute timeframe.
Cause: The Wi-Fi router has a feature for handling “SIP” enabled (sometimes written “SIP ALG”).
Solution: Disable any router feature that mentions SIP. Note that this is NOT the same as SPI, which is occasionally, but much less often, a problem.
Problem: Wi-Fi calls drop at exactly 15 minutes.
Cause(1): Battery Manager app on phone is turning off Wi-Fi.
Solution(1): Set Battery Manager to “Performance mode”
Cause(2): Issues within Republic’s infrastructure.
Solution(2): Report the problem to Republic.
(With thanks to @andreas and @southpawkb for reminding me of the (1) cause/solution)