If the error message “not acceptable here” appears, all outbound calls made from the extension will be unsuccessful. This may be the result of an Audio Codec setting or Call encryption.
Deselecting Call Encryption
Go to ‘Admin’ >> ‘VoIP Account’ >> ‘extension’ and check if encryption is selected. This is indicated by a locked crescent moon as displayed in “201/AccountsI1” in the screenshot below:
Click on the three dots next to ‘password’ and select ‘edit’
Go to ‘Change VoIP account’ >> ‘Advanced (SIP) Settings’. Deselect ‘Use encryption’, click Acknowledge and save.
Once the VoIP account is updated and the encryption is disabled (the locked crescent moon is now gone. See screenshot below), go back to the ZoiPer app. Uninstall ZoiPer, reinstall and reconfigure. The transport type will be automatically selected. You will now be able to make outbound calls.
Changing the Audio Codec
If all else fails, take a look at your audio codec settings.
The variable bit rate codec iLBC 30 is recommended
OPUS is best for lower bandwidth and jitter
ZoiPer G.729 is a high compression codec, developed for low bandwidth networks.
To check your codec settings go to ‘Settings’ >> ‘Accounts’ >> SIP tab >> Extension >> Scroll down to ‘Audio Codec Settings’. The audio codecs below are automatically selected.