What can I do about poor voice quality when using softphone?

Question:
What can I do about poor voice quality when using softphone?

Solution 1
Remove the following codecs from the list of available codecs in the SIP gateway on the XPhone Connect administration interface (Telephony > Gateways > SIP) or alternatively put them in the back of the list

- OPUS
- G722

Solution 2
Poor voice quality during conferences in connection with Softphone may occur due to a set bypass media flag. Remove this flag in the SIP gateway on the XPhone Connect administration interface (Telephony > Gateways > SIP).

Solution 3
Set the following registry keys on your client computer:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters.

Parameters: REG_DWORD
Name: DisableUserTOSSetting
Value: 0

Parameter: REG_SZ
Name: Do not use NLA
Value: 1

Also check the steps from the following article:

https://www.c4b.com/de/knowledgebase/xcc/analyse-sprachqualitaet.php