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

Solution 4

• Increase the JITTER BUFFER. This sets how large the time period for collecting voice packets is

→ fixes choppy voice transmission

• Increasing the BUFFER. This sets the size of the buffer. The larger it is, the more voice packets are contained here. Important: the larger, the longer the delay in voice transmission. This delay is added to the jitter buffer delay.

→ fixes distorted speech transmission

• To be able to edit the JITTER and BUFFER, this registry key must be created: 

         [HKEY_CURRENT_USER\Software\C4B\Softphone\ReadOnly].

The registry keys and the ReadOnly key do not exist and must be created by hand.

Type     Name                           Value Corresponds to

String   JitterBufferSize                0   JITTER BUFFER

String   NAudioSinkBufferSize     25 BUFFER

String   NAudioSourceBufferSize 25 BUFFER

The lower two BUFFER values must always be identical. You can increase the default value from 25 to 100 for the first adjustment, and then increase it further in steps of 20.

• Here you can find another registry file with the default values. This file can be used to set the registry keys, but it should be edited first with the desired values and only then distributed.