FreePBX Conference Sound Quality

We are running Asterisk Version = with FreePBX Version

Phone calls both internally and externally work perfectly as do conferences with internal callers only.

However once an external caller enters the conference sound quality of the conference is very low and appears to be choppy. We are using B410P card with Telstra ISDN2 lines, has anyone seen this issue before?

Try turning acpi=off in your kernel boot line …fixed that for me once.