To optimize G711 fallback fax completion rates, please use the following settings in the SPA's "LINE 1" tab:
- network jitter buffer - very high
- Jitter buffer adjustment - disable
- Call Waiting: no
- 3 Way Calling: no
- Echo Canceller: no
- Silence suppression: no
- Preferred Codec: G711a
- Use pref. codec only: yes