- Always update your device to latest firmware to help resolve bugs and security issues
- Register a device account to only one server at a time. Using a backup server often results in registration hopping, which can confuse routers and cause missed inbound calls.
- Disabled unused codecs. The only required codec is g.711u, aka PCMU, ULAW, etc. This is the standard codec for North America. The others are not currently used.
- Set server expiration between 2 and 5 minutes. We typically use 3 minutes (180 seconds). The default is 1 hour (3600 seconds), which is too long and may result in router port timeouts and missed inbound calls.
- Enable the "ghost" or "phantom" call filter specific to your phone. Refer to your phone manufacturer for details. This setting blocks port scan tooks that probe your network, causing your phone to ring with no one there.
Yealink ghost call filter
1. Make sure your phone has latest firmware from Yealink website support page
2. Install firmware .rom file on the Settings > Upgrade setting in your phone
3. Next, click the Features tab on top menu, then the General Information tab on left menu.
4. Change the Accept SIP Trust Server Only field to Enabled
5. Change the Allow IP Call field to Disabled
6. Click the Confirm button at bottom of the page
1. Update firmware
2. Enable the SSAF SIP Source Address Filter on the VoIP account settings page
Cisco ghost call filter
1. Update firmware
2. Enable the Restrict Source IP feature in the SIP settings
Grandstream ghost call filter (several possible settings, depending on mdel)
- Update firmware, then look for 1 or more of the following...
- Enable "Accept incoming SIP from Proxy Only"
- Enable "Authenticate Incoming Invite"
- Enable "Check SIP User ID for Incoming Invite"
Obi
- Update firmware
- Disable SP2 and Obitalk features
