Troubleshooting note for a situation (a brand new installation) but the VoIP phone got disconnected randomly.
- Phone Polycom
- PBX : asterisk
- Switches : Cisco SG-300
- Sonicwall Soho (TZ Series)
Let’s start with the switch. Cisco have a feature enabled by default called : “Green Ethernet” if you have a non managed switch. Simply : Trash it. Purchase a switch : Netgear GS105E-200NAS
For Managed switch, there’s a more simple solution, turn off the Green Ethernet and the 802.3 Energy Saving
In the Firewall Rules, OpenUP the port : 5000 up to 5500 UDP, 10000-20000 UDP and TCP – Any to Any (Incoming)
In the VoIP Section :
Check Enable Consistent Nat and Check Enable SIP Transformation and
The MOST IMPORTANT is this setting :
Disable the DPI Setting :
In the Firewall, Advanced, Connections switch the option to Maximum SPI connection (DPI Services Disabled)
After those changes you need to Reboot the Sonicwall appliance.
Monitor the phones and they should stay connected “forever”.