We have tested and confirmed on several cases that the softwarefirewallblocks phone registration if enabled because the stockfirewallrules only allow SIP signaling throughport5060.
The softwarefirewallis actually disabled by default because it can cause phone and other problems.
Thegatewaydoesn't allow changing the the SIPfirewallrule port to 6060 or 6061 for Secure SIP, which Intermedia phones use. Custom rules cannot be created as well so the softwarefirewallneeds to be disabled.
This does not mean your network is left unprotected. Your network is still protected by the NATfirewall. Disabling thefirewallabove just disables the stockfirewallrules that block phone registration.
If you are concerned about security, then we strongly recommend you purchase afirewallthat will allow you to create customfirewallrules, which will give you far greater security than thisISP-provided device. A ZyXEL USG-seriesfirewallor SonicWall are excellent options.
Certain Firmware versions have SIP ALG enabled by default. If you have this device, please contact Intermedia Cloud Voice Technical Support so we can run our SIP ALG detector tools to verify whether this gateway has SIP ALG or not.
Login to the gateway.
Click on Advanced Setting at the top of the page. Then click on Security on the left-pane menu and choose IPv4 Firewall from a list.
Set the stealth mode state - leave at the default setting, which isDisabled.
Select the IP address or IP addressing type to which the firewall rules should apply - All Dynamic IP Addresses.
Select the Firewall Security Level to be Off. This is the default setting.
Click on Applyto save changes.
If you are concerned about security, see the Known Issues section above.
This step is needed only if you have or plan to purchase Polycom phones.
These changes will take your computers, phones, and all other devices online for 10 minutes or much longer if an unexpected problem arises.
Make sure to only change the settings below when you can afford to take your network offline:
Under DHCP Settings scroll down to "5. Set DNS servers allocated with DHCP requests" and select Custom Servers. Then enter the following:
Primary DNS: 220.127.116.11.
Secondary DNS: 18.104.22.168.
Click on Applyand wait for the gateway to save changes.
Reboot all Polycom phones.
Check each computer and other network devices to verify they can still browse the internet. If any cannot, reboot them. Windows computers may require running the following command from Command Prompt to restore their internet connection:
The steps below explain how to disable SIP ALG on most CenturyLink-branded gateways. Please let us know if the instructions below do not work for you:
Enter the following link into the address field of your web browser: