Cisco RV220W Router Settings

Posted by Chris P. on 24 April 2019 02:46 PM

Known Issues:

SIP ALG: Causes problems if enabled, but it can be disabled on at least one firmware version.
MTU: Set to Auto by default, which can be set to 576, too low, causing intermittent phone feature failures & loss of call audio (RTP) mid-calls.

Resolution:

Disable SIP ALG:
- Log into the router.
- Navigate to Firewall > Basic Settings.
- Uncheck SIP ALG.
- Click Save.
- If there's no option to disable SIP ALG, the IT or a tech-savvy individual should contact Cisco for help upgrading the router to the latest firmware. If the latest firmware still lacks the option, consider replacing the router with a compatible one.
Change MTU Setting:
- Navigate to Networking > WAN (your router might reference 'WAN' as Internet Settings or use different terminology depending on the firmware).
- Change MTU from Auto to one of the following options:
  - 1500 for Cable.
  - 1492 for DSL.
  - 1492 for FiOS using PPPoE (most pre-2006 FiOS circuits).
  - 1500 for FiOS using DHCP (most post-2006 FiOS circuits).
- Contact your ISP if unsure.

Additional Steps for Polycom Phones (if using the RV220W as the DHCP server):

Navigate to Networking > LAN > LAN Configuration.
Set the following:
- Primary DNS Server: 8.8.8.8
- Secondary DNS Server: 8.8.4.4
- LAN Proxy - DNS Proxy: Uncheck.
Click Save.