I moved a customer into a new office over the weekend and at the same time hooked up cloud-based VoIP phones provided by a third party. The business is using a Cisco/Linksys E4200 router. All phones (4) and computers (3) are connected to the E4200 via switches placed in each of 4 locations around the large office space.
The phones are supposed to all ring for incoming calls, but it seems on each call at least one phone is not ringing and it jumps around from phone to phone on each call. In addition, conversations are choppy.
This is my first experience with VoIP service so I'm at a loss for what the issue could be. I have disabled the SPI firewall and added a QoS prioritization for ports 10000-20000 and 5060, to no avail. I was advised by the VoIP provider to increase UDP timeout to 10 minutes but, since this option does not exist in this router's config, I was told I needed to upgrade routers to a Cisco RV220W which does have this setting.
Is there anything I can do to continue using the E4200 and if not, is there a better router than the RV220W that I should go with?