An Application Layer Gateway (ALG) is a common function on router, however such functionality is not always implemented in the same way across different vendors. A SIP ALG will modify the VoIP traffic and in most cases cause the service to work unreliably if at all. We therefore STRONGLY recommend that you use a device without a SIP ALG, or one that allows you to fully disable such functionality.

Whenever possible you should choose a router that has QoS (Quality of Service) if you plan to share the same Internet connection with non-VoIP services.

We also recommend that you always make sure your modem is bridged and updated to the newest firmware available.

Incompatible Router List


Airport Time Capsule, Airport Extreme (Wireless G)

Asus RT-N10, RT-N66U
Belkin F5D, F6D, F7D, FDS, and F9K Series, Any
D-Link DIR600, DIR601, DIR615, DIR628, DIR825, DIR835, DIR655 Rev B (or newer)
Linksys BEFSR Series (BEFSR41, BEFSR81, BEFSRX1, etc.)
Linksys E1200, E3000
Linksys RVS4000
Linksys WRT110N, WRT120N, WRT160N, WRT320N, WRT350N
Linksys WRT55AG, WRT54G, WRT54G2, WRT54GL
Linksys WRTU54G-TM
Linksys WRV54G, WRV200, WRV210
Netgear CGD24G
Netgear FVS318
Netgear CG3000
Netgear WGR614
Netgear WNDR3700, WNDR4000
Netgear WNR1000, WNR2000, WNR2500, WNR3500, WNR834B
Netgear CG814WCOM, CG814WG, CG814WT
Netgear WGT624
Thomson DWG-855
Thomson TG585, TG587