Supersize your WAN

We look at some of the dual-WAN routers available on the market

Six years ago, we tested dual-WAN routers as a way to pump more bandwidth into small businesses that couldn't afford a T-1 and were stuck with relatively slow DSL and cable connections.

Today, speed is less of an issue. For example, our suburban test lab has an 18Mbps connection with AT&T's U-verse service and 15Mbps (with burst downloads as high as 30Mbps) with Time Warner Cable's Road Runner Turbo.

The critical need today is maintaining connectivity. The ability for dual-WAN routers to combine throughput from two sources, continue if one drops, then reconnect when the link comes back is a key selling point.

Of course, cost is important, too. A T-1 delivers better uptime than any connection from a phone or cable company, and a synchronous connection in and out, but at hundreds of dollars a month. Two 15M to 20Mbps small business broadband connections combined provide far more downstream throughput and 100% network redundancy, all for a total of $80 to $120 per month.

We tested six dual-WAN routers: Check Point 1000N, D-Link DFL-210, Netgear FVS336G, SonicWall TZ200, TRENDnet BRV324 and Xincom DPG603. All units share a fairly long list of standard features, including VPN support, DMZ support, some level of QoS, and firewalls of varying strength and granularity. Several of the more expensive units offer intrusion detection and prevention.

We found that the ability to separate traffic between two active WAN links is much improved compared with our last test. All units allow you to weight one WAN connection more heavily than the other in order to push traffic in that direction. Most offer ways to segment users or protocols to a specific WAN link. All support firewalls capable of passing the full throughput of almost all inexpensive broadband links that will be tied together by these dual-WAN routers.

Dual-WAN routers don't really double the throughput to any one computer, but they deliver their true worth when several computers are pulling lots of traffic. No longer will the video download fanatic suck up all available bandwidth.

In our redundancy testing, each router continued after one WAN link was dropped, and recovered when the link came back up. The occasional five minute "pause" that randomly afflicts residential broadband service in our area disappeared, as the second WAN took up the slack invisibly.

Our VoIP phone had connection troubles with some routers when we configured them to split traffic based on bytes or packets. Setting the load balancing metric to IP addresses eliminated those issues.

For small businesses, Netgear and TRENDnet are priced right, easy to use, and provide basic but not overwhelming firewall and security support. For branch offices with remote management and security policies to enforce, investigate Check Point and SonicWall first.


Dual-WAN routers have come a long way. WAN connections are easier to establish, and all units we tested have configurable load balancing. The performance increase, not to mention the redundant Internet connections that all but guarantee uptime, should put these dual-WAN routers at the top of the shopping list for every small business that needs a router.

Gaskin is an author, consultant and speaker. He can be reached at

Read more about lan and wan in Network World's LAN & WAN section.

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Tags wirelessNetworkingrouternetgearsonicwallat&ttime warnerLAN & WANwan routers

More about Check Point Software TechnologiesD-LinkLANNetgear AustraliaSonicWallTime WarnerTRENDnet

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