Other features of the router, including Firewall, Content Filter, and VPN, are also easily accessible. The X-550NH has a built-in IPSec VPN with 2 IPSec VPN tunnels for secure data transfer between remote sites and the central sever. The Content Filter feature is rather simple. You can restrict Web features such as ActiveX, Java, cookies, and Web proxies, and you can block access to the Internet via URL keywords. For example, if you block the keyword "CN," then you won't be able to access sites with this keyword in their domain names, such as cnet.com or cnn.com.
For security, the router supports all existing wireless-encryption methods including WEP, WPA, and WPA2. As mentioned earlier, it also comes with Wi-Fi Protected Setup features that allow you to add a new client to the network at the press of a button, instead of having to type in the encryption key manually.
We tested the Zyxel X-550NH with a Linksys WUSB600N wireless adapter and the router performed terribly when it came to data transferring, both with the stock antennas and with the high-gain antennas.
In the Throughput test, where we test a router at its best settings with a wireless client that's only 15 feet away, the X-550NH scored 16Mbps, compared with the X-550N's 50.2Mbps. At this speed, the router would take more than 4 minutes to finish transmitting 500MB of data.
Performance didn't improve in the Range test, where the client is 100 feet away from the test router. In this test, the X-550NH registered only 7.2Mbps. In the Mixed mode test, where the router was set to work with both Wireless-N and legacy wireless-G and B clients, it scored merely 9.6Mbps.
These scores were by far the slowest we've seen in a wireless router. We suspected that the router came with some faulty firmware, but the Zyxel's support site doesn't offer any firmware updates, even though it did for the X-550N.
The router also failed our 24-hour stress test. In this test we transfer a large amount of data back and forth from different wireless clients to see if the test router can hold the connections continuously over an extended amount of time. The Zyxel X-550NH's signal reset after a very short time, and continued to do this every a few hours. We also lost the connection to the Internet from the wireless client at times, even when the local connection was live.
Despite the extremely long range--more than 340 feet away with the use of the high-gain antennas--we couldn't see how the X-550NH is useful as a viable wireless networking solution. Hopefully a firmware update can fix this.
(Longer bars indicate better performance)
Service and support
The Zyxel X-550NH comes with a two-year warranty, which is better than the one-year warranty that most routers come with. The support page on Zyxel's site offers nothing for the router except for a PDF of the router's spec sheet; there's no sign that there will be firmware update in the future. The company's toll-free technical support is available Monday through Friday from 7 a.m. till 7 p.m. PT, and Saturday and Sunday from 8 a.m. till 2 p.m.