10. Wireless Performance

NOTES:
• "Signal Quality" readings were not available
• VPN and WEP disabled unless otherwise noted
• Testing was done with an ORiNOCO 802.11b Gold client card in a WinXP Home Dell Inspiron 4100 laptop

I used an ORiNOCO 802.11g Gold card for my testing, mainly because I also used it for the Sonicwall SOHO TZW's testing. I also quickly tried NETGEAR's new WG511T 802.11g card, which uses Atheros' latest "Super-G" stuff, to see how the router handled 802.11g clients. It passed this test with flying colors turning in essentially the same performance as the 802.11b client in my close-range "Location 1" test.

With the wireless test partner chosen, I ran my four location throughput test with the results shown in Figure 10.

Figure 10: Four Location Throughput test
(click on the image for a full-sized view)

To keep things simple I ran the tests with no encryption and no VPN. As you can see, the TZW had consistent throughput in all test locations, but with around 3.8Mbps average throughput - significantly lower than the best case throughput of many current-generation 802.11b products.

Unfortunately, enabling either WEP or VPN security features lowered throughput even more, as Figure 11 illustrates.

Figure 11: Security option throughput comparison
(click on the image for a full-sized view)

Figure 11 shows four Chariot "Location 1" (close range) runs with:

neither VPN nor WEP enabled VPN only enabled WEP 128 only enabled VPN and WEP 128 both enabled

You can see that enabling WEP knocks the 3.8Mbps best case wireless throughput down about 20% to 3.1Mbps. Using a more secure IPsec tunnel, however, lowers throughput only by about 10% to 3.5Mbps. If for some reason you choose to use both WEP and an IPsec tunnel, you'll get almost a 25% throughput hit.

I'm surprised that the tunnel had any effect on wireless throughput, since the wired VPN tests showed an average 5.5Mbps tunnel throughput. But unfortunately, it appears that you'll pay a throughput price when using VPN-secured wireless clients.

The good news is that the WatchGuard's 3.5Mbps wireless VPN performance is better than the Sonicwall SOHO TZW's 3Mbps (by about 15%). The downside is that both may be inadequate to secure busy wireless LANs.

802.11b Wireless Performance Test Results

Test Conditions - WEP encryption: DISABLED - Tx Rate: Automatic - Power Save: Disabled - Test Partner: ORiNOCO Gold 802.11b card			Firmware/Driver Versions AP f/w: 6.2.20 Wireless client driver: WinXP 7.43.0.9 Wireless client f/w: No Info
Test Description	Signal Quality (%)	Transfer Rate (Mbps)	Response Time (msec)	UDP stream
				Throughput (kbps)	Lost data (%)
Client to AP - Condition 1	0	3.8 [No WEP] 3.1 [w/ WEP]	3 (avg) 4 (max)	499	0
Client to AP - Condition 2	0	3.7	3 (avg) 4 (max)	499	0
Client to AP - Condition 3	0	3.8	3 (avg) 4 (max)	499	0
Client to AP - Condition 4	0	3.7	3 (avg) 4 (max)	499	0

See details of how we test.