WWAN, or Wireless Wide Area Network, is the term used for Wireless Internet services offered by cell phone providers such as Verizon, AT&T/Cingular, and Sprint. The TZ 190 is a full featured Router and Firewall, yet the WWAN feature sets it apart. The TZ 190 can use a WWAN connection as failover for a primary WAN connection, or it can use the WWAN connection as the primary Internet service in areas where wired services are not available.
As described in the Setup, I configured the TZ 190 with a primary WAN service and the WWAN connection as failover. I successfully tested both Verizon and Sprint WWAN cards with standard monthly packages for this test. Verizon and Sprint aren't the focus of this review, though. There are multiple WWAN service providers and card types supported; SonicWALL has a compatibility listing here.
WWAN services are priced with individual laptop users in mind, and intended for basic email and Internet usage. Using a single-user WWAN service in a router could exceed those limits and result in getting your service terminated. Verizon sets the limit at 5GB per month for their standard $59.99/month WWAN card.
To help with this, the TZ 190 tracks usage on the WWAN service and allows configuring limits. You can limit your usage by billing cycle, and then set a data limit. Below, you can see I've configured the TZ 190 for a billing cycle that starts on the first of the month, with a monthly limit of 5GB.
Figure 6: Setting WWAN data usage limits
The TZ 190 also has a nice report on WWAN utilization. Through several days of failover testing, I only used approximately 22 MB of my 5GB limit. This is a handy feature to be able to see when the WWAN utilization occurred and how heavily it was used.
An additional useful tool in the TZ 190 is the ability to schedule when the WWAN can and can't be used. For example, if there is no need for network connectivity between 12 AM and 6 AM (which is a common maintenance window for service providers), you can configure a schedule to prevent WWAN use, even if the WAN connection fails during these hours. This is helpful to conserve on WWAN utilization.
Testing the WWAN failover service was straightforward. I set up a continuous ping to a public website (ping google.com -t), disconnected the WAN cable from the back of the router, and measured the time it took until the ping succeeded over the WWAN. Switching from a WAN connection to a WWAN connection shows a clear difference in network latency as evidenced by ping response times. Look at the ping times in ms in the top half (WAN) and the bottom half (WWAN) of the below output.
Figure 7: Pinging the WAN while switching to wireless
To test restoral, I reconnected the WAN cable to see how long before the TZ 190 would switch back to the WAN connection. At the point I reconnected the WAN, I had two working Internet connections, so it was interesting to see how the SonicWALL handled this situation. I was impressed; WAN restoral resulted in little or no interruption to Internet connectivity as there was with WWAN failover.
I ran this test numerous times to measure average duration for failover and restoral. On average, it took 1 minute 45 seconds for failover connectivity to be established on the WWAN interface once the WAN was down. For restoral, it took only an average of 25 seconds for the router to recognize the WAN interface was restored and switch from WWAN back to WAN. These results will vary depending on your WWAN provider and signal strength, but they demonstrate the functionality. (The above results were using the Verizon WWAN service.) It is important to recognize there will be some interruption of service while the device switches from WAN to WWAN.
I tried two different WWAN services in this review, Verizon and Sprint. Both have their strengths and weaknesses; you need to choose the one that works best in your area. In my testing, both worked, but I got better signal strength and throughput using Sprint.