WWAN - more
I spent a lot of time testing the WWAN connectivity, and learned a couple of key things. The TZ 190 has to be located in an area where there is good cell phone reception to your provider. Telecom and network equipment is often installed in a basement or wiring closet, which may not be the best place for a cell phone connection. If you're thinking about installing WWAN connectivity in your network, make some test calls with a cell phone from your WWAN service provider at the location you plan to install the router.
In addition, you may need to configure the TZ 190 DHCP server with DNS IP addresses from both the WAN and WWAN connections. Devices on your LAN will need DNS IP addresses that work on both the WAN and WWAN connections. The TZ 190 DHCP server default configurations will provide DNS IPs from the WAN connection that may not work for the WWAN connection. I set the TZ 190's DNS Server 1 and 3 to be from the WAN, and DNS Server 2 to be from the WWAN, as below.
Figure 8: DHCP server configuration
The TZ 190W has an optional port, cleverly labeled "OPT," which can be configured as a second WAN port, a DMZ port, or an additional LAN port. Dual WAN connections are another means of redundancy and failover for Internet service. The OPT port works as advertised. With only one WAN service, I couldn't test failover from WAN to OPT, but was able to configure the OPT port as a WAN connection and move my WAN cable to the OPT port and use the Internet. As you can see from the below picture, the TZ 190 Interface Settings shows the WAN connection with “No Link,” and shows the OPT connection as “Connected” with a public IP.
Figure 9: The OPT port
As a side note, if you're using the OPT for a secondary WAN, it is a good idea to look into the cable paths your ISPs use to your location. For example, DSL or T1 connections from a Bell company (Verizon, Qwest, AT&T) and a Competitive Local Exchange Carrier (CLEC) may be non-redundant, as their outside wires could be traveling the same path. What good is it having two T1 connections to the same Central Office (CO) if that CO’s Internet connection fails? On the other hand, the outside wires for cable companies are often different from those of telephone companies, so having DSL and cable Internet connections could provide good redundancy.
For Dual WAN connections, SonicWALL provides four Load Balancing options: Failover, Per Connection Round Robin, Spillover-Based, and Percentage-Based. The Failover option sets the router to use the primary WAN port exclusively unless it fails, when it will then switch to the OPT port. The Per Connection Round Robin will alternate between the WAN and OPT connections with each request to a different URL or destination.
The Spillover-Based option enables the network administrator to set a bandwidth threshold on the TZ 190, which is triggered when the sustained outbound traffic across the Primary WAN interface exceeds that threshold. Upon exceeding the threshold, the TZ 190 will utilize the Secondary WAN interface.
The Percentage-Based option allows you to actively utilize both Primary and Secondary WAN interfaces by assigning a percentage of traffic to each WAN interface. This option effectively increases your total bandwidth with dual WAN connections.