* When cable and DSL back each other
We’ve often suggested considering DSL and cable modem Internet connectivity services for SOHO and even ROBO (remote office/branch office) locations. As the corporate infrastructure continues to fragment into smaller, more distributed sites, this becomes an important option.
Consumer-grade connections usually cost less than $50 per month. However, dial backup is often not a viable alternative, other than perhaps in transaction-centric retail sites not transmitting Web-based traffic, leaving you with a less-than-perfect failover configuration.
With the proliferation of DSL and cable services, though, you can now often have both for less than $100 per month. Until recently, this has required that you manually switch your router from one service to the other in the event of a failure. And this has meant paying for a pretty good service sitting there most of the time in standby mode.
For this reason, we’ve been pushing for the availability of SOHO/ROBO routers with dual Ethernet interfaces. Note that such products at very reasonable prices ($199 – $499) recently became available from Cisco’s Linksys division. Similar, higher-end products were tested and reviewed by Network World from Fortinet, Hawking Technologies, SonicWall, Xincom and ZyWall in September (for results, see https://www.nwfusion.com/reviews/2004/0913rev.html).
Using such products, you can use two inexpensive broadband services, and if one fails, the other kicks in automatically for the whole load. And if both services are live, you can load balance between the two for still better throughput.
This pretty much solves the reliability issue because you now have parallel independent transmission paths. For instance, even if the reliability of each service were only 95%, the reliability of having at least one of the two parallel paths available is 99.75%. And if you assign the more realistic probability of 99% availability for each service, you end up with 99.99% availability of one of the two paths.
We’re curious about your thoughts on the reliability potential of this setup. Historically, we’ve heard from many of you that, in general, consumer-grade broadband services are not ready for prime time for business use. Meanwhile, though, service providers are rolling out residential VoIP services that use them as the infrastructure. In some cases, these services even provide E-911 capabilities.
There’s a bit of a disconnect here. Not good enough for business. But good enough to trust for emergency services? Let us know your thoughts.
