June 2012 IT Business Consulting Newsletter

Improved Internet Reliability

By Tom K

A while back, I showed you how to easily increase Internet reliability with redundant Internet circuits (see “Improve the Reliability and Speed of Your Business Internet Connection”).

In this month’s newsletter I describe a simple addition to the original solution to further enhance your Business Internet connection redundancy.

Original Solution

The original solution is simple but elegant – deploy a relatively inexpensive firewall that can load balance two Internet circuits, typically Cable and DSL. Since the firewall is load balancing the two circuits, they are both "live" full time and your enterprise gets full use of the aggregate bandwidth from both circuits. If one circuit goes down, your enterprise continues to use the bandwidth from the circuit that remains up. When the down circuit comes back up, the firewall provides the bandwidth from the restored circuit to your enterprise.

So, if you have a 16 Mb Cable circuit and a 7 Mb DSL circuit, your office sees a 23 Mb connection to the Internet. If the DSL goes down, your office does see an overall Internet connection speed reduction to 16 Mb, but does NOT experience an Internet outage. This is completely transparent, and when the DSL comes back up, your office Internet bandwidth pops back to 23 Mb. This solution (the firewall) only costs about $400... a tiny price to pay for greatly reduced Internet outages!

But What If ?

So what happens if you have redundant Cable and DSL circuits and they fail concurrently? We find this to be quite rare (we monitor and log all of our clients’ Internet circuits real time), but it can happen. Additionally, we have clients whose Cable and DSL providers share a core trunk. If the trunk fails, both providers’ circuits (Cable and DSL) fail and the client's Internet is down.

Enhanced Solution

To provide an additional level of redundancy, we plug a 3G Cell Card into the firewall. As the 3G bandwidth can be somewhat expensive, we configure it to be a “Fail Over” circuit, rather than being part of the Load Balancing system. The 3G card just sits there unused but waiting. If both primary circuits are concurrently down for 2 minutes, the 3G card goes live to provide Internet connectivity. As soon as either primary circuit comes back, the 3G card hands traffic over to the primary circuit and goes back to a wait state.

While the solution does not provide extensive bandwidth, it does provide emergency bandwidth to update your web site for real-time availability and booking, and for email. And, since the card only operates in emergency situations, it is relatively inexpensive.

If you have any questions or comments concerning this article, or would like assistance setting up redundant Internet circuits for your enterprise, I’d be happy to discuss this with you at your convenience. Feel free to contact me at TomK@TomKConsulting.com, or via my cell 443.310.5110.

Next month I’ll begin a series of discussions on Identity Theft issues and protections. See "Protect Your Company Bank Accounts".