Sooner or later, you will live this nightmare. At some point, every digital circuit has a problem. The only questions are:
* When will it happen?
* What is the impact to your firm, your customers and your employees?
* Have you provided for failover so you can keep communicating?
* Do you want to protect yourself?
With regard to impact, you'll need to consider whether your customers will wait to reach you ... or simply call the competition. If you have a 911-type emergency, will the person involved be able to reach 911? If your phone lines are down, sometimes the person in an emergency situation can't use a cell phone or doesn't have one or it doesn't work.
Do you really want that risk? Your liability (since you can't provide for continued communication) could be hundreds of thousands of dollars, or even millions. And finally, can your employees do the work they are supposed to do without the phone lines they depend on?
The means for protection are relatively simple. They fall into two categories -- dial in and dial out.
For dial in, it is both a carrier and phone system issue. You must use a telephone carrier that can provide automatic failover to another telephone circuit or circuits. If your carrier can't do this, switch to one that can. You will need more than one phone circuit.
The second circuit (or circuits) can be regular telephone lines (call POTS) or another digital phone line. Determine what you need to continue to conduct business and what fits your budget.
If you want the best protection, you want phone lines from two different carriers -- with one carrier failing over to the second carrier. Very few carriers will do this, but a few do.
Program the phone system and make sure the provisioning is done correctly with the carriers so that the call routing that you want to use in failover mode works. That means incoming calls go where you want them to, both in normal operation and in failover mode.
Finally, test the failover. Don't wait until a problem happens to find out that the carrier and/or the phone system programming does not provide the failover protection and continued operation that you require.
For dial out, it is a phone system issue. Program your phone system to dial out on different circuits if the primary circuits don't work. If your phone system can't do that, consider changing systems.
If voice communication is absolutely critical, it is possible to have more than one phone company central office servicing your site. So even if one blows up, you still have a dial tone and can receive calls. It is quite expensive, however.
Check to see how your phone system can be made fault-tolerant and redundant, or how you can continue to take and make phone calls even if your phone system dies.
Randy Wear is president of Decision Systems Plus Inc., a member of the Technology Assurance Group (TAG). DSP provides computer and telephone technology infrastructure sales and support nationwide to increase client's productivity and profitability. Reach him at firstname.lastname@example.org or (847) 544-5818.