CorpWest VOIP Disaster Recovery

Given recent natural disasters and the general need for enterprises to assure business continuity, disaster recovery of voice networks is a critical consideration. Traditional circuit-switched telephony networks generally exhibit a very high level of reliability (often greater than 99.999% uptime at the switch level). However, during disasters or other sudden major changes, the centralization of TDM/circuit-switched telephony can prove to be a liability. Here a VoIP system may excel in providing telecommunications continuity. Given the ubiquity, robustness and distributed nature of IP Networks, it is understood that IP Networks can be engineered to a higher degree of fault tolerance, than their fixed line, circuit-switched counter parts.

The weakest link in a IP-based phone system is the "last mile" - the IP link between our secured, redundant data centers where the IP PBX is located and the end-user location where the phone handsets are. This is typically delivered over vDSL or T1s but is often only over traditional DSL lines where bandwidth is shared with web browsing and other Internet traffic.

Even if the "last mile" is up and the Internet connection is live, conditions at the customer location can cause a VOIP outage or quality issue. Wiring problems, power outages, and equipment becoming unplugged are some of the most common causes of IP phone issues at a customer location.


By hosting your IP PBX in our data center, your server has the highest "up-time" available. Incoming calls have a very good chance of reaching your IP PBX. If your actual extension is unavailable for ANY reason, the IP PBX will automatically take a message for you which can then be retrieved from any phone or over the Internet. If your primary location is completely down (power outage, network or Internet failure, building disaster), you can easily route your incoming calls to another location:

All of the above are easily and quickly reversed once the situation is over. None of the above are available in a traditional phone system.

CorpWest has multiple connections to the traditional telephony networks in both their San Jose and Los Angeles data centers. If a particular outgoing connection is congested or experiencing poor quality, we can re-route that traffic over a different carrier. Since most phone companies not pass traffic digitally, your calls stay digital until the "last mile" to ensure the highest possible call quality.

Should there be a problem with your hosted IP PBX, we can quickly move your configuration to a stand-by server including all of your extensions, voice trees, and settings (except saved voicemails). Even your contacts and buddies on your Polycom phones are saved and backed up on the servers so that even if your Polycom phone fails, all of your settings and contacts will be transferred to the replacement.

Most customers also subscribe to our E911 service. If a call is placed from a customer location that has E911, the call is routed directly over our IP system to the correct 911 call center for that location. In the event the phones are unable to reach the phone system, we have several backup methods available:

  1. Cell phones: Cell phones are very useful in an emergency. They are portable and do not require power or physical phone lines.
  2. Fax line: Many customers have a fax machine with a handset that can be used to call 911. Because it uses a land line, the 911 service knows exactly where and who is calling. The fax line itself is not dependant on power, Internet or network - just the physical line from the phone company to the actual fax machine.
  3. ATA Adapter on the fax line: With an adapter, we can connect a regular analog phone yo your fax line. The analog phone is both an extension on the phone system during normal operations and can place calls over your fax line in an emergency.
  4. SIP Proxy with FXO: A SIP proxy box provides the same features as the ATA adapter, but also would allow the other IP phones to use the FAX line to place an outgoing call if they still had power and were attached to the local network. The working extensions would also be able to call each other.

At the customer location, there are a few steps that we can take to avoid potential VOIP outages and maintain call quality. First, we recommend either a dedicated Internet connection just for VOIP traffic or a high-speed shared connection with QOS at both end to prioritize VOIP traffic. If you are in the SF Bay Area, CorpWest can usually provide either. A properly sized and installed UPS can provide you with phone service even in a short power failure when combined with a PoE switch and proper in-house wiring. Upgrading your old hub and switches to new smart or managed switches can improve the speed of all your network traffic as well as assist in tracing wiring problems should they occur.


Because the phone system and phone lines are no longer physically connected to your primary location, you now have options for disaster planning and outage planning on your both your incoming and outgoing calls. With proper design and execution, a VOIP system can help maintain communications with your customers and employees even in a disaster. But each customer's needs, current resources, and budgets are different so discuss your disaster plan with one of our VOIP consultants as you plan your move to an IP phone system so we can design, implement, and support a VOIP system with your particular disaster recovery needs in mind.