Chapter 27: Disaster Prevention and Recovery

Good disaster planning for telecommunications prevents emergency conditions from disrupting communications. The objective in planning for disaster is to identify the risks to communications viability and choose the proper prevention remedies. Costs must be considered when choosing how to best prevent communications loss as a result of disaster.

All managers of telecommunications should consider it essential to have in place an emergency response team. Each team member should have a clearly defined role during an emergency. As part of planning for emergency situations the following tasks must be performed.

·        Risk Assessment – Facility inventory, list of services and providers names, prioritize.

·        Damage Assessment – Good record keeping of facility wiring, software listing, network data specifics like hardware IP addresses, etc.

·        Document the Disaster Plan – Who does what, who has authority to activate the plan and when. What vendors are permitted access to what systems/areas.

Good disaster planning includes good disaster prevention. Prevention may help minimize damage from natural and man made incidents. Systems should be in place to prevent and control fire, water damage, earthquake damage, storm damage, and human caused damaged.

There are four main categories in communications systems that are vulnerable to hazards.
·        Loss of switching system
·        Loss of corporate data or voice WAN
·        Loss of LEC - local telephone service
·        Loss of IXC - long distance service

Provide redundancy where you can. Cell phone backup is wise. If dependant on toll free numbers for incoming calls, consider backup lines.

Use redundant PBX processors and power supplies; use power-fail transfer devices, etc.

This is very rare. If it happens it will take very long to restore services (days, not hours). If possible subscribe to service from two central offices and preferably from two different LECS. Avoid CLECS – some do not install their equipment in facilities built to the accepted telco industry standards.

Hospitals, public service agencies and law enforcement can be made not subject to loss of service during the LEC’s line load control.

Wide Area Network Loss

The WAN encompasses the public network. There is not much you can do here to prevent an outage. You can take some measures to limit loss of service. All connectivity types can suffer losses in the WAN; Frame Relay, ATM, etc.

Limit the effect of local loop loss by having alternate routes to/from the LEC to your facilities. This could be in the form of:
·        Self-healing fiber
·        Multiple physical connection locations to/from the LEC
·        Route diversity via separate cabling

Loss of IXC Service

The closer to the IXC switching office you are, the less likely outages will occur (shorter loop). To limit loss you can:
·        Reroute toll-free calls to local trunks
·        Split T-1s to IXC to two different switching systems (two paths from you to them)
·        Reroute toll-free calls to a second answering location

Private Network Losses

An organizations LAN and WAN are as susceptible to losses as any other system. Some measures can be taken to limit the loss of outages.
·        Routers can be programmed not to pass non-essential traffic
·        PBXs with broadband capability can serve as backup capacity when data circuit outages occur
·        Routers can be supplied with dialed ISDN backup service

PFT’s can be used in two situations – PBX failure and power failure. Power failure is most likely; PBX’s are installed with UPS backup. PFT’s are used to route analog lines around a failed PBX to normally non-operable POTS telephones. When power to the PBX fails (and after the UPS dies – usually 1 hour) analog lines are connected to the normally dormant analog phones.