Disaster Recovery in the Cloud

Telecom Clouds Play a Critical Role in Disaster Recovery


In case of an emergency, time is short and communication is essential. Disaster strikes when you least expect it but business continuity planning can minimize its impact. A cloud based communications recovery plan designed in advance to automatically invoke if your PBX, PRI or power goes down is good business sense.
A typical legacy PBX failover plan sends the calls to backup analog lines or diverse carriers in the event of a primary PRI T1 failure assuming access to the building remains intact. Abacus Enhanced SIP Trunks in failover mode pull the calls back to the cloud for full business continuity and communications recovery.
What are the real costs of lost service or business to you? How many lines and critical staff need to be incorporated into your communications disaster recovery plan? Can you operate at 20% capacity in an emergency? Abacus will replicate your auto attendant(s) in the cloud and together we will decide the appropriate level of services based upon your goals. For example, let’s assume you have a 200 person company that can run at 20% capacity in an emergency situation. You identify 40 people who will be assigned a virtual extension in the cloud. We assume that 1 in 4 are on the phone at any given time. We configure 10 talk paths (SIP trunks) in the cloud. You choose the less expensive metered pay for usage plan because you anticipate the failover plan will not be used. It’s insurance and most of us can get by with the minimum. Plus cloud services “burst” upon demand in the event you exceed the limit – in this case 10.


Enhanced SIP Trunks are call paths or concurrent calls that are routed over an IP network connecting the customer to the cloud based servers. Abacus Enhanced SIP Trunks with PBX fail over protection and virtual PBX extensions are a creative way to backup or replace legacy PBXs and traditional PRI/analog circuits.
Enhanced SIP Trunks with built in PBX Failover offer more value than standard SIP trunk services. If your onsite PBX, PRI or power fails for any reason, enhanced SIP Trunks automatically handle and route your calls until the service outage is resolved. We pre-program the fail over sequence in advance. You have full access to self manage and change routing, extensions, voicemail boxes, groups and auto attendants.
Inbound calls divert to any outside number you choose – another office, a cell phone, a home number and keep the same auto attendant and voice mail functions. If the call is not answered after going through the routing scheme, the call goes to voice mail in the cloud. Outbound calls are made from SIP phones pre-programmed with the external IP address of the cloud PBX server and can operate from any location with an internet connection. In all cases, you maintain a consistent look to the outside world.

How it Works

Standard SIP trunk

If there is no handshake after a specified amount of time (i.e. the PBX does not answer) then the caller will get a busy (typically after 2 seconds).

Enhanced SIP Trunk

Tries a remote PBX or SIP device first. If busy, or offline, or no handshake after 2 seconds, pull the call back to the hosted PBX in the cloud. Call the 2nd extension that is pre-built in the cloud and configured as an auto attendant, ring group, call queue, outside number, cell phone, home number, remote office or voicemail box.

Benefits Enhanced Trunks

1)     Customized DR plans – one size does not fit all
2)     Reroute to cloud based voice mail, another office, cell phone or home number
3)     Reroute every worker or a cluster of emergency ready workers
4)     Option to self manage and change routing, extensions, voicemail, groups and auto attendants
5)     Built in preconfigured PBX failover protection
6)     Redundancy and flexibility not available with old style PRI or POTS lines
7)     Affordable communications disaster recovery using existing equipment
8)     Eliminate multiple providers for multi-office locations
9)     Proactive NOC monitoring 24x7x365
10)Ability to easily set up drills to test procedures and scripts during normal hours and after hours
11)Backup up as many primary and underlying auto attendants as you need
12)Backup every voice mail box or selected voice mail boxes
13)Backup as many ring groups / call queues as you need
14)Quadruple redundant Tier 1 PSTN and internet carriers for blended bandwidth
15)Fortress like data centers with geographic diversity
16)VoIP survivability – local mode and dual Ethernet WAN virtual failover
17)Architecture: n+1 clustered server redundancy

Configuration of SIP Trunks

1)     Registration: to connect your remote PBX or SIP device to the Abacus Cloud you will need to enter the SIP Registration Hostname, SIP Username, and SIP Password into your remote PBX system or SIP device-supplied by Abacus or viewed online.
2)     Authentication: User name and password or IP Address based
3)     Caller ID: Decide whether to use the same phone number for every outbound call or pass through the caller ID of remote PBX or SIP device
4)     E911 Caller ID: Decide whether to use the same phone number for every outbound call or pass through the caller ID of the remote PBX or SIP device. In this scenario, we will register pass through Caller IDs with the E911 provider
5)     Advanced options are generally left to the default settings: codec, DTMP mode, NAT, can reinvite, qualify and progress in band.
6)     Test the call flow during normal business and after hours to determine failover extensions are pointed direct to auto attendant or outside numbers. Test 0-9, *, #
7)     Install CPE equipment if needed. Direct connection to SIP compliant PBX or connect to gateway device for legacy PBX