While our ESI Hosted Services SIP trunking service offers Geo-redundancy between the ESI Hosted Services data centers in Los Angeles and New York City, some customers may require Disaster Recovery services in the event of a failure of their ISP, IP-PBX, or other localized network components. Below is a current description of our Disaster Recovery options for SIP trunking customers:

1. Standard Disaster Recovery setting: If we receive no SIP responses to an invite (an inbound call), we send it to an off-net DID number. We can do this on either a single DID, a range of DIDs, or everything pointed to your trunk. No additional charges for configuration of a single disaster recovery DID.
    
2. Advanced Disaster Recovery setting: If we receive no SIP responses to an invite (an inbound call), we send it to an Auto Attendant hosted on our platform and then we can send the calls to most anywhere - Voicemail2Email, POTS line, cell phone, etc. Service charges apply for use of Virtual Extensions and Auto Attendant. 


3. SIP to SIP call routing modification: This isn’t commonly requested, but let’s say that you have two internet circuits (connection A and connection B).  We would build a SIP connection to each circuit IP address and then implement call routing so that if all calls to connection A's IP address fail, then we’d route to connection B's IP address and vice-versa (something that might be useful if you either have two separate call centers or two circuits feeding into a single IP-PBX/LAN).  Additionally, just like options 1 and 2, we can do this on either just one DID, a range of DIDs, or everything. Service charges will apply for additional trunk and channels.