I'm managing communications for a company with about 1,000 employees spread across 10 locations. We're using a full mesh SD-WAN setup for our network. Currently, 6 of our sites have a dedicated PRI installed with their own phone numbers, while the remaining 4 sites share a PRI. I'm trying to understand the key differences between PRI and SIP calling. Specifically, in a disaster situation, if the building housing the PRI goes down, that location completely loses its calling capabilities. The ISP mentioned it would take 30 days to move the PRI and numbers elsewhere, which isn't feasible for us if we want to be operational within a day. Does SIP offer a quicker recovery option? Any insights would be greatly appreciated!
7 Answers
PRI is an older technology connecting phones over traditional lines, while SIP is digital and supports unlimited connections. If you're looking for something more adaptable in emergencies, consider SIP trunking.
Exactly! SIP allows for much quicker recovery. If you have a modern setup, waiting on PRI reconnections can really slow things down. SIP, being more internet-based, performs better in these recovery scenarios.
Your ISP might take 30 days to install a new PRI in a different building. However, in a disaster, you should request call forwarding to another number. A good provider could set this up in minutes. SIP can have failover almost immediately with the right setup, especially if you keep backup hardware at another site. Expect some level of downtime if a location is destroyed, though.
That 30 days estimate sounds optimistic. Usually, it takes 60-90 days for such installations unless it’s for a location that's already connected.
SIP is much more versatile since it doesn't depend on physical connections like a PRI. With SIP trunking, you can update your routing IP easily or forward calls to a different number. For best results, consider having redundant phone systems across locations, allowing for automatic call routing failover.
SIP has a significant advantage in recovery time. You might also consider implementing a Starlink system for even quicker failover, like some major retailers do!
SIP allows for pretty much instantaneous failover, assuming your sites are configured for it, especially concerning signaling and firewalls. For example, Twilio offers SIP trunking with built-in redundancy across their locations, meaning calls can route via the best available path without downtime.
Exactly what I needed! Our ISP does SIP trunking, so I’m not sure why they didn’t mention this approach. Thanks!
In a disaster recovery scenario, it’s practical to set up another service provider with new phone numbers and then create a call forwarding plan. Alternatively, a reliable SIP connection to your main site could simplify managing service level agreements. Also, how you deploy these systems influences their effectiveness—keep that in mind!
Thanks for clarifying! SIP trunking is what I meant by SIP calling.