What can you do for contingency when your ITSP's provider goes down?


One of the major carriers that provides inbound calls to one of the ITSPs I use had a 3 hour issue whereby inbound calls were not getting to my ITSP. I fail-over in place when we lose connection to our ITSP, but I cannot see a way to get fail-over if the ITSP’s provider has a problem.

Anyone have any thoughts or suggestions?


apart from having another ITSP as a fail over there is very little you can do.


Yes Kev, but how do you arrange inbound fail-over from another ITSP?


in all what you are trying to achieve is an ITSP failover …

If it was your own company… I would suggest the following ways: You be the ITSP

  • Create your own ITSP so that your own lines are delegated via your company so that you can use an external service perhaps using AWS Amazon as the database lookup and pointer… if 1 x Internet connection goes down to your office, fire up a 4G dongle and repoint the database record for the end point to the 4G dongle IP

HA using AWS Amazon servers. there are plenty of Voip carrier grade software solutions out there to use…

If you can throw a copious amount of money at it there will always be a solution… but at what cost…


There is nothing you can do about it other than using an ITSP that has (geo) redundant data centers that can pickup the load when a currently on-line center is impacted and can no longer handle calls.


Actually you can still be your own ITSP - use AWS Amazon servers with the appropriate VoIP carriage software…

and be your own ITSP !

There is always a way… just throw money in the pit… but then again you can be the latest ITSP for others and reap the rewards for your expertise instead of relying on the ITSP that failed you recently…


That’s what I thought. And even then, if their upstream provider goes down, there is no way to redirect the incoming number.

No. The problem is having incoming calls from the main phone number be redirected when your provider’s provider goes down.

I have fail-over if my connection to my provider goes down. It’s how to get redundancy for a given phone number when things upstream fail.


In many cases, even primary carriers still have some level of disaster recovery. You need to ask your ITSP. Century Link, Windstream, AT&T and others all have disaster plans in anticipation of various issues to mitigate the impact, but you still have to ask the ITSP as this is your interface and then check around with others to see how they might handle it.

Of course, not knowing the details of your case, I assume it possible that there was nothing that could be done. However, if your ITSP has a center in NY and another in CA, the feeds from the upstream carrier may not be the same so that one may be down, the other not. Not much different than if the ITSP lost their center in NY and rolled to CA.


You have redundancy for internet failures… your ITSP needs to have redundancy for when issues arise where they cant deliver by the means you are connected or get another provider.

You could also become the ITSP and use multiple data centre servers from the AWS Amazon farm.


Connections from PSTN via DID to your ITSP are typically one point. If that point goes down, your incoming calls are down. Short of @lpneblett’s suggestion of geo-based failover from your LEC provider, that’s not going to happen.

I know of no LEC that offers that capability today.


From a LEC/PSTN transition no, I agree. I do not know if any may have been on-network calls nor who or how the ITSP is set or not to handle such.