Site survivability

[hood]

Hi All,

I have a question regarding multi site deployments.

In a scenario with one head office, and multiple branch offices in a star topology. Each branch office will have an 3CX SBC, and also a PSTN gateway device.

In the event that comms go down between head office and the branch office, will the site be able to survive, ie make / receive calls using the SBC and on site PSTN gateway?

Or if not, how can we achieve such a thing?

Thanks

 

[leejor]

In a word...No.
There are/were some gateways, such as the now discontinued, single line, SPA-3102, that had a relay to connect an analogue set (FXS port) to the PSTN line (FXO port) in the event of a power failure. However, what you want to achieve would require a full PBX (of some sort), at the remote location, capable of controlling both the sets and the gateway.

 

[NTB Inc]

There are a few different ways to achieve this. This is what we have done.....

Assuming your IP Phones support PBX redundancy or failover (each manufacturer uses a different term slightly) basically allowing you to define 2 PBXs the phone will register to, you can modify your 3cx provisioning profile to include a local gateway at each site to register to as the secondary. Should the WAN/3cx experience an issue, the local site phones will register to the local gateway after the configurable failover interval. There are many survivability gateways out there that should work just fine. We use the Patton SN4114s with the SIP registrar licensing for this to work, we can then failover and use POTS lines for calling and/or if desired could do some basic inbound routing as well. https://www.patton.com/voip-gateway/sn4110/
Sangoma also has some options for this as well: http://www.sangoma.com/solutions/branch-office-survivability/

The key feature is the SIP registrar licensing as this runs a "mini-PBX" enough that call handling can happen, you won't have auto attendants or anything fancy but its enough to do some basic in/out calling depending on your config. We have a robust WAN/3cx infrastructure so we seldom use these and they are more for the allowing 911 calling, emergency calls and keeping "connected" than normal day to day but it works well.

 

[hood]

Crap.

Burt thank you for offering up a solution. We would be using Yealink T4x series handsets, and Patton 4114 gateways, so that is a positive.

Does this solution seem to work well?

 

[NTB Inc]

Yes works very well, some good reading....

Yealink Redundancy: http://download.support.yealink.com/download?path=upload/attachment/2015-3-10/3/2497e56d-76cd-4b6f-b14a-09effb6c7c1f/Using Server Redundancy on Yealink IP Phones.pdf

We use the T23G phones and it works well. In your 3cx provisioning profile depending on which account you are using look for account.1.sip_server.2.address and account.1.sip_server.2.port these will setup the secondary PBX options to the local Pattons. There are also some failover timing adjustments you may want to make as well but we just use the defaults. You will need to keep good notes of what you changed in provisioning though as most updates to the templates will overwrite and/or you will want to use the latest templates from 3cx so you will need to re-incorporate the changes. Depending on your setup you may need to have a provisioning profile per site so each site is provisioned to use its local Patton.

You will need to buy the SIP Registrar licensing for your Patton SN4114, you can do up to 3 registrations for free but beyond that you need to license, the license is cheap though, here is their KB article on that: https://www.patton.com/support/kb_art.asp?art=196&
Most Patton dealers can sell the license, I believe its part # SNSW-REG
Again you will have very limited calling (no voicemail, auto attendant, etc.) basically only in/out BUT in a WAN/3cx down situation at least people can call out, call 911, etc. For us the key piece is being able to have folks pickup the IP phone and still call 911 if needed during an outage.

 

[leejor]

I stand corrected.

 

[3CXDude]

Also worth a look

http://www.beronet.com/products/beronet-sba-app/

 

[hood]

Thank you NTB Inc and 3CXDude!

Would we be able to achieve intra-site calls in the failover scenario when the handsets are registered to the Patton device?

 

[3CXDude]

I can't speak for Patton, but yes on BeroNet