Multi-Location newb question

[kidjake28]

Hey there, was wondering if someone could chime in and explain multi-location set up for me.

If I have office A and B at different sites:

1) Do A and B have to be on the same subnet?
2) Does A have to be able to reach B and vice-versa?
3) What is the best method to set multi-location up?

Any help appreciated.

 

[Adrian Fretwell]

More questions than answers I'm afraid. From a Fusion PBX point of view, the phones can be physically anywhere, as long as they can connect to the server running FusionPBX. There is no "Best method" for multi-location just a solution that is right for you.

I'm guessing that the two sites are just local LANs NATed behind broadband routes? Do you intend to host the PBX installation at one of these sites or elsewhere in public address space?
Do you intend linking the two sites with any kind of VPN?
What other services do you intend to share between the two sites?

Pay close attention to network design, it can make or break an installation.

 

[kidjake28]

Thank you so much for the reply.

I'll try and answer your questions as best as I can.

A site (fusionpbx) will be hosted in the cloud (amazon).
B and C are both local lans with a broadband connection however both of them have vpn connections to A. However both B and C will have separate subnets. For now, until I figure it out or unless I don't need to, B cannot talk to C.
I just want to provide voice service, provisioning nothing more (i.e. video, chat).

And yes I'm trying to figure this network all out now so that I don't run into any pitfalls.

 

[Adrian Fretwell]

It sounds like your setup is fairly straight forward. Ok I'll make another assumption that the VPNs teminate in A on a private network where your server is in a DMZ? (I have no experience of Amazon Cloud).
Separate (different) subnets at B and C can make this easier to manage, you just need to make sure that the machine/router that is the gateway(s) at B and C have routes to A and that A knows how to route to B and C.
With the VPNs in place, all the phones should have access to register with your FusionPBX without having to go through and kind of NAT traversal.

 

[kidjake28]

Yes the vpn's terminate in A on a private network which the fusionpbx is part of (no DMZ required).
Both B and C know how to route to A (and fusionbpx server) no issues at all. A knows how to route back to B and C.
Phones in site B and C can register without any issue on the fusionpbx server. I've done with with separate servers and it's working fine. This is my first multi-location.

My concern is that if a phone in site B calls a phone in site C does phone B require a direct connection to phone C or is the voice relayed/brokered/proxied through by fusionpbx server?

 

[Adrian Fretwell]

FusionPBX acts as a back to back user agent (B2BUA) so in it's default configuration all signalling and RTP goes through the server. I know we often see VOIP diagrams where SIP signalling is exchanged between B and A and between A and C and the RTP media stream is sent directly between B and C, but this is not the case with Fusion.

Sounds like you have got it sorted.
A.

 

[EasyBB]

My concern is that if a phone in site B calls a phone in site C does phone B require a direct connection to phone C or is the voice relayed/brokered/proxied through by fusionpbx server?

There are situations where you could send media between clients bypassing Fusion:



I don't think it will work in your situation though, since separate VPN tunnels are involved.

 

[kidjake28]

Thank you Adrian for all the help. I really do appreciate it.

EasyBB. I guess you are correct as the two tunnels won't be able to talk to each other. I'm curious what would be the benefits of switching this option to Bypass Media? (Not even sure where this option is)?

 

[EasyBB]

I'm curious what would be the benefits of switching this option to Bypass Media? (Not even sure where this option is)?

When bypass media is active, RTP media won't go through the Fusion box. This will be particularly helpful if you have a large enough office where Fusion runs in the cloud, so media between extensions can stay within the LAN (hopefully!).

 

[kidjake28]

That sounds good but what if you have a multi-location scenario. I'd want local RTP to stay within the LAN but obviously not when connection to the other site.