Client with multiple sites

[Brett Garfitt]

Hi

Hope I can get some advice concerning this. I have been able to glean some great advice from other threads but was just looking for some clarification

We have a client with four sites and we intend pushing out 3CX to each site. Total of around 140 extensions with approximately 60/50/25/5 split between the sites, using Yealink handsets.

We had one idea of cloud-basing the Windows-based 3CX at a datacentre with SBCs at each site. The sites are VPN connected, but we did not want issues at one site to cause no phones for all sites, hence not basing at one of the client sites. We also considered having a 3CX at the two main sites and creating a bridge setup. This would allow some form of redundancy to the two larger sites but while BLF functionality is there, the ability to share Company Phonebook between sites is not. Hope I am right there.

We also looked at the Enterprise failover setup, possibly using two cloud-based solutions for automatic failover, relying on the SBC(s) at each site. We considered our own failover system based on using replicated VMs which would be fine, however, with different external IP addresses, that would not work without re-installing the 3CX for the new external IP, even though the FQDN would still be the same - am I right on that theory?

We understand that we would need multiple SBCs at the sites in a 20:1 ratio.

Ultimately, my main question is: what might be the best solution, providing the best uptime, when pushing out to multiple sites?

Thanks

 

[NickD_3CX]

I want to start by saying that if you ask this same question to 10 different people, you will probably get 5 different answers, all of which are correct. It is much down to personal preference and what you feel more comfortable with.

My personal opinion would be that, by the time you have all 4 sites VPN'd with each other already which implies that you have VPN capable devices at each site, I would go with putting 3CX in the Cloud.
I would make sure that the platform I go for allows you to setup a VPN, so that each site also has a VPN towards the Cloud Platform where 3CX will be installed.

Then all you would need to do is provision the phones as "Local" extensions. Note that PnP probably won't work, so remember that you would have to manually enter the provisioning link into each phone the first time around (or use DHCP Option 66).

The reason this would be the way I set it up is because on calls between local extensions, the audio traffic would stay local and not go over the SBC, and for call between extensions from other sites, it would go over the between them VPN link.
Downside? The WAN connection goes down for a site and nothing works (unless you have a backup WAN, which you probably might have at the 2 bigger ones)

 

[Brett Garfitt]

Thanks for that. It's always good to get an insight into other people's ideas as they often have some really creative solutions which you had never thought of.

 

[DSXVOICE]

Hi Brett,

Nick's answer is well thought out. Of course, I differ just slightly. You do want local SBCs and while VPN's are handy for maintenance, you're better off letting the VOIP traffic traverse the internet. VPN's do not failover or recover quickly when internet connections fail. They also require a higher tier engineer to diagnose and repair. Users have little patience for VOIP outages.

Best,

Kirk

 

[Brett Garfitt]

Thanks, Kirk.

I will agree that relying on the VPNs is a potential issue. I am happy to rely on the secure tunnel using the SBC as that does bypass the VPN and at least allow the phones to work. That was a decision which I liked and the SBC works well in testing.

 

[cobaltit]

@Brett Garfitt

Also, you mentioned 20:1 for the SBC. That only applies to the Raspberry Pi based SBC. If you install the SBC on regular PC hardware (or VM) you can support more phones on the SBC.

 

[Brett Garfitt]

Good point. Thanks.

 

[eddv123]

To extend a little further-Windows and Linux SBC's support 50 extensions per SBC and multiple SBC's can be supported per site to increase this number.

I personally am not a great fan of the multiple SBC option however and if I required more than 50 extensions per site would most likely opt for VPN.