Hosted installation / Yealink phones / SBC / Different subnets

[cybernerd]

Dear,

We are planning to rollout a specific setup:
- 3CX SaaS hosted.
- SBC on headquarter (Linux distri in a vmware cluster)
- Around 50 physical Yealink phones.

The phones are located in different subnets and on different locations. All locations are interconnected via IPSEC tunnels. We have full control over the network, we can change routing, allow routing/ports and so on. We have well known network knowledge in house to configure all things properly.

Is this setup possible? How do the phones knows how to connect to SBC? How are these phones provisioned? We want to route all traffic from the phones to the SBC. Does the phones uses broadcasting to know where their SBC is?

We have good 3CX knowledge, but never worked with SBC. SBC becomes more and more familiair since most new customers want to use 3CX hosted as a SaaS solution.

Many thanks!

 

[Alphabetic]

You'll want to stick an SBC on each physical site if there's more then one.

Check system requirements https://www.3cx.com/docs/recommended-hardware-specifications-for-3cx/

You will provision what SBC phones use via the mgmt console, phones will pickup config from an RPS request.

SBC will discover phones via multicast and they'll be visible in the mgmt console to assign.

you'll need configure your routing so the phones can communicate with the SBC.

 

[SteveITS]

Or several Yealink phone models can be “router phones” to act as an SBC for up to 10 each.

 

[cybernerd]

Dear,

Thanks for reply.
So if we configure all phones using SBC, there is no routing necessary between phones directly? Only between all phones and SBC?
Am I right?

I know several Yealinks can act as SBC, but this is not an interesting setup for us at this moment (we have a huge HQ with around 50 phones and the other buildings often contains only one phone...)

Thanks, Pieter

 

[SteveITS]

The phones use multicast to discover the SBC. You can use only VPNs if multicast will get to the 3CX server and they are all considered “local LAN” phones.

With one phone, a SBC or router phone is still needed. A router phone connecting through itself is portable to any network.

https://www.3cx.com/community/threads/which-subnet-for-sbc.79244/

 

[cybernerd]

Dear,

Thanks for your reply.
But still unclear. If:
- We have installed a SBC on a separate subnet.
- We foresee routing between all phones <> and SBC (and offcourse SBC will be able to connect correctly to 3CX hosted).

Will all phones be able to call between each other (audio in both directions)?
We can foresee DHCP offers with options on each subnet > that's no issue.

What will happen? Will it be more difficult to provision phones or will the phones be unable to call internally between subnets?

Thanks!

 

[SteveITS]

Phones behind the same SBC will connect to each other across the network. Phones behind a different SBC will connect through the 3CX server.

All users can call each other regardless of whether they are using an SBC or not.

It is much easier to use an SBC because you do not need to worry about routing, firewalls, etc., and phones behind an SBC show up in 3CX when they are plugged in.

 

[SweetAction]

Is this setup possible? How do the phones knows how to connect to SBC? How are these phones provisioned? We want to route all traffic from the phones to the SBC. Does the phones uses broadcasting to know where their SBC is?

Yes, this is possible.

The phone knows where the SBC is because it uses the proxy field in the phone. This is in the provisioning file 3CX gives it.

So if the phone can talk to the SBC (RTP ports, SIP, HTTP/S, etc) without being NATd, it doesn't really matter where the phone is and the SBC is. For PnP provisioning it uses multicast, but once provisioned, doesn't technically need it for operation (unless multicast paging)

The correct way to do this is to have the main site use a SBC (50 phones, run it as a Linux distri in a vmware cluster) and for each remote site that only has 1 phone, you just use a router phone. No hardware needed, it's built into the T43U (the T43U is a SBC AND ALSO uses it's own SBC to connect back).

In fact, you could just use router phones for every phone, each one being a router phone for themselves if you want. Only reason to do a Linux distri in a vmware cluster as a SBC is if you have phones that can't be a router phone.

 

[SteveITS]

you could just use router phones for every phone, each one being a router phone for themselves if you want. Only reason to do a Linux distri in a vmware cluster as a SBC is if you have phones that can't be a router phone

While definitely possible, and that makes each phone portable, that would send all internal call audio through the 3CX server. Also we have clients with multiple router phones and it's a bit annoying to get the trunk "up" message from all the phones on every Internet connection blip at the office...currently there's no way to alert on trunks, SBC, and router phones separately.

 

[ivank]

Also we have clients with multiple router phones and it's a bit annoying to get the trunk "up" message from all the phones on every Internet connection blip at the office...currently there's no way to alert on trunks, SBC, and router phones separately.

Hi SteveITS!
Are they on v18? In v20 router phones should not generate this event/email.

 

[SteveITS]

Ah, will look at that. Yes v18.