Multicast Paging Questions

[MrZabudske]

I was wondering if someone could help clarify a few things with 3cx and multicast paging...

1) Can someone explain the flow of the operation once the phone dials said multicast page extension, and where exactly does the multicast group come in play as we noticed the phones didn't send an IGMP join request.

2) In my deployment the phone server IP address is xxx.xxx.xxx.1. Is that the source for all multicast streams?

 

[eddv123]

There are several solid responses on how multicast paging works on this page here:
https://www.3cx.com/community/threads/multicast-paging.59105/

Note: best check your switch must support MultiCast traffic also.

 

[MrZabudske]

Note: best check your switch must support MultiCast traffic also.

All switches support multicast and it is enabled on all switches.

When you create a multicast group in 3CX and then call that groups extension number the request is sent by the PBX to the members of the Group. If you set it up directly on the phone the request is sent directly from the phone. So i suspect that the request cannot traverse the VPN and reach the endpoints on the other side so the paging fails.

How would I set up the phone to send the request directly (we have Yealink T23G phones) ?

 

[eddv123]

Please explain your use case - direct paging (at least in my vocabulary) is a one to one intercom call.

If you are wanting a call to go out on loudspeaker to a group of individuals - for example in an emergency or to a business to inform when lock-up is occurring then you definitely want a paging group.

If using group also how many users within the group ?

 

[MrZabudske]

Please explain your use case - direct paging (at least in my vocabulary) is a one to one intercom call.

If you are wanting a call to go out on loudspeaker to a group of individuals - for example in an emergency or to a business to inform when lock-up is occurring then you definitely want a paging group.

If using group also how many users within the group ?

I have 3 locations. Main location has phone server. Main location phones are in a multicast paging group. Any phone from any location can dial that extension (8000) and the page comes over the phones in the group. Phones at location B are in a different multicast paging group (extension 8001). When dialing that multicast extension the page does not work from any phone from any location.

I have involved firewall support and ISP support and after capturing traffic logs the firewall support wants to know the answers to my original questions.

 

[eddv123]

How are these sites connected - VPN ?

It is normally the case that you cannot pass multicast traffic down a VPN tunnel with 3CX at least in the case of phone provisioning.

 

[MrZabudske]

How are these sites connected - VPN ?

It is normally the case that you cannot pass multicast traffic down a VPN tunnel with 3CX at least in the case of phone provisioning.

What about over MPLS or using an RP Server that our ISP sets up? If I can not accomplish multicast paging this way is the only other way to use https://www.cyberdata.net/products/011233 ?

 

[cobaltit]

This really isn't a 3CX specific question per se. Multicast traffice is just that regardless of the use and is typically limited to broadcast domains so it's not going to go across the VPN without some sort of helper. So if you can't set that upon your firewall/routers then yes your options are some sort of paging adapter like Cyberdata which is what we normally use or you would have to setup a custom template for your far locations to do local multicast paging (direct from the phones as you mentioned).

 

[MrZabudske]

setup a custom template for your far locations to do local multicast paging (direct from the phones as you mentioned).

Is there a link to how to configure this?

 

[cobaltit]

https://www.3cx.com/docs/custom-ip-phone-templates/

 

[MrZabudske]

https://www.3cx.com/docs/custom-ip-phone-templates/

And what specifically within the template do I change? I know where the templates are and how to create my own.

 

[cobaltit]

3CX doesn't support custom templates and the changes aren't 3CX specific so your best resource is going to be the admin guide for the Yealink phone, the Yealink forums or simply googling 'yealink multicast paging'. You'll find several guides on the necessary changes for Yealink localized paging.

 

[eddv123]

What about over MPLS or using an RP Server that our ISP sets up?

No - MPLS is layer 3 (routed). You also can get VPLS which is layer 2 routed however it would most likely work exactly the same as a VPN connection (IP's can be seen but different subnets).

 

[MrZabudske]

2) In my deployment the phone server IP address is xxx.xxx.xxx.1. Is that the source for all multicast streams?

Can I get an answer to this? Is the default source of multicast paging the server or the phone making the call?

 

[eddv123]

I know as much as to say that 3CX listens for multicast streams, but to my knowledge I have not read anything to support that it actually generates them: https://www.3cx.com/docs/plug-and-play-ip-phone/

As standard Multicast Paging functionality allows you to send pages to groups of phones directly, without the PBX being involved in the page, I believe 3CX is no different.

I would await a response from a 3CX representative on this one.

 

[YiannisH_3CX]

Can I get an answer to this? Is the default source of multicast paging the server or the phone making the call?

When using multicast paging created in the PBX, the source of the multicast page will be the PBX.