Multicast without PBX?

[fonewiz]

First my question:

Is it possible to configure T42 and T46 phones to page each other using multicast, without the PBX handling anything?

Now a little more explanation:
I have a customer we setup with 3CX as the phone system and about 35 T42's plus about 10 T46's. 3CX has a paging feature but it completely fails when more than 15 handsets are in the paging group. So, since there doesn't seem to be a solution for this for whatever reason on the 3CX side, I am thinking about going the Multi-Cast route.

I don't know much about multi-cast paging at this point so I am learning all I can.

One of my concerns with doing multi-cast paging is that the 3CX system and the Yealinks are on two separate subnets. Not knowing a lot about multi-cast, I am not sure it even works across subnets but, my guess is that it doesn't. If multi-cast won't work across subnets, then using it along with 3CX is not an option at all.

So, that leads me to the idea that, maybe, 3CX doesn't have to have anything to do with the multi-cast setup.

Can the Yealinks be setup to page across the same subnet they are on without the need for 3CX in the middle? If so, how would I go about setting this up?

Thanks in advance for any help you can provide.