Voice call via Ethernet

Hey everyone

I going to build up a kind of Walkie-talkie with Arduino, based on Ethernet.

I mean I’ve 12 clients and 1 master that I need each client can communicate with master by sound and via Ethernet, it’s kind of VoIP.

So do you think Arduino can handle this problem? and UDP protocol is suitable for this work? And what about the latency and the other issues?

Any help would be greatly appreciated.