IM&P two organisations connection

[MarcST1984]

Hello,
I'm trying to connect two organizations with Cisco Jabber. Chat,presence functions are to be used.

Which ports have to be opened for this ?
IM/P communication always goes from client to client.

Ports:
Org A: Client -> Client Org B:

[Jaime Valencia]

Plenty of information on how to do that, look at the federation documents and choose which option works best for you, and no, messages don't go directly from one client to the other one, all traffic goes through the IM&P server for compliance purposes.