On the Lifesize Cloud help page for Lync federation you can read:
- Firewall configured to allow TCP/TLS port 5061 and TCP/UDP ports 30000-50000 to and from Lifesize Cloud Lync Server
But the Lifesize Lync Server IPs are notr to be found in an easy way. They are in the LTAS documentaion but I don't think that the end customer will look there.
My suggestion is to add the Lync Server IPs to the Management portal just like the Node addresses.