Very odd request. Customer needs MRA to Internet as normal spanning over firewalls. But security is setup so that no workstations can communicate to any other workstation. So point-to-point traffic such as audio/video, screen share, file transfer, screen capture/paste to chat all fail. So though is to standup another Expressway C/E cluster internally so all internal workstations would also use MRA allowing all point-to-point traffic to flow through Expressway's instead of trying to go point-to-point. Can't use same as Internet is using because traffic from external E would have to be allowed through all firewalls to inside clients and also causes series routing/NAT issues (expressway seeing 2000 clients all coming from same NAT IP for example). Yes a lot of network reworking could resolve these issues, but customer is unwilling to do that. 2nd MRA cluster is quick easy fix. But does Cisco CUCM and IMP allow 2 different Expressway clusters to do MRA connections? Any tech details, notes, experience?
Expressway clustering is allowed with the below prerequisite but I am not sure whether that will solve your issue:
We are needing 2 different Expressway clusters. Each doing MRA to one Cisco Cluster. That is the key to the question. Can 2 different Expressway clusters both do MRA to one Cisco UC Cluster.