CTIOS chat - agent on A side not able to send chat to agent on B side

We are facing issues with CTIOS chat functionality. The CTIOS version is UCCE 9 duplex. All the registry configuration are configured correctly on both the servers. AgentChatLevel and SupervisorChatLevel are configured same i.e. Unrestricted on the both the registry.

Still agent on A side can't send message to agent on B side and vice versa. Agent can send the messages to agents on same side.

Are we missing any chat related registry setting for peer communication? Please help.

Are you able to Chat to both sides using the Out of Box CTIOS Agent Desktop?  If not, open a TAC case for assistance.

I can chat to the same side, but can not chat on opposite side i.e. on peer side. The same behavior is with the OUT of Box CTIOS Desktop. I have already raised a TAC case since last 1 week but haven't received the single reply yet. since raising question in this forum.

Since the behavior is the same with the out of box CTIOS Desktop, this is a CTIOS product configuration issue which the TAC will need to address.

One thing you can check is the setup of the communication port of peer on each CTIOS side.  It is usually 42028 depending on how the CTIOS was configured. 

That was the only reason our peer communication for chat is not working. After correcting the port, chat is working on both side.