Can you explain what you mean?

I appreciate your comments and apologize for the delay.
Unfortunately, I have never setup a clustered Asterisk solution, so I would not be able to help you. I have only deployed multiple Asterisk boxes in the mentioned method to allow an office in Germany to communicate with an office in the USA, for example. I hope you find what you are looking for. I encourage you to come back here and share what you learn. I would love to hear how you have your system setup.

Thanks for all the great tutorials so far.
My scenario is as follows: I have multipleAsterisk servers, all connected RealTime to a common database. While the agents are connected to one server, the real traffic and the customer support calls are incoming on another server. The problem is when a client leaves a message on server A, and server A is trying to call an agent on Server B, I receive OutgoingSpoolFailed because Server B doesn’t find the sip username of the agent.

So, what I actually need is the right configuration to get these multiple servers act like an Asterisk Cluster. I am asking for the right setup of qualify and rtcachefriends, so when a server dials to a sip username it goes directly, without involving the Asterisk Server of the sip username.

I am sorry if I am not clear enough..I will try to explain better if required.
Thanks so much in advance