[OpenSER-Users] OpenSER in front of Asterisk

Hi all, I'm relatively new to OpenSER (and SER for that matter). I have the following need and can't quite figure out how to do it. We have several Asterisk servers being used strictly for IVR purposes (IVR cluster). We also have several Asterisk servers used for standard telephone services and Agent/Queue services (telephone Cluster). We would like to setup one or two OpenSER machines in front of all that to serve the following purposes: 1) Route incoming calls appropriately to either the IVR cluster or the telephone cluster based on the DNIS 2) Be used as LCR servers so that the telephone cluster will send all outbound calls to and the OpenSER will determine if it needs to reach one of our termination carriers or simply just handle it internally (e.g. extension-to-extension calling) 3) When a caller in the IVR presses certain options, the caller may be transferred to an agent. So, we need to take the call away from the IVR cluster (possibly back to the OpenSER server) and redirect it to the telephone cluster so that an agent may handle the caller 4) CDR and billing purposes 5) Ideally, all our telephone users would register with OpenSER (instead of the Asterisk telephone cluster) and for "regular" calls, we could just handle everything within OpenSER, and only involve the telephone cluster if we need to redirect to voicemail or something like that We have read on the wiki about integrating SER with Asterisk for voicemail. We also have some snippets, mainly from the mailing list, about SER load balancing traffic to Asterisk. However, we really haven't found something that could address all items above. Could anyone provide some hits, snippets, or references to what we need in order to accomplish these goals? Thanks