I've been told that High Availability of CRS 4.x is not supported with ICM. I've been told you configure things differently to send the call to a second IVR server. We have purchased the additional server and the correct licenses to have two CRS servers. We purchased the second server thinking we would be using High Availability (Hot/Warm Standby). Can these two CRS servers still be clustered but not as "high availability"? In other words, two stand alone CRS Engine servers but share the same script repository and prompts.
An example of what I'm thinking our design will might look like assuming it's possible:
JTAPI Trigger/CTI Route Point 8400 configured on one IVR server with "Forward No Coverage" set to 8500 which would be a JTAPI trigger on the other IVR server.
Both 8400 and 8500 would be "scheduled" in ICM to trigger the same routing scripts.
My hope is that if I upload an IVR script to one CRS server, it shows up in the other IVR server even though they aren't configured for High Availability...there's redundancy but NOT Warm Standby. Likewise with the sound files...upload to one server and they are automatically loaded onto the second server. I want to avoid having to upload all the same scripts and prompts twice everytime there is a change.
CRS does support redundancy, however not "stateful" meaning that if CRS fails while the call is "parked" on it, then the call will br dropped and a caller will have to call again.
From the setup perspective they are setup as a separate standalone boxes, however they DO share the same DC directory on Call Manager, so they "see" the same scripts. You can change/upload/delete the script from one of the CRS boxes and the second one will reflet the change (same DC = same database). This is unfortunately not the case with prompts that will have to be manually copied onto the each CRS :-(
The way to make use of both CRSes is actually from the ICM routing scripts and from Translation route to VRU nodes in particular.
Each of those nodes (yes, you have to go over all your scripts!) will need to be modified to include service configured for second CRS (I assume that VRU-ICM integration was completed including Translation Routing configs) and an IF statement that makes ICM perform a check of whether the VRU is online and whether is have enough available trunks (CTI ports) to accept the call. Once those checks pass, the calls will be distributed between the CRS.
It is upto ICM to decide which CRS the call should go to, i.e. with Label to return in Route_Response to the Routing Client. This implies that Labels need to be associated with your Routing Clients....
It's a high overview :-)