Our UC design is multi-site distributed call processing model with several UC luster spread in different countries. Each of those clusters serves several neighbooring countries which are connected to the PSTN through their local gateway. Each cluster is linked internally to other clusters through ICT trunks to route internal calls through the network.
As clusters keep groing through M&A this model is not really viable anymore. Inter-cluster trunks are growing exponentials and integration of new clusters to our environment is slowed down.
We would like to keep each cluster independant but get them interconnected by connecting each of them to a central gateway/router type of server. Just 1 trunk per cluster to the central sytem and no more multiplied inter-cluster trunk.
Looking at Cisco products UC SME sounds like a solution but on all the designs I can see, the PSTN access is then centralized to the UC SME cluster which we don't want to do. We want each office to keep it's local PSTN access ; the centralized system being only for internal call. Is it possible with SME or not ?
The other thing I'm concerned about is that it seems that UC SME is a "stateful" technology, so the entire call goes through the SME, not just the call the setup traffic but the actual data. This would mean that if we have a UC cluster in Japan and on in Australia, connected through a centralized SME in the US, the entire call would go all the way to the US from Japan to Australia instead of going direct through the MPLS. Is that correct ?
It sounds like we should be able to achieve what we want by just setting-up a centralized CUCM cluster, build trunk betwwen leaf clusters to the centralized cluster in a star design and with proper routing on the central cluster achieve the above goals.
If that is the case I'm wondering what is the added value of SME ?
Thanks in advance
