I'm wondering if anyone can provide insight to a CME design that I'm building. The main area that I'm trying to find more documentation on and gain additional knowledge involves centralized routing. It looks as if my options are GK, CCM, or possibly even a VOIP Tandem Gateway. There will be about 175 CME locations initially, and will scale to beyond 250.
It is possible that the customer may have a centralized ccm cluster supporting the gateways and phones at the HQ. If this is the case, I am considering adding the CME locations to the cluster as h323 gateways to meet my centralized routing requirements.
If the customer does not require the ccm cluster than I would think to go the GK route, but I would like to explore the possibilities of the VOIP Tandem Gateway. I am aware that the GK would provide CAC, where the VTG would not, but I really don't know much more than that, or even if the VTG is a viable option. I'm also having a difficult time locating a link that discusses GK sizing.
Does anyone have experience with any of these solutions, or centralized routing solutions in general for CME?