Greetings, firstly id like to say that ive had very good experience with the CME product line in combination with 1800 and 2800 ISR's and more recently the UC500 platform.
One piece of information though that has always alluded me is the exact number of IP Phones that can be registered across a VPN ie: Teleworkers as ive found this topic hard to clarify looking through the data sheets, my colleagues are also at a loss, i haven't yet had an issue but would if someone could confirm the numbers for both the 1800, 2800 and 3800 series it would be appreciated.
This is maximum number of sccp phones for each model, note it does not matter if phone are local or remote:
1861 10 (?)
Note these are the actual maximum configurable, the official numbers are a bit lower.
Hope this helps, please rate post if it does!