I have a cusotomer with 4 to 5 sites within India.. all the sites are connected by 2 Mbps MPLS link.
Each site is terminated on 2811 router with below image and card..
Now I need to implement IP-telephony in this network..
As a pilot we are planning to have 2 to 3 IP phones on each site and once it is successfull we will migrate all PBX to IP-Phone.
Number of IP-phones at each office will not cross 50.
Now I am planing to suggest distributed CME at each office and route call between CME's, by upgrading existing 2811 to CUCME 8.0 with lates phones 8900 or 9900 which has inbuilt video in it.
As far as my knowledge i just have to upgrade existing 2811(at all sites) IP Base image to IP VOICE image and should buy a PVDM and a FXO/E1 card to connect to PSTN. AM I right?
Will be there any other challenges that I should consider? your suggestions with your past experiences will really help..