I don't know if what you ask is possible, but copy all .cnf.xml file from the CUCM tftp server to another tftp server looks technicaly fine to be (you would then need to configure your dhcp server to point to your temporary tftp server) But don't forget about the phone firmware that could be different from the default one on CUCM =>should also be present on tftp.
One question : how do you know those 3000 (new ?) phones will register at the same time ?
Thank u for ur reply.
@ iantra: We have enough bandwidth for the WAN link but the point is that the phones will be registering to the UCAAS (cisco hosted cluster) from UK. Thus it would take longer than usual time to register the phones.
@ James: The firmware is not an issue we can use the same at both places. Also the DHCP option for TFTP can be easily changed.
The issue is that i am not aware if we can use a default cnf file for all the phones or we would need a seperate file for all the phones.
We know that the 3000 phones would register at the same time b coz the site is being migrated from an Avaya PBX to Cisco IPT.
So lets take it other way round now. It seems that the actual time that a phone takes to load is the firmware file and not the configuration file. So i think if we use a local tftp to host the firmware files and then get the phones to register to the original CUCM to dowload the cnf file would it resolve the issue??