We have a client with 3 Cisco UC520 8 port boxes. The 3 are networked for ext to ext dialing between the sites. Each runs their own Auto Attendant.
Two of the sites are out of state running on analog services, the 3rd/Main site is local and runs SIP.
We're ready to upgrade all 3 to 20T, but wondered if we can upgrade one at a time without causing any issues ?
We'd start with the Main site...
Any input or advice would be appreciated.