To download and use a bootable ISO for Cisco Unified Communications Manager (CUCM) 12.5
For customers who have already purchased the software but need to re-download the installation media. cucm 12.5 bootable iso download
When you finally have the legitimate ISO: To download and use a bootable ISO for
If you are a student or studying for CCNP Collaboration, use the Cisco Modeling Labs (CML) or the free Cisco DevNet Sandbox. They provide pre-installed images, though you may not get a raw ISO. cucm 12.5 bootable iso download
sudo dd if=UCSInstall_UCOS_12.5.sgn.iso of=/dev/sdX bs=4M status=progress