We would like to upgrade an existing ws-3750-48ts-s from the ip base to the ip services image. From what I understand we could download and install one of the ip services images but would then be out of license. I also understand that we can purchase CD-3750-EMI= to upgrade to ip services and be in license. My question is can we download and install the ip services image now while we wait for the CD-3750-EMI= to be delivered? Is CD-3750-EMI= just the license and maybe an image on a CD or does it actually change somethine else in the switch?