Not a big deal, just make sure your PBX is talking to your Symposium via your HSL. when I did my ugrade, I had to re-enable the HSL in load 48. Also, if you have a call recording software and voicemail, I would go ahead and reboot voicemail, symposim, and call recording software (i.e. NICE) so they can sync up correctly with the upgrade. You don't have to do this, but Nortel recommends it.