Thanks Paul.
With regards to the ERS4500's, I'm unsure which files I should be downloading from Avaya's "Ethernet Routing Switch 4000 series v5.7.3 Downloads" page.
We have 5 x 4548GT-PWR devices, and I have noticed that all have different HW values, these being 03, 06, and 12.
I'm not sure what impact the HW version has, as I've not had much experience with Nortel/Avaya switching devices.
I can see SW update "4000_573031s.img", would "4500_PoE_400.img" also be required for the 4548GT-PWR switches?
Thanks