Upgrade 3845 IOS from 12.3 to 15.1(4)M1

[csco11030279]

to upgrade the IOS on this router 3845 , do I need Licenses for the new IOS , and licenses for Voice features ?!

what is the part number for the IOS

[Karsten Iwen]

It depends what you have now. If you have IPBase and want to upgrade to IP Voice you need the license FL38-IPB-IPV= as outlined in the Cisco 3800 Q&A.

The question if you are allowed to upgrade from 12.3 to 15 depends on your support-contract. And if you come from 12.3 it's very likely that you also need a RAM and Flash-Upgrade.