I recently upgraded my PBX to 25.40 and bought some M3904s which are rls 3. I have a remote office that is on 25.30 and their M3904s are rls 2. Can i put rls 3 phones in my remote office? does the phone rls have anything to do with the PBX rls? i can program a lot more digits in my personal directory on my rls 3 phones than i can on my rls 2 phones and I'd like to know if i can just swap out the rls 2s for rls 3s and what impact that will have. thank you.