[cisco-voip] 2 questions: 2800 IOS versions, and Unity analog integrations?

[David]

Hello, I'm deploying a bunch of 2800 series routers and I was
wondering if there was a particular IOS version that people have been
happy with or if there were any to avoid?  They currently seem to have
12.3(8r)T7 loaded.

Also, does anyone have any experience with integrating Unity and
traditional PBXs via the analog integration?  Specifically, I'm
wondering how Unity gets the extension from the PBX...  Does it pull
this information from the name that's being sent from the PBX?  Or
does the extension get passed along as called number?  Hopefully that
makes sense.  I'm basically wondering if we'll have to reprogram our
1,000 stations on the PBX.  On the PBX, the stations are currently
configured as Last name, First name only.

Any guidance is most appreciated, thanks so much!