i need major diffference between 9.1 and 11.x

[mohdsf159@gmail.com]

please any can suggest major Difference between 9.1 and 11.x 

please can suggest the Notes 

[Jaime Valencia]

The release notes for every version contain the new and changed information that outlines what you're asking, you would need to review the docs for the versions between the two releases you're interested in.

[TONY SMITH]

Do you need this to justify an upgrade?  If so then the major difference is that 9.1 is no longer supported by Cisco.

[VoIP Engineer]

If memory serves, you'll get queued hunt groups and read only API users (among other things)

[TONY SMITH]

Native Call Queuing exists in 9.1.