Documentation for CCM 3.0 is nearly impossible to find, due to the age of this release, so this information is hard to verify.Have a look at the most recent ccm compatibilty matrix and the oldest version is ccm 3.1.4;
Cisco CallManager 3.1(1) was released on Cisco.com on July 31, 2001, and was further enhanced and substituted by several maintenance and feature releases ending with Release 3.1(4). As each new release became available, it became a better alternative to a previous release, so that, over time, demand for the previous release versions decreased. With previous releases compatibility was ensured through extensive testing. This notice applies to all versions of Cisco CallManager 3.1(X). Sales of these releases ended on December 18, 2003, with the availability of Cisco CallManager 3.3(2).
Customers can choose to continue using Cisco on CallManager 3.1(X). Customers with the appropriate support contract will continue to receive support form the Cisco Technical Assistance Center (TAC). However, customers with 3.1(X) releases deployed who encounter stability or defect issues that have been corrected in releases 3.2(X), 3.3(X) or 4.0 will be directed to upgrade to these versions to resolve the defects. The last maintenance version for Cisco CallManager 3.1 was 3.1(4). Limiting the number of orderable Cisco CallManager releases improves customer satisfaction with Cisco IP Communications solutions by allowing Cisco Systems? to concentrate more engineering resources on improved quality and performance in current releases.
From this doc;
Clarification of Sale and Support Status of Cisco CallManager 3.1
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...