A company requires a video conferencing solution where users have to dial an Auto Attendant to join the session bridge. Which bridge do you recommend?

The 3845 ISR is a routing platform, not a video conferencing bridge, and lacks native multiparty video bridging or Auto Attendant features.

The Multiparty Media Appliance is an older hardware platform for multiparty conferencing that does not provide the Auto Attendant dial-in session bridge functionality described.

While an MCU can serve as a conference bridge, it is hardware-based and does not natively include the Auto Attendant feature required to dial into a session bridge in the described scenario.

The Cisco TelePresence Server is a software-based conferencing bridge that includes built-in Auto Attendant capabilities, allowing users to dial a number and be connected to a hosted conference bridge. It supports scalable multiparty video conferencing with dial-in access, making it the appropriate recommendation when Auto Attendant access to a session bridge is required.