Which three features require Cisco Express Forwarding?

Explanation: QoS Features That Require CEF
These class-based QoS features are supported only on routers that run CEF.
•Network Based Application Recognition (NBAR) provides intelligent network classification. For
more information, refer to Network Based Application Recognition.
• The AutoQoS -VoIP feature simplifies and speeds up the implementation and provisioning of
QoS for VoIP traffic. This feature is enabled with the help of the auto qos voip command. CEF
must be enabled at the interface or ATM PVC before the auto qos command can be used. For
more information about this feature and its prerequisites, refer to AutoQoS – VoIP.
From MPLS Fundamentals – Luc De Ghein
Why Is CEF Needed in MPLS Networks?
Concerning MPLS, CEF is special for a certain reason; otherwise, this book would not explicitly
cover it. Labeled packets that enter the router are switched according to the label forwarding
information base (LFIB) on the router. IP packets that enter the router are switched according to
the CEF table on the router. Regardless of whether the packet is switched according to the LFIB
or the CEF table, the outgoing packet can be a labeled packet or an IP packet
Reference. http://www.cisco.com/c/en/us/support/docs/asynchronous-transfer-mode-atm/ip-toatm-class-of-service/4800-cefreq.html