A. On congested links， all forms of traffic will require some form of QoS.
B. All traffic types and requirements should be examined to determine the number of traffic classes required.
C. In the implementation of link efficiency mechanisms on links that typically transport relatively large packets， header compression will be most efficient.
D. In the implementation of link efficiency mechanisms on links that typically transport relatively small packets， header compression will be most efficient.
E. In the implementation of link efficiency mechanisms on links that typically transport relatively small packets， payload compression will be most efficient.
F. Payload compression provides more available bandwidth and reduces processing delay time.

A. Because services are allocated throughout the network before the transmission of data begins， traffic classes can be guaranteed QoS services.
B. Traffic classes are marked with Layer 2 markings to allow for more granularity in identifying traffic classes.
C. Traffic classes are marked with Layer 3 markings to allow them to traverse different network types without loss of QoS information.
D. Traffic classes allow networks to provide proper QoS treatment of packets without applications having to request services.
E. Based upon the network capabilities， QoS markings are placed on packets as needed throughout the network to allow for proper QoS treatment of packets.
F. QoS markings are placed on packets as close to the network edge as possible to allow distribution and core devices to determine QoS actions as quickly as possible.

A. ISR can perform the functions of a multipoint control unit to facilitate voice conferencing.
B. ISR can perform the function of a call agent in the event of loss of communication with a CallManager.
C. ISR can provide XML applications to the phones.
D. ISR can provide all of the functionality of a CallManager in the event of loss ofcommunication to the CallManager.
E. ISR can act as a voice gateway to the PSTN.

A. Channel-associated signaling transmits control signals in band and therefore reduces the bandwidth available for the voice data stream.
B. Channel-associated signaling utilizes a separate TDM channel for transmitting control signals.
C. Common channel signaling transmits control signals in band and therefore reduces the bandwidth available for the voice data stream.
D. Common channel signaling uses one of the TDM channels to transmit control information reducing the number of channels available for voice.
E. ISDN BRIs implement channel-associated signaling.

A. Analog phones， connected to the PSTN， act as internal call agents if IP communication to the CallManager is lost.
B. An onsite gateway reroutes calls over the PSTN if IP communication to the CallManager is lost.
C. The IP phones can reroute calls over the PSTN if IP communication to the CallManager is lost.
D. Local voice gateways can assume the function of a call agent if IP communication to the CallManager is lost.
E. IP phones use an internal call agent if IP communication to the CallManager is lost.