A. Weighted fair queuing (WFQ)
C. Voice over IP (VoIP)
D. Session Initiation Protocol (SIP)
Correct Answer: B
Section: Voice Video
VoIP Control and Transport Protocols
A number of different protocols are used in a VoIP environment for call control, device provisioning, and addressing.
Figure 14-15 shows those protocols focused on VoIP control and transport.
Some of the most significant protocols are:
Dynamic Host Configuration Protocol (DHCP): Used to provide device configuration parameters such as IP configuration (address, subnet mask,
default gateway) and TFTP servers (via DHCP option 150).
TFTP: To obtain ring tones, backgrounds, configuration files, and firmware files.
Skinny Client Control Protocol (SCCP): Used for call control for Cisco IP phones (Cisco proprietary).
Real-time Transport Protocol (RTP): For voice stream (VoIP) station-to-station traffic in an active call.
Real-time Transport Control Protocol (RTCP): For RTP control and reporting (accompanying stream to RTP between endpoints).
Media Gateway Control Protocol (MGCP): A client/server protocol for control of endpoints and gateways. In the MGCP model, intelligence resides on
the call agent (server), and the device is controlled by the agent.
H.323: An ITU standard for VoIP networks that is a peer-to-peer system (call processing logic is local to each device) used for gateways and endpoints.
Session Initiation Protocol (SIP): A standard for VoIP networks defined by the IETF and used for gateways and endpoints. SIP is feature rich (native IM,
presence, and video support),lightweight, and designed for easy troubleshooting (ASCII-based messages).