IP telephony is one of the three components of Cisco's AVVID framework. When implementing an IP telephony solution, you must consider network management, high availability, security, and QoS. QoS can guarantee necessary bandwidth and acceptable delay, jitter, and packet loss. For VoIP traffic, packet loss should be less than 1%, one-way delay less than 60ms per leg, and jitter less than 20ms. QoS does this through prioritization. Voice and video, transactional applications, and data transfers are typically prioritized as listed.

QoS includes classification, marking, forwarding, policing, queuing, scheduling, shaping, and dropping of traffic. FIFO lacks QoS. IntServ provides QoS on a connection-by-connection basis, whereas DiffServ provides ...

Get BCMSN Exam Cram™ 2 (Exam Cram 642-811) now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.