Chapter 2. Understanding Quality of Service

It is important to ensure that networks over which voice traffic is transported support tight quality of service (QoS) requirements in terms of delay, jitter, and packet loss.

QoS can be implemented using two different architectures: Differentiated Services (DiffServ, RFC 2475) or Integrated Services (IntServ, RFC 1633). The IntServ architecture implements flow-based guarantees and uses a signaling protocol to inform routers in the network path what level of service to provide for a particular flow. When deploying the IntServ architecture, the Resource Reservation Protocol (RSVP) can be used as the signaling protocol.

In the DiffServ architecture, packets are marked using a method that indicates to ...

Get CCIE Voice Exam Quick Reference Sheets now with O’Reilly online learning.

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