IP Quality of Service Duration: 2 days

IP Quality of Service
Quality of service in a network context is the measurable service level offered by the network. In best effort networks (no QoS differentiation) all traffic gets the same service. Using the QoS tools available in IP networks it is possible to offer more services the right service level and thereby satisfying service requirements while still making the network more efficient. For this reason using IP QoS through diffserv is standard practice in IP network design today.
The purpose of this course is to get the general understanding of IP QoS concepts and tools. The emphasis is on differentiated services. The participants will get acquainted with the IETF diffserv architecture and the tools used to implement diffserv in an IP network such as classification, traffic conditioning, scheduling and congestion avoidance. The course also gives an introduction to network design, planning and performance monitoring aspects when using diffserv.

The target audience for this product is technical personnel or others who need technical knowledge in the area.

Basic knowledge of data communication or telecommunication and basic knowledge of the TCP/IP protocol.

This course is a well-balanced mix of lectures, presentations, discussions and labs.

NOTE: This course is not delivered with the FoldOut methodology.

Introduction to QoS

  • QoS concepts
  • Understanding traffic characteristics
  • Understanding network characteristics
  • Reservation vs. differentiation

IETF Differentiated Services (Diffserv)

  • Diffserv concepts
    • SLA, Behaviour Aggregates, Per Hop Behaviour
  • Classification and marking
    • Use of the DSCP field and defined markings
  • Defined per-hop behaviours
    • Assured Forwarding, Expedited Forwarding

Class of Service

  • Ethernet
  • MPLS
  • Mapping between Diffserv and CoS

Traffic conditioning

  • Marking, re-marking
  • Policing
  • Scheduling

Queuing and scheduling

  • First in first out queuing
  • CSQ-router (Classification queuing scheduling)
  • Examples of schedulers
    • Priority queuing, Round Robin, Weighted Fair Queuing (WFQ), Class Based WFQ

Congestion avoidance

  • TCP vs UDP
  • Random Early Detection
  • Weighted RED
  • Explicit Congestion Notification

Applications and Service Classes

  • Application requirements
  • Application to service class mapping

Network design and planning

  •  Service class design
    • Assured Forwarding, Expedited Forwarding
  • Capacity planning and dimensioning
  • Domains and layering
    • Impairment budgets
    • Service class aggregation


  • SLA
  • Definition of QOS parameters
    • Delay, Delay variation/Jitter, Loss
  • Passive measurements
  • Active measurements

Labs in Cisco environment