Quality of Service

Basic Concept for Converging Networks

Voice and Video over IP are applications which demand an appropriate Quality of Service (QoS) from the network. Controlled delay, low jitter, and low losses have to be completed by assured bandwidth. This is the only way to guarantee high quality for the end user. The methods required for achieving this objective will be discussed thoroughly in this course. Having attended this course, you will understand in detail which functional network elements are required for a good QoS and how to implement them using the common technologies. Hands-on exercises and demonstrations at the test network will ensure a lasting learning success. You will, thus, be perfectly able to ensure optimum QoS in your own projects.

Course Contents

Media Streams and the Real-Time Control Protocol (RTP)
Audio and Video Codecs and their Typical Bandwidths
Prioritization
Traffic Contracts, Policing, and Shaping
Delay, Jitter, and Packet Loss
Admission Control
Bandwidth Requirements and Reservation
Access Lists
QoS Measures in the LAN and IEEE 802.3p
Queuing Methods
QoS Models for Packet-Switched Networks
DiffServ, Classes of Service (CoS), and Per-Hop Behavior
DSCP Values and Drop Precedence
MPLS and DiffServ

You will receive the comprehensive course documentation of the ExperTeach Networking series in German language. Optionally, we provide the printed version or an ExperTeach e-book.

Target Group

This course is optimally suited for students interested in concepts and design and also for participants with focus on technology. If you are aiming to understand the technical possibilities and interactions in the QoS environment, this course is precisely what you need.

Knowledge Prerequisites

A good knowledge of the TCP/IP protocol stack and of the Ethernet is mandatory. Sound basic knowledge about telephony and signaling is another prerequisite. Students should be fond of looking into technical details.

1 What are qualities of service?

1.1 Applications and their requirements

1.1.1 Parameters - which are important?

1.1.2 QoS parameters for VoIP

1.2 Requirements of VoIP

1.2.1 Data streams

1.2.2 Signaling

1.2.3 Media streams

1.2.4 Codecs and bandwidths

1.3 Video over IP

1.3.1 Media streams

1.3.2 Video parameters

1.4 Requirements of interactive TCP applications

1.4.1 Throughput - bit rate used

1.4.2 Flow control by TCP

1.4.3 Behavior in case of packet loss

1.4.4 Optimizations for TCP

1.5 What is Quality of Service?

1.5.1 Typical times

1.5.2 Queueing as a tool

1.6 Building blocks for QoS

1.6.1 Traffic contracts - SLAs

2 QoS models for IP networks

2.1 QoS models

2.2 IntServ

2.2.1 Dynamics through routing protocols

2.2.2 RSVP and scalability

2.3 DiffServ

2.3.1 The DiffServ code point

2.3.2 Classes of Service and Per Hop Behaviors

2.3.3 CoS and PHB

2.3.4 Limitations of DiffServ

2.3.5 Load at the Far End

2.3.6 Admission Control

2.4 DiffServ according to RFC 4594

2.4.1 Service Classes

2.4.2 Markers for the Service Classes

2.4.3 QoS actions according to RFC 4594

3 QoS Actions and Queueing

3.1 Congestion management versus traffic management

3.2 QoS actions

3.3 Classification

3.3.1 Typical problems

3.3.2 NBAR - Network Based Application Recognition

3.3.3 Application Visibility and Control

3.4 Queueing

3.4.1 Where is queueing needed?

3.4.2 Round Robin Queueing and Priority Queueing

3.4.3 Fair Queueing

3.4.4 Queueing with Cisco Routers

3.4.5 Modified Deficit Round Robin at Juniper

3.4.6 Shaped Round Robin

3.4.7 Queueing on modular systems

3.5 Discarding

3.5.1 Behavior of TCP

3.5.2 Weighted Random Early Discard

3.5.3 Weighted Tail Drop

3.5.4 Example in Cisco IOS

3.6 Policing

3.6.1 Traffic Parameters

3.6.2 The Token Bucket

3.6.3 The Dual Token Bucket

3.6.4 Handling already classified traffic

3.6.5 Examples on Cisco systems

3.7 Shaping

3.7.1 Hierarchical QoS

3.8 QoS Design and Best Practices

3.8.1 Recommended QoS Models

3.9 A concrete example

3.9.1 LAN Interface, CE Router

3.9.2 WAN Interface, CE and PE Router

4 QoS in the LAN

4.1 Design of the LAN

4.1.1 Redundancy and Spanning Tree

4.2 IEEE 802.1Q and 802.1p

4.2.1 Who marks the frames?

4.2.2 DSCP mutation

4.2.3 The connection of IP telephones

4.2.4 The telephone as a switch

4.2.5 Problems with softphones

4.3 QoS in the WLAN: IEEE 802.11e

4.3.1 WMM - Wi-Fi Multimedia

4.3.2 CF and PCF

4.3.3 HCF - Hybrid Coordination Function

5 QoS concepts for the WAN

5.1 Connection to the backbone

5.1.1 Bottlenecks in the WAN

5.2 The components of an MPLS network

5.2.1 Label switched paths

5.2.2 The Shim Header

5.2.3 Forwarding Information Base

5.2.4 Structure of the LSPs

5.3 DiffServ with MPLS

5.3.1 E-LSPs: Using the Experimental Field

5.3.2 L-LSPs - use of the label

5.3.3 MPLS VPNs and QoS

5.3.4 Traffic engineering with MPLS

5.4 Carrier Ethernet Services and Ethernet Virtual Connection

5.4.1 Realization

5.4.2 Classes of Service

6 Further Aspects

6.1 Active and passive probes

6.1.1 IP Service Level Agreements

6.1.2 Real-Time Performance Monitoring (RPM)

6.1.3 Inline Video Monitoring from Juniper

6.1.4 Ixia

6.1.5 Spirent

6.2 QoS and tunnels

6.2.1 Queueing on Tunnel Connections

6.2.2 Shaping on tunnel interfaces

6.3 Microbursts

6.3.1 Microburst detection

6.4 QoS and Security

6.4.1 Protection of the Control Plane at Cisco

6.4.2 Local Packet Transport Services (LPTS)

6.4.3 Protection of the Routing Engine at Juniper

6.5 QoS for IPv6

6.5.1 Differentiation of IPv4 and IPv6

6.6 QoS in virtual environments

6.6.1 Throughput of a virtual machine

6.7 Performance Routing (PfRv3)

6.7.1 The concept

6.8 Lossless Ethernet

6.8.1 Can Ethernet be "lossless"?

6.8.2 Flow control in Ethernet

6.8.3 Bandwidth management

Classroom training: Do you prefer the classic training method? A course in one of our Training Centers, with a competent trainer and the direct exchange between all course participants? Then you should book one of our classroom training dates!
Hybrid training: Hybrid training means that online participants can additionally attend a classroom course. The dynamics of a real seminar are maintained, and the online participants are able to benefit from that. Online participants of a hybrid course use a collaboration platform, such as WebEx Training Center or Saba Meeting. To do this, a PC with browser and Internet access is required, as well as a headset and ideally a Web cam. In the seminar room, we use specially developed and customized audio- and video-technologies. This makes sure that the communication between all persons involved works in a convenient and fault-free way.
Online training: You wish to attend a course in online mode? We offer you online course dates for this course topic. To attend these seminars, you need to have a PC with Internet access (minimum data rate 1Mbps), a headset when working via VoIP and optionally a camera. For further information and technical recommendations, please refer to.
Tailor-made courses: You need a special course for your team? In addition to our standard offer, we will also support you in creating your customized courses, which precisely meet your individual demands. We will be glad to consult you and create an individual offer for you.
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You can find the complete description of this course with dates and prices ready for download at as PDF.