Cairo%20University

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Cairo University Faculty of Engineering Electronic
s Communication dpt. 4th year
Supervisor Prof. Dr. Khaled Foad
El-Sayed. Submitted byAshraf Kamal Rahoma Hazem
Mohamed Sobhi Hassanein Hossam El-Sayed Abd
Allah Tarek Amr Hamed Zein El-Abidin Mohamed WALI
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Internet Protocol (IP).was designed to provide
best-effort service. VoIP FTP
QOS Quality of Service (QoS) implies the
ability to differentiate traffic streams and to
define a level of performance for those traffic
streams across a network. When heavily utilized
networks are carrying various types of traffic
for different users, QoS is a mean of offering
better service
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1. Latencythe delay a flow experiences when passing
   through a device
2. Jitter the latency variations
3. loss probabilitybandwidth distribution and
   availability (throughput or goodput)

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IntServ vs. DiffServ
IntServ overview
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RSVP Protocol
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RSVP Protocol
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RSVP Protocol
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RSVP Protocol
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IntServ vs. DiffServ
Each has its won points of strength And weakness
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DiffServ Architecture
DiffServ Architectural Model
Differentiated Services Domain
DS Boundary Nodes and Interior Nodes DS Ingress
Node and Egress Node Differentiated Services
Region Traffic Classification and
Conditioning Classifiers Traffic
Profiles Traffic Conditioners
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Meters Markers Shapers Droppers
Location of Traffic Conditioners and MF
Classifiers Within the Source Domain At the
Boundary of a DS Domain In non-DS-Capable
Domains In Interior DS Nodes
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ToS VS DSCP
Introduction
Type of service byte definition
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Type of service byte definition
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Disadvantages of ToS

• The IP-precedence scheme allows only
  specification of relative priority of a packet.
  it has no provisions to specify different drop
  precedence for packets of a certain priority.
• The 3 bits restrict the number of possible
  priority classes to 8
• The ToS mechanism is not powerful enough to allow
  an application to quantify the level of service
  it desires.

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Differentiated services field definition
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Per Hop Behavior PHB
A per-hop behavior (PHB) is a description of the
externally observable forwarding behavior of a
DS node applied to a particular DS behavior
aggregate (BA).
Different PHBs
Currently there are 4 standard different per hop
behaviors PHBs Default PHB Class-Selector
PHB. Assured Forwarding (AFny) PHB. Expedited
Forwarding (EF) PHB.
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DiffServ Support under Linux
Linux Traffic Control Overview
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Linux Traffic Controller
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Implementation and Code
TC Implementation
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Note In this drawing only one AF class is shown
for the simplicity of the drawing, the other ones
are just the same. DSMARK CBQ pFIFO Low
queuing delay (latency). Well defined minimum
departure rate, i.e. independent of the other
traffic at the node. No burst. (policing). 4
CBQ Four AF classes with different fractions of
the bandwidth allocated for each. In each one we
have three dropping precedences (RED) Bandwidth
assurance, RED No bandwidth guarantee. No
quality of service No policing filters, no
shaping.
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Traffic Classes
Variables Setting Functions Constructor. Destr
uctor Set Device Set Network Set Rates Set
PHBs Set Police Set ToS
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Infra-structure Functions
Filtering Functions Make Filter Get Command
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Software implementation

• Architecture Overview.

• Graphical User Interface (GUI).

• System programming.

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using C Classes

• To ensure encapsulation independence

• To control the communication error tracing

• To give the ability to change or update any
  specific parts.

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using C Classes
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Detailed view
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Communication between Classes
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We have performed testing on 3 basic levels 1.
Marking Testing if packets were marked according
to specified classification. 2. ToS Testing if
the classification according to ToS and
monitoring packets flow were mapped to the
required PHB 3. PHBs Implementation
Monitoring different rates assigned to each class
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Than You !