Transcript Introduction to QoS

What Quality of Service is About
Hanoch Levy
March 2001
3/2/2001
Hanoch Levy, CS, TAU
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Communications Network and
QoS
• Communications Network is like a set of
car roads
• Communication applications are like
streams of cars.
• QoS deals with how to operate these roads
in order to provide the cars with good
quality of service.
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Hanoch Levy, CS, TAU
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How does it look like
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Hanoch Levy, CS, TAU
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Problems of Interest (Importance)
1. Traffic classification and characterization
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Properties of traffic
Requirements of the system
Impact on the system
Hanoch Levy, CS, TAU
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Problems of interest (cont):
2. Policing and shaping
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Monitor traffic for obeying the rules
Location: typically at network entrance
3. Node (“Intersection”) design:
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Create fast intersections
Introduce mechanisms of prioritization into the
intersections
Guarantee QoS to a traffic stream despite interference
of other streams (fair queuing)
Location: In the nodes
Hanoch Levy, CS, TAU
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Problem of interest (cont)
• 4. Do not overflow your nodes
(intersections) – estimate node capacity
(Call Admission Control)
• 5. Efficient navigation of traffic (Routing)
while obeying QoS
• 6. Managing your traffic: Virtual paths
(transform your cars into trains…)
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Problem of interest (cont)
• 7. Coordinate through network nodes
(reservations): Traffic engineering.
• 8. Traffic characterization.
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Course Structure
1.
2.
3.
4.
5.
Lectures (show up).
Projects (exam?).
Class topics: See home page.
Register for mailing list.
Project topics: see last year, and talk to
me.
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Hanoch Levy, CS, TAU
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Course structure
1. Describe mechanisms as developed for
ATM.
2. Examine mechanisms for IP.
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