Download presentation
Presentation is loading. Please wait.
Published byJoella Jackson Modified over 9 years ago
1
Mar-16 1 Cairo University Faculty of Engineering Electronics &Communication dpt. 4th year Linux-based Implementation Of a Router (B.Sc Graduation project) Supervisor: Prof. Dr. Khaled Foad El-Sayed. Submitted by: Ashraf Kamal Rahoma Hazem Mohamed Sobhi Hassanein Hossam El-Sayed Abd Allah Tarek Amr Hamed Zein El-Abidin Mohamed WALI
2
Mar-16 2 Introduction to QoS: Motivation: QoS Terminology and Parameters: 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
3
Mar-16 3 Parameters 1.Latency the delay a flow experiences when passing through a device 2.Jitter the latency variations 3.loss probability bandwidth distribution and availability (throughput or goodput)
4
Mar-16 4 IntServ vs. DiffServ IntServ overview
5
Mar-16 5 RSVP Protocol
6
Mar-16 6 RSVP Protocol
7
Mar-16 7 RSVP Protocol
8
Mar-16 8 RSVP Protocol
9
Mar-16 9 IntServ vs. DiffServ Each has its won points of strength And weakness
10
Mar-16 10 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:
11
Mar-16 11 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:
12
Mar-16 12 ToS VS DSCP Introduction Type of service byte definition
13
Mar-16 13 Type of service byte definition
14
Mar-16 14
15
Mar-16 15 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.
16
Mar-16 16 Differentiated services field definition
17
Mar-16 17 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 PHB’s Currently there are 4 standard different per hop behaviors PHB’s: Default PHB Class-Selector PHB. Assured Forwarding (AFny) PHB. Expedited Forwarding (EF) PHB.
18
Mar-16 18
19
Mar-16 19 DiffServ Support under Linux Linux Traffic Control Overview
20
Mar-16 20 Linux Traffic Controller
21
Mar-16 21 Implementation and Code TC Implementation
22
Mar-16 22 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 precedence’s (RED) Bandwidth assurance, RED: No bandwidth guarantee. No quality of service: No policing filters, no shaping.
23
Mar-16 23 Traffic Classes Variables: Setting Functions: Constructor. Destructor Set Device Set Network Set Rates Set PHB’s Set Police Set ToS
24
Mar-16 24 Infra-structure Functions: t_start( ) Make_phb( ) make_EF( ) make_AF( ) make_BE( ) make_Subfilter( ) make_marker( ) t_reset( ) Filtering Functions: Make Filter Get Command
25
Mar-16 25 Software implementation Architecture Overview. Graphical User Interface (GUI). System programming.
26
Mar-16 26 using C++ Classes Architecture Overview To ensure encapsulation & independence To control the communication & error tracing To give the ability to change or update any specific parts.
27
Mar-16 27 using C++ Classes Architecture Overview
28
Mar-16 28 Detailed view
29
Mar-16 29 Communication between Classes
30
Mar-16 30 GUI tabs PHB configuration tab
31
Mar-16 31 Advanced PHB
32
Mar-16 32 Filter Setup Tab
33
Mar-16 33 Summary view Tab
34
Mar-16 34 TC Experts Tab
35
Mar-16 35 4.4 Testing:
36
Mar-16 36 4.5 Testing procedure 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. PHB’s Implementation: Monitoring different rates assigned to each class
37
Mar-16 37 Than You !
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.