facultatea de electronica, telecomunicatii si tehnologia informatiei
DESCRIPTION
Mecanisme QoS in retele IP multimedia Baiculescu Andra Sorina Master IISC. Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei. Cuprins. Introducere in retelele IP multimedia Serviciile oferite in retelele IP Definirea notiunii de QoS Traffic policing si Traffic shaping - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/1.jpg)
Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei
Mecanisme QoS in retele IP multimedia
Baiculescu Andra SorinaMaster IISC
![Page 2: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/2.jpg)
Cuprins
Introducere in retelele IP multimedia Serviciile oferite in retelele IP Definirea notiunii de QoS Traffic policing si Traffic shaping Cozi si planificarea acestora Mecanisme de control a congestiei Concluzii
![Page 3: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/3.jpg)
Introducere in retelele IP multimedia
Subsistemul IP multimedia Componente QoS
![Page 4: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/4.jpg)
Serviciile oferite in retelele IP
Nivelele de servicii oferite de retelele IP:-Best-effort
-Diferentiate
-Garantate
Parametrii care pot afecta calitatea serviciilor:-Banda
-Intarzierea
-Jitter
-Pierderea de pachete
![Page 5: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/5.jpg)
Definirea notiunii de QoS
Ce este calitatea serviciilor? Parametrii de care depinde calitatea serviciilor:
-Performanta suportului serviciului
-Performanta operabilitatii serviciului
-Serviabilitatea
-Performanta retelei
![Page 6: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/6.jpg)
Mecanismele de traffic policing si traffic shaping
1.Clasificarea/Marcarea pachetelor de trafic
Criteriile dupa care se impart pachetele Diffserv si Per-Hop Behavior
![Page 7: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/7.jpg)
2.Mecanismul de traffic policing
Leaky Bucket Token Bucket
![Page 8: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/8.jpg)
3.Mecanismul de traffic shaping
Traffic shaping Algoritmi de masurare a ratei de sosire
-Algoritmi generali
-Token Bucket
-Extensii ale Token Bucket
![Page 9: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/9.jpg)
Cozi si planificarea acestora
Tipuri de cozi -FIFO (First In First Out)
-FQ (Fair Queing)
-WFQ (Weighted Fair Queing)
-PQ (Priority Queing)
Mecanisme de planificare a traficului best-effort Metode de planificare pentru oferirea de servicii
![Page 10: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/10.jpg)
Mecanisme de control a congestiei
Clasificarea mecanismelor-Mecanisme de tip Router-Centric si Host-Centric
-Mecanisme pe baza de rezervare si pe baza de feedback
-Mecanisme pe baza de fereastra si pe baza de rata
![Page 11: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/11.jpg)
Mecanisme de control ale fluxului
RED (Random Early Detection) Principiu AlgoritmInitializareavg <- 0count <- -1Pentru fiecare pachet care sosesteDaca coada nu este goalaavg <- (1-ωp) x avg+ ωp x qAltfelm <- f(timp – q_timp)avg <- (1- ωp)m x avgDaca minth ≤ avg≤ maxth
Incrementeaza countpb <-pa <-Cu probabilitatea pa:Marcheaza pachetul care soseste count<- 0Altfel daca maxth < avgMarcheaza pachetul care sosestecount <- 0Altfel count <- -1Atunci cand coada devine goalaq_timp <- timp
![Page 12: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/12.jpg)
Weighted Random Early Detection
![Page 13: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/13.jpg)
Alte mecanisme de control a fluxului
Tail drop
RIO (Random Early Detection with In/Out)
ARED (Adaptive Random Early Detection)
FRED (Flow Random Early Detection)
![Page 14: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/14.jpg)
Concluzii
![Page 15: Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei](https://reader036.vdocumente.com/reader036/viewer/2022082402/56815e41550346895dccb09a/html5/thumbnails/15.jpg)
Bibliografie
[1]. Tatiana Radulescu, Henri-George Coanda - QoS în Retelele IP Multimedia
[2]. Lefteris Mamatas, Tobias Harks, and Vassilis Tsaoussidis - Approaches to Congestion Control in packet networks
[3]. Shudong Jin, Liang Guo, Ibrahim Matta, Azer Bestavros - A Spectrum of TCP-Friendly Window-Based Congestion Control Algorithm
[4]. www.wikipedia.org
[5]. Baswaraj, D.C.Tomar - Modeling of packet switched network over TCP/Ipto suggest modified routing to reduce congestion
[6]. J. Tao – RED: Algorithm, Modeling and Parameters Configuration