Alcatel OmniPCX Enterprise
|
|
- Shana Fitzgerald
- 6 years ago
- Views:
Transcription
1 Alcatel OmniPCX Enterprise QoS for VoIP Overview 1 OBJECTIVE: Describe the essential parameters for QoS
2 The QoS parameters regarding the data network IP Packet Transfer Delay (IPTD): Time for the packet to cross the network IP Packet Delay Variation (IPDV): Variation in the transfer delay of the IP packet IP Packet Loss Ratio (IPLR) : = lost packets / transmitted packets IPDV IPTD 2 IP Device IP network IP Device IPLR 2 IP Packet Transfer Delay = Transit delay IP Packet Delay Variation = Jitter The topic here concerns the carrying of the voice, which is a full duplex type of communication. Every of those parameters will have to be considered in both ways: one way and return.
3 Transit Delay The transit delay has to be considered from end to end Example: Processing delay Play out delay Algorithm delay Packetization delay Serialization delay Propagation delay Component delay Impact on a voice communication Below 100 ms, most users will not notice the delay Between 100 ms and 300 ms, users will notice a slight hesitation in their partner s response Beyond 300 ms, delay is obvious and communications becomes quasi half-duplex communications 3 Codec delay : G ms G ms G ms Packetization delay : Link to the framing period 20 ms usually used. Means that the samples of voice are stored and sent every 20 ms In case of G723.1 the framing is 30 ms Serialization delay : Time necessary to transmit the IP packet. Example with G711 on IP level the payload is 240 Bytes Wan connection time/bit time/packet 64Kb/s 156 micro seconds 30 ms 256Kb/s 3,9 micro seconds 7,5 ms 2Mb/s 0,5 micro seconds 0,96 ms Propagation delay : Time necessary for the signal to travel along the transmission medium (function of the distance). Around 5 microseconds/km in a cable. In case of satellite the delay is around 110 ms for a km altitude satellite and around 260 ms for a km altitude satellite. Component Delay : These are delays caused by the various components within the transmission system. For example a frame passing through a router has to move from the input port to the output port through the backplane. There is some minimum delay due to the speed of the backplane and some variable delays due to queuing and router processing. Processing delay : Time due to the jitter buffer and the play out processing
4 Alcatel devices delay Average of delays introduced by IP boards (GA/GD/INTIP) for one packetisation/depacketisation in G711 :100 ms for one compression/decompression in G723 : 150 ms for one compression/decompression in G729 : 120 ms For transit operation (INTIP only) : 20 ms Average of delays introduced by IP Phones (e-reflexes/x8 serie) for one packetisation/depacketisation in G711 : 60 ms for one compression/decompression in G723 : 90 ms for one compression/decompression in G729 : 70 ms Average of delays introduced in case of communication between an IP phone and a legacy set (VoIP board involved in the communication) for one packetisation/depacketisation in G711 : 80 ms for one compression/decompression in G723 : 120 ms for one compression/decompression in G729 : 100 ms 4 * Transit is not available on GD board nor with G711algorithm.
5 Jitter Variable transit delays means JITTER Reminder: definition of jitter: Packets arriving too early or late compared with the initial rate Burst or gaps in packets. Note: VoIP quality is very sensitive on the timely delivery of packets. => Dejitter buffer to smooth out variable packet reception * 5 * but increases end-to-end delay
6 Jitter (Cont.) Jitter Principle Timestamp Voice sample sende r Net work receiver Network delay Total delay Dejittering delay Packet loss Variable delay Out-of-order arrival time Origin of the jitter network: congestion, queuing delay due the variation in the volume of other traffic streams equipment: capabilities... 6
7 Packet loss Essential parameter to define the quality of voice over IP Loss of 2/3 packets: crackling, metallic voice Sensitivity to packet loss depends on codec (e.g. G711 more sensitive than G723.1 or G729) Origin of packet loss in the network Congestion, queues overflow Router traffic management (packet discarding: RED...) Packet get lost when arriving too late at the receiver Dejitter buffer to avoid packet loss Balance between size of jitter buffer and packet loss to optimize audio quality 7 RED: Random Early Drop. Some routers start to discard packets when the traffic is too high. It was not a problem for data exchange because of the retransmission mechanism but for voice packet it is very bad.
8 Bad Frame Interpolation (BFI) If a packet is lost or corrupted then a BFI (Bad Frame Interpolation) is generated Interpolates lost and/or corrupted packets by using the previously received voice frames for increasing voice quality BFI process is able to estimate how to build the missing packet BFI have impact on communication: 1 BFI: unnoticed 2 consecutive BFI: discrepancies 3 consecutive BFI: silence Remark: if a packet arrives rapidly after a silence, it generates a variation of decibels that will prompt a metallic sound 8 For more information concerning BFI you can check the ITU G113 recommendation about transmissions impairments.
9 Packetization time or Framing The packetization time is the frequency used by the equipment before to send the voice samples The samples are generated according to the frequency used by the algorithm and are stored in a buffer This buffer is empty at the selected framing value If the framing is decreased then the quality is better because the delay is reduced but there is no optimization of the bandwidth and the loading of the equipment is heavy The useful data represent a small part of the frame compared to the header information and there are more frames 9
10 Packetization time or Framing (Cont.) If the framing is increased then the quality is lower because the delay is more important but there is optimization of the bandwidth The useful data represent a more important part of the frame compared to the header information It is possible to increase the framing when the delay is very low in the network Because the framing will add some delay if the network is really reliable packets are bigger and the quantity of voice sample lost is more important That s why the more common values are 20 or 30 ms 10
11 The three quality profiles TOLL-QUALITY = identical to a conventional system Network Round Trip delay < 150ms Jitter < 20 ms Packet loss ratio < 1% NEAR TOLL-QUALITY = some disruptions, inability to recognize tone of voice and crackling (GSM level) Network Round Trip delay < 400ms Jitter < 50 ms Packet loss ratio < 3% BEST-EFFORT QUALITY= metallic sounding voice, loss of syllables and dropouts (marine radio level) Network Round Trip delay < 600ms Jitter < 75 ms Packet loss ratio < 5% 11 Source: AHM Technologies Corporation Algorithmic delay Algorithm G.711 PCM G PCM Delay (ms) Line speed 10 Mbps Ethernet T1 512 Kbs 64 Kbs ASDL ( 640 Kbs) Delay (ms) Propagation delay, e.g ms x distance in km for coax and radio relay systems ms x distance in km for optical fiber systems ms x distance in km for submarine coax systems Component delay, e.g. - vary depending on the component - for example, 1.5 ms for echo cancellers
12 Available bandwidth according to the type of Codec Vocoder Bit rate Packetisa- tion time Packets per second RTP payload size (bytes) IP frame size = payload +RTP(12)+ UDP(8)+IP(20) Bandwith at IP level Bandwith at Ethernet level G Kb/s (MP-MLQ) MLQ) 30 ms Bytes 17.1Kb Kb/s 27.2 Kb/s G.729A 8 Kb/s 30 ms Bytes 18.7 Kb/s 28.8 Kb/s G Kb/s 30 ms Bytes 74.7 Kb/s 84.7 Kb/s FAX 9600 b/s 40 ms Bytes 15.4 Kb/s 23 Kb/s 12 For bandwidth estimation do not take into account the potential gain of VAD. 20% of margin must be added for security. For RTP payload calculation you have to take : -The bit rate of the algorithm that you convert in Bytes : bits /s = 8000 Bytes /s -The framing value : 30 ms -You calculate the frequency per second : 1/0.03 = 33,33 -Then you do the following operation : 8000 / 33,33 = 240 Bytes
13 Echo The echo problem is more often noticed when a communication is made with an analog set or an analog public line Digital sets may introduce echo by acoustic coupling Possible causes for acoustic coupling Hands free feature Speaker feature Digital lines (e.g. ISDN) or VoIP can not cause echo 13
14 Echo (Cont.) IP devices (IP phones, IP gateways) Can not be the cause of the echo (digital components) Compression/decompression (G711, G723.1, G729) may accentuate the echo phenomenon by the introduced delay The embedded echo cancellation feature may not be effective if the echo delay is too long 14
15 Echo (Cont.) Echo cancellation Depth of echo cancellation can not be configured and will be the best the hardware can provide GIP4 4/ 1 and MADA1/MADA3 will use 64 ms GIP6 and MCV8 and MCV 24 boards will use 32 ms 15
16 VoIP quality measurement MOS (Mean Opinion Score) is a subjective method of voice quality measurement There are two test methods: Conversation opinion test Listening-opinion test Test subjects judge the quality of the voice transmission system either by carrying on a conversation or by listening to speech samples. They then rank the voice quality using the following scale: 5 Excellent, 4 Good, 3 Fair, 2 Poor, 1 Bad 16 You can check the ITU-T P.800 recommendation for more details concerning MOS. Coding Standard MOS G (64 kbps) G (8 kbps) G (6.3 kbps) 3.5 (5.3 kbps)
17 VoIP quality measurement (Cont.) MOS is then computed by averaging the scores of the test subjects An average score of 4 and above is considered as tollquality. 17
18 QoS at level 2 and level 3 LAN (level 2) Implement End to End QoS policy Main solution: IEEE 802.1Q (qualification ): traffic separation IEEE 802.1p (priorization): traffic priorization WAN (level 3) Implement End to End QoS policy Main solutions: TOS precedence (TOSp) : traffic priorization DiffServ (DS byte): traffic priorization 18 See network and QoS protocols module for more details
19 QoS at level 2 and level 3 You need to discuss with the LAN administrator to know what type of QoS is implemented in the network To know if you need to provide from the IP devices the QoS information or if the LAN manager has defined the rules directly in the switches and routers 19 See the QoS management module for more information concerning the parameters.
20 20
Introduction to Quality of Service
Introduction to Quality of Service The use of IP as a foundation for converged networks has raised several issues for both enterprise IT departments and ISPs. IP and Ethernet are connectionless technologies
More informationSynopsis of Basic VoIP Concepts
APPENDIX B The Catalyst 4224 Access Gateway Switch (Catalyst 4224) provides Voice over IP (VoIP) gateway applications for a micro branch office. This chapter introduces some basic VoIP concepts. This chapter
More informationNetwork Management & Monitoring
Network Management & Monitoring Network Delay These materials are licensed under the Creative Commons Attribution-Noncommercial 3.0 Unported license (http://creativecommons.org/licenses/by-nc/3.0/) End-to-end
More informationA common issue that affects the QoS of packetized audio is jitter. Voice data requires a constant packet interarrival rate at receivers to convert
A common issue that affects the QoS of packetized audio is jitter. Voice data requires a constant packet interarrival rate at receivers to convert data into a proper analog signal for playback. The variations
More informationSpeech-Coding Techniques. Chapter 3
Speech-Coding Techniques Chapter 3 Introduction Efficient speech-coding techniques Advantages for VoIP Digital streams of ones and zeros The lower the bandwidth, the lower the quality RTP payload types
More informationETSF10 Internet Protocols Transport Layer Protocols
ETSF10 Internet Protocols Transport Layer Protocols 2012, Part 2, Lecture 2.2 Kaan Bür, Jens Andersson Transport Layer Protocols Special Topic: Quality of Service (QoS) [ed.4 ch.24.1+5-6] [ed.5 ch.30.1-2]
More informationABSTRACT. that it avoids the tolls charged by ordinary telephone service
ABSTRACT VoIP (voice over IP - that is, voice delivered using the Internet Protocol) is a term used in IP telephony for a set of facilities for managing the delivery of voice information using the Internet
More informationManaging the Performance of Enterprise and Residential VoIP Services. Alan Clark Telchemy
Managing the Performance of Enterprise and Residential VoIP Services Alan Clark Telchemy Outline Problems affecting Residential VoIP and Teleworkers VoIP Performance and Quality Challenges VoIP Performance
More informationOvercoming Barriers to High-Quality Voice over IP Deployments
Whitepaper Overcoming Barriers to High-Quality Voice over IP Deployments Intel in Communications Overcoming Barriers to High-Quality Voice over IP Deployments Whitepaper Contents Executive Summary 1 Introduction
More informationWhitepaper IP SLA: Jitter. plixer. International
Whitepaper IP SLA: Jitter 1 plixer Table of Contents Table of Contents Introduction IP SLA VoIP Measurement Tools Jitter Latency Packet Loss MOS ICPIF Score IOS Version Warning Steps to Configure the IP
More informationPerformance Management: Key to IP Telephony Success
Performance Management: Key to Telephony Success Alan Clark, President & CEO Telchemy, Incorporated http://www.telchemy.com Vo Performance Management Voice, Video and other Real Time Applications Vo Performance
More informationAi-Chun Pang, Office Number: 417. Homework x 3 30% One mid-term exam (5/14) 40% One term project (proposal: 5/7) 30%
IP Telephony Instructor Ai-Chun Pang, acpang@csie.ntu.edu.tw Office Number: 417 Textbook Carrier Grade Voice over IP, D. Collins, McGraw-Hill, Second Edition, 2003. Requirements Homework x 3 30% One mid-term
More informationAssessing Call Quality of VoIP and Data Traffic over Wireless LAN
Assessing Call Quality of VoIP and Data Traffic over Wireless LAN Wen-Tzu Chen and Chih-Yuan Lee Institute of Telecommunications Management, National Cheng Kung University, No. 1 University Road, Tainan
More informationVOIP Network Pre-Requisites
VOIP Network Pre-Requisites Executive Summary This document contains basic network requirements that are foundational for good voice quality when using Vogtec VoIP products/solutions over a data network.
More informationIP Network Emulation
Developing and Testing IP Products Under www.packetstorm.com 2017 PacketStorm Communications, Inc. PacketStorm is a trademark of PacketStorm Communications. Other brand and product names mentioned in this
More informationETSF10 Internet Protocols Transport Layer Protocols
ETSF10 Internet Protocols Transport Layer Protocols 2012, Part 2, Lecture 2.1 Kaan Bür, Jens Andersson Transport Layer Protocols Process-to-process delivery [ed.4 ch.23.1] [ed.5 ch.24.1] Transmission Control
More informationGUIDELINES FOR VOIP NETWORK PREREQUISITES
GUIDELINES FOR VOIP NETWORK PREREQUISITES WHITE PAPER October 2016 Unified Networks Unified User Clients Unified Messaging Mobility 100+ Call Management Features Executive Summary This document contains
More informationModule objectives. Integrated services. Support for real-time applications. Real-time flows and the current Internet protocols
Integrated services Reading: S. Keshav, An Engineering Approach to Computer Networking, chapters 6, 9 and 4 Module objectives Learn and understand about: Support for real-time applications: network-layer
More informationQuality of Service (QoS)
Quality of Service (QoS) The Internet was originally designed for best-effort service without guarantee of predictable performance. Best-effort service is often sufficient for a traffic that is not sensitive
More informationRSVP Support for RTP Header Compression, Phase 1
RSVP Support for RTP Header Compression, Phase 1 The Resource Reservation Protocol (RSVP) Support for Real-Time Transport Protocol (RTP) Header Compression, Phase 1 feature provides a method for decreasing
More informationBasics (cont.) Characteristics of data communication technologies OSI-Model
48 Basics (cont.) Characteristics of data communication technologies OSI-Model Topologies Packet switching / Circuit switching Medium Access Control (MAC) mechanisms Coding Quality of Service (QoS) 49
More informationChapter 9. Multimedia Networking. Computer Networking: A Top Down Approach
Chapter 9 Multimedia Networking A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations;
More informationTroubleshooting Packet Loss. Steven van Houttum
Troubleshooting Packet Loss Steven van Houttum INTRODUCTION Steven van Houttum Consultant/Trainer MVP Office Server & Services (Skype for Business) TROUBLESHOOTING PACKET LOSS, IS IT REALLY THE NETWORK?
More informationReal-Time Protocol (RTP)
Real-Time Protocol (RTP) Provides standard packet format for real-time application Typically runs over UDP Specifies header fields below Payload Type: 7 bits, providing 128 possible different types of
More informationIntroduction to VoIP. Cisco Networking Academy Program Cisco Systems, Inc. All rights reserved. Cisco Public. IP Telephony
Introduction to VoIP Cisco Networking Academy Program 1 Requirements of Voice in an IP Internetwork 2 IP Internetwork IP is connectionless. IP provides multiple paths from source to destination. 3 Packet
More informationGSM Network and Services
GSM Network and Services Voice coding 1 From voice to radio waves voice/source coding channel coding block coding convolutional coding interleaving encryption burst building modulation diff encoding symbol
More informationINTERNATIONAL TELECOMMUNICATION UNION
INTERNATIONAL TELECOMMUNICATION UNION TELECOMMUNICATION STANDARDIZATION SECTOR STUDY PERIOD 21-24 English only Questions: 12 and 16/12 Geneva, 27-31 January 23 STUDY GROUP 12 DELAYED CONTRIBUTION 98 Source:
More informationParameter Equipment Motivation Monitoring method. Smooth play-out Test stream
IP transport requirements Packet Loss Ratio The ratio between the number of the packets lost in the network total and number the of transmitted packets1. Latency The time interval between initial transmission
More informationChapter 5 VoIP. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March Multmedia Networking
Chapter 5 VoIP Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Multmedia Networking audio signal amplitude Multimedia: audio analog audio signal sampled
More informationSIMULATION FRAMEWORK MODELING
CHAPTER 5 SIMULATION FRAMEWORK MODELING 5.1 INTRODUCTION This chapter starts with the design and development of the universal mobile communication system network and implementation of the TCP congestion
More informationENSC 427 Communication Networks Final Project Presentation Spring Comparison and analysis of FIFO, PQ, and WFQ Disciplines in OPNET
1 ENSC 427 Communication Networks Final Project Presentation Spring 2011 Comparison and analysis of FIFO, PQ, and WFQ Disciplines in OPNET 2 Shadi: Shadi: Presentation Structure Introduction Background
More informationPfR Voice Traffic Optimization Using Active Probes
PfR Voice Traffic Optimization Using Active Probes This module documents a Performance Routing (PfR) solution that supports outbound optimization of voice traffic based on the voice metrics, jitter and
More informationMultimedia Networking
Multimedia Networking #2 Multimedia Networking Semester Ganjil 2012 PTIIK Universitas Brawijaya #2 Multimedia Applications 1 Schedule of Class Meeting 1. Introduction 2. Applications of MN 3. Requirements
More informationQoS User view From modelling to service class
QoS User view From modelling to service class STQ Workshop - 1 & 2 July 2009 P-Y Hebert AFUTT User Group vice-chairman ETSI 2009. All rights reserved Index UMTS Classes of Service (CoS) ITU-T Y.1541 QoS
More informationMultiple unconnected networks
TCP/IP Life in the Early 1970s Multiple unconnected networks ARPAnet Data-over-cable Packet satellite (Aloha) Packet radio ARPAnet satellite net Differences Across Packet-Switched Networks Addressing Maximum
More informationInvestigation of Algorithms for VoIP Signaling
Journal of Electrical Engineering 4 (2016) 203-207 doi: 10.17265/2328-2223/2016.04.007 D DAVID PUBLISHING Todorka Georgieva 1, Ekaterina Dimitrova 2 and Slava Yordanova 3 1. Telecommunication Department,
More informationApplication Notes. Introduction. Performance Management & Cable Telephony. Contents
Title Managing Cable Telephony Services Series VoIP Performance Management Date June 2004 Overview This application note describes the typical performance issues that cable operators encounter when deploying
More informationVoice over IP (VoIP)
Voice over IP (VoIP) David Wang, Ph.D. UT Arlington 1 Purposes of this Lecture To present an overview of Voice over IP To use VoIP as an example To review what we have learned so far To use what we have
More informationWhite Paper Voice Quality Sound design is an art form at Snom and is at the core of our development utilising some of the world's most advance voice
White Paper Voice Quality Sound design is an art form at and is at the core of our development utilising some of the world's most advance voice quality engineering tools White Paper - Audio Quality Table
More informationCCVP QOS Quick Reference Sheets
Why You Need Quality of Service (QoS)...3 QoS Basics...5 QoS Deployment...6 QoS Components...6 CCVP QOS Quick Reference Sheets Basic QoS Configuration...11 Traffic Classification and Marking...15 Queuing...26
More informationTheoretical and Practical Aspects of Triple Play
Theoretical and Practical Aspects of Triple Play 1. Introduction 2. Network and Protocol Architecture for Triple Play 3. Characteristics and Parameters of Triple Play 4. Main QoS and QoE Methods and Standards
More informationMonitoring the Cisco Unified IP Phone Remotely
CHAPTER 8 Each Cisco Unified IP Phone has a web page from which you can view a variety of information about the phone, including: Device information Network configuration information Network statistics
More informationJOURNAL OF HUMANITIE COLLEGE No ISSN:
JOURNAL OF HUMANITIE COLLEGE No. 7 2017 ISSN: 2226-0714 1 Journal of University College of Humanity Studies A Refereed Scientiefic Journal Pubilshed by The University College of Humanity Studies Republic
More informationENSC 427 Communication Networks
1 ENSC 427 Communication Networks Final Project Demo Spring 2011 Comparison and analysis of FIFO, PQ, and WFQ Disciplines in OPNET 2 Introduction and Motivation Queuing methods are used to handle network
More informationCommunication Networks
Communication Networks Chapter 3 Multiplexing Frequency Division Multiplexing (FDM) Useful bandwidth of medium exceeds required bandwidth of channel Each signal is modulated to a different carrier frequency
More informationENSC 427 COMMUNICATION NETWORKS
ENSC 427 COMMUNICATION NETWORKS Implementation of VoIP over a Campus Wide Network Spring 2010 FINAL PROJECT Xuan Lu Kevan Thompson Zhiyu Zhou http://www.sfu.ca/~zzhou/project.html xla9@sfu.ca kjthomps@sfu.ca
More informationCS 457 Multimedia Applications. Fall 2014
CS 457 Multimedia Applications Fall 2014 Topics Digital audio and video Sampling, quantizing, and compressing Multimedia applications Streaming audio and video for playback Live, interactive audio and
More informationMultimedia Networking
Multimedia Networking 1 Multimedia, Quality of Service (QoS): What is it? Multimedia applications: Network audio and video ( continuous media ) QoS Network provides application with level of performance
More informationQoS Targets for IP Networks & Services: Challenges and Opportunities
QoS Targets for IP Networks & Services: Challenges and Opportunities Dave Mustill Performance & QoS Standards BT Group Chief Technology Office Presentation Outline Speech quality in the PSTN and beyond
More informationNetwork Management & Monitoring Network Delay
Network Management & Monitoring Network Delay These materials are licensed under the Creative Commons Attribution-Noncommercial 3.0 Unported license (http://creativecommons.org/licenses/by-nc/3.0/) End-to-end
More informationLecture 14: Performance Architecture
Lecture 14: Performance Architecture Prof. Shervin Shirmohammadi SITE, University of Ottawa Prof. Shervin Shirmohammadi CEG 4185 14-1 Background Performance: levels for capacity, delay, and RMA. Performance
More informationProgramming Guide KX-TDA5480 KX-TDA Channel VoIP Gateway Card. Model
4-Channel VoIP Gateway Card Programming Guide Model KX-TDA548 KX-TDA484 Thank you for purchasing a Panasonic 4-Channel VoIP Gateway Card. Please read this manual carefully before using this product and
More informationMultimedia Networking
Multimedia Networking Raj Jain Washington University in Saint Louis Saint Louis, MO 63130 Jain@wustl.edu Audio/Video recordings of this lecture are available on-line at: http://www.cse.wustl.edu/~jain/cse473-09/
More informationRecommended QoS Configuration Settings for. AdTran NetVanta 3448 Router
Recommended QoS Configuration Settings for AdTran NetVanta 3448 Router Recommended QoS Configuration AdTran NetVanta 3448 Contents Contents Introduction....................................... 3 Supported
More informationMobility Management for VoIP on Heterogeneous Networks: Evaluation of Adaptive Schemes
Mobility Management for VoIP on Heterogeneous Networks: Evaluation of Adaptive Schemes Authors:Massimo Bernaschi, Filippo Cacace, Giulio Lannello Presented by:rukmini Sarvamangala OBJECTIVE OF THE PAPER
More informationMultimedia Networking
CE443 Computer Networks Multimedia Networking Behnam Momeni Computer Engineering Department Sharif University of Technology Acknowledgments: Lecture slides are from Computer networks course thought by
More informationMaking IP Networks Voice Enabled
Human Echo Human CSMA/CD Human Patience Making IP Networks Voice Enabled A 1999 White Paper Updated This is a white paper that was originally written in June of 1999 when IP was just beginning to be used
More informationIntroduction to Wireless Networking ECE 401WN Spring 2008
Introduction to Wireless Networking ECE 401WN Spring 2008 Lecture 2: Communication Networks The first major topic we will study will be WLANs. But before that, we need to consider a few basics of networking.
More informationCS 344/444 Computer Network Fundamentals Final Exam Solutions Spring 2007
CS 344/444 Computer Network Fundamentals Final Exam Solutions Spring 2007 Question 344 Points 444 Points Score 1 10 10 2 10 10 3 20 20 4 20 10 5 20 20 6 20 10 7-20 Total: 100 100 Instructions: 1. Question
More informationData Link Control Protocols
Protocols : Introduction to Data Communications Sirindhorn International Institute of Technology Thammasat University Prepared by Steven Gordon on 23 May 2012 Y12S1L07, Steve/Courses/2012/s1/its323/lectures/datalink.tex,
More informationAffects of Queuing Mechanisms on RTP Traffic Comparative Analysis of Jitter, End-to- End Delay and Packet Loss
Comparative Analysis of Jitter, End-to- End Delay and Packet Loss Gregory Epiphaniou 1 Carsten Maple 1 Paul Sant 1 Matthew Reeves 2 1 Institute for Research in Applicable Computing University of Bedfordshire
More informationMultimedia! 23/03/18. Part 3: Lecture 3! Content and multimedia! Internet traffic!
Part 3: Lecture 3 Content and multimedia Internet traffic Multimedia How can multimedia be transmitted? Interactive/real-time Streaming 1 Voice over IP Interactive multimedia Voice and multimedia sessions
More informationPart 3: Lecture 3! Content and multimedia!
Part 3: Lecture 3! Content and multimedia! Internet traffic! Multimedia! How can multimedia be transmitted?! Interactive/real-time! Streaming! Interactive multimedia! Voice over IP! Voice and multimedia
More informationQoS on Low Bandwidth High Delay Links. Prakash Shende Planning & Engg. Team Data Network Reliance Infocomm
QoS on Low Bandwidth High Delay Links Prakash Shende Planning & Engg. Team Data Network Reliance Infocomm Agenda QoS Some Basics What are the characteristics of High Delay Low Bandwidth link What factors
More informationPLEASE READ CAREFULLY BEFORE YOU START
Page 1 of 11 MIDTERM EXAMINATION #1 OCT. 16, 2013 COMPUTER NETWORKS : 03-60-367-01 U N I V E R S I T Y O F W I N D S O R S C H O O L O F C O M P U T E R S C I E N C E Fall 2013-75 minutes This examination
More informationModel Information, Status, and Statistics
Overview, page 1 Display Model Information Screen, page 1 Status Menu, page 2 Overview This chapter describes how to use the following menu and screen on the Cisco Unified IP Phone 7931G to view model
More informationAT&T Collaborate TM. Network Assessment Tool
AT&T Collaborate TM Network Assessment Tool 2016 AT&T Intellectual Property. All rights reserved. AT&T, Globe logo, Mobilizing Your World and DIRECTV are registered trademarks and service marks of AT&T
More informationMultimedia Communications
Multimedia Communications Directions and Innovations Introduction István Beszteri istvan.beszteri@hut.fi Multimedia Communications: Source Representations, Networks and Applications! Introduction! Networks
More informationPASS4TEST. IT Certification Guaranteed, The Easy Way! We offer free update service for one year
PASS4TEST IT Certification Guaranteed, The Easy Way! \ http://www.pass4test.com We offer free update service for one year Exam : 642-845 Title : Optimizing Converged Cisco Networks Vendors : Cisco Version
More informationAT&T Collaborate TM. Network Assessment Tool
AT&T Collaborate TM Network Assessment Tool 2016 AT&T Intellectual Property. All rights reserved. AT&T, Globe logo, Mobilizing Your World and DIRECTV are registered trademarks and service marks of AT&T
More informationDoing a VoIP Assessment with Chariot VoIP Assessor
Doing a VoIP Assessment with Chariot VoIP Assessor by Susan Pearsall and John Q. Walker, NetIQ Corporation susan.pearsall@netiq.com johnq@netiq.com Contents Why Run a VoIP Readiness Assessment?...3 How
More informationfair-queue aggregate-limit
Quality of Service Commands aggregate-limit aggregate-limit To set the maximum number of packets in all queues combined for VIP-distributed weighted fair queueing (DWFQ), use the aggregate-limit interface
More informationIntroduction to Real-Time Communications. Real-Time and Embedded Systems (M) Lecture 15
Introduction to Real-Time Communications Real-Time and Embedded Systems (M) Lecture 15 Lecture Outline Modelling real-time communications Traffic and network models Properties of networks Throughput, delay
More informationCSE 473 Introduction to Computer Networks. Final Exam. Your name here: 12/17/2012
CSE 473 Introduction to Computer Networks Jon Turner Final Exam Your name here: 12/17/2012 1. (8 points). The figure below shows a network path connecting a server to a client. 200 km 2000 km 2 km X Y
More informationQoS in a SOHO Virtual Private Network for IP Telephony
CHAPTER 5 QoS in a SOHO Virtual Private Network for Telephony This chapter provides information about implementing QoS in an AVVID-enabled Small Office Home Office (SOHO) Virtual Private Network (VPN)
More informationThe Benefit of Low Bit Rate Voice Compression Technologies as Part of a Converged Network Deployment Strategy
The Benefit of Low Bit Rate Voice Compression Technologies as Part of a Converged Network Deployment Strategy DSLcon Spring 2000 San Jose, CA 4 April 2000 Session: T-210 Dennis R Gatens Product Management
More informationCSC 4900 Computer Networks: Multimedia Applications
CSC 4900 Computer Networks: Multimedia Applications Professor Henry Carter Fall 2017 Last Time What is a VPN? What technology/protocol suite is generally used to implement them? How much protection does
More informationGigE & 10GigE Ethernet Technology Overview & Testing Approaching
GigE & 10GigE Ethernet Technology Overview & Testing Approaching Ray Lanier ray.lanier@ccairep.com Concord Communications Associates, Inc. 214 South Main Street Concord, NH 03301 Tel: 603-228-8627 Fax:
More informationTransporting audio-video. over the Internet
Transporting audio-video over the Internet Key requirements Bit rate requirements Audio requirements Video requirements Delay requirements Jitter Inter-media synchronization On compression... TCP, UDP
More informationA QoS Oriented Analysis of ertps and UGS flows in voice application over WIMAX
A QoS Oriented Analysis of ertps and UGS flows in voice application over WIMAX Abdalla A\ Alrahman Mohamed Abdalla 1, Dr. Amin Babiker A\ Nabi 2, Dr. Ashraf A. Osman 3 1,2,3 Department of communication,
More informationETSF05/ETSF10 Internet Protocols. Performance & QoS Congestion Control
ETSF05/ETSF10 Internet Protocols Performance & QoS Congestion Control Quality of Service (QoS) Maintaining a functioning network Meeting applications demands User s demands = QoE (Quality of Experience)
More informationMOHAMMAD ZAKI BIN NORANI THESIS SUBMITTED IN FULFILMENT OF THE DEGREE OF COMPUTER SCIENCE (COMPUTER SYSTEM AND NETWORKING)
PERFORMANCE ANALYSIS OF 8KBPS VOICE CODEC (G.729, G.711 ALAW, G.711 ULAW) FOR VOIP OVER WIRELESS LOCAL AREA NETWORK WITH RESPECTIVE SIGNAL-TO- NOISE RATIO MOHAMMAD ZAKI BIN NORANI THESIS SUBMITTED IN FULFILMENT
More informationAn Effective Calibration of VOIP Internet Telephony Performance using VPN between PAC and PNS
An Effective Calibration of VOIP Internet Telephony Performance using VPN between PAC and PNS Hyung Moo Kim, and Jae Soo Yoo, Member, IEEE Abstract In this paper, we have created VoIP terminals that use
More informationSeries Aggregation Services Routers.
Overview of the Cisco DSP SPA for the ASR 1000 Series Aggregation Services Routers This chapter provides an overview of the release history, features, and MIB support for the Cisco Voice SPA for the ASR
More informationImproving QoS of VoIP over Wireless Networks (IQ-VW)
Improving QoS of VoIP over Wireless Networks (IQ-VW) Mona Habib & Nirmala Bulusu CS522 12/09/2002 1 Agenda Voice over IP (VoIP): Why? VoIP Protocols: H.323 and SIP Quality of Service (QoS) Wireless Networks
More informationAdvanced Computer Networks
Advanced Computer Networks QoS in IP networks Prof. Andrzej Duda duda@imag.fr Contents QoS principles Traffic shaping leaky bucket token bucket Scheduling FIFO Fair queueing RED IntServ DiffServ http://duda.imag.fr
More informationFine-tuning Voice over Packet services. Written by: Yuval Boger, VP Business Development, RADCOM Ltd.
Fine-tuning Voice over Packet services Written by: Yuval Boger, VP Business Development, RADCOM Ltd. Introduction The transfer of voice traffic over packet networks, and especially voice over IP, is rapidly
More informationKommunikationssysteme [KS]
Kommunikationssysteme [KS] Dr.-Ing. Falko Dressler Computer Networks and Communication Systems Department of Computer Sciences University of Erlangen-Nürnberg http://www7.informatik.uni-erlangen.de/~dressler/
More informationAgilent Technologies IP Telephony Reporter J5422A
Established 1981 Advanced Test Equipment Rentals www.atecorp.com 800-404-ATEC (2832) Agilent Technologies IP Telephony Reporter J5422A Product Overview Voice Quality 255 Interations 135.0 250 200 Clarity
More informationMeasurement QoS Parameters of VoIP Codecs as a Function of the Network Traffic Level
Measurement QoS Parameters of VoIP Codecs as a Function of the Network Traffic Level Jugoslav Jocić *, Zoran Veličković ** * Telekom Srbija AD, Prokuplje, Serbia ** College of Applied Technical Sciences,
More informationStandard 1.2 September 2001
555-8421-103 Remote Office Network Engineering Guidelines Standard 1.2 September 2001 Copyright 2000 2001 Nortel Networks, All Rights Reserved. Printed in Canada. All information contained in this document
More informationIntroduction to Voice over IP. Introduction to technologies for transmitting voice over IP
Introduction to Voice over IP Introduction to technologies for transmitting voice over IP 1 Telephone network and circuit switching Static circuit allocation 64Kbps full duplex Characteristics No compression
More informationAdvanced Lab in Computer Communications Meeting 6 QoS. Instructor: Tom Mahler
Advanced Lab in Computer Communications Meeting 6 QoS Instructor: Tom Mahler Motivation Internet provides only single class of best-effort service. Some applications can be elastic. Tolerate delays and
More informationCHAPTER 3 EFFECTIVE ADMISSION CONTROL MECHANISM IN WIRELESS MESH NETWORKS
28 CHAPTER 3 EFFECTIVE ADMISSION CONTROL MECHANISM IN WIRELESS MESH NETWORKS Introduction Measurement-based scheme, that constantly monitors the network, will incorporate the current network state in the
More informationPSTN Fallback. Finding Feature Information
The feature monitors congestion in the IP network and redirects calls to the Public Switched Telephone Network (PSTN) or rejects calls on the basis of network congestion. This feature can also use the
More informationVoice over Internet Protocol
Voice over Internet Protocol Voice over Internet Protocol Contents Introduction Benefits of Integrating Voice and Data Networks Converting Voice to Data Efficient and Reliable Network Infrastructures
More informationIntegrated t Services Digital it Network (ISDN) Digital Subscriber Line (DSL) Cable modems Hybrid Fiber Coax (HFC)
Digital Local Loop Technologies Integrated t Services Digital it Network (ISDN) Handles voice and data Relatively l high h cost for low bandwidth (Skip) Digital Subscriber Line (DSL) Cable modems Hybrid
More informationUnderstanding SROS Priority Queuing, Class-Based WFQ, and QoS Maps
Configuration Guide 5991-2121 May 2006 Understanding SROS Priority Queuing, Class-Based WFQ, and QoS Maps This Configuration Guide explains the concepts behind configuring your Secure Router Operating
More informationQuality of Service. Ib Hansen TECRST-2500_c Cisco Systems, Inc. All rights reserved. Cisco Public 1
Quality of Service Ib Hansen ibhansen@cisco.com 1 Why Enable QoS? Security Quality of Service High Availability QoS: Enables UC and other collaborative applications Drives productivity by enhancing service
More informationStreaming (Multi)media
Streaming (Multi)media Overview POTS, IN SIP, H.323 Circuit Switched Networks Packet Switched Networks 1 POTS, IN SIP, H.323 Circuit Switched Networks Packet Switched Networks Circuit Switching Connection-oriented
More information