By: Saba Ahsan Supervisor: Prof. Jörg Ott

Slides:



Advertisements
Similar presentations
Streaming Video over the Internet
Advertisements

Umut Girit  One of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer.
CCNA – Network Fundamentals
McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Chapter 28 Real-Time Traffic over the Internet.
29.1 Chapter 29 Multimedia Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
29.1 Chapter 29 Multimedia Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
RTP: A Transport Protocol for Real-Time Applications Provides end-to-end delivery services for data with real-time characteristics, such as interactive.
TCP/IP Protocol Suite 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 25 Multimedia.
Using FEC for Rate Adaptation of Multimedia Streams Marcin Nagy Supervised by: Jörg Ott Instructed by: Varun Singh Conducted at Comnet, School of Electrical.
User Control of Streaming Media: RTSP
© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public 1 Version 4.0 OSI Transport Layer Network Fundamentals – Chapter 4.
Introduction Future wireless systems will be characterized by their heterogeneity - availability of multiple access systems in the same physical space.
Source-Adaptive Multilayered Multicast Algorithms for Real- Time Video Distribution Brett J. Vickers, Celio Albuquerque, and Tatsuya Suda IEEE/ACM Transactions.
School of Information Technologies Revision NETS3303/3603 Week 13.
1 Solutions to Performance Problems in VOIP over Wireless LAN Wei Wang, Soung C. Liew Presented By Syed Zaidi.
Real-time traffic Dr. Abdulaziz Almulhem. Almulhem©20012 Agenda RT traffic characteristic RT traffic profiles RT traffic requirements RT Architecture.
TCP/IP Protocol Suite 1 Chapter 25 Upon completion you will be able to: Multimedia Know the characteristics of the 3 types of services Understand the methods.
Multimedia Communications over the Internet. IP Packet-Switching Networks Packet-switching protocols based on the Internet Protocol (IP) generally consist.
WXES2106 Network Technology Semester /2005 Chapter 8 Intermediate TCP CCNA2: Module 10.
Error Checking continued. Network Layers in Action Each layer in the OSI Model will add header information that pertains to that specific protocol. On.
RTP/RTCP – Real Time Transport Protocol/ Real Time Control Protocol Presented by Manoj Sivakumar.
RTP/RTCP(RFC 1889) Real-time transport protocol (RTP) is the de facto standard media transport protocol in the Internet Media transport: audio, vedio,
Jani Pousi Supervisor: Jukka Manner Espoo,
IP Ports and Protocols used by H.323 Devices Liane Tarouco.
Computer Networks: Multimedia Applications Ivan Marsic Rutgers University Chapter 3 – Multimedia & Real-time Applications.
Introduction to Networks CS587x Lecture 1 Department of Computer Science Iowa State University.
Digital Multimedia, 2nd edition Nigel Chapman & Jenny Chapman Chapter 17 This presentation © 2004, MacAvon Media Productions Multimedia and Networks.
Multimedia Over IP: RTP, RTCP, RTSP “Computer Science” Department of Informatics Athens University of Economics and Business Λουκάς Ελευθέριος.
TCP/IP Protocol Suite 1 Chapter 25 Upon completion you will be able to: Multimedia Know the characteristics of the 3 types of services Understand the methods.
University of the Western Cape Chapter 12: The Transport Layer.
E Multimedia Communications Anandi Giridharan Electrical Communication Engineering, Indian Institute of Science, Bangalore – , India Multimedia.
Bjorn Landfeldt, The University of Sydney 1 NETS 3303 Networked Systems Revision.
Real Time Protocol (RTP) 김 준
Streaming Media Control n The protocol components of the streaming n RTP/RTCP n RVSP n Real-Time Streaming Protocol (RTSP)
TCP Trunking: Design, Implementation and Performance H.T. Kung and S. Y. Wang.
03/11/2015 Michael Chai; Behrouz Forouzan Staffordshire University School of Computing Streaming 1.
Chapter 28. Network Management Chapter 29. Multimedia
Multimedia and Networks. Protocols (rules) Rules governing the exchange of data over networks Conceptually organized into stacked layers – Application-oriented.
Chapter 24 Transport Control Protocol (TCP) Layer 4 protocol Responsible for reliable end-to-end transmission Provides illusion of reliable network to.
Digital Multimedia, 2nd edition Nigel Chapman & Jenny Chapman Chapter 17 This presentation © 2004, MacAvon Media Productions Multimedia and Networks.
E Multimedia Communications Anandi Giridharan Electrical Communication Engineering, Indian Institute of Science, Bangalore – , India Multimedia.
TCP/IP Protocol Suite 1 Chapter 25 Upon completion you will be able to: Multimedia Know the characteristics of the 3 types of services Understand the methods.
An Extensible RTCP Control Framework for Large Multimedia Distributions Paper by: Julian Chesterfield Eve M. Schooler Presented by: Phillip H. Jones.
Optimization Problems in Wireless Coding Networks Alex Sprintson Computer Engineering Group Department of Electrical and Computer Engineering.
Multimedia Streaming I. Fatimah Alzahrani. Introduction We can divide audio and video services into three broad categories: streaming stored audio/video,
1 Internet Telephony: Architecture and Protocols an IETF Perspective Authors:Henning Schulzrinne, Jonathan Rosenberg. Presenter: Sambhrama Mundkur.
3/10/2016 Subject Name: Computer Networks - II Subject Code: 10CS64 Prepared By: Madhuleena Das Department: Computer Science & Engineering Date :
Congestion Control: UDP. What is Congestion Control? Refers to the management of packet loss and signal degradation Handled by both Network and Transport.
Transmission Control Protocol (TCP) TCP Flow Control and Congestion Control CS 60008: Internet Architecture and Protocols Department of CSE, IIT Kharagpur.
11 CS716 Advanced Computer Networks By Dr. Amir Qayyum.
The Transport Layer Congestion Control & UDP
Chapter 9: Transport Layer
Chapter 29 Multimedia Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Instructor Materials Chapter 9: Transport Layer
By, Nirnimesh Ghose, Master of Science,
RTP: A Transport Protocol for Real-Time Applications
Process-to-Process Delivery, TCP and UDP protocols
Long-haul Transport Protocols
RTP: A Transport Protocol for Real-Time Applications
RTP – Real-time Transport Protocol
Chapter 25 Multimedia TCP/IP Protocol Suite
Congestion Control, Internet transport protocols: udp
SCTP: Stream Control Transport Protocol
Multimedia and Networks
Process-to-Process Delivery:
IT351: Mobile & Wireless Computing
Congestion Control, Internet Transport Protocols: UDP
CPEG514 Advanced Computer Networkst
Computer Networks Protocols
Error Checking continued
Presentation transcript:

Multipath RTP Applying Multipath Communication to Real time Applications By: Saba Ahsan Supervisor: Prof. Jörg Ott Conducted at Comnet, Aalto University of Science & Technology

Contents Motivation Problem Statement Background MPRTP Protocol Goals Architecture MPRTP Header Extension Implementation – RAMP-UP Receiver Jitter Buffer RAMP-UP Sender Testing and Results Conclusion

Motivation Most transport protocols select a single path for communication flow between two end hosts, even when multiple paths exist. Such flows are unable to fully utilize the available resources. Multihomed clients have more than one network interface. Multipath capability refers to the simultaneous use of multiple paths through the network, which may significantly improve performance and reliability. In real-time communication this could would improve the end-user experience by enhancing the QoS. Bandwidth-hungry applications such as video streaming and IP-TV can benefit from the increased, combined throughput available to multihomed clients retransmission of lost data is often uncharacteristic of real-time traffic because of time constraints; multipath senders can avoid lossy paths or send redundant data over multiple paths session-based real-time communication can benefit from the redundancy by implementing failover in case of network failures

Problem Statement Design a solution for the transport of real-time data while simultaneously using multiple paths on multihomed clients. Design of Multipath RTP (MPRTP) an extension of RTP protocol, with multipath capabilities. Design, implementation and testing of an MPRTP based solution for video streaming to a single receiver, when multiple paths exist between the sender and receiver.

Background Real-Time Protocol (RTP) RTP is an end-to-end protocol designed for transporting real-time traffic such as voice and video, over multicast and unicast. It uses RTCP (Real-time Control Protocol) for monitoring the transmission quality, however it does not guarantee QoS. It is independent of the transport and network layers. A signalling protocol such as SIP or SDP is used for managing RTP sessions. It does not care about congestion control or fair usage like TCP.

MPRTP Protocol Internet Draft : https://datatracker.ietf.org/doc/draft-singh-avt-mprtp/

MPRTP Goals Increased Throughput Improved Reliability Compatibility Concurrent use of paths such that the combined available capacity is higher than the capacity of any individual path Improved Reliability MPRTP should be able to transmit redundant streams on different paths for reliability and support fallback in case of path failures for robustness. Compatibility Application Compatibility: MPRTP stack must be capable of working with legacy RTP applications. Network Compatibility: MPRTP subflows should appear as RTP flows and be able to traverse through NATs and Firewalls.

Architecture Each path represents an MPRTP subflow. Like RTP, MPRTP can work with different transport protocols. Application MPRTP RTP … UDP/TCP IP Physical

MPRTP Specification Internet Path Management Path awareness and management of port+IP pair bindings. MPRTP is designed to use in-band signaling for path advertisements and/or connectivity checks. Interface discovery may be done using ICE. Packet Scheduling Splitting of data into multiple subflows across different paths. Subflow recombination Recombining the subflows, so that it appears as a single stream to the application MPRTP Sender MPRTP Receiver Internet subflow 1 subflow 2 subflow 3 MPRTP Flow Gather characteristics of different paths and schedule packets accordingly Reorder the data correctly and hand over to application, send reports about quality

MPRTP Header Extension for RTP RTP sequence numbers used for packet reordering of the stream Flow-specific sequence numbers increase monotonically for each path, independent of other paths. 1 2 3 4 5 6 7 8 9 10 20 30 V=2 P X CC M PT Sequence number Timestamp Synchronization source (SSRC) identifier Contributing source (CSRC) identifiers …… RTP H-Ext ID length MPR_Type Flow ID Flow specific sequence number RTP payload …….

RTP Adaptation for Multiple Paths – Using Percentage distribution MPRTP Implementation RAMP-UP RTP Adaptation for Multiple Paths – Using Percentage distribution

RAMP-UP Receiver Ordering is based on overall sequence number. Packets are inserted into the jitter buffer as soon as they arrive. Playout starts after a predefined latency period. We use 2 seconds for our testing. Late packets are discarded 9 5 8 6 4 7 3 2 1 Time Path 1 Path 2 Reordering in Jitter Buffer

RAMP-UP Sender (1) RAMP-UP sender is designed for video streaming across multiple paths. We assume that the bitrate of the video is higher than the bitrate of any of the available paths and hence it is necessary to use more than one path. A common bottleneck may exist. However, if it is common to all available paths, then congestion/losses can not be avoided. The sender is not capable of reducing video bitrate. We utilize a non-aggressive approach, which implies that we do not put more traffic on a path unless necessary. This in turn implies that the full capacity of certain paths may never be known.

RAMP-UP Sender (2) RAMP-UP uses percentage distribution on the paths. Percentages are assigned according to measured characteristics. This approach eliminates flapping and ensures equal distribution of traffic on all paths if video rate is increased. Measurements are based on data gathered by RTCP reports. All packets of a frame are sent on the same path. Initially, equal percentage is assigned to each path. Path 1 Queue To Receiver Sender’s Buffer Decision based on percentage level Path 2 Queue

RAMP-UP Sender (3) Using RTCP reports, the sender is able to calculate the bitrate observed on each path (TBi) The observed bitrate depends on the amount of traffic being sent on the path, hence the sender would only update bitrate values if they are higher than what was previously recorded, except if the ratio of lost packets (Li) is greater than 0 in the RTCP RR. Average packet size (Si) is calculated for each interval during which the bitrate was measured. If a path has continuous losses, it is considered congested, and in this case the observed bitrate is stored in another variable called CBi . The sender assigns a percentage of traffic to each path using TBi values if path is not congested, and CBi value if path is congested. Congestion condition is cleared if losses don’t appear for a predefined amount of time ( in our testing we use 25 seconds)

RAMP-UP Sender (4) Sender Receiver HSN = 1000 HSN2 = 2300, t2 t2 -t1 HSN = 2300 RTP RTCP

Testing & Results

Test Setup The test environment consists of virtual machines running on a single physical machine. Network properties are emulated using Network Emulator (NetEm) MPRTP Sender MPRTP Receiver Router1 Router2 Router3 Virtual Environment

Results: Bitrate of data being sent on each path as measured by the sender when three paths are available. Path capacities are changed during simulation. Bitrate (kpbs) Time (s)

Results: Percentages assigned to the paths over time Total Packets lost = 1.6%, Frames lost = 6%, BER = 1.8% Assigned Ratios Time (s)

Conclusion It is possible to achieve higher bitrates using multiple paths, which may help streaming higher quality videos. The extra paths may be used to avoid losses due to temporary congestion on any of the paths. Video streaming, is just one of the many applications of MPRTP. MPRTP protocol is still in its infancy. RAMP-UP focuses on video streaming only. The scheduling algorithm can be improved further. Multiple streams (voice/video, lip-sync) and rate-control mechanism can be incorporated. Many research opportunities arise from this study MPRTP for mobile environments, 3G, GPRS & WLAN interfaces MPRTP for voice fallback