This document discusses protocols for quality of service (QoS) support in computer networks. It introduces the Resource Reservation Protocol (RSVP), which allows network nodes to reserve resources for particular data flows to support QoS. RSVP is receiver-initiated and uses soft state to maintain reservations in the face of changing network conditions or routes. The document also covers Multiprotocol Label Switching (MPLS), which assigns labels to data flows to enable QoS support and traffic engineering within an MPLS domain.
This document discusses TCP flow and congestion control in high speed networks. It covers topics such as TCP flow control using a credit allocation scheme, TCP header fields for flow control, credit allocation flexibility, effects of window size, complicating factors, retransmission strategy using timers, adaptive retransmission timer algorithms, implementation policy options, congestion control difficulties, slow start, dynamic window sizing, fast retransmit, fast recovery, limited transmit, performance of TCP over ATM networks using UBR service, effects of switch buffer size, observations, partial packet discard techniques, and TCP over ABR service.
This document provides an overview of high speed networks including Frame Relay networks, Asynchronous Transfer Mode (ATM), ATM protocol architecture, logical connections, cells, service categories, and high speed LANs. It discusses the architecture, user data transfer, and call control of Frame Relay networks. For ATM, it describes the protocol model, logical connections, cells, adaptation layer, and service categories. It also provides an introduction to emerging high speed LAN technologies.
This document discusses unit 2 of a course on high speed networks. It covers queuing analysis and models, including single server queues, effects of congestion and congestion control, traffic management, and congestion control in packet switching networks and frame relay. It provides an overview of key concepts like performance measures, solution methodologies, queuing system concepts, stability and steady-state, and causes of delay and bottlenecks. It also discusses analytical and simulation approaches to modeling queues and provides examples.
The document discusses flow control in TCP. It explains that TCP uses a sliding window mechanism for flow control to balance the sender's transmission rate with the receiver's reception rate. The sliding window allows packets within the window to be transmitted, and slides to the right when acknowledgments are received, making room for more packets. Problems like delayed acknowledgments, silly window syndrome, and solutions like Nagle's algorithm are also covered. TCP provides reliable data transfer using error control mechanisms like checksums, acknowledgments, and retransmissions of lost packets.
RTP is a protocol for delivering audio and video over IP networks. It works on top of UDP to provide real-time media streaming. RTP provides mechanisms for sequencing packets, time stamping media, and detecting packet loss to enable real-time playback of media. RTSP is a control protocol that establishes and controls media sessions between end points, allowing features like play, pause, and teardown of RTP streams. Together, RTP and RTSP enable real-time streaming applications like video calls and media streaming.
The document provides an overview of three transport layer protocols: UDP, TCP, and SCTP. It discusses their features such as connection-oriented vs connectionless delivery, reliable vs unreliable transmission, and use of ports, segments, and packets. Examples are given of how each protocol handles tasks like flow control, error control, and establishing connections between processes. Diagrams illustrate concepts like sliding windows, checksum calculation, and protocol headers.
The document discusses the differences between packets and frames, and provides details on the transport layer. It explains that the transport layer is responsible for process-to-process delivery and uses port numbers for addressing. Connection-oriented protocols like TCP use three-way handshaking for connection establishment and termination, and implement flow and error control using mechanisms like sliding windows. Connectionless protocols like UDP are simpler but unreliable, treating each packet independently.
This document discusses integrated services architecture (ISA) and differentiated services (DS) for providing quality of service (QoS) in computer networks. It describes the components and functions of ISA, including reservation protocol, admission control, routing, queuing disciplines, and services. It also covers traffic classification, scheduling, and dropping policies implemented in routers. Random early detection (RED) is presented as a proactive packet discard mechanism for congestion management. Differentiated services is introduced as a simpler alternative to ISA that uses traffic classes in packet headers to provide different performance levels.
This document discusses TCP flow and congestion control in high speed networks. It covers topics such as TCP flow control using a credit allocation scheme, TCP header fields for flow control, credit allocation flexibility, effects of window size, complicating factors, retransmission strategy using timers, adaptive retransmission timer algorithms, implementation policy options, congestion control difficulties, slow start, dynamic window sizing, fast retransmit, fast recovery, limited transmit, performance of TCP over ATM networks using UBR service, effects of switch buffer size, observations, partial packet discard techniques, and TCP over ABR service.
This document provides an overview of high speed networks including Frame Relay networks, Asynchronous Transfer Mode (ATM), ATM protocol architecture, logical connections, cells, service categories, and high speed LANs. It discusses the architecture, user data transfer, and call control of Frame Relay networks. For ATM, it describes the protocol model, logical connections, cells, adaptation layer, and service categories. It also provides an introduction to emerging high speed LAN technologies.
This document discusses unit 2 of a course on high speed networks. It covers queuing analysis and models, including single server queues, effects of congestion and congestion control, traffic management, and congestion control in packet switching networks and frame relay. It provides an overview of key concepts like performance measures, solution methodologies, queuing system concepts, stability and steady-state, and causes of delay and bottlenecks. It also discusses analytical and simulation approaches to modeling queues and provides examples.
The document discusses flow control in TCP. It explains that TCP uses a sliding window mechanism for flow control to balance the sender's transmission rate with the receiver's reception rate. The sliding window allows packets within the window to be transmitted, and slides to the right when acknowledgments are received, making room for more packets. Problems like delayed acknowledgments, silly window syndrome, and solutions like Nagle's algorithm are also covered. TCP provides reliable data transfer using error control mechanisms like checksums, acknowledgments, and retransmissions of lost packets.
RTP is a protocol for delivering audio and video over IP networks. It works on top of UDP to provide real-time media streaming. RTP provides mechanisms for sequencing packets, time stamping media, and detecting packet loss to enable real-time playback of media. RTSP is a control protocol that establishes and controls media sessions between end points, allowing features like play, pause, and teardown of RTP streams. Together, RTP and RTSP enable real-time streaming applications like video calls and media streaming.
The document provides an overview of three transport layer protocols: UDP, TCP, and SCTP. It discusses their features such as connection-oriented vs connectionless delivery, reliable vs unreliable transmission, and use of ports, segments, and packets. Examples are given of how each protocol handles tasks like flow control, error control, and establishing connections between processes. Diagrams illustrate concepts like sliding windows, checksum calculation, and protocol headers.
The document discusses the differences between packets and frames, and provides details on the transport layer. It explains that the transport layer is responsible for process-to-process delivery and uses port numbers for addressing. Connection-oriented protocols like TCP use three-way handshaking for connection establishment and termination, and implement flow and error control using mechanisms like sliding windows. Connectionless protocols like UDP are simpler but unreliable, treating each packet independently.
This document discusses integrated services architecture (ISA) and differentiated services (DS) for providing quality of service (QoS) in computer networks. It describes the components and functions of ISA, including reservation protocol, admission control, routing, queuing disciplines, and services. It also covers traffic classification, scheduling, and dropping policies implemented in routers. Random early detection (RED) is presented as a proactive packet discard mechanism for congestion management. Differentiated services is introduced as a simpler alternative to ISA that uses traffic classes in packet headers to provide different performance levels.
TELNET is a general-purpose client/server application that allows users to access applications on remote computers. Electronic mail is one of the most popular Internet services, using user agents, message transfer agents, and message access agents. File Transfer Protocol (FTP) allows transferring files between computers using separate TCP connections for control commands and data transfer.
Traffic and Congestion Control in ATM Networks Chapter 13daniel ayalew
This document discusses traffic and congestion control in ATM networks. It describes how ATM networks require different approaches than other networks due to factors like high speeds, small cell sizes, and the need to support both real-time and bursty traffic. It outlines the ITU-T and ATM forum frameworks for congestion control, including schemes for delay-sensitive traffic like voice and video as well as bursty traffic using techniques like Available Bit Rate and Guaranteed Frame Rate. Key issues discussed include latency effects, cell delay variation, and how the network contributes to delay variation.
TCP/IP is a set of communication protocols used to connect devices on the internet. It includes lower level protocols like IP that handle basic transport of data and higher level protocols like TCP that ensure reliable delivery of data between applications. TCP establishes connections between clients and servers that allow for reliable transmission of data streams. UDP provides a simpler transmission model without ensuring delivery but is useful for applications like broadcasting.
TCP & UDP ( Transmission Control Protocol and User Datagram Protocol)Kruti Niranjan
This document provides information about the Transport Layer protocols TCP and UDP. It describes:
1) TCP is a connection-oriented protocol that provides reliable, in-order delivery of data through features like flow control, error control, and congestion control. UDP is a connectionless protocol that does not guarantee delivery or order of packets.
2) The TCP header contains fields for source/destination ports, sequence numbers, acknowledgement numbers, flags, window size, checksum, and options. The UDP header contains fields for source/destination ports, length, and checksum.
3) The main differences between TCP and UDP are that TCP is connection-oriented, provides error control and flow control, and supports full duplex communication
Overview of transport protocols.
The transport layer (OSI layer 4) is the interface between the network and application (network API).
The transport layer provides data transport service and some level of quality of service (QoS) to the application.
While all transport protocols offer data transport services, they have varying levels of quality of service in terms of error detection and correction, packet ordering and packet delay.
Simple transport protocols like UDP are often connectionless while connection-oriented transport protocols like TCP provide many quality of service properties.
RTP and RTCP are protocols used for delivering audio and video over IP networks. RTP carries the media streams, while RTCP monitors transmission quality and aids synchronization. RTCP sends periodic reports containing statistics like packet loss to allow senders to adapt transmission rates. While TCP is not suitable due to retransmissions causing delay, RTP supports features needed for real-time multimedia like sequencing, timestamps, error concealment, and quality of service feedback.
This document discusses several internet protocols, including ARP and RARP. ARP is used to convert IP addresses to physical addresses like Ethernet addresses. It operates below the network layer to interface between OSI layers. A host broadcasts an ARP request to obtain another device's physical address. RARP is used to resolve an IP address from a given hardware address. It has been replaced by newer protocols but was used by clients to request IP addresses from a network.
TCP uses congestion control to determine how much capacity is available in the network and regulate how many packets can be in transit. It uses additive increase/multiplicative decrease (AIMD) where the congestion window is increased slowly with each ACK but halved upon timeout. Slow start is used initially and after idle periods to grow the window exponentially until congestion is detected. Fast retransmit and fast recovery help detect and recover from packet loss without requiring a timeout.
T/TCP is a protocol that aims to reduce the number of packets needed for transaction-style applications by allowing a client to open a connection, send data, and close the connection in a single packet. It utilizes a mechanism called TCP Accelerated Open (TAO) to bypass the standard 3-way TCP handshake. Testing showed T/TCP saved an average of 5 packets per transaction compared to TCP. However, the percentage savings decreased with larger data transfers as T/TCP is most beneficial for small transactions. While improving performance, T/TCP also introduced some security and operational issues that needed to be addressed for broader adoption.
Dijkstra's algorithm finds the shortest path from a starting node to all other nodes in a graph. It does this by examining all possible paths from the starting node and progressively eliminating longer paths, until arriving at the shortest path to each node. Flooding is a simple routing algorithm where every incoming packet is sent through every outgoing link except the one it arrived on, ensuring delivery but wasting bandwidth through duplicate packets circulating forever without precautions.
This document summarizes key aspects of the transport layer:
- The transport layer provides logical communication between application processes running on different hosts and handles reliable data transfer.
- It provides both connection-oriented and connectionless services to the application layer. Quality of service parameters like throughput and delay can be negotiated.
- Transport layer protocols like TCP and UDP are described. TCP provides reliable byte-stream delivery using connections while UDP provides best-effort unreliable datagram delivery.
This document discusses the Transmission Control Protocol (TCP) which provides reliable, connection-oriented data transmission over the internet. TCP establishes a virtual connection between endpoints, ensuring reliable delivery through mechanisms like positive acknowledgement and retransmission. It uses a sliding window algorithm to guarantee reliable and in-order delivery while enforcing flow control between sender and receiver. Key aspects of TCP include connection establishment and termination, port numbers, segments, headers, and addressing end-to-end issues over heterogeneous networks.
The document discusses wireless LAN (IEEE 802.11) standards. It describes how wireless LANs provide flexibility, portability and mobility by connecting devices using wireless transmission instead of physical wires. The key wireless LAN standard is IEEE 802.11, which was first published in 1997 and defines the physical and data link layer specifications. The standard provides benefits like interoperability, fast product development and support for future technologies. Common wireless LAN applications include use in medical facilities, schools, temporary situations and emergency response centers.
This document describes the sliding window protocol. It discusses key concepts like both the sender and receiver maintaining buffers to hold packets, acknowledgements being sent for every received packet, and the sender being able to send a window of packets before receiving an acknowledgement. It then explains the sender side process of numbering packets and maintaining a sending window. The receiver side maintains a window size of 1 and acknowledges by sending the next expected sequence number. A one bit sliding window protocol acts like stop and wait. Merits include multiple packets being sent without waiting for acknowledgements while demerits include potential bandwidth waste in some situations.
The document provides an overview of the World Wide Web (WWW) and Hypertext Transfer Protocol (HTTP). It discusses the structure of the WWW including clients, servers, caches and components like HTML, URLs, and browsers. HTTP is described as the application protocol that allows for data communication across the internet using requests and responses. Key aspects of HTTP like features, architecture, status codes, and request methods are summarized.
The document discusses various IEEE 802 standards for networking technologies including Ethernet, wireless LAN (802.11), and their variants and evolutions over time. It provides details on Ethernet standards and implementations such as 802.3, 10BASE5, 10BASE2, 10BASE-T, 10BASE-F, Fast Ethernet, and Gigabit Ethernet. It also summarizes key aspects of wireless networking standards such as 802.11 components, frame format, and physical layer specifications including FHSS, DSSS, OFDM, and associated data rates and frequencies.
The document discusses bandwidth utilization techniques including multiplexing and spreading. Multiplexing allows simultaneous transmission of multiple signals across a single data link by dividing the bandwidth into channels. Efficiency is achieved through multiplexing while privacy and anti-jamming is achieved through spreading techniques that add redundancy such as frequency hopping spread spectrum and direct sequence spread spectrum. The document provides examples and diagrams to illustrate concepts such as frequency-division multiplexing, time-division multiplexing, and digital signal hierarchies.
This document provides an overview of various topics related to the network layer, including IPv4, IPv6, ARP, RARP, mobile IP, routing algorithms, and routing protocols. It begins with basics of IPv4 such as its addressing scheme and role in interconnecting networks. IPv6 is then introduced, along with reasons for its development and key features like its large 128-bit addresses. Address Resolution Protocol (ARP) and Reverse ARP (RARP) are also covered. The document concludes by discussing routing algorithms like link-state and distance-vector, as well as protocols including RIP, OSPF, and BGP.
Integrated and Differentiated services Chapter 17daniel ayalew
The document discusses integrated and differentiated services for managing internet traffic. Integrated services (ISA) allow traffic to reserve resources and receive guaranteed quality of service. Differentiated services classify traffic into groups that receive different treatment. Interior routers implement per-hop behaviors like expedited forwarding to give preferential treatment based on packet codes. Boundary routers condition traffic to enforce service level agreements.
Exterior Routing Protocols And Multi casting Chapter 16daniel ayalew
This document discusses exterior routing protocols and multicasting. It begins by explaining the limitations of distance-vector and link-state routing protocols for exterior routing between autonomous systems. It then describes path vector routing and the Border Gateway Protocol (BGP) which allows routers in different autonomous systems to exchange routing information. The document provides details on BGP neighbor acquisition, reachability, and network reachability procedures. It also discusses multicast addressing, protocols like IGMP for host group management, and multicast routing protocols like PIM that establish distribution trees independent of unicast routing.
TELNET is a general-purpose client/server application that allows users to access applications on remote computers. Electronic mail is one of the most popular Internet services, using user agents, message transfer agents, and message access agents. File Transfer Protocol (FTP) allows transferring files between computers using separate TCP connections for control commands and data transfer.
Traffic and Congestion Control in ATM Networks Chapter 13daniel ayalew
This document discusses traffic and congestion control in ATM networks. It describes how ATM networks require different approaches than other networks due to factors like high speeds, small cell sizes, and the need to support both real-time and bursty traffic. It outlines the ITU-T and ATM forum frameworks for congestion control, including schemes for delay-sensitive traffic like voice and video as well as bursty traffic using techniques like Available Bit Rate and Guaranteed Frame Rate. Key issues discussed include latency effects, cell delay variation, and how the network contributes to delay variation.
TCP/IP is a set of communication protocols used to connect devices on the internet. It includes lower level protocols like IP that handle basic transport of data and higher level protocols like TCP that ensure reliable delivery of data between applications. TCP establishes connections between clients and servers that allow for reliable transmission of data streams. UDP provides a simpler transmission model without ensuring delivery but is useful for applications like broadcasting.
TCP & UDP ( Transmission Control Protocol and User Datagram Protocol)Kruti Niranjan
This document provides information about the Transport Layer protocols TCP and UDP. It describes:
1) TCP is a connection-oriented protocol that provides reliable, in-order delivery of data through features like flow control, error control, and congestion control. UDP is a connectionless protocol that does not guarantee delivery or order of packets.
2) The TCP header contains fields for source/destination ports, sequence numbers, acknowledgement numbers, flags, window size, checksum, and options. The UDP header contains fields for source/destination ports, length, and checksum.
3) The main differences between TCP and UDP are that TCP is connection-oriented, provides error control and flow control, and supports full duplex communication
Overview of transport protocols.
The transport layer (OSI layer 4) is the interface between the network and application (network API).
The transport layer provides data transport service and some level of quality of service (QoS) to the application.
While all transport protocols offer data transport services, they have varying levels of quality of service in terms of error detection and correction, packet ordering and packet delay.
Simple transport protocols like UDP are often connectionless while connection-oriented transport protocols like TCP provide many quality of service properties.
RTP and RTCP are protocols used for delivering audio and video over IP networks. RTP carries the media streams, while RTCP monitors transmission quality and aids synchronization. RTCP sends periodic reports containing statistics like packet loss to allow senders to adapt transmission rates. While TCP is not suitable due to retransmissions causing delay, RTP supports features needed for real-time multimedia like sequencing, timestamps, error concealment, and quality of service feedback.
This document discusses several internet protocols, including ARP and RARP. ARP is used to convert IP addresses to physical addresses like Ethernet addresses. It operates below the network layer to interface between OSI layers. A host broadcasts an ARP request to obtain another device's physical address. RARP is used to resolve an IP address from a given hardware address. It has been replaced by newer protocols but was used by clients to request IP addresses from a network.
TCP uses congestion control to determine how much capacity is available in the network and regulate how many packets can be in transit. It uses additive increase/multiplicative decrease (AIMD) where the congestion window is increased slowly with each ACK but halved upon timeout. Slow start is used initially and after idle periods to grow the window exponentially until congestion is detected. Fast retransmit and fast recovery help detect and recover from packet loss without requiring a timeout.
T/TCP is a protocol that aims to reduce the number of packets needed for transaction-style applications by allowing a client to open a connection, send data, and close the connection in a single packet. It utilizes a mechanism called TCP Accelerated Open (TAO) to bypass the standard 3-way TCP handshake. Testing showed T/TCP saved an average of 5 packets per transaction compared to TCP. However, the percentage savings decreased with larger data transfers as T/TCP is most beneficial for small transactions. While improving performance, T/TCP also introduced some security and operational issues that needed to be addressed for broader adoption.
Dijkstra's algorithm finds the shortest path from a starting node to all other nodes in a graph. It does this by examining all possible paths from the starting node and progressively eliminating longer paths, until arriving at the shortest path to each node. Flooding is a simple routing algorithm where every incoming packet is sent through every outgoing link except the one it arrived on, ensuring delivery but wasting bandwidth through duplicate packets circulating forever without precautions.
This document summarizes key aspects of the transport layer:
- The transport layer provides logical communication between application processes running on different hosts and handles reliable data transfer.
- It provides both connection-oriented and connectionless services to the application layer. Quality of service parameters like throughput and delay can be negotiated.
- Transport layer protocols like TCP and UDP are described. TCP provides reliable byte-stream delivery using connections while UDP provides best-effort unreliable datagram delivery.
This document discusses the Transmission Control Protocol (TCP) which provides reliable, connection-oriented data transmission over the internet. TCP establishes a virtual connection between endpoints, ensuring reliable delivery through mechanisms like positive acknowledgement and retransmission. It uses a sliding window algorithm to guarantee reliable and in-order delivery while enforcing flow control between sender and receiver. Key aspects of TCP include connection establishment and termination, port numbers, segments, headers, and addressing end-to-end issues over heterogeneous networks.
The document discusses wireless LAN (IEEE 802.11) standards. It describes how wireless LANs provide flexibility, portability and mobility by connecting devices using wireless transmission instead of physical wires. The key wireless LAN standard is IEEE 802.11, which was first published in 1997 and defines the physical and data link layer specifications. The standard provides benefits like interoperability, fast product development and support for future technologies. Common wireless LAN applications include use in medical facilities, schools, temporary situations and emergency response centers.
This document describes the sliding window protocol. It discusses key concepts like both the sender and receiver maintaining buffers to hold packets, acknowledgements being sent for every received packet, and the sender being able to send a window of packets before receiving an acknowledgement. It then explains the sender side process of numbering packets and maintaining a sending window. The receiver side maintains a window size of 1 and acknowledges by sending the next expected sequence number. A one bit sliding window protocol acts like stop and wait. Merits include multiple packets being sent without waiting for acknowledgements while demerits include potential bandwidth waste in some situations.
The document provides an overview of the World Wide Web (WWW) and Hypertext Transfer Protocol (HTTP). It discusses the structure of the WWW including clients, servers, caches and components like HTML, URLs, and browsers. HTTP is described as the application protocol that allows for data communication across the internet using requests and responses. Key aspects of HTTP like features, architecture, status codes, and request methods are summarized.
The document discusses various IEEE 802 standards for networking technologies including Ethernet, wireless LAN (802.11), and their variants and evolutions over time. It provides details on Ethernet standards and implementations such as 802.3, 10BASE5, 10BASE2, 10BASE-T, 10BASE-F, Fast Ethernet, and Gigabit Ethernet. It also summarizes key aspects of wireless networking standards such as 802.11 components, frame format, and physical layer specifications including FHSS, DSSS, OFDM, and associated data rates and frequencies.
The document discusses bandwidth utilization techniques including multiplexing and spreading. Multiplexing allows simultaneous transmission of multiple signals across a single data link by dividing the bandwidth into channels. Efficiency is achieved through multiplexing while privacy and anti-jamming is achieved through spreading techniques that add redundancy such as frequency hopping spread spectrum and direct sequence spread spectrum. The document provides examples and diagrams to illustrate concepts such as frequency-division multiplexing, time-division multiplexing, and digital signal hierarchies.
This document provides an overview of various topics related to the network layer, including IPv4, IPv6, ARP, RARP, mobile IP, routing algorithms, and routing protocols. It begins with basics of IPv4 such as its addressing scheme and role in interconnecting networks. IPv6 is then introduced, along with reasons for its development and key features like its large 128-bit addresses. Address Resolution Protocol (ARP) and Reverse ARP (RARP) are also covered. The document concludes by discussing routing algorithms like link-state and distance-vector, as well as protocols including RIP, OSPF, and BGP.
Integrated and Differentiated services Chapter 17daniel ayalew
The document discusses integrated and differentiated services for managing internet traffic. Integrated services (ISA) allow traffic to reserve resources and receive guaranteed quality of service. Differentiated services classify traffic into groups that receive different treatment. Interior routers implement per-hop behaviors like expedited forwarding to give preferential treatment based on packet codes. Boundary routers condition traffic to enforce service level agreements.
Exterior Routing Protocols And Multi casting Chapter 16daniel ayalew
This document discusses exterior routing protocols and multicasting. It begins by explaining the limitations of distance-vector and link-state routing protocols for exterior routing between autonomous systems. It then describes path vector routing and the Border Gateway Protocol (BGP) which allows routers in different autonomous systems to exchange routing information. The document provides details on BGP neighbor acquisition, reachability, and network reachability procedures. It also discusses multicast addressing, protocols like IGMP for host group management, and multicast routing protocols like PIM that establish distribution trees independent of unicast routing.
This document discusses different types of virtual private networks (VPNs) and their requirements. It describes four main types of VPNs: virtual leased lines, virtual private routed networks, virtual private LAN segments, and virtual private dial networks. For each type, it covers definitions, benefits, issues that need to be addressed, and recommendations. Overall recommendations include further standardizing a generic VPN tunneling protocol, VPN membership configuration and dissemination, and addressing security and scalability challenges in supporting quality of service guarantees for VPNs.
This document discusses different types of virtual private networks (VPNs) and their requirements. It describes four main types of VPNs: virtual leased lines, virtual private routed networks, virtual private LAN segments, and virtual private dial networks. For each type, it outlines their motivations, implementations, requirements around tunneling protocols, addressing, and quality of service guarantees. Further standardization is needed on a generic VPN identifier, membership configuration and dissemination, and addressing security and scalability issues.
RSVP is a network control protocol that allows applications to request different qualities of service for their data flows. It works with routing protocols to implement reservations across a network without requiring migration to a new routing protocol. RSVP supports both unicast and multicast sessions, with three service levels - best effort, rate sensitive, and delay sensitive. It uses soft state to dynamically maintain reservations in response to changes in network conditions or routing.
Sigtran and SS7 over IP technologies allow the transport of SS7 signaling over an IP network. Sigtran defines protocols like SCTP and M3UA that encapsulate SS7 and ensure reliable delivery over IP. A phased deployment strategy migrates SS7 links onto IP in stages to test performance before full conversion. Testing focuses on priority, failure handling, latency, and interoperability to ensure equivalent functionality over IP.
Sigtran and SS7oIP technologies allow the transport of SS7 signaling over IP networks. Sigtran defines protocols like SCTP and M3UA that encapsulate SS7 messages for transport over IP. A phased deployment strategy migrates SS7 links onto SS7oIP devices to realize cost savings. Initial deployments place half the links in a city or STP over IP. Full deployment moves all A, B, and C links to IP. Testing validates capabilities like priority, rerouting, and interoperability before full migration.
This document discusses quality of service (QoS) techniques for prioritizing different types of network traffic such as voice over IP. It describes several QoS mechanisms including weighted fair queuing, priority queuing, class-based weighted fair queuing, IP precedence, policy routing, and resource reservation protocol. These mechanisms allow administrators to classify and manage network traffic to ensure sufficient bandwidth and latency for applications like VoIP that have sensitive network requirements.
The document provides an overview of Switched Digital Video (SDV) technology, including what it is, how it works, and its benefits. SDV enables cable providers to offer more channels without using additional bandwidth by only broadcasting channels that are currently being watched. It reduces equipment and bandwidth costs compared to traditional broadcasting of all channels at once. SDV works by dynamically allocating bandwidth to requested channels and freeing it up for other channels once viewers switch to something else.
TechWiseTV Workshop: Segment Routing for the DatacenterRobb Boyd
(This was a Live Webinar on July 21, 2016 at 10:00 am Pacific Time / 1:00 pm Eastern Time)
Watch the Replay at: bit.ly/29Mw58Q
Catch the original TV episode or any other topics at www.techwisetv.com
Description:
Networks are moving toward simplification, increased operational efficiency, and programmability using technologies such as software-defined networking. Cisco continues to demonstrate innovation by introducing the concept of segment routing in the data center, making the network more intelligent and adaptive to the applications running on top of it. Segment routing delivers application-optimized network transport. Encoding the path information directly at the source (that is, either at the virtual switch or at the top of rack) and using per-app policies, segment routing puts control in the hands of the network operators by empowering them to create secure, adaptive, and optimal paths based on the requirements of the application itself.
Please join us in the session to learn how Cisco is helping organizations increase network efficiency by allocating resources on demand and optimizing the network to better support business-critical applications, all while preserving security.
Agenda
Topics to discuss include:
- Introducing segment routing
- Why the need for application-optimized transport
- Features and benefits of segment routing
- Differences between segment routing and MPLS transport
- Relevance of segment routing in the data center
- Use cases and applicability of segment routing
- Summary and conclusion
PLNOG16: Usługi w sieciach operatorskich, Marcin AronowskiPROIDEA
This document discusses network services in carrier networks. It begins with an agenda for a 168 slide, 40 minute presentation on multiservice IP next-generation networks (NGN). It then discusses concepts like quality of service (QoS), multicasting, and TCP performance in the context of modern networking technologies like HTTP/2, over-the-top services, and 100 gigabit Ethernet. The rest of the document provides details on implementing QoS, guidelines for QoS for video, the history and uses of multicasting, and fundamentals of multicast addressing.
Intelligent Network Services through Active Flow ManipulationTal Lavian Ph.D.
Active Flow Manipulation Abstractions:
Aggregate data into traffic flows
Flows whose characteristics can be identified in real-time
E.g., “all UDP packets to a particular service”, “all TCP packets from a particular machine”.
Actions to be performed in the traffic flows
Actions that can be performed in real-time
E.g., “Change the priority of all traffic destined to a particular service on a particular machine”, “Stop all traffic out of a particular link of a router”.
This document summarizes how the Recursive InterNetwork Architecture (RINA) approach simplifies multi-layer network management compared to the traditional IP approach. RINA uses a single, consistent layer type and management protocol (CDAP) across all layers, reducing complexity compared to IP which has unique layer types and protocols. This common structure in RINA simplifies management models and enables greater automation of multi-layer networks. The document provides examples comparing IP and RINA models for data center fabric management and tenant network management.
This document summarizes an approach called RINA (Recursive InterNetwork Architecture) for simplifying multi-layer network management. RINA proposes a common, repeating structure across layers with only two protocols - one for data transfer and one for layer management. This significantly reduces the complexity of management models compared to the IP protocol suite, which has unique protocols at each layer. A case study shows how RINA could simplify network management in a large-scale data center network by reducing the number of required addresses, forwarding entities, and management protocols. The consistent structure of RINA opens the door to increased network automation by making management models simpler and more standardized.
The document provides an overview of SIGTRAN (Signaling System 7 (SS7) over IP), including:
- SIGTRAN allows SS7, ISDN, and other PSTN signaling protocols to be carried over IP networks using SCTP.
- The key SIGTRAN components are signaling gateways, media gateways, and media gateway controllers. Signaling gateways translate between SS7 and IP, while media gateways handle voice streams.
- User adaptation layers like M3UA, M2UA, SUA, and IUA translate different SS7 protocol layers into SCTP for transport over IP.
RTP provides end-to-end delivery services for real-time audio and video traffic over UDP. It includes payload identification, sequence numbering, timestamping and delivery monitoring. RTP runs on top of UDP and is designed to support multimedia conferences using IP multicast. RTCP monitors quality of service and conveys information about participants. Profiles and payload formats can customize RTP to support specific applications.
Converged network quality issues include lack of bandwidth, end-to-end delay, variation of delay (jitter), and packet loss. These issues are caused by multiple flows competing for limited bandwidth over network devices and links, resulting in increased processing, queuing, and propagation delays as well as dropped packets during congestion. Implementing quality of service features such as priority queuing, traffic shaping, and dropping can help address these issues by classifying and prioritizing important traffic.
The document discusses the evolution from 4G's point-to-point core network architecture to 5G's service-based architecture. It describes the need for change driven by new 5G use cases requiring network slicing and easier integration of new features. The current 3GPP Release 15 5G service-based architecture is presented, including its protocol layering using HTTP/2 and JSON, API design principles, and support for network slicing and security. Future releases will enhance the architecture for massive IoT, ultra-reliable low latency communication, and other use cases.
Similar to Protocol for QoS Support Chapter 18 (20)
The document discusses interior routing protocols. It describes fixed routing, where routes are manually configured and do not change dynamically. It also covers adaptive routing, where routers exchange information to dynamically update their routing tables in response to network changes. The document focuses on two common interior routing protocols: Routing Information Protocol (RIP) which uses distance vector routing, and Open Shortest Path First (OSPF) which uses link state routing to calculate the optimal path between any two points.
Overview of Graph Theory and Least-Cost Paths Chapter 14daniel ayalew
This chapter provides an overview of graph theory and shortest path algorithms. It defines basic graph concepts such as vertices, edges, paths, and adjacency matrices. It also covers trees, spanning trees, and algorithms for finding shortest paths such as breadth-first search, Dijkstra's algorithm, and Bellman-Ford algorithm. These algorithms are used for routing in communication networks to find the lowest-cost path between nodes.
This chapter discusses TCP traffic control and congestion control. It introduces TCP flow control using a credit allocation scheme and sliding window mechanism. TCP congestion control dynamically adjusts the transmission window size in response to packet loss to control bandwidth. Key TCP congestion control algorithms discussed are slow start, congestion avoidance, fast retransmit, and fast recovery. The performance of TCP over ATM networks is also examined.
Link-Level Flow and Error Control Chapter11daniel ayalew
This document summarizes flow and error control mechanisms at the link layer. It discusses stop-and-wait, go-back-N, and selective reject protocols for automatic repeat request (ARQ). These protocols use sliding windows, acknowledgments, and retransmissions to provide reliable data transfer over unreliable links. Performance analysis is presented showing how throughput is affected by window size, propagation delay, and error rates. High-level data link control (HDLC) is also introduced as an important link layer protocol.
Congestion Control in Data Networks And Internets Chapter 10daniel ayalew
This chapter discusses congestion control in data networks. It begins by defining congestion as occurring when the number of packets approaches network capacity. The objective of congestion control is to keep the number of packets below a level where performance drops off dramatically. It then discusses queuing theory and how network queues can grow without bound if arrival rates exceed transmission rates. The chapter covers different congestion control strategies including backpressure, implicit signaling of congestion, and explicit congestion signaling. It also addresses traffic management concerns like fairness and quality of service.
This chapter discusses high-speed local area networks (LANs) such as Fast Ethernet, Gigabit Ethernet, Fibre Channel, and wireless LANs. It describes how classical Ethernet networks using CSMA/CD were limited to 10 Mbps and discusses solutions to increase speeds, including the emergence of switches, bridges, and routers. Newer technologies like 10 Gbps Ethernet and Fibre Channel are able to provide faster speeds of up to 800 Mbps over longer distances of up to 10 km using small fiber optic connectors. Wireless LAN standards such as IEEE 802.11 support high data rates, large numbers of nodes, and services including association, reassociation, and authentication.
ATM uses fixed-size cells and virtual connections to transfer data between network entities. It defines several adaptation layers to map various protocols to ATM cells. AAL1 is for constant bitrate traffic. AAL3/4 supports both connectionless and connected services. AAL5 provides a streamlined transport for connection-oriented protocols and reduces overhead. Control signaling is used to establish and release virtual paths and channels in ATM networks.
Frame Relay is a packet switching technology that was developed to improve on X.25 networks. It uses virtual circuits to transfer user data in frames more efficiently than X.25 by eliminating much of the overhead and removing hop-by-hop flow and error control. Frame Relay networks operate at the data link layer and use logical connections identified by a Data Link Connection Identifier to multiplex and switch user data frames, while call setup and teardown is handled on a separate control channel.
TCP provides reliable, ordered delivery of data through the use of sequence numbers and acknowledgments. It accumulates data into segments and ensures delivery through retransmissions. UDP is a simpler protocol that does not ensure delivery or order, making it faster but unreliable. IP handles addressing and fragmentation of packets to accommodate networks with different maximum sizes. IPv6 was developed to support more devices, longer addresses, extension headers and simplified header processing.
protocol and the TCP/IP suite Chapter 02daniel ayalew
The document discusses protocols and the TCP/IP protocol suite. It introduces the layered protocol architecture and describes the need for coordination between communicating systems. It explains key aspects of protocols including syntax, semantics, and timing. The TCP/IP protocol suite is presented including the layers of physical, network access, internet, and transport. TCP and UDP are described as transport layer protocols, with TCP providing reliable connection-oriented delivery and UDP being unreliable and connectionless. The OSI reference model layers and concepts of internetworking such as routers are also summarized.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
Null Bangalore | Pentesters Approach to AWS IAMDivyanshu
#Abstract:
- Learn more about the real-world methods for auditing AWS IAM (Identity and Access Management) as a pentester. So let us proceed with a brief discussion of IAM as well as some typical misconfigurations and their potential exploits in order to reinforce the understanding of IAM security best practices.
- Gain actionable insights into AWS IAM policies and roles, using hands on approach.
#Prerequisites:
- Basic understanding of AWS services and architecture
- Familiarity with cloud security concepts
- Experience using the AWS Management Console or AWS CLI.
- For hands on lab create account on [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
# Scenario Covered:
- Basics of IAM in AWS
- Implementing IAM Policies with Least Privilege to Manage S3 Bucket
- Objective: Create an S3 bucket with least privilege IAM policy and validate access.
- Steps:
- Create S3 bucket.
- Attach least privilege policy to IAM user.
- Validate access.
- Exploiting IAM PassRole Misconfiguration
-Allows a user to pass a specific IAM role to an AWS service (ec2), typically used for service access delegation. Then exploit PassRole Misconfiguration granting unauthorized access to sensitive resources.
- Objective: Demonstrate how a PassRole misconfiguration can grant unauthorized access.
- Steps:
- Allow user to pass IAM role to EC2.
- Exploit misconfiguration for unauthorized access.
- Access sensitive resources.
- Exploiting IAM AssumeRole Misconfiguration with Overly Permissive Role
- An overly permissive IAM role configuration can lead to privilege escalation by creating a role with administrative privileges and allow a user to assume this role.
- Objective: Show how overly permissive IAM roles can lead to privilege escalation.
- Steps:
- Create role with administrative privileges.
- Allow user to assume the role.
- Perform administrative actions.
- Differentiation between PassRole vs AssumeRole
Try at [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
AI assisted telemedicine KIOSK for Rural India.pptx
Protocol for QoS Support Chapter 18
1. Chapter 18 Protocols for QoS Support
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ChapterChapter 1818
Protocols for QoS Support
2. Chapter 18 Protocols for QoS Support
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Increased DemandsIncreased Demands
Need to incorporate bursty and stream traffic in
TCP/IP architecture
Increase capacity
– Faster links, switches, routers
– Intelligent routing policies
– End-to-end flow control
Multicasting
Quality of Service (QoS) capability
Transport protocol for streaming
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Resource Reservation -Resource Reservation -
UnicastUnicast
Prevention as well as reaction to congestion
required
Can do this by resource reservation
Unicast
– End users agree on QoS for task and request from
network
– May reserve resources
– Routers pre-allocate resources
– If QoS not available, may wait or try at reduced QoS
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Resource Reservation –Resource Reservation –
MulticastMulticast
Generate vast traffic
– High volume application like video
– Lots of destinations
Can reduce load
– Some members of group may not want current
transmission
“Channels” of video
– Some members may only be able to handle part of
transmission
Basic and enhanced video components of video stream
Routers can decide if they can meet demand
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Resource ReservationResource Reservation
Problems on an InternetProblems on an Internet
Must interact with dynamic routing
– Reservations must follow changes in route
Soft state – a set of state information at a
router that expires unless refreshed
– End users periodically renew resource
requests
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Resource ReSerVationResource ReSerVation
Protocol (RSVP) Design GoalsProtocol (RSVP) Design Goals
Enable receivers to make reservations
– Different reservations among members of same multicast group
allowed
Deal gracefully with changes in group membership
– Dynamic reservations, separate for each member of group
Aggregate for group should reflect resources needed
– Take into account common path to different members of group
Receivers can select one of multiple sources (channel
selection)
Deal gracefully with changes in routes
– Re-establish reservations
Control protocol overhead
Independent of routing protocol
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RSVP CharacteristicsRSVP Characteristics
Unicast and Multicast
Simplex
– Unidirectional data flow
– Separate reservations in two directions
Receiver initiated
– Receiver knows which subset of source transmissions it wants
Maintain soft state in internet
– Responsibility of end users
Providing different reservation styles
– Users specify how reservations for groups are aggregated
Transparent operation through non-RSVP routers
Support IPv4 (ToS field) and IPv6 (Flow label field)
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Data Flows - SessionData Flows - Session
Data flow identified by destination
Resources allocated by router for duration
of session
Defined by
– Destination IP address
Unicast or multicast
– IP protocol identifier
TCP, UDP etc.
– Destination port
May not be used in multicast
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Flow DescriptorFlow Descriptor
Reservation Request
– Flow spec
Desired QoS
Used to set parameters in node’s packet scheduler
Service class, Rspec (reserve), Tspec (traffic)
– Filter spec
Set of packets for this reservation
Source address, source prot
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Treatment of Packets of OneTreatment of Packets of One
Session at One RouterSession at One Router
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RSVP Operation DiagramRSVP Operation Diagram
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RSVP OperationRSVP Operation
G1, G2, G3 members of multicast group
S1, S2 sources transmitting to that group
Heavy black line is routing tree for S1, heavy
grey line for S2
Arrowed lines are packet transmission from S1
(black) and S2 (grey)
All four routers need to know reservation s for
each multicast address
– Resource requests must propagate back through
routing tree
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FilteringFiltering
G3 has reservation filter spec including S1 and S2
G1, G2 from S1 only
R3 delivers from S2 to G3 but does not forward to R4
G1, G2 send RSVP request with filter excluding S2
G1, G2 only members of group reached through R4
– R4 doesn’t need to forward packets from this session
– R4 merges filter spec requests and sends to R3
R3 no longer forwards this session’s packets to R4
– Handling of filtered packets not specified
– Here they are dropped but could be best efforts delivery
R3 needs to forward to G3
– Stores filter spec but doesn’t propagate it
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Reservation StylesReservation Styles
Determines manner in which resource
requirements from members of group are
aggregated
Reservation attribute
– Reservation shared among senders (shared)
Characterizing entire flow received on multicast address
– Allocated to each sender (distinct)
Simultaneously capable of receiving data flow from each
sender
Sender selection
– List of sources (explicit)
– All sources, no filter spec (wild card)
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Wild Card Filter StyleWild Card Filter Style
Single resource reservation shared by all senders
to this address
If used by all receivers: shared pipe whose
capacity is largest of resource requests from
receivers downstream from any point on tree
Independent of number of senders using it
Propagated upstream to all senders
WF(*{Q})
– * = wild card sender
– Q = flowspec
Audio teleconferencing with multiple sites
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Fixed Filter StyleFixed Filter Style
Distinct reservation for each sender
Explicit list of senders
FF(S1{Q!}, S2{Q2},…)
Video distribution
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Shared Explicit StyleShared Explicit Style
Single reservation shared among specific
list of senders
SE(S1, S2, S3, …{Q})
Multicast applications with multiple data
sources but unlikely to transmit
simultaneously
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Reservation Style ExamplesReservation Style Examples
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RSVP Protocol MechanismsRSVP Protocol Mechanisms
Two message types
– Resv
Originate at multicast group receivers
Propagate upstream
Merged and packet when appropriate
Create soft states
Reach sender
– Allow host to set up traffic control for first hop
– Path
Provide upstream routing information
Issued by sending hosts
Transmitted through distribution tree to all destinations
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Multiprotocol Label SwitchingMultiprotocol Label Switching
(MPLS)(MPLS)
Routing algorithms provide support for
performance goals
– Distributed and dynamic
React to congestion
Load balance across network
– Based on metrics
Develop information that can be used in handling different
service needs
Enhancements provide direct support
– IS, DS, RSVP
Nothing directly improves throughput or delay
MPLS tries to match ATM QoS support
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BackgroundBackground
Efforts to marry IP and ATM
IP switching (Ipsilon)
Tag switching (Cisco)
Aggregate route based IP switching (IBM)
Cascade (IP navigator)
All use standard routing protocols to define paths
between end points
Assign packets to path as they enter network
Use ATM switches to move packets along paths
– ATM switching (was) much faster than IP routers
– Use faster technology
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DevelopmentsDevelopments
IETF working group in 1997, proposed standard
2001
Routers developed to be as fast as ATM switches
– Remove the need to provide both technologies in
same network
MPLS does provide new capabilities
– QoS support
– Traffic engineering
– Virtual private networks
– Multiprotocol support
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Connection Oriented QoSConnection Oriented QoS
SupportSupport
Guarantee fixed capacity for specific applications
Control latency/jitter
Ensure capacity for voice
Provide specific, guaranteed quantifiable SLAs
Configure varying degrees of QoS for multiple
customers
MPLS imposes connection oriented framework
on IP based internets
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Traffic EngineeringTraffic Engineering
Ability to dynamically define routes, plan resource
commitments based on known demands and optimize
network utilization
Basic IP allows primitive traffic engineering
– E.g. dynamic routing
MPLS makes network resource commitment easy
– Able to balance load in face of demand
– Able to commit to different levels of support to meet user traffic
requirements
– Aware of traffic flows with QoS requirements and predicted
demand
– Intelligent re-routing when congested
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VPN SupportVPN Support
Traffic from a given enterprise or group
passes transparently through an internet
Segregated from other traffic on internet
Performance guarantees
Security
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Multiprotocol SupportMultiprotocol Support
MPLS can be used on different network
technologies
IP
– Requires router upgrades
Coexist with ordinary routers
ATM
– Enables and ordinary switches co-exist
Frame relay
– Enables and ordinary switches co-exist
Mixed network
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MPLS OperationMPLS Operation
Label switched routers capable of switching and
routing packets based on label appended to
packet
Labels define a flow of packets between end
points or multicast destinations
Each distinct flow (forward equivalence class –
FEC) has specific path through LSRs defined
– Connection oriented
Each FEC has QoS requirements
IP header not examined
– Forward based on label value
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MPLS Operation DiagramMPLS Operation Diagram
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Explanation - SetupExplanation - Setup
Labelled switched path established prior to
routing and delivery of packets
QoS parameters established along path
– Resource commitment
– Queuing and discard policy at LSR
– Interior routing protocol e.g. OSPF used
– Labels assigned
Local significance only
Manually or using Label distribution protocol (LDP) or
enhanced version of RSVP
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Explanation – Packet HandlingExplanation – Packet Handling
Packet enters domain through edge LSR
– Processed to determine QoS
LSR assigns packet to FEC and hence LSP
– May need co-operation to set up new LSP
Append label
Forward packet
Within domain LSR receives packet
Remove incoming label, attach outgoing label
and forward
Egress edge strips label, reads IP header and
forwards
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NotesNotes
MPLS domain is contiguous set of MPLS enabled routers
Traffic may enter or exit via direct connection to MPLS router or
from non-MPLS router
FEC determined by parameters, e.g.
– Source/destination IP address or network IP address
– Port numbers
– IP protocol id
– Differentiated services codepoint
– IPv6 flow label
Forwarding is simple lookup in predefined table
– Map label to next hop
Can define PHB at an LSR for given FEC
Packets between same end points may belong to different FEC
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MPLS Packet ForwardingMPLS Packet Forwarding
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Label StackingLabel Stacking
Packet may carry number of labels
LIFO (stack)
– Processing based on top label
– Any LSR may push or pop label
Unlimited levels
– Allows aggregation of LSPs into single LSP for part
of route
– C.f. ATM virtual channels inside virtual paths
– E.g. aggregate all enterprise traffic into one LSP for
access provider to handle
– Reduces size of tables
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Label Format DiagramLabel Format Diagram
Label value: Locally significant 20 bit
Exp: 3 bit reserved for experimental use
– E.g. DS information or PHB guidance
S: 1 for oldest entry in stack, zero otherwise
Time to live (TTL): hop count or TTL value
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Time to Live ProcessingTime to Live Processing
Needed to support TTL since IP header not read
First label TTL set to IP header TTL on entry to MPLS
domain
TTL of top entry on stack decremented at internal LSR
– If zero, packet dropped or passed to ordinary error processing
(e.g. ICMP)
– If positive, value placed in TTL of top label on stack and packet
forwarded
At exit from domain, (single stack entry) TTL
decremented
– If zero, as above
– If positive, placed in TTL field of Ip header and forwarded
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Label StackLabel Stack
Appear after data link layer header, before network layer
header
Top of stack is earliest (closest to network layer header)
Network layer packet follows label stack entry with S=1
Over connection oriented services
– Topmost label value in ATM header VPI/VCI field
Facilitates ATM switching
– Top label inserted between cell header and IP header
– In DLCI field of Frame Relay
– Note: TTL problem
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Position of MPLS Label StackPosition of MPLS Label Stack
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FECs, LSPs, and LabelsFECs, LSPs, and Labels
Traffic grouped into FECs
Traffic in a FEC transits an MLPS domain along an LSP
Packets identified by locally significant label
At each LSR, labelled packets forwarded on basis of
label.
– LSR replaces incoming label with outgoing label
Each flow must be assigned to a FEC
Routing protocol must determine topology and current
conditions so LSP can be assigned to FEC
– Must be able to gather and use information to support QoS
LSRs must be aware of LSP for given FEC, assign
incoming label to LSP, communicate label to other LSRs
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Topology of LSPsTopology of LSPs
Unique ingress and egress LSR
– Single path through domain
Unique egress, multiple ingress LSRs
– Multiple paths, possibly sharing final few
hops
Multiple egress LSRs for unicast traffic
Multicast
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Route SelectionRoute Selection
Selection of LSP for particular FEC
Hop-by-hop
– LSR independently chooses next hop
– Ordinary routing protocols e.g. OSPF
– Doesn’t support traffic engineering or policy routing
Explicit
– LSR (usually ingress or egress) specifies some or all
LSRs in LSP for given FEC
– Selected by configuration,or dynamically
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Constraint Based RoutingConstraint Based Routing
AlgorithmAlgorithm
Take in to account traffic requirements of flows
and resources available along hops
– Current utilization, existing capacity, committed
services
– Additional metrics over and above traditional routing
protocols (OSPF)
Max link data rate
Current capacity reservation
Packet loss ratio
Link propagation delay
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Label DistributionLabel Distribution
Setting up LSP
Assign label to LSP
Inform all potential upstream nodes of
label assigned by LSR to FEC
– Allows proper packet labelling
– Learn next hop for LSP and label that
downstream node has assigned to FEC
Allow LSR to map incoming to outgoing label
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Real Time Transport ProtocolReal Time Transport Protocol
TCP not suited to real time distributed
application
– Point to point so not suitable for multicast
– Retransmitted segments arrive out of order
– No way to associate timing with segments
UDP does not include timing information
nor any support for real time applications
Solution is real-time transport protocol
RTP
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RTP ArchitectureRTP Architecture
Close coupling between protocol and
application layer functionality
– Framework for application to implement
single protocol
Application level framing
Integrated layer processing
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Application Level FramingApplication Level Framing
Recovery of lost data done by application rather than
transport layer
– Application may accept less than perfect delivery
Real time audio and video
Inform source about quality of delivery rather than retransmit
Source can switch to lower quality
– Application may provide data for retransmission
Sending application may recompute lost values rather than storing
them
Sending application can provide revised values
Can send new data to “fix” consequences of loss
Lower layers deal with data in units provided by
application
– Application data units (ADU)
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Integrated Layer ProcessingIntegrated Layer Processing
Adjacent layers in protocol stack tightly
coupled
Allows out of order or parallel functions
from different layers
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RTP Architecture DiagramRTP Architecture Diagram
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RTP Data Transfer ProtocolRTP Data Transfer Protocol
Transport of real time data among number
of participants in a session, defined by:
– RTP Port number
UDP destination port number if using UDP
– RTP Control Protocol (RTCP) port number
Destination port address used by all participants
for RTCP transfer
– IP addresses
Multicast or set of unicast
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Multicast SupportMulticast Support
Each RTP data unit includes:
Source identifier
Timestamp
Payload format
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RelaysRelays
Intermediate system acting as receiver and
transmitter for given protocol layer
Mixers
– Receives streams of RTP packets from one or more
sources
– Combines streams
– Forwards new stream
Translators
– Produce one or more outgoing RTP packets for each
incoming packet
– E.g. convert video to lower quality
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RTP Control Protocol (RTCP)RTP Control Protocol (RTCP)
RTP is for user data
RTCP is multicast provision of feedback to
sources and session participants
Uses same underlying transport protocol
(usually UDP) and different port number
RTCP packet issued periodically by each
participant to other session members
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RTCP FunctionsRTCP Functions
QoS and congestion control
Identification
Session size estimation and scaling
Session control
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RTCP TransmissionRTCP Transmission
Number of separate RTCP packets
bundled in single UDP datagram
– Sender report
– Receiver report
– Source description
– Goodbye
– Application specific
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Packet Fields (All Packets)Packet Fields (All Packets)
Version (2 bit) currently version 2
Padding (1 bit) indicates padding bits at end of
control information, with number of octets as last
octet of padding
Count (5 bit) of reception report blocks in SR or
RR, or source items in SDES or BYE
Packet type (8 bit)
Length (16 bit) in 32 bit words minus 1
In addition Sender and receiver reports have:
– Synchronization Source Identifier
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Packet Fields (Sender Report)Packet Fields (Sender Report)
Sender Information BlockSender Information Block
NTP timestamp: absolute wall clock time
when report sent
RTP Timestamp: Relative time used to
create timestamps in RTP packets
Sender’s packet count (for this session)
Sender’s octet count (for this session)
61. Chapter 18 Protocols for QoS Support
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Packet Fields (Sender Report)Packet Fields (Sender Report)
Reception Report BlockReception Report Block
SSRC_n (32 bit) identifies source refered to by this
report block
Fraction lost (8 bits) since previous SR or RR
Cumulative number of packets lost (24 bit) during this
session
Extended highest sequence number received (32 bit)
– Least significant 16 bits is highest RTP data sequence number
received from SSRC_n
– Most significant 16 bits is number of times sequence number has
wrapped to zero
Interarrival jitter (32 bit)
Last SR timestamp (32 bit)
Delay since last SR (32 bit)
62. Chapter 18 Protocols for QoS Support
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Receiver ReportReceiver Report
Same as sender report except:
– Packet type field has different value
– No sender information block
63. Chapter 18 Protocols for QoS Support
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Source Description PacketSource Description Packet
Used by source to give more information
32 bit header followed by zero or more
additional information chunks
E.g.:
0 END End of SDES list
1 CNAME Canonical name
2 NAME Real user name of source
3 EMAIL Email address
64. Chapter 18 Protocols for QoS Support
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Goodbye (BYE)Goodbye (BYE)
Indicates one or more sources no linger
active
– Confirms departure rather than failure of
network
65. Chapter 18 Protocols for QoS Support
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Application Defined PacketApplication Defined Packet
Experimental use
For functions & features that are
application specific