- The document proposes a new routing paradigm called Failure-Carrying Packets (FCP) that aims to eliminate routing convergence by having routers carry failure information in packet headers instead of propagating updates.
- Under FCP, when a router detects a failure, it reroutes packets locally around the failure and includes the failed link in packet headers. Other routers can then route packets avoiding the failed component using only the information in packet headers.
- This avoids routing convergence but introduces computational overhead as each router must recalculate routes. The paper proposes FCP with Source-Path Routing to reduce this overhead by having routers include the source route in packet headers instead of recomputing routes.
Application of N jobs M machine Job Sequencing Technique for MPLS Traffic Eng...CSCJournals
This paper discusses Traffic Engineering with Multi-Protocol Label Switching (MPLS) in an Internet Service Provider’s (ISP) network. In this paper, we first briefly describe MPLS, Constraint-based Routing, MPLS-TE, N jobs M machine Job sequencing technique and how to implement the job sequencing technique for Multi-Protocol Label Switching Traffic Engineering. And also improve the quality of service of the network, using this technique firstly reduce the congestion for traffic engineering; minimize the packet loss in complex MPLS domain. In small network packet loss is negligible. We used NS2 discrete event simulator for simulate the above work. Keywords: Traffic Engineering, Multi-Protocol Label Switching, Constraint based routing, N jobs M machine Job Sequencing Technique, Qos, MPLS-TE.
In simple terms, detailed descriptions on how RSVP works in this document have been made. Some detail issues are not covered, such as CSPF or protection mechanisms. Purpose of this document is to create an idea of the working structure of the protocol and how to manage it in general.
The concept of the spanning tree protocol was devised to address broadcast storming. The spanning tree algorithm itself is defined by the IEEE standard 802.1D and its later revisions.
The IEEE Standard 802.1 uses the term bridge to define the spanning tree operation, and uses terms such as Bridge Protocol Data Units and Root Bridge when defining spanning tree protocol functions.
When a bridge receives a frame, it reads the source and destination address fields. The bridge then enters the frame’s source address in its forwarding database. In doing this the bridge associates the frame’s source address with the network attached to the por t on which the frame was received. The bridge also reads the destination address and if it can find this address in its forwarding database, it forwards the frame to the appropriate port. If the bridge does not recognize the destination address, it forwards the frame out from all its por ts except for the one on which the frame was received, and then waits for a reply. This process is known as “flooding”. Similarly, packets with broadcast or multicast destination MAC addresses will be flooded by a bridge.
A significant problem arises where bridges connect via multiple paths. A frame that arrives with an unknown or broadcast/multicast destination address is flooded over all available paths. The arrival of these frames at another network via different paths and bridges produces major problems. The bridges find the same source MAC address arriving on
multiple different por ts, making it impossible to maintain a reliable forwarding database. As a result, increasing numbers of packets will be forwarded to multiple paths. This process is selfperpetuating and produces a condition known as a packet storm, where the increase of circulating frames can eventually overload the network.
The document discusses Label Distribution Protocol (LDP) configuration on a MPLS network using Juniper routers. It describes using logical systems to partition a single physical router into multiple logical devices. LDP is configured between logical systems LS1-P1, LS11-PE1, and other logical systems. LDP establishes MPLS LSPs along the best path determined by OSPF. The label bindings are verified between routers to ensure end-to-end connectivity across the MPLS domain.
The document describes the Internet Protocol version 4 (IPv4). It discusses the IPv4 datagram format including the header fields, fragmentation, and options. It also covers how IPv4 provides an unreliable datagram delivery service and must be paired with TCP for reliability. The document discusses security issues with IPv4 like packet sniffing, modification, and spoofing, and how IPSec can provide protection against these attacks.
The document discusses the configuration of static MPLS label switched paths (LSPs) across a network topology consisting of routers in various cities. It describes how each router is configured to either push a label, swap a label, or pop the top label as packets traverse the LSP from Jakarta to Makasar and back. Traceroute outputs are provided to show the functioning LSP paths versus normal IGP routing. Complete configuration snippets are included in an appendix.
The Network Layer is concerned about getting packets from source to destination, no matter how many hops it may take. It’s all about routing.
5.1 Network Layer Design Issues
What do we need to think about in this layer?
5.2 Routing Algorithms
Strategies for getting from source to destination.
5.3 Congestion Control Algorithms
How do we keep from bottlenecking from too many packets?
5.4 Internetworking
Working with multiple networks and protocols in order to deliver packets.
5.5 The Network Layer in the Internet
Gluing together a collection of subnets.
Application of N jobs M machine Job Sequencing Technique for MPLS Traffic Eng...CSCJournals
This paper discusses Traffic Engineering with Multi-Protocol Label Switching (MPLS) in an Internet Service Provider’s (ISP) network. In this paper, we first briefly describe MPLS, Constraint-based Routing, MPLS-TE, N jobs M machine Job sequencing technique and how to implement the job sequencing technique for Multi-Protocol Label Switching Traffic Engineering. And also improve the quality of service of the network, using this technique firstly reduce the congestion for traffic engineering; minimize the packet loss in complex MPLS domain. In small network packet loss is negligible. We used NS2 discrete event simulator for simulate the above work. Keywords: Traffic Engineering, Multi-Protocol Label Switching, Constraint based routing, N jobs M machine Job Sequencing Technique, Qos, MPLS-TE.
In simple terms, detailed descriptions on how RSVP works in this document have been made. Some detail issues are not covered, such as CSPF or protection mechanisms. Purpose of this document is to create an idea of the working structure of the protocol and how to manage it in general.
The concept of the spanning tree protocol was devised to address broadcast storming. The spanning tree algorithm itself is defined by the IEEE standard 802.1D and its later revisions.
The IEEE Standard 802.1 uses the term bridge to define the spanning tree operation, and uses terms such as Bridge Protocol Data Units and Root Bridge when defining spanning tree protocol functions.
When a bridge receives a frame, it reads the source and destination address fields. The bridge then enters the frame’s source address in its forwarding database. In doing this the bridge associates the frame’s source address with the network attached to the por t on which the frame was received. The bridge also reads the destination address and if it can find this address in its forwarding database, it forwards the frame to the appropriate port. If the bridge does not recognize the destination address, it forwards the frame out from all its por ts except for the one on which the frame was received, and then waits for a reply. This process is known as “flooding”. Similarly, packets with broadcast or multicast destination MAC addresses will be flooded by a bridge.
A significant problem arises where bridges connect via multiple paths. A frame that arrives with an unknown or broadcast/multicast destination address is flooded over all available paths. The arrival of these frames at another network via different paths and bridges produces major problems. The bridges find the same source MAC address arriving on
multiple different por ts, making it impossible to maintain a reliable forwarding database. As a result, increasing numbers of packets will be forwarded to multiple paths. This process is selfperpetuating and produces a condition known as a packet storm, where the increase of circulating frames can eventually overload the network.
The document discusses Label Distribution Protocol (LDP) configuration on a MPLS network using Juniper routers. It describes using logical systems to partition a single physical router into multiple logical devices. LDP is configured between logical systems LS1-P1, LS11-PE1, and other logical systems. LDP establishes MPLS LSPs along the best path determined by OSPF. The label bindings are verified between routers to ensure end-to-end connectivity across the MPLS domain.
The document describes the Internet Protocol version 4 (IPv4). It discusses the IPv4 datagram format including the header fields, fragmentation, and options. It also covers how IPv4 provides an unreliable datagram delivery service and must be paired with TCP for reliability. The document discusses security issues with IPv4 like packet sniffing, modification, and spoofing, and how IPSec can provide protection against these attacks.
The document discusses the configuration of static MPLS label switched paths (LSPs) across a network topology consisting of routers in various cities. It describes how each router is configured to either push a label, swap a label, or pop the top label as packets traverse the LSP from Jakarta to Makasar and back. Traceroute outputs are provided to show the functioning LSP paths versus normal IGP routing. Complete configuration snippets are included in an appendix.
The Network Layer is concerned about getting packets from source to destination, no matter how many hops it may take. It’s all about routing.
5.1 Network Layer Design Issues
What do we need to think about in this layer?
5.2 Routing Algorithms
Strategies for getting from source to destination.
5.3 Congestion Control Algorithms
How do we keep from bottlenecking from too many packets?
5.4 Internetworking
Working with multiple networks and protocols in order to deliver packets.
5.5 The Network Layer in the Internet
Gluing together a collection of subnets.
The document discusses topics related to the network layer, including:
1. It describes virtual circuits and datagrams, which are two methods for transferring data across networks.
2. It covers IPv4 addressing concepts such as address space, notations, classful and classless addressing, subnetting, and network address translation.
3. It provides an overview of additional network layer topics like IPv6 addressing, routing algorithms, internet control protocols, and routing protocols.
The document discusses various methods of configuring MPLS in a network, including:
1. Configuring LDP to automatically establish label-switched paths between routers.
2. Configuring RSVP signaling to establish an explicit LSP from Batam to Ambon with a bandwidth reservation of 500Mb.
3. Integrating LSP routes into the unicast routing table and verifying LSP establishment through traceroute.
OSPF is a link-state routing protocol that uses link-state information to make routing decisions. Each router running OSPF floods link-state advertisements (LSAs) throughout the area or autonomous system that contain information about that router's attached interfaces and metrics. Routers then use the information in LSAs to calculate the shortest path to each network and build routing tables. OSPF supports different network types including broadcast, point-to-point, non-broadcast multi-access (NBMA), and point-to-multipoint. It elects a designated router on broadcast networks to reduce the number of adjacencies formed and amount of routing information exchanged.
Packet switching approaches include datagram and virtual-circuit approaches. The virtual-circuit approach involves three phases: setup, data transfer, and teardown. During setup, routers create entries for a virtual circuit based on request and acknowledgment packets exchanged. This establishes a defined path for network-layer packets to follow, identified by a flow label. Once the virtual circuit is set up, packets can be forwarded independently based only on the flow label. Finally, teardown packets remove the entries from router tables once transfer is complete.
SCTP-MANET NEW EXTENSION OF SCTP PROTOCOL FOR THE OPTIMIZATION OF MANET PERFO...ijwmn
Ad Hoc mobile networks are constituted of nodes that move freely without a centralized administration.
These nodes contribute in the routing of data packets that are sent by a source. This happens when the
latter is not capable of reaching its destination. On the other hand, their mobility causes recurrent
breakdowns of the routing paths notably with sparse MANET. In order to optimize the performance of such
networks, we suggest a new extension of protocols: Stream Control Transmission Protocols (SCTP) named
SCTP-MANET. Their main function is therefore to improve the availability of the links in sparse MANET
protocols. This could be achieved by a better integration of Multihoming. With this aim in mind, this new
extension is based on a cross-layer interface between transport and routing layers as well as the use of
specific messages.
This document discusses ICMPv4 (Internet Control Message Protocol version 4). It describes ICMPv4's role in error reporting and querying, including error messages like Destination Unreachable and query tools like Ping and Traceroute. ICMPv4 messages have a header and variable data. The protocol is used to supplement deficiencies in the IP protocol for notification and querying between hosts.
The network layer is responsible for delivering packets from source to destination. It must know the topology of the subnet and choose appropriate paths. When sources and destinations are in different networks, the network layer must deal with these differences. The network layer uses logical addressing that is independent of the underlying physical network. Routing ensures packets are delivered through routers and switches from source to destination across interconnected networks.
The document discusses data link control and various related topics:
1. Link throughput is reduced by factors like frame overheads, propagation delay, acknowledgements, and retransmissions. HDLC and PPP are protocols that use frames for data transmission.
2. Flow control uses window mechanisms to regulate the maximum number of unacknowledged frames sent to prevent overflow. This affects throughput.
3. Link management procedures are needed to handle link and node failures and ensure frames are delivered properly.
Performance Evaluation of Routing Protocols Ankush Mehta
This is a research project based on Performance checking of the Routing Protocols. This Presentation shows the basic knowledge of the Protocols use (AODV, DSDV and DSR) and in the end it shows the Result and Conclusion by comparing the graphs which are generated through out the work.
PERFORMANCE ANALYSIS AND COMPARISON OF IMPROVED DSR WITH DSR, AODV AND DSDV R...ijp2p
Mobile Ad-hoc networks are categorized by multi-hop wireless connectivity and numbers of nodes are connecting each other through wireless network. It includes several routing protocols specifically designed for ad-hoc routing. The most widely used ad hoc routing protocols are Ad-hoc On Demand Distance Vector (AODV), Destination Sequence Distance Vector (DSDV), and Dynamic Source Routing (DSR). In this paper, we present an analysis of DSR protocol and propose our algorithm to improve the performance of DSR protocol by using small delay applied on last route ACK path when an original route fails in Mobile Ad Hoc networks. Past researchers the MANET have focused on simulation study by varying network parameters, such as network size, number of nodes. The simulation results shows that the M-DSR protocol
having some excellent performance Metrics then other protocols. We have taken different performance parameters over the comparison of Modified -DSR with other three protocols in mobility as well as Nonmobility scenario up to 300 nodes in MANETs using NS2 simulator. To achieve this goal DSR is modified by using modified algorithm technique in order to load balancing, to avoid congestion and lower packet
delivery.
Our area of interest for the paper is the improvement of performance of DSR routing protocol by
changing in algorithm and this Improved DSR protocol should compare with remaining protocols
taken in this research paper.
2. In this paper we made changesin traditional DSR protocol and generation of new improved DSR the
different performance parameters and compare with AODV/DSR/DSDV protocols in mobility and
non- mobility scenarios nodes up to 300.
3. We can plot the graphs throughput, End to end Delay, Packet delivery Ratio, Dropping Ratio, and
average energy consumption on Mobility and Non-Mobility scenario by using Network Simulator
version 2.34 for Modified DSR protocols. M-DSR, DSDV perform well when Mobility is low.
This document describes three TCP-aware link layer protocols: Snooping TCP, Wireless TCP, and Delayed DACK. Snooping TCP uses an agent at the base station to snoop and buffer TCP connections, ensuring packets are delivered to the mobile node in order and retransmitting lost packets. Wireless TCP modifies timestamps to compensate for increased round-trip time. Delayed DACK delays acknowledgments to allow time for lost packets to be recovered before triggering retransmissions.
The document provides information about an upcoming training course on deploying MPLS L3 VPNs. It includes details about the trainers, Nurul Islam Roman and Jessica Wei, their backgrounds and areas of expertise. It also outlines the course agenda which will cover topics such as MPLS VPN models, terminology, operation, configuration examples and service deployment scenarios.
The document discusses network layer performance and congestion control. It covers key network layer performance metrics like delay, throughput and packet loss. It then discusses various sources of delay like transmission, propagation, processing and queuing delays. It also discusses throughput and packet loss. The second half of the document focuses on congestion control techniques including open-loop methods like retransmission policies and closed-loop methods like backpressure and explicit signaling.
Mobile Ad-hoc Network (MANET) Routing Algorithms─ Part 2Sushant Kushwaha
The document discusses several routing algorithms for mobile ad-hoc networks: TORA is a reactive protocol that reacts to changes and link reversals in highly dynamic networks; CGSR is a hierarchical and proactive protocol where routing tables are pre-built so paths are immediately available; flat routing table based protocols pre-build routing tables showing all paths while optimized link state protocols only update required routing data to reduce overhead.
MPLS provides mechanisms for traffic engineering by allowing routers to forward packets based on fixed-length labels rather than long variable length IP addresses. MPLS labels are assigned to packets at ingress routers and swapped or removed by transit and egress routers along the Label Switched Path (LSP). Routers can be configured with constraints and administrative groups to calculate optimal LSP paths using protocols like RSVP and LDP.
The document discusses contention networks, carrier sense multiple access (CSMA), components of routers, modular network interfaces in routers, differences between hubs, layer 2 switches and layer 3 switches, packet tunneling, shortest path routing, packet fragmentation, functions of routing processors, evolution of router construction, minimum spanning trees, routing protocols for mobile hosts, TCP/IP tunneling over ATM, distance vector routing, link state routing, hierarchical routing, ATM networks, creating ATM virtual circuits, segmentation and reassembly in ATM, internetworking using concatenated virtual circuits and connectionless internetworking, network properties, and an example of the TCP/IP protocol in action.
This document discusses IP packet forwarding and routing tables. It explains that IP packets can be forwarded either based on the destination address using a connectionless protocol, or based on an attached label using a connection-oriented protocol. Forwarding requires looking up routing information in a forwarding table. The forwarding table structure for classless addressing requires the network mask, address, interface, and next hop router for each route. MPLS allows packets to be forwarded like routers, based on destination address, or like switches, based on an attached label.
MPLS Traffic Engineering provides mechanisms to optimize network traffic flow and efficiently utilize bandwidth. It determines paths based on additional parameters like available resources and constraints. This allows load balancing across unequal paths and routing around failed links or nodes. MPLS TE uses extensions to IGPs to distribute link attributes and tunnel information. Constrained Shortest Path First (CSPF) is used for path computation to find paths meeting constraints like bandwidth and affinities. Tunnels are set up using RSVP-TE and traffic can be forwarded down tunnels using methods like static routes, auto-routing, or policy routing. Fast Re-Route provides local repair of TE tunnels if a link or node fails to minimize traffic loss.
The document summarizes routing tables and routing algorithms. It discusses how routing tables are structured with an array of buckets containing linked lists of route records. It describes the data fields within each route record and how routing lookups and maintenance are performed using procedures like netnum, netmatch, netmask, rthash, and rtget.
Este documento resume las actividades realizadas por el autor durante su pasantía en la Embotelladora Atlántida S.A. Incluye una breve historia de la compañía y descripciones de los departamentos de operaciones, contabilidad y el Centro de Distribución Inmediata Barrio Inglés. También presenta aportes del autor como la creación de un departamento de crédito y cobranzas, diseños de rótulos y formatos, y recomendaciones para una nueva planta y CDI. El documento concluye resumiendo las lecciones
The family was busy working around the house doing various chores like cleaning the floor, working in the garden, vacuum cleaning, helping in the kitchen with cooking, washing dishes, and doing laundry such as folding clothes. They also did other tasks like painting the house, washing the car, and cleaning the table.
The document discusses topics related to the network layer, including:
1. It describes virtual circuits and datagrams, which are two methods for transferring data across networks.
2. It covers IPv4 addressing concepts such as address space, notations, classful and classless addressing, subnetting, and network address translation.
3. It provides an overview of additional network layer topics like IPv6 addressing, routing algorithms, internet control protocols, and routing protocols.
The document discusses various methods of configuring MPLS in a network, including:
1. Configuring LDP to automatically establish label-switched paths between routers.
2. Configuring RSVP signaling to establish an explicit LSP from Batam to Ambon with a bandwidth reservation of 500Mb.
3. Integrating LSP routes into the unicast routing table and verifying LSP establishment through traceroute.
OSPF is a link-state routing protocol that uses link-state information to make routing decisions. Each router running OSPF floods link-state advertisements (LSAs) throughout the area or autonomous system that contain information about that router's attached interfaces and metrics. Routers then use the information in LSAs to calculate the shortest path to each network and build routing tables. OSPF supports different network types including broadcast, point-to-point, non-broadcast multi-access (NBMA), and point-to-multipoint. It elects a designated router on broadcast networks to reduce the number of adjacencies formed and amount of routing information exchanged.
Packet switching approaches include datagram and virtual-circuit approaches. The virtual-circuit approach involves three phases: setup, data transfer, and teardown. During setup, routers create entries for a virtual circuit based on request and acknowledgment packets exchanged. This establishes a defined path for network-layer packets to follow, identified by a flow label. Once the virtual circuit is set up, packets can be forwarded independently based only on the flow label. Finally, teardown packets remove the entries from router tables once transfer is complete.
SCTP-MANET NEW EXTENSION OF SCTP PROTOCOL FOR THE OPTIMIZATION OF MANET PERFO...ijwmn
Ad Hoc mobile networks are constituted of nodes that move freely without a centralized administration.
These nodes contribute in the routing of data packets that are sent by a source. This happens when the
latter is not capable of reaching its destination. On the other hand, their mobility causes recurrent
breakdowns of the routing paths notably with sparse MANET. In order to optimize the performance of such
networks, we suggest a new extension of protocols: Stream Control Transmission Protocols (SCTP) named
SCTP-MANET. Their main function is therefore to improve the availability of the links in sparse MANET
protocols. This could be achieved by a better integration of Multihoming. With this aim in mind, this new
extension is based on a cross-layer interface between transport and routing layers as well as the use of
specific messages.
This document discusses ICMPv4 (Internet Control Message Protocol version 4). It describes ICMPv4's role in error reporting and querying, including error messages like Destination Unreachable and query tools like Ping and Traceroute. ICMPv4 messages have a header and variable data. The protocol is used to supplement deficiencies in the IP protocol for notification and querying between hosts.
The network layer is responsible for delivering packets from source to destination. It must know the topology of the subnet and choose appropriate paths. When sources and destinations are in different networks, the network layer must deal with these differences. The network layer uses logical addressing that is independent of the underlying physical network. Routing ensures packets are delivered through routers and switches from source to destination across interconnected networks.
The document discusses data link control and various related topics:
1. Link throughput is reduced by factors like frame overheads, propagation delay, acknowledgements, and retransmissions. HDLC and PPP are protocols that use frames for data transmission.
2. Flow control uses window mechanisms to regulate the maximum number of unacknowledged frames sent to prevent overflow. This affects throughput.
3. Link management procedures are needed to handle link and node failures and ensure frames are delivered properly.
Performance Evaluation of Routing Protocols Ankush Mehta
This is a research project based on Performance checking of the Routing Protocols. This Presentation shows the basic knowledge of the Protocols use (AODV, DSDV and DSR) and in the end it shows the Result and Conclusion by comparing the graphs which are generated through out the work.
PERFORMANCE ANALYSIS AND COMPARISON OF IMPROVED DSR WITH DSR, AODV AND DSDV R...ijp2p
Mobile Ad-hoc networks are categorized by multi-hop wireless connectivity and numbers of nodes are connecting each other through wireless network. It includes several routing protocols specifically designed for ad-hoc routing. The most widely used ad hoc routing protocols are Ad-hoc On Demand Distance Vector (AODV), Destination Sequence Distance Vector (DSDV), and Dynamic Source Routing (DSR). In this paper, we present an analysis of DSR protocol and propose our algorithm to improve the performance of DSR protocol by using small delay applied on last route ACK path when an original route fails in Mobile Ad Hoc networks. Past researchers the MANET have focused on simulation study by varying network parameters, such as network size, number of nodes. The simulation results shows that the M-DSR protocol
having some excellent performance Metrics then other protocols. We have taken different performance parameters over the comparison of Modified -DSR with other three protocols in mobility as well as Nonmobility scenario up to 300 nodes in MANETs using NS2 simulator. To achieve this goal DSR is modified by using modified algorithm technique in order to load balancing, to avoid congestion and lower packet
delivery.
Our area of interest for the paper is the improvement of performance of DSR routing protocol by
changing in algorithm and this Improved DSR protocol should compare with remaining protocols
taken in this research paper.
2. In this paper we made changesin traditional DSR protocol and generation of new improved DSR the
different performance parameters and compare with AODV/DSR/DSDV protocols in mobility and
non- mobility scenarios nodes up to 300.
3. We can plot the graphs throughput, End to end Delay, Packet delivery Ratio, Dropping Ratio, and
average energy consumption on Mobility and Non-Mobility scenario by using Network Simulator
version 2.34 for Modified DSR protocols. M-DSR, DSDV perform well when Mobility is low.
This document describes three TCP-aware link layer protocols: Snooping TCP, Wireless TCP, and Delayed DACK. Snooping TCP uses an agent at the base station to snoop and buffer TCP connections, ensuring packets are delivered to the mobile node in order and retransmitting lost packets. Wireless TCP modifies timestamps to compensate for increased round-trip time. Delayed DACK delays acknowledgments to allow time for lost packets to be recovered before triggering retransmissions.
The document provides information about an upcoming training course on deploying MPLS L3 VPNs. It includes details about the trainers, Nurul Islam Roman and Jessica Wei, their backgrounds and areas of expertise. It also outlines the course agenda which will cover topics such as MPLS VPN models, terminology, operation, configuration examples and service deployment scenarios.
The document discusses network layer performance and congestion control. It covers key network layer performance metrics like delay, throughput and packet loss. It then discusses various sources of delay like transmission, propagation, processing and queuing delays. It also discusses throughput and packet loss. The second half of the document focuses on congestion control techniques including open-loop methods like retransmission policies and closed-loop methods like backpressure and explicit signaling.
Mobile Ad-hoc Network (MANET) Routing Algorithms─ Part 2Sushant Kushwaha
The document discusses several routing algorithms for mobile ad-hoc networks: TORA is a reactive protocol that reacts to changes and link reversals in highly dynamic networks; CGSR is a hierarchical and proactive protocol where routing tables are pre-built so paths are immediately available; flat routing table based protocols pre-build routing tables showing all paths while optimized link state protocols only update required routing data to reduce overhead.
MPLS provides mechanisms for traffic engineering by allowing routers to forward packets based on fixed-length labels rather than long variable length IP addresses. MPLS labels are assigned to packets at ingress routers and swapped or removed by transit and egress routers along the Label Switched Path (LSP). Routers can be configured with constraints and administrative groups to calculate optimal LSP paths using protocols like RSVP and LDP.
The document discusses contention networks, carrier sense multiple access (CSMA), components of routers, modular network interfaces in routers, differences between hubs, layer 2 switches and layer 3 switches, packet tunneling, shortest path routing, packet fragmentation, functions of routing processors, evolution of router construction, minimum spanning trees, routing protocols for mobile hosts, TCP/IP tunneling over ATM, distance vector routing, link state routing, hierarchical routing, ATM networks, creating ATM virtual circuits, segmentation and reassembly in ATM, internetworking using concatenated virtual circuits and connectionless internetworking, network properties, and an example of the TCP/IP protocol in action.
This document discusses IP packet forwarding and routing tables. It explains that IP packets can be forwarded either based on the destination address using a connectionless protocol, or based on an attached label using a connection-oriented protocol. Forwarding requires looking up routing information in a forwarding table. The forwarding table structure for classless addressing requires the network mask, address, interface, and next hop router for each route. MPLS allows packets to be forwarded like routers, based on destination address, or like switches, based on an attached label.
MPLS Traffic Engineering provides mechanisms to optimize network traffic flow and efficiently utilize bandwidth. It determines paths based on additional parameters like available resources and constraints. This allows load balancing across unequal paths and routing around failed links or nodes. MPLS TE uses extensions to IGPs to distribute link attributes and tunnel information. Constrained Shortest Path First (CSPF) is used for path computation to find paths meeting constraints like bandwidth and affinities. Tunnels are set up using RSVP-TE and traffic can be forwarded down tunnels using methods like static routes, auto-routing, or policy routing. Fast Re-Route provides local repair of TE tunnels if a link or node fails to minimize traffic loss.
The document summarizes routing tables and routing algorithms. It discusses how routing tables are structured with an array of buckets containing linked lists of route records. It describes the data fields within each route record and how routing lookups and maintenance are performed using procedures like netnum, netmatch, netmask, rthash, and rtget.
Este documento resume las actividades realizadas por el autor durante su pasantía en la Embotelladora Atlántida S.A. Incluye una breve historia de la compañía y descripciones de los departamentos de operaciones, contabilidad y el Centro de Distribución Inmediata Barrio Inglés. También presenta aportes del autor como la creación de un departamento de crédito y cobranzas, diseños de rótulos y formatos, y recomendaciones para una nueva planta y CDI. El documento concluye resumiendo las lecciones
The family was busy working around the house doing various chores like cleaning the floor, working in the garden, vacuum cleaning, helping in the kitchen with cooking, washing dishes, and doing laundry such as folding clothes. They also did other tasks like painting the house, washing the car, and cleaning the table.
Lindsey Stirling is a violinist who blends elements of classical music, dubstep, and dance in her music. She gained popularity through her YouTube channel, which now has over 1 million subscribers. Stirling's unique style combines her classical violin training with electronic dance genres like dubstep. She hopes her music and success inspires others to embrace their individuality.
El documento identifica cuatro áreas prioritarias para América Latina y el Caribe: seguridad alimentaria y nutricional, cambio climático y sostenibilidad ambiental, agricultura familiar, y sanidad agropecuaria e inocuidad de alimentos. Se sugiere mantener estas mismas áreas prioritarias para el próximo bienio, reconociendo las especificidades de cada subregión.
Destination Aware APU Strategy for Geographic Routing in MANETEditor IJCATR
In this paper, we have explained the Enhanced Adaptive Position Update strategy for geographic routing in mobile ad hoc
network In Adaptive Position Update strategy, there are two techniques: Mobility prediction rule and On-demand learning rule. Proposed
system is based on the destination aware routing in which path to transfer the data over the network is based on the distance from highly
stable node to the destination node. Results of the proposed system are compared with Periodic Beaconing on the basis of packet delivery
ratio, beacon overhead, energy consumption. Experiment results show a high improvement in results on the parameters energy
consumption, packet delivery ratio and beacon overhead. Proposed work is implemented on the NS2 (Network Simulator) Environment
to perform experiments.
11.a study of congestion aware adaptive routing protocols in manetAlexander Decker
This document summarizes and compares several congestion-aware routing protocols for mobile ad hoc networks (MANETs). It discusses the Congestion Adaptive Routing Protocol (CRP), which uses bypass routes to avoid congested areas and splits traffic between primary and bypass routes adaptively. It also describes the Efficient Congestion Adaptive Routing Protocol (ECARP), which modifies AODV parameters to improve congestion handling, and the Congestion Aware Routing plus Rate Adaptation (CARA) protocol, which establishes routes around congested areas. Finally, it discusses the Congestion Aware Routing Protocol for Mobile ad hoc networks (CARM), which uses a weighted channel delay metric to measure
SCTP-MANET NEW EXTENSION OF SCTP PROTOCOL FOR THE OPTIMIZATION OF MANET PERFO...ijwmn
This document summarizes a research paper that proposes a new extension of the SCTP protocol, called SCTP-MANET, to optimize the performance of sparse mobile ad hoc networks (MANETs). SCTP-MANET uses a cross-layer interface between the transport and routing layers, along with specific messaging, to establish multiple paths between source and destination nodes. This allows data to be switched to an alternative path automatically if the primary path fails, without requiring new route discovery. The researchers analyze the throughput of SCTP-MANET compared to standard SCTP in different MANET topologies using simulation software.
SCTP-MANET NEW EXTENSION OF SCTP PROTOCOL FOR THE OPTIMIZATION OF MANET PERFO...ijwmn
Ad Hoc mobile networks are constituted of nodes that move freely without a centralized administration.
These nodes contribute in the routing of data packets that are sent by a source. This happens when the
latter is not capable of reaching its destination. On the other hand, their mobility causes recurrent
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1. International Journal of Engineering Science Invention
ISSN (Online): 2319 – 6734, ISSN (Print): 2319 – 6726
www.ijesi.org Volume 3 Issue 2 ǁ February. 2014 ǁ PP.28-33
www.ijesi.org 28 | Page
Removing Convergence Using Fcp with Source Path Routing
1
Dnyaneshwar Dhangar, 2
Saina Ismail Patel, 3
Shruti Santosh Dudwadkar,
4
Apurva Ashok Gawad
1, 2, 3, 4
(Computer, Rajiv Gandhi Institute of Technology/ Mumbai University, India)
ABSTRACT: Current distributed routing paradigms (such as link-state, distance-vector, and path-vector)
involve a convergence process. Due to the convergence process the router load is increased, outages and
transient loops are introduced, and it results in slow reaction to failures. We propose a new routing paradigm
where the goal is not to reduce the convergence time but rather to eliminate the convergence process
completely. We propose a technique called Failure-Carrying Packets (FCP) that allows data packets to find a
working path without requiring completely up-to-date state in routers. But this involves computational overhead
at each router. The techniques to reduce the computational overhead involve a lot of state being maintained at
each router. To this end, we propose a slight extension to the FCP algorithm called FCP with Source-Path
Routing to reduce the computational overhead of FCP without keeping any heavy amount of state at the routers.
KEYWORDS: Convergence, Failure carrying packet, network map, source path routing.
I. INTRODUCTION
The current Internet is an enormous size network consisting of thousands of Autonomous Systems
(AS) operated by different institutions, such as the Internet Service Providers (ISP), companies, universities etc.
It is now used as a general-purpose network for commercial purposes. Such evolution of the Internet has seen a
large number of applications being deployed on it for commercial purposes. Many of these applications, such as
VoIP, gaming etc, have stringent delay and loss requirements. Such stringent requirements call for a stable
routing environment in the Internet.
Stable routing demands routing stability in case of failure or up gradation of any network component.
When any failure occurs, the router adjacent to the failure has the responsibility of informing every other router
in the routes avoiding the failure. Other routers, in response to the failure, update their routing tables computing
new routes avoiding the failure. This process, in which every router involves itself in computing the new view
of the network is called routing convergence.
Sometimes loops can be formed during routing. Such loops can lead to delay in routing packets or even
loss of packets, resulting in serious performance degradation of the applications.
We will see failure carrying packets technique to remove convergence. We will also see techniques that
solve the overhead problem of FCP. We propose our technique that is most efficient in removing computational
overhead in each router and reducing load at router. This technique is called FCP Using Source Path Routing.
II. FAILURE CARRYING PACKETS
In this [1], we propose a completely different approach, than the traditional routing protocols for
dealing with failures in the network. Instead of converging after the failure, this protocol eliminates convergence
period altogether. Under FCP, the router detecting the failure simply reroutes the data packet around the failure,
inserting the information of the failure within the packet header.
Thus other routers receiving the packet use this information locally to compute the path to the packet’s
destination avoiding the failed component. This eliminates the need for immediate propagation of the failure
information by the detecting router. We describe the FCP protocol in detail in the following section.
2.1 FCP Concept
In case of no failure FCP reduces to link state protocol, where every router maintains a consistent view
of the potential set of links which is called as the Network Map. This set of potential links consists of only those
links that are operational over a long period of time. FCP uses this map to compute a stable path to all the
destinations in the absence of failure. FCP behaves quite differently when failure occurs.
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The main intuition behind FCP is that, since all routers maintain the same Network Map at a particular
time, all which is needed by the routers for dealing with a failure(s) is to know the set of link(s) that have
currently failed in the network. Any router having this information will be able to compute a path to any
destination, avoiding the failure, if a path exists. The best part about FCP is that, instead of sending separate
protocol messages for propagating the failure information to the other routers, it adds this failure information in
the packet header and computes new shortest path and sends the packet according to new path. In this way the
convergence period is completely removed because the failure information is passed through the packet itself.
To understand FCP better, consider the example in Fig. 1, a network with unit link weights. Assume N1
sends a message to N4, and that links N3−N4 and N7−N6 are down. Since only nodes adjacent to the failed links
know about the failure, the packet is forwarded along the shortest path in the original graph, (N1, N2, N3, N4),
until it reaches the failed link N3−N4. At this point, N3 computes a new shortest path to N4 based on the map
minus link N3−N4, and includes the failed link N3−N4 in the header. Let us assume that this path is (N3, N7, N6,
N4). When the packet reaches N7, N7 adds the failed link N7−N6 to the header, and computes a new shortest path
that does not include the two failed links.
2.2 FCP Algorithm
F: failed link field
1. Initialize F=null;
2. When the packet arrives to a router
a. If (F!=null)
Compute a new route to the destination removing the failed
link
If (new route does not exist)
Abort
Else If (next hop on the path has failed link)
Add that link to F and go to step 2(a).
Else
Forward the packet to the next hop router.
Fig. 2 FCP Algorithm
As the Figure2 above shows, when a packet arrives at a router, its next-hop is computed using the
network map minus the failed links in the packet header. If this next-hop would send the packet out an interface
that has a failed link, then the router inserts the failed link in the header
2.3 FCP Properties
2.3.1 Guaranteed reach ability
This property says that a packet p entering a network at a certain time t1 will be delivered to the
destination by the time t2, provided (1) there are at most f failures during [t1,t2], where f is an upper bound on
the number of failures in the network during the interval, and (2) the network remains connected during [t1,t2].
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2.3.2 Path Isolation
The path isolation property says that a malicious node cannot impact the path followed by a packet
unless it is already on that path i.e. off-path malicious nodes cannot affect the routing process. This directly
follows from the fact that an off-path node cannot contaminate the routing state of the nodes along the packet’s
path as these nodes compute the route solely based on the disseminated map and the list of failed links in the
packet’s header.
2.4 FCP Challenges
Challenges in FCP include:
Computational overhead: FCP presents an overhead that every router on the failure-carrying packet’s
path has to compute new routes to the packet’s destination.
Map dissemination and updates: As FCP relies on all routers having a consistent view of the network
map, there is a map dissemination and update protocol.
2.5 Overcoming FCP Challenges
2.5.1 Nodes precompute backup path
Pre compute “backup next-hop” for each destination. This saves router from re computation of new
route to a packet’s destination on failure. Thus re computation is required only when failures happen on primary
and backup paths.
2.5.2 Caching
This includes computation and maintenance of caching information of paths in case of failures seen
on both primary and backup paths.
2.5.3 . Disadvantages of these methods:
Keeping backup paths for every destination at a router doubles the router state
Cached paths to route around failures on primary and backup paths adds even more to router state.
III. FAILURE CARRYING PACKETS USING SOURCE PATH ROUTING
In order to reduce the computational overhead- if the backup path for each destination is pre- computed
and stored, and incase if there is failure on backup path ,then maintaining cache paths for each combination of
failures seen in the packet header – incur a lot of state being maintained at each router. Moreover the state
maintained are mostly hard state which is unnecessary considering that most failures occurring in the network
are short-lived and transient.
Fig. 3. An example illustrating FCP routing with source path
To this end, we propose an extension to the FCP algorithm called Failure Carrying Packets with
Source-Path Routing extension which aims at reducing computational overhead of FCP without maintaining
heavy amount of state at the routers. Below we discuss the extension along with the algorithm.
Consider again the same example given below, reproduced here for convenience.
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All the links are assumed to have unit weights. Assume N1 sends a message to N4 which is the
destination, and that links N3−N4 and N7−N6 are down. Since only the adjacent nodes know about the failed
links, the packet is forwarded along the shortest path in the original graph, (N1,N2,N3,N4), until it reaches the
failed link N3−N4. At this point, N3 computes a new shortest path to N4 based on the map minus link N3−N4. In
the original design, FCP will include the failed link N3−N4 and insert it into the packet header, and forwards the
packet along the newly computed route. But in this extension, the router not only adds the failed link N3−N4 in
the packet, but also adds the newly computed shortest route to the destination which is N3→N7→N6→N4 in the
header and forwards it to N7 . Now node N7 knows that there is link failure at N7−N6 and hence it adds this
failed link in the packet header. Now N7 will compute the shortest path to the destination minus link N7−N6 from
the network map. The shortest route N7→N5→N6→N4 which is computed is now inserted in the packet header.
Subsequent routers N5 and N6 will forward the packet along the path inserted by N7. Finally the packet reaches
the destination N4. Thus only nodes encountering failures on the primary path or source path need to recompute
the shortest path to destination and other nodes simply forward packets along the computed shortest path. Since
most of the failures occurring are only single link failures, very few nodes may encounter a failure combination
where a link from both primary as well as source-path have failed and thus may need to perform recomputation
to route a packet encountering failures along its journey to destination. Moreover this recomputation needs to be
performed only for the first packet that were to pass through the failed link(s), as all the routers cache the newly
computed paths to route around the failure.
F: failed link field
S/P: source path field
1. Initialize F=null, S/P=null;
2. When the packet arrives to a router
a. If (F!=null)
Compute a new route to the destination removing the
failed link and add the source path in packet header.
If (new route does not exist)
Abort
Else If (next hop on the path has failed link)
Add that link to F and go to step 2(a).
Else
Forward the packet to the next hop router.
Fig. 4. FCP with source path routing Algorithm
IV. IMPLEMENTATION APPROACH
FCP adopts a link-state approach to routing and hence it is implemented by modifying Open Shortest
Path First (OSPF) protocol which is also a link-state routing protocol currently used in the Internet for Intra-
domain routing. Modifications are also required to be made to Internet Protocol (IP) protocol as FCP’s
forwarding functionality differs from IP. In the following section we detail the approach to be taken to simulate
the behavior of FCP using OSPF and IP.
4.1 Map dissemination of FCP
FCP’s map dissemination approach differs quite from that of OSPF. OSPF keeps the routers updated
with the current network state by making each router periodically propagate link-state, whereas FCP consists of
a centralized coordinator that periodically floods all the routers only with long-term changes made to the
network. To simulate such behavior with OSPF, the link-state of the network is propagated only when the
network boots and subsequent update messages need to be suppressed. Only if a change to the network is
deemed permanent then the protocol should propagate an update message. This can be achieved by making
changes to the timers associated with the OSPF link-state update messages.
.
4.2 Packet forwarding approach of FCP
Conventional packet forwarding requires a destination IP address lookup operation to be made on the
forwarding table by IP and determine the outgoing interface for the packet and forward the packet. Incase if
there is link failure the forwarding operation remains the same with the only change that the detecting router
locally reroutes the packet avoiding the failure. Through routing protocol messages the other routers are
informed about the failure. Thus IP has nothing to do with the failure. But in case of FCP, since the failure
information and source-path information is carried in the IP header, IP has a role to play here. The forwarding
engine here examines the packet for failure or source-path information. In case source-path is present IP
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forwards the packet along the source-path if the adjacent link on the source path is alive. If there is failure in the
adjacent link then IP needs to invoke the services of FCP that computes the new route to destination, if any
exists. IP inserts the new route and the failure information in the packet header and forwards the packet along
the newly computed path.
4.3 Changes to be made to IP Header
Extra state needs to be incorporated in the IP header such as failure and source-path information. This
can be accomplished by use of Options field of the IP header.
Changes to be made to IP header:
IP header needs to carry failure info and source-path. Use of IP Options field can be made. The length
of the Option field is variable, and the end of a packet header has to be aligned to a 32-bit boundary, so an
additional padding field of the appropriate length is added (and set to 0 by default).
Fig 5. IP Header
4.3.1. IP Options and Source Routing
Normally, IP datagram’s are routed without any specific instructions from devices regarding the path a
datagram should take from the source to the destination. It's the job of routers, using routing protocols, to figure
out those details. In some cases, however, it may be advantageous to have the source of a datagram specify the
route a datagram takes through the network. This is called source routing.
There are two IP options that support source routing. In each, the option includes a list of IP addresses
specifying the routers that must be used, to reach the destination. When strict source routing is used, this means
that the path specified in the option must be used exactly, in sequence, with no other routers permitted to handle
the datagram at all. In contrast, loose source routing specifies a list of IP addresses that must be followed in
sequence, but having intervening hops in between the devices on the list is allowed.
4.3.2. IP Datagram Options and Option Format:
All IP datagram’s must include the standard 20-byte header, which contains key information such as
the source and destination address of the datagram, fragmentation control parameters, length information and
more. In addition to these invariable fields, the creators of IPv4 included the ability to add options that provide
additional flexibility in how IP handles datagram’s. Use of these options is, of course, optional. However, all
devices that handle IP datagram must be capable of properly reading and handling them.
The IP datagram may contain zero, one or more options, which makes the total length of
the Options field in the IP header variable. Each of the options can be either a single byte long, or multiple bytes
in length, depending on how much information the option needs to convey. When more than one option is
included they are just concatenated together and put into the Options field as a whole. Since the IP header must
be a multiple of 32 bits, a Padding field is included if the number of bits in all options together is not a multiple
of 32 bits.
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IP Option Format
Each IP option has its own subfield format. For most options, all three subfields are used: Option
Type, Option Length and Option Data. For a few simple options, however, this complex substructure is not
needed. In those cases, the option type itself communicates all the information required, so the Option
Type field appears alone, while the Option Length and Option Data subfields are omitted.
Fig 6. Options Field
V. CONCLUSION AND FUTURE WORK
Although the proposed extension aims at reducing computational overhead and router state of FCP, it is
really to needed to quantify the savings achieved. Moreover the techniques are needed to be evaluated on some
real topologies and failure instances.
Thus the future work of the project would include implementation of original FCP protocol as it is
proposed by the authors first and its evaluation and then implementation of the extended version and its
comparative evaluation with the original one.
The parameters of evaluation would be amount of router state, computational requirements and packet
overhead for both the versions of the protocol.
VI. ACKNOWLEDGMENT
We wish to express our sincere gratitude to Dr. U. V. Bhosle, Principal and Prof. S. B. Wankhade,
H.O.D of Computer Department of RGIT for providing us an opportunity to do our project work on “Removing
Convergence using FCP with source path routing ".
This project bears on imprint of many people. We sincerely thank our project guide Prof. D. J.
Dhangar for his guidance and encouragement.
REFERENCES
[1] P. Francois and O. Bonaventure, “Avoiding transient loops during IGP convergence in IP networks,” In Proc. INFOCOM, 2005.
[2] C. Alaettinoglu, V. Jacobson, and H. Yu, “Towards Millisecond IGP Convergence”, IETF Internet draft 2000.
[3] Kvalbein, A. F. Hansen, T. Cicic, S. Gjessing, and O. Lysne, “Fast IP Network Recovery using Mumtiple Routing
Configurations”,
[4] K. K. Lakshminarayanan, M. C. Caesar, M. Rangan, T. Anderson, S. Shenker, and I. Stoica,
“Achieving Convergence-Free Routing using Failure-Carrying Packets,” In SIGCOMM, 2007.
[5] S. Rai, B. Mukherji, and O. Deshpande, “IP Resilience within an Autonomous System: Current
Approaches, Challenges, and Future Directions,” IEEE Communications Magazine, vol. 43, no. 10,
pp. 142-149, Oct. 2005