The document discusses and compares Mobile IP Version 4 (MIPv4) and Mobile IP Version 6 (MIPv6), which are protocols that allow nodes to move between networks while maintaining ongoing connections. MIPv4 uses home agents and foreign agents to tunnel packets to a mobile node's care-of address, but has problems like triangular routing and security issues. MIPv6 aims to address these problems by removing the foreign agent and using other methods like return routability procedures and bindings to register locations securely.
Mobile IP allows devices to change networks while maintaining the same IP address, enabling continuous internet connectivity regardless of location. It works by assigning devices a permanent home IP address and registering a care-of address with a foreign agent when not in the home network, allowing the foreign agent to forward packets to the device's current location. Mobile IP supports security through authentication and aims to optimize routing efficiency.
Mobile IP allows mobile devices to change their point of attachment between networks while maintaining ongoing connections. It uses the mobile node's home address and care-of address to forward data packets as the mobile node roams. When away from its home network, a mobile node registers its care-of address with its home agent, which intercepts and encapsulates packets to the care-of address so the mobile node can receive them on foreign networks. This allows mobile nodes to move between networks while keeping the same IP address.
Mobile IP is a protocol that allows mobile devices to change location while maintaining the same IP address. It works by assigning mobile devices a permanent home address and registering a care-of address with their home agent when visiting foreign networks. The home agent intercepts packets destined for the mobile device's home address and tunnels them to its current care-of address. This allows the mobile device to stay connected to the internet as it moves between networks while keeping the same home address.
1. Mobile IP allows mobile devices like laptops and phones to change their point of attachment to the internet while maintaining the same IP address. It uses home and foreign agents and tunneling to redirect traffic to the mobile device's current location.
2. Key entities in Mobile IP include the mobile node, home agent, and foreign agent. The home agent intercepts traffic for the mobile node and tunnels it to the foreign agent near the mobile node.
3. The mobile IP process involves agent discovery, registration of the mobile node's location with its home and foreign agent, and tunneling of traffic by the home agent to the mobile node's current location.
Mobile IP is an Internet Engineering Task Force (IETF) standard designed to allow mobile device users to move between networks while maintaining a permanent IP address. It uses a home address for identification and a care-of address for routing. Key functions include foreign agent discovery, home agent registration using registration requests and replies, and tunneling via encapsulation to forward packets to the mobile node's care-of address. Route optimization enables direct communication between a correspondent node and the mobile node to improve efficiency.
This document discusses the key aspects of mobile IP, including addressing, agents, communication phases, and inefficiencies. It explains that mobile IP uses two addresses - a home address and care-of address. Agents (home and foreign) are used to route traffic to mobile hosts as they change locations. Communication involves three phases - discovery, registration, and data transfer. Inefficiencies can occur through double crossing routing or triangle routing rather than more direct paths.
Mobile IP uses three key mechanisms:
1) Discovering the care-of-address through agent advertisements and solicitations.
2) Registering the care-of-address with the home agent to establish a mobility binding.
3) Tunneling datagrams to the care-of-address using IP-within-IP encapsulation with the home agent as the tunnel endpoint.
Mobile IP allows devices to change networks while maintaining the same IP address, enabling continuous internet connectivity regardless of location. It works by assigning devices a permanent home IP address and registering a care-of address with a foreign agent when not in the home network, allowing the foreign agent to forward packets to the device's current location. Mobile IP supports security through authentication and aims to optimize routing efficiency.
Mobile IP allows mobile devices to change their point of attachment between networks while maintaining ongoing connections. It uses the mobile node's home address and care-of address to forward data packets as the mobile node roams. When away from its home network, a mobile node registers its care-of address with its home agent, which intercepts and encapsulates packets to the care-of address so the mobile node can receive them on foreign networks. This allows mobile nodes to move between networks while keeping the same IP address.
Mobile IP is a protocol that allows mobile devices to change location while maintaining the same IP address. It works by assigning mobile devices a permanent home address and registering a care-of address with their home agent when visiting foreign networks. The home agent intercepts packets destined for the mobile device's home address and tunnels them to its current care-of address. This allows the mobile device to stay connected to the internet as it moves between networks while keeping the same home address.
1. Mobile IP allows mobile devices like laptops and phones to change their point of attachment to the internet while maintaining the same IP address. It uses home and foreign agents and tunneling to redirect traffic to the mobile device's current location.
2. Key entities in Mobile IP include the mobile node, home agent, and foreign agent. The home agent intercepts traffic for the mobile node and tunnels it to the foreign agent near the mobile node.
3. The mobile IP process involves agent discovery, registration of the mobile node's location with its home and foreign agent, and tunneling of traffic by the home agent to the mobile node's current location.
Mobile IP is an Internet Engineering Task Force (IETF) standard designed to allow mobile device users to move between networks while maintaining a permanent IP address. It uses a home address for identification and a care-of address for routing. Key functions include foreign agent discovery, home agent registration using registration requests and replies, and tunneling via encapsulation to forward packets to the mobile node's care-of address. Route optimization enables direct communication between a correspondent node and the mobile node to improve efficiency.
This document discusses the key aspects of mobile IP, including addressing, agents, communication phases, and inefficiencies. It explains that mobile IP uses two addresses - a home address and care-of address. Agents (home and foreign) are used to route traffic to mobile hosts as they change locations. Communication involves three phases - discovery, registration, and data transfer. Inefficiencies can occur through double crossing routing or triangle routing rather than more direct paths.
Mobile IP uses three key mechanisms:
1) Discovering the care-of-address through agent advertisements and solicitations.
2) Registering the care-of-address with the home agent to establish a mobility binding.
3) Tunneling datagrams to the care-of-address using IP-within-IP encapsulation with the home agent as the tunnel endpoint.
This document provides an overview of Mobile IP and how it enables users to stay connected to the internet while moving between different networks. It defines key terms like home address, home network, home agent, foreign network, and care-of address. Mobile IP separates the locator and identifier functions that were previously bound together in IP addresses. It allows session continuity and reachability so communication can flow seamlessly as a mobile node moves. The home agent intercepts messages destined for the mobile node's home address and forwards them to its current care-of address in a foreign network.
The document summarizes the key concepts of Mobile IP, which allows devices to maintain the same IP address when connecting to different networks. Mobile IP uses two addresses - the home address that stays fixed, and a care-of address that changes based on the foreign network. A home agent forwards packets to the device's current care-of address, while the device's home address remains the same from the perspective of other devices. This allows seamless internet access for devices that roam across networks while maintaining persistent connectivity and identity.
This document discusses Mobile IP, which allows mobile devices to change their point of attachment between different networks while maintaining ongoing connections. It describes the key entities in Mobile IP including the Mobile Node, Home Agent, Foreign Agent, and Correspondent Node. The operations of Mobile IP are summarized, including agent discovery, registration processes, encapsulation and decapsulation of packets, and the tables maintained on routers. Problems with Mobile IP and its applications are also briefly mentioned.
This document discusses IP mobility and the Mobile IP standard. It provides an overview of the key concepts in Mobile IP, including:
- Mobile IP uses two IP addresses for mobile nodes - a permanent "home address" and a temporary "care-of address" used when roaming away from home.
- Functional entities include the mobile node, home agent on the home network, and foreign agents on visited networks.
- The basic concept is that when away from home, the mobile node registers its care-of address with its home agent. Packets are then tunneled from the home agent to the mobile node's current location.
- Key mechanisms involve agent discovery, registration of the mobile node's
Mobile IP is an IETF standard that allows mobile devices to change location between networks while maintaining the same IP address. It works by having a home agent forward data to the mobile node's current foreign agent when it is away from its home network. All data uses the mobile node's home address, while the care-of address identifies its current location and is used for tunneling data through foreign agents back to the mobile node.
Mobile IP allows mobile nodes to roam between networks while maintaining ongoing connections. It uses home and foreign agents to manage registration and tunnel packets sent to a mobile node's permanent home address to its current location. However, this can result in inefficient triangle routing. Mobile IP also faces challenges from security vulnerabilities and frequent location updates.
Mobile IP allows users to move between networks while maintaining the same IP address. It uses home and foreign agents and care-of addresses. A mobile node can register its care-of address with its home agent to receive packets when away from home. There are three main processes: agent discovery to find foreign agents, registration of the mobile node's care-of address with its home agent, and data transfer either via indirect routing through home and foreign agents or direct routing from correspondent nodes to the mobile node. Mobile IP supports host mobility across networks in a transparent manner without changing IP addresses.
This document provides an introduction to mobile computing. It defines mobile computing as using a computer while on the move, involving mobility, computing, and network connectivity. The key aspects of mobile computing are discussed, including mobile communication infrastructure, software, hardware, and devices. Common network types that enable mobile computing like WLAN, MAN, WAN, and wireless networks are also summarized. The relationship between mobile computing and wireless networking is described, with wireless networking providing the basic communication capabilities. Examples of mobile computing applications are given for various fields.
The document discusses desirable features of mobile IP, including transparency, compatibility, security, and efficiency & scalability. Transparency refers to mobile IP being invisible to higher level protocols and applications. Compatibility means mobile IP should be compatible with existing Internet protocols and support all web browsers. Security involves authenticating mobile IP and protecting against attackers with fake IP addresses. Efficiency & scalability requires mobile IP to not flood the network or compromise efficiency as it supports billions of moving hosts and various devices.
Performance of Various Mobile IP Protocols and Security ConsiderationsCSCJournals
This document discusses and compares different mobile IP protocols. It presents an analytic model to evaluate the performance of Mobile IP (MIP), Hierarchical Mobile IP (HMIP), and Dynamic HMIP (DHMIP) based on mean signaling delay and bandwidth per call under different types of mobile terminal mobility. The model divides call holding time into small time intervals and calculates bandwidth used in each interval, accounting for both data bandwidth and signaling bandwidth during handoffs. The analysis finds that HMIP outperforms MIP and DHMIP in most cases studied due to its ability to localize registration processes and reduce signaling burden through a hierarchy of foreign agents and gateway agents.
Mobile IP is a protocol that allows mobile devices like phones and laptops to change location between networks while maintaining the same IP address. When a mobile node changes to a foreign network, its home agent intercepts any data packets and tunnels them to the mobile node's care-of address at its new location. The foreign agent then decapsulates the tunneled packets and delivers them locally to the mobile node. This allows the mobile node to seamlessly change networks without disrupting communications.
A review study of handover performance in mobile ipIJCNCJournal
The Mobile Internet Protocol (Mobile IP) is an extension to the Internet Protocol proposed by the Internet
Engineering Task Force (IETF) that addresses the mobility issues. In order to support un-interrupted
services and seamless mobility of nodes across the networks (and/or sub-networks) with permanent IP
addresses, handover is performed in mobile IP enabled networks. Handover in mobile IP is source cause of
performance degradation as it results in increased latency and packet loss during handover. Other issues
like scalability issues, ordered packet delivery issues, control plane management issues etc are also
adversely affected by it. The paper provides a constructive survey by classifying, discussing and comparing
different handover techniques that have been proposed so far, for enhancing the performance during
handovers. Finally some general solutions that have been used to solve handover related problems are
briefly discussed.
Overview of Mobile IP , Features of Mobile IP , Key Mechanism in Mobile IP , route Optimization , Overview of TCP/IP , Architecture of TCP/IP , Adaptation of TCP Window , Improvement in TCP Performance,mobile computing.
Internet considered as the most important types of wide area networks and the most
important sources for information, that is because its ability to give many electronic services, like
email, communication services, voice over IP, Internet telephony and other services, to get these
services requires accessing to the web server. It is obvious that to make sure the connection oriented
with the Internet service providers, requires remaining and operating the received device within the
arriving zone of Internet signal, and this device will stop to receive this Internet signal, if it moves to
a new position lies outside this area. The researchers presented through their scientific researches
many ideas and ways of ensuring the continued achievement of the Internet access, despite of the
mobility of the recipient device outside the area of the original service provider, the flow of these
ideas led to do a new networking technique known as multi-homing mobility technique, the
researchers are developed several topologies and protocols to suit their operation with this kind of
mobile networks. This paper presents a new approach for developing the multi-homing mobility
network system that increases the performance operation in spite of the far mobility of the recipient
device to new positions. This approach gives also a new way of network topology, new protocols of
programming internetworking devices, as well as applying the mobile IP addressing for sending and
receiving the packets between the Internet service provider and the mobile recipient, and gives a
reliable algorithm for enhancing troubleshooting packet loss. To test and check the ability of this
approach, we design a hypothetical multi-homing mobility network system that operates under these
proposed algorithms, apply packet tracer v.5 simulator for testing the performance of this proposed
approach.
Mobile IP allows hosts to stay connected to the Internet regardless of location by enabling hosts to be tracked without changing their IP address. It requires additional infrastructure such as home agents and foreign agents. Home agents intercept packets destined for mobile nodes and forward them to the node's current location. This allows mobile nodes to use a permanent home address while roaming between networks.
Mobile IP allows devices to move between networks while maintaining the same IP address. It uses a home agent and foreign agent to forward data to the device's current location. When a mobile node moves to a new network, it acquires a care-of address and registers this with its home agent so data can be tunneled to it. The home agent intercepts data for the mobile node and encapsulates it for forwarding to the care-of address via direct delivery or through the foreign agent. This allows seamless mobility as the mobile node does not need a new IP address when changing networks.
Mobile IPv6 integrates mobility support directly into IPv6 and offers improvements over Mobile IPv4 such as no need for foreign agents, auto-configuration of care-of addresses, support for multiple care-of addresses, and route optimization as a fundamental part of the protocol. Security measures in Mobile IPv6 include using hash-based message authentication codes and nonces to authenticate nodes and prevent replay attacks during registration and data forwarding.
1) The document discusses route optimization techniques for solving the triangle routing problem in Mobile IPv4, specifically evaluating the performance of the Internet Service Provider Mobile Border Gateway (ISP MBG) scheme.
2) It provides background on Mobile IP, the triangle routing problem, and introduces the ISP MBG technique for optimizing routes.
3) The study evaluates the performance of ISP MBG by varying system parameters like number of nodes and zones, finding it provides shorter transmission times compared to conventional Mobile IP.
The document discusses Mobile IP and the Wireless Application Protocol (WAP). Mobile IP allows devices to change their network point of attachment while maintaining ongoing connections. It uses home and foreign agents to register devices' locations and tunnel traffic to their new addresses. WAP provides a standard for internet access from wireless devices. It defines protocols like WML, WTP, and WDP to support limited devices over various wireless networks.
Unit 2.design mobile computing architectureSwapnali Pawar
This document contains a question bank on designing mobile computing architecture. It includes 57 multiple choice and theory questions covering topics like characteristics of mobile communication, security concerns, middleware, mobile IP, and satellite communication. The questions address layers of communication systems, features of mobile networks, advantages of mobility, and concepts such as user/device mobility, home/foreign agents, registration, tunneling, and route optimization in mobile IP.
In this ppt you'll learn about the packet delivery. How the Ip packet is delivered from transmitter to receiver when the Mobile node is in the Foreign network. Also you'll be able to learn all definitions like What is mobile node, correspondent node, Home agent, Foreign Agent, Tunneling, Encapsulation, COA(care of address) etc. After that you'll learn about the Agent advertisement and registering of care of address including different steps.
This document provides an overview of Mobile IP and how it enables users to stay connected to the internet while moving between different networks. It defines key terms like home address, home network, home agent, foreign network, and care-of address. Mobile IP separates the locator and identifier functions that were previously bound together in IP addresses. It allows session continuity and reachability so communication can flow seamlessly as a mobile node moves. The home agent intercepts messages destined for the mobile node's home address and forwards them to its current care-of address in a foreign network.
The document summarizes the key concepts of Mobile IP, which allows devices to maintain the same IP address when connecting to different networks. Mobile IP uses two addresses - the home address that stays fixed, and a care-of address that changes based on the foreign network. A home agent forwards packets to the device's current care-of address, while the device's home address remains the same from the perspective of other devices. This allows seamless internet access for devices that roam across networks while maintaining persistent connectivity and identity.
This document discusses Mobile IP, which allows mobile devices to change their point of attachment between different networks while maintaining ongoing connections. It describes the key entities in Mobile IP including the Mobile Node, Home Agent, Foreign Agent, and Correspondent Node. The operations of Mobile IP are summarized, including agent discovery, registration processes, encapsulation and decapsulation of packets, and the tables maintained on routers. Problems with Mobile IP and its applications are also briefly mentioned.
This document discusses IP mobility and the Mobile IP standard. It provides an overview of the key concepts in Mobile IP, including:
- Mobile IP uses two IP addresses for mobile nodes - a permanent "home address" and a temporary "care-of address" used when roaming away from home.
- Functional entities include the mobile node, home agent on the home network, and foreign agents on visited networks.
- The basic concept is that when away from home, the mobile node registers its care-of address with its home agent. Packets are then tunneled from the home agent to the mobile node's current location.
- Key mechanisms involve agent discovery, registration of the mobile node's
Mobile IP is an IETF standard that allows mobile devices to change location between networks while maintaining the same IP address. It works by having a home agent forward data to the mobile node's current foreign agent when it is away from its home network. All data uses the mobile node's home address, while the care-of address identifies its current location and is used for tunneling data through foreign agents back to the mobile node.
Mobile IP allows mobile nodes to roam between networks while maintaining ongoing connections. It uses home and foreign agents to manage registration and tunnel packets sent to a mobile node's permanent home address to its current location. However, this can result in inefficient triangle routing. Mobile IP also faces challenges from security vulnerabilities and frequent location updates.
Mobile IP allows users to move between networks while maintaining the same IP address. It uses home and foreign agents and care-of addresses. A mobile node can register its care-of address with its home agent to receive packets when away from home. There are three main processes: agent discovery to find foreign agents, registration of the mobile node's care-of address with its home agent, and data transfer either via indirect routing through home and foreign agents or direct routing from correspondent nodes to the mobile node. Mobile IP supports host mobility across networks in a transparent manner without changing IP addresses.
This document provides an introduction to mobile computing. It defines mobile computing as using a computer while on the move, involving mobility, computing, and network connectivity. The key aspects of mobile computing are discussed, including mobile communication infrastructure, software, hardware, and devices. Common network types that enable mobile computing like WLAN, MAN, WAN, and wireless networks are also summarized. The relationship between mobile computing and wireless networking is described, with wireless networking providing the basic communication capabilities. Examples of mobile computing applications are given for various fields.
The document discusses desirable features of mobile IP, including transparency, compatibility, security, and efficiency & scalability. Transparency refers to mobile IP being invisible to higher level protocols and applications. Compatibility means mobile IP should be compatible with existing Internet protocols and support all web browsers. Security involves authenticating mobile IP and protecting against attackers with fake IP addresses. Efficiency & scalability requires mobile IP to not flood the network or compromise efficiency as it supports billions of moving hosts and various devices.
Performance of Various Mobile IP Protocols and Security ConsiderationsCSCJournals
This document discusses and compares different mobile IP protocols. It presents an analytic model to evaluate the performance of Mobile IP (MIP), Hierarchical Mobile IP (HMIP), and Dynamic HMIP (DHMIP) based on mean signaling delay and bandwidth per call under different types of mobile terminal mobility. The model divides call holding time into small time intervals and calculates bandwidth used in each interval, accounting for both data bandwidth and signaling bandwidth during handoffs. The analysis finds that HMIP outperforms MIP and DHMIP in most cases studied due to its ability to localize registration processes and reduce signaling burden through a hierarchy of foreign agents and gateway agents.
Mobile IP is a protocol that allows mobile devices like phones and laptops to change location between networks while maintaining the same IP address. When a mobile node changes to a foreign network, its home agent intercepts any data packets and tunnels them to the mobile node's care-of address at its new location. The foreign agent then decapsulates the tunneled packets and delivers them locally to the mobile node. This allows the mobile node to seamlessly change networks without disrupting communications.
A review study of handover performance in mobile ipIJCNCJournal
The Mobile Internet Protocol (Mobile IP) is an extension to the Internet Protocol proposed by the Internet
Engineering Task Force (IETF) that addresses the mobility issues. In order to support un-interrupted
services and seamless mobility of nodes across the networks (and/or sub-networks) with permanent IP
addresses, handover is performed in mobile IP enabled networks. Handover in mobile IP is source cause of
performance degradation as it results in increased latency and packet loss during handover. Other issues
like scalability issues, ordered packet delivery issues, control plane management issues etc are also
adversely affected by it. The paper provides a constructive survey by classifying, discussing and comparing
different handover techniques that have been proposed so far, for enhancing the performance during
handovers. Finally some general solutions that have been used to solve handover related problems are
briefly discussed.
Overview of Mobile IP , Features of Mobile IP , Key Mechanism in Mobile IP , route Optimization , Overview of TCP/IP , Architecture of TCP/IP , Adaptation of TCP Window , Improvement in TCP Performance,mobile computing.
Internet considered as the most important types of wide area networks and the most
important sources for information, that is because its ability to give many electronic services, like
email, communication services, voice over IP, Internet telephony and other services, to get these
services requires accessing to the web server. It is obvious that to make sure the connection oriented
with the Internet service providers, requires remaining and operating the received device within the
arriving zone of Internet signal, and this device will stop to receive this Internet signal, if it moves to
a new position lies outside this area. The researchers presented through their scientific researches
many ideas and ways of ensuring the continued achievement of the Internet access, despite of the
mobility of the recipient device outside the area of the original service provider, the flow of these
ideas led to do a new networking technique known as multi-homing mobility technique, the
researchers are developed several topologies and protocols to suit their operation with this kind of
mobile networks. This paper presents a new approach for developing the multi-homing mobility
network system that increases the performance operation in spite of the far mobility of the recipient
device to new positions. This approach gives also a new way of network topology, new protocols of
programming internetworking devices, as well as applying the mobile IP addressing for sending and
receiving the packets between the Internet service provider and the mobile recipient, and gives a
reliable algorithm for enhancing troubleshooting packet loss. To test and check the ability of this
approach, we design a hypothetical multi-homing mobility network system that operates under these
proposed algorithms, apply packet tracer v.5 simulator for testing the performance of this proposed
approach.
Mobile IP allows hosts to stay connected to the Internet regardless of location by enabling hosts to be tracked without changing their IP address. It requires additional infrastructure such as home agents and foreign agents. Home agents intercept packets destined for mobile nodes and forward them to the node's current location. This allows mobile nodes to use a permanent home address while roaming between networks.
Mobile IP allows devices to move between networks while maintaining the same IP address. It uses a home agent and foreign agent to forward data to the device's current location. When a mobile node moves to a new network, it acquires a care-of address and registers this with its home agent so data can be tunneled to it. The home agent intercepts data for the mobile node and encapsulates it for forwarding to the care-of address via direct delivery or through the foreign agent. This allows seamless mobility as the mobile node does not need a new IP address when changing networks.
Mobile IPv6 integrates mobility support directly into IPv6 and offers improvements over Mobile IPv4 such as no need for foreign agents, auto-configuration of care-of addresses, support for multiple care-of addresses, and route optimization as a fundamental part of the protocol. Security measures in Mobile IPv6 include using hash-based message authentication codes and nonces to authenticate nodes and prevent replay attacks during registration and data forwarding.
1) The document discusses route optimization techniques for solving the triangle routing problem in Mobile IPv4, specifically evaluating the performance of the Internet Service Provider Mobile Border Gateway (ISP MBG) scheme.
2) It provides background on Mobile IP, the triangle routing problem, and introduces the ISP MBG technique for optimizing routes.
3) The study evaluates the performance of ISP MBG by varying system parameters like number of nodes and zones, finding it provides shorter transmission times compared to conventional Mobile IP.
The document discusses Mobile IP and the Wireless Application Protocol (WAP). Mobile IP allows devices to change their network point of attachment while maintaining ongoing connections. It uses home and foreign agents to register devices' locations and tunnel traffic to their new addresses. WAP provides a standard for internet access from wireless devices. It defines protocols like WML, WTP, and WDP to support limited devices over various wireless networks.
Unit 2.design mobile computing architectureSwapnali Pawar
This document contains a question bank on designing mobile computing architecture. It includes 57 multiple choice and theory questions covering topics like characteristics of mobile communication, security concerns, middleware, mobile IP, and satellite communication. The questions address layers of communication systems, features of mobile networks, advantages of mobility, and concepts such as user/device mobility, home/foreign agents, registration, tunneling, and route optimization in mobile IP.
In this ppt you'll learn about the packet delivery. How the Ip packet is delivered from transmitter to receiver when the Mobile node is in the Foreign network. Also you'll be able to learn all definitions like What is mobile node, correspondent node, Home agent, Foreign Agent, Tunneling, Encapsulation, COA(care of address) etc. After that you'll learn about the Agent advertisement and registering of care of address including different steps.
UNIT IV MOBILE NETWORK AND TRANSPORT LAYERS
Mobile IP – Dynamic Host Configuration Protocol-Mobile Ad Hoc Routing Protocols–Multicast routing-TCP over Wireless Networks – Indirect TCP – Snooping TCP – Mobile TCP – Fast Retransmit / Fast Recovery – Transmission/Timeout Freezing-Selective Retransmission – Transaction Oriented TCP- TCP over 2.5 / 3G wireless Networks
MOBILE IP_INTRODUCTION_OVERVIEW OF MOBILE IP_KEY MECHANISMS OF MOBILE IP_SCHEMATIC MODEL OF MOBILE IP_TUNNELLING_CARE OF ADDRESS-TCP_PACKET FORWARDING_TCP SLIDING WINDOWS
Mobile IP is an open standard that allows devices to change networks while maintaining the same IP address. This ensures ongoing connections and applications are not dropped when switching networks. It works by assigning two IP addresses - a static home address and a care-of address that changes based on the device's current network location. When the device roams away from its home network, its traffic is encapsulated and tunneled through its home network to maintain connectivity using its home address. Mobile IP provides mobility across IP networks while cellular IP focuses on optimizing mobility within cellular networks.
Mobile IP is an open standard that allows devices to change networks while maintaining the same IP address. This allows ongoing connections and applications to continue without being dropped when the device roams to a new network. Mobile IP works by assigning the device two IP addresses - a home address that stays the same and a care-of address that changes based on the new network point of attachment. Tunneling is used to forward packets to the device's current location. Mobile IPv6 improves upon Mobile IPv4 by simplifying the mobility management process and integrating support for route optimization.
Mobile IP allows nodes to change their point of attachment to the network while maintaining ongoing communications using the same IP address. It works by associating each mobile node with a home network and address, and registering the node's current location, or care-of address, with a home agent in the home network. When packets are sent to the mobile node's home address, the home agent intercepts them and tunnels them to the node's current care-of address via encapsulation. This allows the node to receive packets no matter where it is connected.
This document discusses Mobile IP and key concepts related to it. Mobile IP allows mobile devices to stay connected to the internet as they move between different networks. It extends the IP protocol to make mobility transparent to applications. The key mechanisms in Mobile IP are discovering a device's care-of-address in a foreign network, registering that address with the home agent, and tunneling packets to the device's current location using that care-of-address.
Extended Study on the Performance Evaluation of ISP MBG based Route Optimiza...IOSR Journals
This document provides an extended study on the performance evaluation of an Internet Service Provider (ISP) Mobile Border Gateway (MBG) based route optimization scheme in Mobile IPv4. The study evaluates the scheme's performance under different system parameters like number of nodes, zones, and points of presence serving each zone. The ISP MBG technique aims to solve the triangle routing problem in conventional Mobile IPv4 by providing a shorter route with lower transmission times between correspondent nodes and mobile nodes. Simulation results presented in the paper prove that the ISP MBG framework successfully addresses triangle routing issues.
Mobile IP allows mobile devices to stay connected to the internet as they move between networks. It extends standard IP to support mobility. There are three key mechanisms:
1) Mobile nodes discover their current location through agent advertisements from foreign agents.
2) They register their care-of address with their home agent to update their location.
3) Tunnelling encapsulates and redirects packets to the mobile node's current location.
Bluetooth and mobile IP technologies enable wireless connectivity and mobility support in IP networks. Bluetooth aims to connect devices like phones and computers wirelessly, while mobile IP uses home agents and foreign agents to forward packets to mobile hosts and maintain location information as hosts move networks. The paper discusses load balancing mechanisms for multiple home agents in mobile IP to avoid bottlenecks when large numbers of mobile hosts are present.
This document provides an overview of Mobile IP, including its key requirements, terminology, and technical processes. Mobile IP allows devices to change networks without losing connectivity by updating their location through registration with a home agent. It aims to remain compatible with existing IP standards while providing transparency to higher-level applications and efficiency at scale. The document explains concepts such as home and foreign networks, care-of addresses, agents, registration, tunneling, and optimization techniques.
Mobile IP allows mobile devices to stay connected to the internet as they move between networks. It uses a home agent and foreign agent to associate a device's permanent home IP address with its changing care-of address on visited networks. When a mobile node moves, it registers its new care-of address with its home agent so that packets can be forwarded to its current location. This process enables seamless internet connectivity regardless of location.
A Proposed Technique For Solving The Triangle Routing Problem In Mobile IPMartha Brown
This paper proposes a technique called the Internet Service Provider Mobile IP Border Gateway (ISP MBG) to solve the triangle routing problem in conventional Mobile IP. The technique uses separate Internet Service Providers connected by Mobile IP Border Gateways. The proposed technique was implemented and tested on the Microsoft .net platform. Simulation results showed that the new framework solved the triangle routing problem by providing a shorter route with minimum transmission time between correspondent and mobile nodes.
The document discusses various topics related to mobile network layer including Mobile IP, DHCP, Ad Hoc networks, and routing protocols.
Mobile IP allows devices to change locations while maintaining network connectivity using care-of addresses, home agents, and tunneling. DHCP dynamically assigns IP addresses in mobile networks. Ad Hoc networks are temporary networks formed without infrastructure between devices using multi-hop routing. Routing protocols for Ad Hoc networks can be proactive, maintaining routes continuously, or reactive, determining routes on demand to reduce overhead.
This document discusses Mobile Internet Protocol (Mobile IP) and how it allows mobile devices to stay connected to the internet without changing their IP address as they move between different networks. It covers key topics such as:
- The basics of Mobile IP including definitions of terms like home agent, foreign agent, and care-of-address.
- How Mobile IP works including the process of discovering the care-of-address, registering with foreign agents, and tunneling packets to the mobile node's current location.
- Adaptations made to transport protocols like TCP to improve performance over wireless networks.
This document discusses topics covered in the textbook "Computer Networks: A Systems Approach, 5e" by Larry L. Peterson and Bruce S. Davie. It covers advanced topics such as Multiprotocol Label Switching (MPLS), routing among mobile devices, end-to-end protocols like UDP and TCP, and congestion control and resource allocation. MPLS is described as an IP packet routing technique that uses labels instead of complex routing tables. Routing among mobile devices presents challenges due to different wireless standards and the need for seamless handovers. UDP provides a simple demultiplexing service while TCP enables reliable byte stream delivery between endpoints.
MOBILE INTERNET PROTOCOL AND TRANSPORT LAYER
Overview of Mobile IP – Features of Mobile IP – Key Mechanism in Mobile IP – route Optimization. Overview of TCP/IP – Architecture of TCP/IP- Adaptation of TCP Window – Improvement in TCP Performance.
1. The document discusses various aspects of mobile internet protocol and transport layer protocols.
2. It provides an overview of Mobile IP including its key components like mobile node, home agent, foreign agent and correspondent node. It also describes how Mobile IP works through agent discovery, registration and tunneling.
3. The document also discusses TCP/IP architecture including its four layers and compares it to the OSI model. It describes various techniques to improve TCP performance over mobile networks like indirect TCP, snooping TCP and mobile TCP.
Mobile IP enables devices to change their Internet connection point while maintaining connectivity. It assigns a temporary IP address and uses tunneling to forward data to the device's care-of address. The Wireless Application Protocol (WAP) provides mobile access to information services over wireless networks using standards like IP, XML and HTTP. It includes the Wireless Transaction Protocol (WTP) and Wireless Transport Layer Security (WTLS) to enable secure transactions over bandwidth-limited wireless connections.
1. MET CS 535
A COMPARATIVE STUDY OF THE
OPERATION OF MOBILE IPV4 AND
MOBILE IPV6
By:
Bishwa P. Pandey
2. 1. Introduction
The number of mobile users have grown exponentially in the last decade, as have the number
of mobile users on these mobile devices. It is estimated that the number of internet users from
mobile subscribers is increasing by a magnitude of thousands each day [2]. This increasing
number of mobile internet subscribers has put a great emphasis on the need for mobility support
to provide seamless internet connectivity
Mobile IP is an extension to the standard Internet Protocol which is implemented for fixed
internet. The major issue surrounding mobility is that TCP/IP the predominant protocol for
fixed internet was not designed with mobility in mind [2]. The issue seen was that when a node
moved from one access point to another the node would re-connect and each time with a
different IP address, which made communication with that node extremely hard. Mobile IP
allows the node to keep its original IP address even when it moves away from its home
network.
MIPv4 is a popular mobility protocol and one of the most promising solution for mobility
management in the current IPv4 network. The basic operation of MIPv4 can be outlined as
follows: Mobility Agents send agent advising messages, after receiving such a message a
mobile node determines whether or not it is on its home network or not. If not, it send its home
agent a care address to which all datagrams addressed to it are to be forwarded to. The
datagrams are sent to the mobile node using a method called tunneling [2].
However it does have some problems. These problems are dealt with in MIPv6 which is the
mobility management protocol for the next generation of IPv6 protocol. MIPv6 does share
many features with MIPv4, it does have some minor differences from MIPv4. For example,
the role of the Foreign Agent in MIPv4 is replaced with an Access Router in MIPv6. Also there
were route optimization extensions were proposed for both MIPv4 and MIPv6, but were only
implemented in MIPv6 [3].
One more reason for the use of MIPv6 is the Internet of Things. The IPv4 address space was
completely depleted by February 1st 2011 [5]. IPv6 was seen to provide a solution for this by
providing a greater number of addresses.
3. Figure 2.
Growing Trends in Mobile Internet Connectivity [1].
2. Mobile Internet ProtocolVersion4 ( MIPv4)
IP version 4 assumes that node’s IP address uniquely identifies the node’s point of attachment
to the internet [2]. Hence a device will only receive datagrams addressed to it if it is located on
the network using the same IP address, else the datagrams will be lost. This is the problem that
is dealt with by MIPv4.
2.1. Terminologies
Mobile Node: This is the node which moves from its home network to other networks. It is
the destination of all the datagrams in out discussion. It has a permanent IP address to which
datagrams are sent to. These datagrams can be sent by other nodes over the internet to the IP
address that the node has on its Home Network.
Home Network: It is the network to which the mobile node is permanently connected. This
subnet corresponds to the home address of the mobile node as well as the home agent [1].
Home Agent: The home agent is tasked with forwarding the packets to the mobile node. This
means that when the mobile node is not on its home network it will intercept all the datagrams
that are addressed to the mobile node’s original IP address and tunnel them to the Care of
Address that the node has registered with the home network.
Foreign Network: This the network that the mobile node connects to when it is not connected
to the home network.
4. Foreign Agent: The foreign agent is a router on the foreign network to which the mobile node
is connected to. The foreign is configured to receive and forward packets which are destined
for the mobile node when the mobile node has a foreign care of address. When using collocated
care of address, this foreign agent is used as a default router or for registering with the foreign
network [1].
Care of Address: This is the address that the mobile node uses for communication with other
nodes when it is not on it is not on its home network. It is also the address to which the home
agent forwards datagrams which were sent to the mobile node’s IP address. This can either be
foreign agent care of address or a collocated care of address [1].
A. Foreign Agent Care of Address: The mobile node uses the foreign agent’s IP address
as its Care of Address.
B. Collocated Care of Address: The network interface of the mobile node is temporarily
assigned an IP number on the IP on the foreign network [1].
Correspondent Node: This is the node which communicates with the mobile node. This node
can be located on any network.
2.2 Mobile IPv4 Basic Operation:
There are three basic related functions to the functioning of Mobile IP:
Agent Discovery: Mobile agents constantly advertise their availability on each of the
links to which they provide services.
Registration: When the mobile node has determined that it is away from its home
network then it registers a care of address with its home network.
Tunneling: This is the method the home agent uses to transport datagrams to the mobile
node while it is away from the foreign network.
The following will give a brief outline of the operation of the Mobile IP using these three
steps.
The Mobile Node is initially given an IP address at its Home Network and as long as it is in
the home network it is treated just as if it is was any other fixed node on the network, and
therefore doesn’t require any mobility support.
In the mean-time, Mobility agents are constantly advertising their availability using the ICMP
Router Advertisement Packet which can be seen in Figure 1. Home agents do not broadcast
5. Figure 2. Basic MIPv4 working[3].
Care of addresses, but they do have to broadcast mobility agent advertisements so the mobile
nodes are aware that they have returned to their home network.
Once a mobile node receives one such advertisement it determines whether or not it is still on
its home network. When a mobile node moves away from its home network it obtains a care
of address on the foreign network, for example, by soliciting or listening for agent
advertisements, or contacting Dynamic Host Configuration Protocol (DHCP) or Point-to –
Point Protocol (PPP) [2].
The mobile node registers its Care of Address with its home network by means of a foreign
agent using a Registration Request Message which is sent to the User Datagram Protocol
(UDP) port 434 of a dedicated entity on the Home Network called home agent. The Request
message informs the Home Network about the current Care of Address and also how long the
node intends to use the care of address. It also tells the home agent of any special features
that are made available by the foreign agent. The Registration Request Message can be seen
in Figure 2 [7]. The most important extension is the Mobile-Home authentication extension,
which is required in every registration in order to allow the home agent to prevent fraudulent
remote redirects [7]. The home agent maintains an up to date list of all mobility bindings
(pairs of Mobile Nodes home addresses and Care of Addresses) and confirms that the
registration has been accepted using the Registration Reply Message. This message is also
sent to the UDP port. The home agent must be configured such that it does not accept a mobile
node if it does not have the necessary resources. The home agent must always be ready to
serve the mobile agent that it serves. Also the foreign agent must constantly advertise its
availability packet, this way a mobile node will know that they have not moved away from
6. it. A mobile node may send out solicitation packets, but this must only be done in the absence
of agent advertisement packets and if a care of address has not been determined by link layer
protocol.
Registrations in Mobile IP must be made secure so as to prevent any fraudulent registrations
from being accepted. If this were to happen a malicious user could gain access to a session
and disrupt communication between the home agent and mobile node. To avoid any malicious
user gaining access, an unforgeable value along with the registration that changes for every
new registration. In order to make each one different, a time stamp or newly generated random
number is inserted into the identification field. The home agents and mobile nodes have to
agree on reasonable values for the timestamp, and protocol for resynchronization [7]. If a
registration reply with an invalid non-zero UDP checksum is received it must be silently
discarded.
There are three authentication extensions defined by mobile IP:
Mobile-Home authentication extension
Mobile-Foreign authentication extension
Foreign-Home authentication extension
The Mobile-Home authentication extension is required in all requests and replies. The SPI
within any authentication extension defines the security context used to compare and check
the authentication algorithm [7]. The job of the SPI is to select an authentication algorithm
and mode and a shared or public/private key pair which is used to verify the mobile node.
Keyed-MD-5 in prefix suffix mode is the default authentication algorithm used.
Once a care of address has been registered with the home agent, all packets that are destined
for the mobile nodes original IP are intercepted by the home agent and sent to the care of
address using a technique called tunneling.
2.3 Tunneling, Routing and ARP
Tunneling is a process by which one IP packet is encapsulated within another IP packet and
transported over a channel. The tunneling can be done by various algorithms but the default
algorithm which must always be supported is simple IP within IP encapsulation by both the
home and foreign agents. If the care of address is a co-located then the mobile node must
also support IP within IP encapsulation. Minimal encapsulation and GRE encapsulation can
also be used.
The encapsulation can be seen in Figure 3. In it we can see that an IP datagram is
encapsulated by preceding it with a new IP header which is called the tunnel header. The
encapsulating header indicates the presence of another datagram within it by using the value
4 in the outer protocol field. No modifications are made to the inner datagram, except that its
TTL is reduced by1. Once a datagram is intercepted by the home agent it is encapsulated by
it and tunneled to the care of address, received at the tunnel end and finally delivered to the
7. node. In the reverse direction datagrams are sent and delivered using standard IP
configurations.
Figure 3. IP-within-IP
encapsulation [7].
It is the job of every Home Agent to intercept every packet that was addressed to the mobile
node. This is done using a variation of the Address Resolution Protocol (ARP), this is called
proxy ARP. Proxy ARP is a variation of ARP wherein a node responds on behalf of another
node to and ARP request. It is likely that most of the nodes which have been communicating
with mobile node on the home network have an ARP cache of that nodes address. This
address becomes invalid or stale once the node moves to a foreign network. If the home agent
receives an ARP request that ask for the mobile nodes link address it must reply to them
using the proxy ARP. It must be noted that the home agent will only carry out proxy ARP
for nodes for which it is the home agent. It makes sure of this by checking the destination
address on the ARP packet with the list of addresses for which it is the home agent. Once it
confirms it is required to reply home agent will flip the sender and target address of the ARP
packet. It must also set the link address of the sender as its own link address over which the
reply will be sent.
When a mobile node registers with a foreign node and registers a binding with the foreign
agent, the home agent is required to send out a gratuitous ARP message to all the nodes on
the home network of the home agent. This causes all the nodes in the network update their
cache which contains the link address of the mobile agent to the link address of the home
agent. This message is sent as a broadcast message, and should be sent a few times because
there is a possibility of the packet not being delivered on local networks such as Ethernet.
When the mobile node returns to its home network, it must send out a gratuitous ARP to
update the caches of the nodes on the home network. It is after doing this that the mobile
node will send out a (de)Registration Request to its home agent. Once the home agent
receives this packet it must send out its own gratuitous ARP packet with the mobile nodes
link address as the home address for the mobile node. One thing that the mobile must never
do while away from its home network is reply to an ARP message. It must also never send
out an ARP request message.
2.4 Security Considerations
One of the main things that needs to be considered while discussing Mobile IP is security.
Most devices using this protocol will be connected to the network wirelessly, and this is one
8. of the fundamental differences between this network and regular computing networks. This
also poses a greater security issue.
The default algorithm used for generation of keys is HMAC-MD5 with a key length of 128
bits or greater. This must be supported by all participating parties of the communication link
[8].
One major step taken to prevent a malicious host getting control of the communication, is
Replay Protections against Registration Requests. The identification field is used to let the
home agent verify that a request is a fresh one and not one which has been replayed by an
attacker. There are two methods by which this is done, Timestamps (mandatory) and Nonces
(optional).
1. Timestamp based Replay Protection: The basic operating principle for this method
is that the sending node inserts its current time when transmitting the packet. The
receiving node will check the time in the packet and compare it to its own current
time and see if the two values are close enough. Unless specified during the
registration the default value of 7 seconds can be used. Whenever a registration
request is received the home agent must compare the tie in the identification and its
own clock and check if it is close enough. It must also check that the time is after all
previously accepted timestamps for the particular mobile node.
2. Replay Protection using Nonces: The basic operating principle for this method is that
Node X sends a random number to Node Y, the next message that is sent by Node Y
to Node X must contain the same random number. An authentication code is used to
prevent any attacks from an attacker. Node Y can also send a nonce in each of its
messages to Node X which must be relayed in each message by node X for Ys
verification. If a registration is rejected due to an incorrect nonce, a new nonce is sent
in the reply. This way nonce protocol is self-synchronizing.
2.5Problems with MIPv4
Security: One of the major problems that plagues MIPv4 is the security aspect.
Prefix+Suffix MD5 is quite easily cracked by a trained attacker and does not
provide enough security. Wherever possible Keyed MD5 should be used as an
additional algorithm since it precludes most of the attacks that are known to
happen to MIPv4 networks.
Triangular Routing: Another major problem that faces MIPv4 is triangular
routing. In MIPv4 all communication to the mobile node must go through the
home agent. Therefore even in the case where the correspondent node is on the
same network as the mobile agent the message must will go through the home
agent before they are tunneled to the mobile agent. This reduces the efficiency of
the network and adds an unnecessary transmission time. This problem can be
solved using Route Optimization which is discussed later on.
9. Figure 4. Triangle Routing Problem [2].
Duplicating fields in “IP within IP”: When we send a datagram in MIPv4, it is
encapsulated within another IP packet, thus the entire message consists of the
original datagram along with the outer header, and this creates unnecessary
overhead in the message size. Also a lot of fields from the inner datagram are
duplicated in the outer datagram which again adds to the overhead. One way to
overcome this problem is to use minimum encapsulation which will only replace
the original destination address with the care of address of the mobile node.
However this method cannot be used if the datagram is fragmented.
Single Home Agent: This is one of the less complicated problems with MIPv4. If
the home agent was to stop functioning for some reason, then the mobile node
would become unreachable. A way to avoid this would be to have more than one
home agent for the mobile nodes.
3 Mobile Internet ProtocolVersion6
To overcome some of the shortcomings of MIPv4 the IETF has been developing MIPv6 as
an improvement. The key advantage offered by MIPv6 stems from the fact that it is based
on IPv6 in which IP addresses are 128 bits long, mobility support in MIPv6 solves many
problems such as tunneling and ingress. However it does not attempt to solve some
problems such as mobile routers, services discovery and distinguishing between packets
lost due bit errors and congestion.
3.1 Terms
A lot of the terms used in Mobile IPv6 are similar to the ones used in Mobile IPv4, the
important ones are listed here.
Binding: A binding is an association between a home agent and a mobile node. It contains
the mobile nodes care of address and the time for which the address is valid.
10. Cookie: It is a random number used by a mobile node to prevent spoofing by a bogus
correspondent node in the return routability procedure.
Return Routability Procedure: It authorizes registration based on cryptographic token
exchange.
Keygen Token: A number which is supplied by the correspondent node in the return
routability procedure for the mobile node to compute the necessary binding management
key so that a binding update can be authorized.
3.2 Basic Operation
In Mobile IPv6, mobile nodes assign their network interface with 3 addresses. These
addresses are required at times when they are roaming away from their home network. The
three addresses are, The Home address- the address which is permanently assigned to it just
like a stationary node on the internet. The second is the nodes current link local address and
the third is nodes care of address which it has acquired on the foreign network. The care of
address can acquired through standard Ipv6 mechanisms such as stateless or stateful auto-
configurations. As long as the mobile node remains on this foreign network all packets routed
to the care of address will be forwarded to the mobile node. An association between the
mobile node and its home node is known as a binding. When a mobile node leaves its home
network it asks a router on the home network to behave as a home agent for it as in MIPv4.
This is done by sending a binding update to the home agent who replies with a binding
acknowledgement.
Nodes that are communicating with the mobile node can also be informed of the mobile nodes
new care of address. This is done through correspondent registration. As a part of this
procedure return routability test is performed to confirm whether the correspondent node can
be trusted or not and whether a binding update should be sent to the correspondent node or
not.
There are two ways through which a correspondent node can communicate with a mobile
node. The first is a bidirectional tunnel, whose operation is similar to that of MIPv4. In this
method, the mobile node does not send a binding update to the correspondent node and the
node just normally sends packets to the mobile nodes IP address. The home agent tasked with
making sure that all such packets reach the mobile node intercepts the packet and tunnels it
to the care of address registered to it and the packet is delivered to the mobile node from there
on. Packets sent by the mobile node to the correspondent node are reverse tunneled to the
correspondent node. The mobile node sends a packet to the home agent who then forwards it
to the correspondent node. This method of communication is called “Bidirectional
Tunneling”.
The second method is called “Route Optimization”. The main idea behind route optimization
is that the routes from correspondent nodes to the mobile nodes can be improved if they if
the correspondent node has an up-to date mobility binding for the mobile node in its routing
table [7]. With an updated mobility binding the correspondent node can tunnel packets
11. directly to the mobile node by encapsulating the intended packet in a packet with the IP
header having the car-of address. This way it would avoid having to send packets and
datagrams to the home agent and then have it tunnel packets to the mobile node, thus
improving the efficiency of communication. However it must be taken into account that the
required that the correspondent node has to be sure of the authenticity of the updates. If not
then the correspondent node will be sending its packets to a malicious third party and thus it
will compromise the security of the communication.
A basic protocol proposed is as follows [7]:
A binding warning control message may be sent to the home agent indicating that the
correspondent node does not know the new care of address of the mobile node.
The correspondent node may send a binding request.
The home agent will then send an authenticatedbinding update containing the mobile
nodes care of address.
A binding acknowledgement is given by the recipient for smooth handoffs.
It should be noted that the binding updates and binding warning messages should not be sent
out blindly without any regards for past history.
MIPv6 also provides the option of having multiple home agents which prevents the mobile
node from being unreachable if its primary home agent goes down.
3.3 Return Routability Procedure
This process allows the correspondent node to determine that the mobile node is in fact
addressable at the care of address it advertised as well as its home address. Only once this
has been determined will the correspondent node be able to send all data for the mobile node
to the claimed care of address.
This is done by testing whether packets sent to both the addresses are routed to the mobile
node or not. The mobile node can only pass this test if it can prove that it has received certain
data, called keygens, which was sent by the correspondent node.
The message flow in this process is as follows:
1. The mobile agent will send a Home Test Init (HoTI) and Care of Test Init (CoTI)
message to the correspondent node.
2. The messages are received by the correspondent node and processed by it.
3. The correspondent node sends the messages back to mobile node one Home Test
(HoT) and one Care of Test (CoT).
Both the messages sent by the mobile node are sent at the same time and require little
processing on the part of the correspondent node.
The Home Test Init message is sent to the correspondent node via the Home Agent, and is
sent so that the mobile agent can obtain the home keygen token. The message contains only
the source address, destination address and the home init cookie. This cookie must be
returned to the mobile node later on. This message is reverse tunneled through the home
agent.
12. Figure 5. Return
Routability Test messages [9].
The Care of Test Init message is sent to the correspondent node directly. The message format
remains the same and the only difference is that in place of the Home Init Cookie a Care of
Init cookie is sent. Again the cookie must be returned to the mobile node. The mobile keeps
track of the values of the cookie, so that it can make sure that the messages it is sending are
in fact being processed by the desired correspondent node.
The Home Test message is in reply to the HoTI, and is sent via the home agent. This
messages contains first and foremost the Home Init Cookie, which has to be there to confirm
to the mobile node that the message is being sent by an intended correspondent node. The
message also contains the Home Keygen Token and Home Nonce Index.
The Home Keygen Token is as follows:
First (64, HMAC-SHA1(kcn(Home Addresss|nonce|0)))
Here the | indicates concatenation and the 0 is used to distinguish the Home Keygen from
the Care of Token. The keygen is made by using the first 64 bits of the MAC. The kcn is
used so that the correspondent node can verify that it has generated the home and care of
nonces, without forcing the node to remember all the values. The nonce index is also sent to
the mobile node so that the correspondent node can find the nonce value it used to generate
the home keygen token.
The Care of Keygen Token is as follows:
First(64, HMAC_SHA1(kcn( Home address|nonce|1)))
The 1 at the end of the message is sent to distinguish it from the Home Keygen Token. The
rest of the message is generated in more or less the same way. The message contains the
nonce index along with the Care of Cookie to verify it was in fact sent the message.
Once the Mobile Node receives both messages, the procedure is completed and it can send
a binding update to the correspondent node. This is done by hashing together the two tokens
to create a 20 octet binding key Kbm.
13. When a binding update is sent it contains a sequence number and MAC. Both these fields
prevent the participants from being subject to replay attacks and replayed binding updates.
Correspondent nodes however must be careful while discarding any bindings because some
bindings have nonces which are still valid and hence cannot be completely discarded.
Figure 6. Movement of Binding
messages [9].
In the case where both the mobile node and the correspondent node are mobile some
problems can arise. In this case return routability signaling is sent to the correspondents
home agent, if it has on, and not to its care of address.
Return Routability is a very important part of the MIPv6 protocol and therefore its security
is extremely important. To ensure that packets sent from the home agent to the mobile node
the packets must be encapsulated securely. Therefore the home agent must be capable of of
supporting IPsec ESP for tunneling these packets. Support of non-null encryptions transform
and authentication algorithms must also be supported [8].
3.4 Handoffs
Mobile nodes keep changing their point off attachments in the internet. Thus it is imperative
that the transition from one connection to another be done smoothly so as to not lose out on
any datagrams that were sent to an old care of address, but are now will be dropped because
the node has now moved to a different point in the internet. Moreover a study of TCPs
working shows that the dropping of datagrams is magnified greatly.
However, using route optimization we can attain smooth handoffs. Former foreign nodes can
maintain a binding with former mobile visitors. This way even if packets are delivered to the
old care of address the mobile host might still receive them courtesy of the binding that exists.
In order to maximize the benefit from using route optimization on handoffs, we should avoid
any involvement of the home agent. This is because the home agent is too far in most cases
and by the time it reacts there might be a large amount of data which is lost.
When a mobile node leaves one foreign agent for another, it can instruct the new foreign
agent to send a binding to its old one. If no fresh binding update is sent to the old foreign
agent it can just deliver the datagram to the home agent for further handling. Such action
could however in theory cause a routing loop. Instead route optimization defines a way to
use special tunnels, which indicate to the home agent the need for special handling. When a
foreign agent send a datagram to the home agent, it lists the source address as the care of
14. address of the foreign address in the newly encapsulated datagram. Now when the datagram
is received by the home agent, it compares the source address with the latest care of address
it has received from the last binding update. If the two addresses match then the home agent
is not required to resend the packet. However if they do not match it is required to tunnel the
decapsulated packet to the new care of address.
An important point to note is that whenever a binding update is transmitted, it must be
accompanied by an authentication extension. This is however when we consider smooth
tradeoffs, mainly because foreign agents are considered as anonymous identities who cannot
be trusted for anything other than following protocol. Thus a mobile node and a foreign agent
do not share any secret. However when a new binding update is sent to the foreign agent
from the mobile nodes new foreign agent, there must be some way to verify that this has not
been forged. Usually when the foreign agent advertises its availability, its flags give an
indication of the security that it can provide to the mobile node. The mobile node will select
one of the menu of possible actions. The foreign agent then responds to the mobile nodes
request and will later if necessary cooperate with the mobile node for a smooth handoffs.
Usually for security the home agent provides a security key. This can be done in two ways,
one if the home and foreign agent share a security association or if they do not have any such
association. In the former case, the home agent picks a suitable number and encrypts it using
the shared security association, and transmits it back to the foreign agent as part of the
registration reply. The home agent also notifies the mobile node about the key value. In the
latter case, usually the foreign agent sends a public key to the home agent along with the
registration request and the home agent follows the same steps as before. If the foreign agent
does not have a public key and does not have any security association with either the home
agent or the mobile node, a Diffie-Hellman key exchange is possible [7].
4 Comparative Analysis
A comparative study of the two protocols is now presented. The results shown a have been
obtained by simulations of both MIPv4 and MIPv6 protocols on the computer using
softwares. The papers used as reference for these results have been clearly cited and listed
in the bibliography.
A comparison of the two protocols is done on some important parameters such as
Throughput, Handover Latency, Percentage of Packets Delivered Correctly, End to End
Delay and Time of delivery. An analysis of all the results obtained has been provided to try
and determine the reasons for the results.
The simulation for MIPv4 is done using a software Network Simulation 2 (NS2.33) and he
one for MIPv6 is done on an NS2.33 extension MOBIWAN.
15. Figure 7.
Simulation Topology [4].
As can be seen from the simulation topology, there is one Mobile Host which is seen moving
through 4 networks. BS1 is acting as a Home agent while others act as Foreign Agents.
There is only on Correspondent Node which is trying to communicate with the Mobile
Agent.
Throughput: Throughput is defined as the rate at which data is processed in a specified
amount of time. The following figure shows the throughput of the two protocols as a function
of time.
17. Analysis: As can be seen from the above diagrams the average through put of MIPv4 is
about 90,000bits/second and that of MIPv6 is just above 250,000bits/second. The graphs
however are not a clear representation of the actual case. This simulation was done in a
situation which maximised the throughput for both cases, however there are many cases
wherein MIPv4 outperforms MIPv6. MIPv6 will not perform well for messages smaller than
512 bytes, which is primarily due to the large overhead in the MIPv6 header [11].
Packet Delivery Ratio: Packet Delivery Ratio is the ratio of received packets to the number
packets transmitted.
Figure 10.PDR of the two protocols [4].
Analysis: As can be seen the delivery ratio is not that different between the two protocols.
This implies that both protocols are just as reliable in transmitting data over the internet. The
reason behind this high level of reliability is that the usual protocol used in conjunction with
IP is TCP. When a packet is dropped in TCP it is usually retransmitted to ensure all the data
is received by the destination. The few packets that are lost are usually due to noise burst
and fading in the channels.
Average End to End Delay: Delay is the amount of time it takes for the packet to get to the
mobile node from the correspondent node.
Figure 11.Average End-to-End Delay of the two protocols [4].
Analysis: As can be seen from the numbers there is stark contrast in the Average End-to-
End Delay between the two protocols. The reason for this is two-fold.
1. In MIPv4, packets have to go through the Home Agent to be sent to the Mobile Node.
This problem of Triangle Routing is the reason for the high average end-to-end delay.
Since all the packets first go through the have to traverse two separate links before
they reach their destination the delay increases. This also increases the chances of
packets being dropped due to a faulty channel and the chances of them being damaged
in transit, causing further delays in processing time which adds to the overall delay.
2. IN MIPv6, the main reason for improved performance in terms of delay is the
implementation of Route optimization. Route optimization allows the correspondent
node to communicate with the mobile node if it has a binding with that node. If it
does not then the correspondent node can request a binding from the mobile node.
18. This greatly reduces the transit time of the packets and improves the efficiency of the
protocol.
A second test setup was referred to examine the Handover Latency of the two Protocols.
This test setup is shown below.
Figure 12.Test Setup to Measure Handover Latency [12].
Handover Latency: When the mobile node moved away from the home network to a
foreign network and the mobile node loses connection with the node while it sets up a
connection foreign node is called Handover Latency. The results for the experiment using
the above setup is show below.
Figure 13.Handover Latency of MIPv4 on the left vs HandoverLatency of MIPv6 on the right [12].
Analysis: As can be seen from the two graphs the latency is definitely less in the MIPv4
graph, as indicated by the smaller valley in the graph. This is because in MIPv6 the node
will confirm that it is no longer in contact with its home agent or previous care of agent by
running a Neighbor Unreachability Test before starting a search for a new care of address.
Following this there is slightly more complex procedure for acquiring a new care of
address, therefore this increases the time for the mobile node to find a new care of address.
4.1 Comparison
MIPv4 MIPv6
Lower Handover Latency Higher Handover Latency
19. Suffers from Triangular Routing Supports Route Optimization to reduce
effect of Triangular Routing
Does not support multiple Home Agents Supports multiple Home Agents
Does not use IPsec and relies on its own
security mechanisms
Uses IPsec for all security requirements
including Binding Requests
Has better Throughput for messages less
than 512 bytes [11].
Better Throughput for messages greater
than 512 bytes [11].
5 A Critique of MIP Naming and Addressing
A major issue seen by people in the Internet and Router manufacturing industry is the
increasing size of the internet. No one expected it to be so popular and grow at such an
exponential rate. Now apart from the exhaustion of IPv4 addresses another problem
catching the eye of experts is the growing size of router tables. This issue is arising because
every time a node moves from one network to another it sends out a new binding which is
being updated in all the routers. Due to this the routing tables keep increasing with different
routes and addresses which causes an increase in hardware for routers, which also in turn
increases the complexity of the network.
A simpler model of naming and addressing was suggested by John Soch and expanded
upon by J. Saltzer. In this mode of addressing, each node will have three hierarchical
addresses whose scope increases with the level of the address.
The logic used was to structure the addresses in a way that was similar to the way operating
system addresses were done. The highest layer would be the Application Layer, this layer
would have a fixed name and would be location independent. The second layer would be
the Node Address and would be location dependent and finally Point of Attachment
Addresses would be route dependent.
The basic idea here is to eliminate some of the big flaws that plague the IP model of
addressing. In this model bindings only change the Point of attachment address and not the
network address and home address as in the case of MIP. Here when a node moves only
the POA is changed and updated to the directory. Routes are computed by finding the next
POA and a list of all POA of neighboring hosts is done to facilitate fast movement of
packets.
By having the application name location independent we can eliminate the role of the home
router since this address is always constant. If a particular node is looking for an application
and cannot find it, it can ask a second node if it has the applications address in its routing
table. If so the data is exchanged and communication is carried out. When routing is done,
instead of having multiple addresses in its address field (IP tunneling) it can just have one
address and let the POAs determine where the packet should be routed using data in their
directory. This will greatly reduce the packet size which can in turn improve the throughput
of the system since less redundant data is sent per packet. A simple way to avoid packets
reaching a POA after the device has changed its POA is for it to also carry the name of the
application so that if it has changed it can simultaneously be routed to the new POA which
would have been update in the current locations directory [12][13].
20. This is just a basic description of a larger idea which has a lot of potential to solve some
fundamental problems of the current addressing protocols being followed.
6 Conclusion and Future Work
With the exponential increase in number of mobile devices being connected to the internet
it was imperative for the IETF to come up with a mobility management protocol.
MIPv4 was a brilliant first attempt at Mobility Management. MIPv6 used the failings of
MIPv4 to develop into a slightly better protocol with many protocols coming as a
modification of MIPv6 such as Fast MIPv6 which deal with handoffs better than both the
previous protocols. MIPv6 is being tipped as the protocol for the future of mobility
management mainly due to the face that it can provide infinite addresses unlike MIPv4
which unfortunately was exhausted at the start of the decade.
With the future of the world being the Internet of Things, MIPv6 has been seen as the
solution for that primary problem. The issue being the overhead in the header creates a
problem and will be a big obstacle to overcome along with the requirement of IPsec to be
implemented in the protocol.
In line with this, a mobility management protocol called MMIP6 is developed in order to
control the mobility of vehicles [3]. MMIP6 is based on the principles of MIPv4 but
designed for MIPv6 organized in ad-hoc networks.
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