Introduction to Mobile IPv6. Major Differences between MIPv4 and MIPv6 No FA in Mobile IPv6 Mobile...
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Transcript of Introduction to Mobile IPv6. Major Differences between MIPv4 and MIPv6 No FA in Mobile IPv6 Mobile...
Introduction to Mobile IPv6
Major Differences between MIPv4 and MIPv6
No FA in Mobile IPv6 Mobile IPv6 requires every mobile node
to support IPv6 Decapsulation Address Autoconfiguration
Major Differences between MIPv4 and MIPv6 (cont.)
Packets delivery MIPv6 mobile node uses care-of address as
source address in foreign links No ingress filtering problem
Correspondence Node uses IPv6 routing
Supports “Route Optimization” naturally
Basic IPv6 Address Typesunicast:
for one-to-onecommunication
multicast:for one-to-manycommunication
anycast:for one-to-nearestcommunication
M
M
M
A
A
A
U
Relevant Features of IPv6
Address AutoconfigurationStateless autoconfiguratoin
Network Prefix + Interface ID
Stateful autoconfiguration DHCPv6
ICMP RoleWhen an IPv6 node discards a
packet, it sends an error message to the source. There are four types of message:
1. Destination unreachable (type=1). Sent by a router to the source when a packet cannot be forwarded to its destination.
2. Packet too big (type =2). Used when the link MUT on the forwarding link is smaller than the packet.
3. Time exceeded (type=3). Indicates that the packet's hop limit field is zero.
4. Parameter problem (type=4). Indicates that a field of the datagram is not recognized as valid and the packet can thus not be processed.
Mobile Node
message Back
Error Message
R
R
Network C
ICMP: Includes the so-called Neighbor Discovery mechanisms, the terminal autoconfiguration mechanisms and address resolution mechanisms.
Mobile IPV6 Transparency Link To achieve Transport layer transparency for the home address while the mobile
node is assigned a care-of address, Mobile IPv6-capable nodes use the following
If a correspondent node is not Mobile IPv6-capable, then packets sent between the correspondent node and the mobile node that is away from home are exchanged via the home agent. The correspondent node sends packets to the mobile node's home address. These packets are intercepted by the home agent and tunneled to the mobile node's care-of address.
Mobile IPv6 Components
Mobile IPv6 Components□ Home agent
Maintain registrations of mobile nodes that are away from home. Tunnels
data sent to the mobile nodes’ address to the mobile node’s home address
to the mobile node’s current address and forwards tunneled data sent by
the mobile node.
□ Home link
The link that is assigned the home subnet prefix, from which the mobile node
obtains its home address.
□ Foreign link
A link that is not the mobile node’s home link.
□ Mobile node
A node that can change its point of attachment from one link to another,
while still being reachable via its home address.
□ Correspondent node
A peer node with which a mobile node is communicating. The correspondent
node may be either mobile or stationary.
Mobile IPv6 Components□ Care-of address
A unicast routable address associated with a mobile node while visiting
a foreign link.
□ Binding
The association of the home address of a mobile node with a care-of address
for that mobile node.
□ Movement
A change in a mobile node’s point of attachment to the internet. If a mobile
node is not currently attached to its home link, the mobile node is said to
be “away from home”.
Mobile IPv6 Data Structures
□ Binding Cache The binding cache is a table maintained by each correspondent node and home agent that contains the current bindings for mobile nodes .□ Binding Update List The binding update list is maintained by a mobile node to record the most
recent binding updates sent for the home agent and correspondent nodes. □ Home Agent List Home agents maintain the home agents list so that they can send the list of home agents to a requesting mobile node away from home during home agent address discovery.
TunnelingDecapsulationEncapsulation
SourceDestination
Tunnel: The path followed by a datagram while it is encapsulated. While encapsulated, a datagram is routed to a knowledgeable agent, which decapsulates the datagram and then forwards it to its ultimate destination.
Return Routability Procedure
□ Home test init ▪ Source Address=home address ▪ Destination Address=correspondent ▪ It is reverse tunneled through the home agent. The mobile node also sends along a home init that the correspondent node must return later. ▪ To assurance that its protocol message are being processed by the desired correspondent node.□ Home test ▪ Response to a home test Init message. ▪ This means that the mobile node already have sent a binding update to the home agent.
Return Routability Procedure□ Care-of Test Init ▪ Source address=care-of address ▪ Destination address=correspondent ▪ The mobile node sends test init message to correspondent node directly and correspondent node must return later.□ Care-of Test ▪ Response to Care-of test init message. ▪ Verify that the mobile node is reachable at the care-pf address.□ Detecting correspondent nodes not mobile IPv6-capable ▪ If CN is not mobile IPV6-capable, it will not recognize message sent by mobile node. Mobile node records the CN lack of support for mobile IPv6 in binding update list. Packet sent to CN via home
agent.
Return Routability Procedure
Mobile IPv6 Operation
Movement DetectionWhile away from home, an MN selects one
router and one subnet prefix advertised by that router to use as the subnet prefix in its primary care-of address
Mobile IPv6 Operation (cont.)
Home Agent Registration
筆記型電腦
電腦
路由器 Internet
路由器
路由器
工作站
Home Agent
Correspondent Node
Mobile Node
Router
Router
Router
Home LinkLink A
Link B
Link C
(1)Binding Update(2)Binding Acknowledgement
(1)
(2)
Indirect delivery via Home Agent (bidirectional tunneling)
Indirect delivery via Home Agent (bidirectional tunneling)
Direct delivery (Route Optimization)
Mobile Node Initiates Communication with a New Correspondent Node
Binding Request
Binding (both at HA and CN) has a life-time. MN is expected to update
HA within this time. CN is requested to seek up
dates.
Mobile Node
Binding Update
Binding Request
R
R
Network C
Correspondent.Node C
InternetMobile Node
Home Agent 2
Home Agent 3
Mobile Node sends Binding Update to the Home AgentsAnycast Address of its home network
One Home Agent answers containing a list of available Home Agents
Home Agent 1
R
R
Home Agent 3 9Home Agent 1 2Home Agent 2 -3
Home Agents List Priority
Dynamic Home Agent Address Discovery
Mobile Node sends Binding Update to the first Home Agentcontained in the Home Agents List
Binding Acknowledgement completes Registration process
InternetMobile Node
Home Agent 2
Home Agent 3
Home Agent 1
R
R
Home Agent 3 9Home Agent 1 2Home Agent 2 -3
Home Agents List Priority
Registration at selected Home Agent
Handover
Three kinds of handover operationsSmooth Handover
Minimizes data loss during the time that the MN is establishing its link to the new access point
Fast Handover Minimizes or eliminates latency for establishing
new communication paths to the MN at the new access router
Seamless Handover Both Smooth and Fast Handover
Summarizes
□ Easy to Implemention.□ Dynamic home agent address discovery mechanism in mobile IPV6 returns a single replay to the mobile node.□ Most packets to a mobile node while away from home in mobile IPV6 are sent using an IPV6 roting header rather than IP encapsulation, reducing the amount of resulting overhead compared to mobile IPV4.□ Support for route optimization is a fundamental part of the protocol ,rather than a nonstardard set of extensions.□ Mobile IPV6 will be an important feature of the next generation Internet.