2002 IPv6 技術巡迴研討會 IPv6 Mobility

Agenda Mobile IP Overview Mobile IPv4 IPv6 and Mobile IPv6 Current status of MIPv4 and MIPv6 Mobile IP in GPRS, 3GPP and 3GPP2 Mobile IP and WLAN

What is Mobile IP ? C. Perkins, “IP Mobility Support”, RFC 2002 Each mobile node is always identified by its home address, regardless of its current point of attachment to the Internet protocol enhancements that allow transparent routing of IP datagrams to mobile nodes in the Internet

Why we need Mobile IP ? Change point of attachment & identified by its home address I want to access Internet. I need an IP address OK, I can offer you DHCP (dynamic host configuration protocol) + NAT (network address translator) No, some special applications such as SIP(Session Initiation Protocol) and NAT are conflict. I need a global unique IP address OK, I can give you DHCP without NAT I need a permanent IP address Why ? ….

Why we need Mobile IP ? (Cont.) If you really need to change your point of attachment but don’t want to change your IP address, why IP is not enough ? IP is based on network-prefix routing Protocol enhancements Mobile IP defines protocol enhancement to support IP mobility

Why we need Mobile IP ? (Cont.) Why do you need to change your point of attachment and also require a permanent IP ? Your devices become mobile You want to be reached by your IP even you are not in your home network Your notebook, PDA, and mobile phone become more and more powerful You want to be a server You want to build up an end-to-end secure connection in IP layer

Summary Mobile IP is an enhancement based on Internet Protocol (IP) Mobile IP is needed in case you need to to change your point of attachment and also require a permanent IP address More and more devices become wireless and mobile (based on different (radio) access technologies) More and more devices are IP-enable and IP-addressable Different (radio) access technologies are co-existing and share the same IP backbone More and more devices request a permanent IP address More and more service need customers to have a permanent IP address L2 mobility is managed by L2 technologies and Mobile IP handles IP mobility (L3 mobility)

Host D IP:140.96.102.49 Subnet Mask : 255.255.255.0 Router B Host C Port D:140.96.102.254 Port C :140.96.103.253 Host D IP:140.96.102.49 Subnet Mask : 255.255.255.0 Router B Host C IP:140.96.102.24 Subnet Mask : 255.255.255.0 Port A:140.96.104.254 Port B :140.96.103.254 Host A IP:140.96.104.49 Subnet Mask : 255.255.255.0 Router A Host B IP:140.96.104.24 Subnet Mask : 255.255.255.0

Host D IP:140.96.102.49 Subnet Mask : 255.255.255.0 Router B Host C Port D:140.96.102.254 Port C :140.96.103.253 Host D IP:140.96.102.49 Subnet Mask : 255.255.255.0 Router B Host C IP:140.96.102.24 Subnet Mask : 255.255.255.0 Port A:140.96.104.254 Port B :140.96.103.254 Host A IP:140.96.104.49 Subnet Mask : 255.255.255.0 Router A Host B IP:140.96.104.24 Subnet Mask : 255.255.255.0

IP Routing (Cont.) Host D IP:140.96.102.49 Subnet Mask : 255.255.255.0 Port D:140.96.102.254 Port C :140.96.103.253 Host D IP:140.96.102.49 Subnet Mask : 255.255.255.0 Router B Host C IP:140.96.102.24 Subnet Mask : 255.255.255.0 Port A:140.96.104.254 Port B :140.96.103.254 Host A IP:140.96.104.49 Subnet Mask : 255.255.255.0 Router A Host B IP:140.96.104.24 Subnet Mask : 255.255.255.0

Mobile IP Operations Overall Architecture

Mobile IP Operations (Cont.) A basic scenario A MN is in its home network It moves to a visit network Somebody, say CN, wants to make a connection with the MN by using its home IP address

Mobile IP Operations (Cont.) Step 1 : Agent advertisement Sent by HA Let MN know HA’s IP MN Store HA’s IP

Mobile IP Operations (Cont.) Step 2 : MN moves to a visit network

Mobile IP Operations (Cont.) Step 3 : Agent advertisement Sent by FA Let MN know it moves to a foreign network Let MN know its new CoA MN Stores CoA

Mobile IP Operations (Cont.) Step 4 : MN Sends registration request to FA Get registration reply from FA FA Relay Reg-Req to HA HA reply Reg-Reply to FA

Mobile IP Operations (Cont.) Step 3’ : MN does not get agent advertisement or FA registration is not required MN Got CoA from DHCP

Mobile IP Operations (Cont.) Step 4’ : MN Sends registration request to HA Get registration reply from HA

Mobile IP Operations (Cont.) Step 5: HA Sends reply ARP (proxy ARP) for MN

Mobile IP Operations (Cont.) Step 6: CN Initiates a connection Router Sends packets to MN IP but with HA’s MAC

Mobile IP Operations (Cont.) Step 7: HA Encapsulate the packets (IP in IP) Tunnels the packets to FA FA Decapsulate the packets Forward packets to MN

Mobile IP Operations (Cont.) Step 8: MN Reply packets to CN through router or Reply packets to CN through FA

Mobile IP Operations (Cont.) Step 8’: MN Sends packets to FA FA tunnels packet and sends to HA HA Decapsulate packets Forward to CN

Mobile IP Operations (Cont.) Step 9: MN Moves back to home network Deregistration its CoAs

Mobile IP Operations (Cont.) In detail (FA/HA) Agent Discovery Registration procedures Packet tunneling

Mobile IP Operations (Cont.) Agent Advertisement Tell MN its location Notify MN with CoA Agent Solicitation Ask agent info

Route optimization & Smooth Handoff Triangle Routing

Route optimization & Smooth Handoff (Cont.) Binding cache

Route optimization & Smooth Handoff (Cont.) Situation 1 Response to a Binding Request message

Route optimization & Smooth Handoff (Cont.) Situation 2 Response to a Binding Warning message

Route optimization & Smooth Handoff (Cont.) Situation 3 Reception of a packet destined for a mobile node

Route optimization & Smooth Handoff (Cont.) Smooth/fast/seamless handover Smooth handover  low loss Fast handover  low delay 30 ms? Seamless handover  smooth and fast

Route optimization & Smooth Handoff (Cont.) Packet lost

Route optimization & Smooth Handoff (Cont.) MN notifies its previous FA FA maintain MN’s binding cache Registration req. extension

Route optimization & Smooth Handoff (Cont.) Packet retunnel

Security Issues (Cont.)

Comparisons of Mobile IPv4 and Mobile IPv6

Mobile IPv6 Operations Overall Architecture

Mobile IPv6 Operations (Cont.) Step 1 : Router advertisement Sent by router Let MN know its location Tell MN HA’s IP MN Store HA’s IP

Mobile IPv6 Operations (Cont.) Step 2 : MN moves to a visit network

Mobile IPv6 Operations (Cont.) Step 3 : Router Router advertisement MN Obtain stateless address by Auto-configuration Stores CCoA

Mobile IPv6 Operations (Cont.) Step 3’ : MN Got stateful CCoA from DHCPv6

Mobile IPv6 Operations (Cont.) Step 4 : MN Sends Binding Update to HA Get Binding Acknowledge from HA

Mobile IPv6 Operations (Cont.) Step 5: HA Sends reply ARP (proxy ARP) for MN

Mobile IPv6 Operations (Cont.) Step 6: CN Initiates a connection Router Sends packets to MN IP but with HA’s MAC

Mobile IPv6 Operations (Cont.) Step 7: HA Encapsulate the packets (IP in IP) Tunnels the packets to MN

Mobile IPv6 Operations (Cont.) Step 8: MN Reply packets to CN through router or Piggyback Binding Update

Mobile IPv6 Operations (Cont.) Step 9: MN Moves back to home network Receive Router Advertisement Send BU to HA and CN

Mobile IPv6 Operations (Cont.) Step 10 Smooth handover Send BU to HA in previous network Use more than one CoA at the same time Receive packets from all CoAs Packets may send to Home IP, previous CoA, and current CoA

Mobile IP current development Hierarchical mobility management Mobile IPv4 Regional Registration MN HA FA 1 Network C Network A Network B FA 2 CN

Hierarchical mobility management Mobile IPv4 Regional Registration MN HA FA 1 Network C Network A Network B FA 2 CN MN

Hierarchical mobility management Mobile IPv4 Regional Registration Reduce number of signaling message to HA Reduce delay when MN moves from one FA to another FA in the same visited network MN HA FA 1 Network C GFA Network A Network B FA 2 CN

Hierarchical mobility management Mobile IPv4 Regional Registration Step 1 : registration at the GFA and the home agent Network A Network B Network C CN MN HA FA 1 FA 2 GFA Local CoA 1 GFA address Authentication Key

Hierarchical mobility management Mobile IPv4 Regional Registration Step 2 : moves to another FA and receives Local FA advertisement MN HA FA 1 Network C GFA Network A Network B FA 2 CN MN

Hierarchical mobility management Mobile IPv4 Regional Registration Step 3 : regional registration at the GFA HA FA 1 Network C GFA Network A Network B FA 2 CN MN

Hierarchical mobility management Hierarchical MIPv6 mobility management MN HA AR1/MAP MAP Network C AR1/MAP Network A Network B CN AR : access router MAP : mobile anchor point

Mobile IP current development (Cont.) Low latency handoffs Why ? Latency involved in handoff can be above the threshold required for the support of delay-sensitive or real-time services Reduce the handoff latency By help of L2 trigger message

Low latency handoffs Low latency mobile IPv4 Handoffs architecture

Low latency handoffs (Cont.) PRE-REGISTRATION handoff protocol

Low latency handoffs (Cont.) PRE-REGISTRATION handoff protocol-Timing Diagram (Network Initiated, Source Trigger)

Low latency handoffs (Cont.) PRE-REGISTRATION handoff protocol-Timing Diagram (Network Initiated, Target Trigger)

Low latency handoffs (Cont.) PRE-REGISTRATION handoff protocol-Timing Diagram (Mobile Initiated)

Low latency handoffs (Cont.) POST-REGISTRATION handoff protocol

Low latency handoffs (Cont.) POST-REGISTRATION handoff protocol – two party handoff

Low latency handoffs (Cont.) POST-REGISTRATION handoff protocol – two party handoff timing diagram (source trigger)

Mobile IP and WLAN Portability Wireless Mobility Ubiquity Change of network attachment point Wireless Wire-less Mobility You can move Ubiquity Utilize heterogeneous wired/wireless network freely Wireless  Mobile  Mobile Wireless

Mobile IP and WLAN (Cont.) cover L1/L2 technologies Only provide wireless feature Do not have mobility management functionality Where is its L3 ?

Mobile IP and WLAN (Cont.) WLAN L3 solution Datacom Session management IP based Mobility management Mobile IP AAA Telecom GPRS SM GPRS GMM HLR/SS7

Mobile IP and WLAN (Cont.) More applications/software/features will be implemented over WLAN AP (that is what differentiate products) Mobile IP VPN NAT AAA IPSec …

Mobile IP and WLAN (Cont.) Is any problem with Mobile IP over WLAN ? Fine for data/no real-time application Problems with VPN AAA Problems with voice/real-time application Handover delay Solutions Low latency mobile IP (work in progress in IETF, but development in progress in vendor) AAA and mobile IP (work in progress in IETF, but development in progress in vendor)