Wireless Networks and Protocols MAP-Tele Manuel P. Ricardo - PowerPoint PPT Presentation

WNP-MPR-mip-mesh 1 Wireless Networks and Protocols MAP-Tele Manuel P. Ricardo Faculdade de Engenharia da Universidade do Porto

WNP-MPR-mip-mesh 2 Topics Scheduled for Today … ♦ Convergence and interoperability of wireless systems: bringing all together » 4G wireless networks » 3GPP approach » Mobile IPv6 approach – Basics on Mobile IP – 3GPP plans for adopting Mobile IPv6 – Media Independent handover » Wireless mesh – Basics on ad-hoc networks – The IEEE 802.11 mesh networks » Research issues …

WNP-MPR-mip-mesh 3 Basics on Mobile IP ♦ How to move between IP networks while maintaining a connection active? ♦ What are the differences between MIPv4 and MIPv6? ♦ How is route optimization performed in MIPv6 ♦ How does the Dual Stack MIPv6 work?

WNP-MPR-mip-mesh 4 Mobile IPv4

WNP-MPR-mip-mesh 5 Motivation ♦ IP datagram forwarding is based on IP destination address ♦ IP network address  physical network ♦ Changing network  changing IP address ♦ How to implement mobility at the IP layer? ♦ Possible solution » Register new IP address near the DNS server » Problems – DNS registration takes time – TCP connections will break

WNP-MPR-mip-mesh 6 Mobile IPv4 - Terminology ♦ MN, Mobile Node ♦ HA, Home Agent registers MN location ♦ FA, Foreign Agent agent in the visited network ♦ COA, Care-of Address MN’s IP address in the visited network ♦ CN, Correspondent Node host which communicates with the MN

WNP-MPR-mip-mesh 7 Example HA MN router home network mobile end-system Internet FA foreign (physical home network network for the MN) router (current physical network for the MN) CN end-system router

WNP-MPR-mip-mesh 8 Data transference to MN HA 2 MN home network 3 receiver Internet foreign FA network 1. Sender sends to the IP address of MN, 1 HA intercepts packet CN 2. HA tunnels packet to COA (FA) by encapsulation 3. FA forwards the packet to the MN sender

WNP-MPR-mip-mesh 9 Data transference from MN HA 1 MN home network sender Internet FA foreign network CN 1. Sender sends to the IP address of the receiver as usual, FA works as default router receiver

WNP-MPR-mip-mesh 10 Mobility phases COA router home router MN FA network HA foreign Internet network CN router 3. router home router MN 2. FA network HA 4. foreign Internet network 1. CN router

WNP-MPR-mip-mesh 11 MN – Agents communication ♦ MN identifies the network » Mobility agents send regularly messages to their networks ICMP Router Advertisement messages » MN listens messages; determines the network – Its home network, or – A visited network  MN obtains new address – the CoA ♦ In the visited network, after obtaining CoA, MN » MN sends COA to HA (via FA)  new location registered at the HA » At the home network – HA assumes the MN home IP address – Packets destined to the MN IP home address are intercepted by HA and tunnelled to the MN (CoA address)

WNP-MPR-mip-mesh 12 ICMP Router Advertisment – Mobility Extensiom 0 7 8 15 16 23 24 31 type code checksum #addresses addr. size lifetime router address 1 R – registration required preference level 1 B – FA busy router address 2 H – agent is HA F – agent is FA preference level 2 M – minimal encaspulation accepted . . . G – GRE encapsulation accepted r – not used T – FA supports reverse tunneling type length sequence number registration lifetime reserved R B H F M G r T COA 1 COA 2 . . . Message sent by mobility agents (HA and FA)

WNP-MPR-mip-mesh 13 To think about ♦ Can we remove the Foreign Agent from MIPv4? What are the consequences of it?

WNP-MPR-mip-mesh 14 MN registration in the Home Agent MN HA MN FA HA t • Co-located address • Tunnel ends at the MN • Address obtained by DHCP, for instance t

WNP-MPR-mip-mesh 15 Registration messages Type – registration request, registration reply port UDP 434 S – Maintain old binding B –broadcast messages shall be forwarded D – co-located address M – minimal encapsulation accepted G – GRE encapsulation accepted r – not used T – FA supports reverse tunneling x - ignored 0 7 8 15 16 23 24 31 type S B DMG r T x lifetime home address home agent COA identification extensions . . .

WNP-MPR-mip-mesh 16 Tunnels original IP header original data new IP header new data outer header inner header original data

WNP-MPR-mip-mesh 17 IP in IP (mandatory) ver. IHL TOS length IP identification flags fragment offset TTL IP-in-IP IP checksum IP address of HA Care-of address COA ver. IHL TOS length IP identification flags fragment offset TTL lay. 4 prot. IP checksum IP address of CN IP address of MN TCP/UDP/ ... payload Tunnel HA  COA

WNP-MPR-mip-mesh 18 To think about ♦ What is NAT (Network Address Translation)?

WNP-MPR-mip-mesh 19 NAT – Network Address Translation

WNP-MPR-mip-mesh 20 To think about ♦ Does this version of MIPv4 work when MN has a private CoA address?

WNP-MPR-mip-mesh 21 Mobile IPv6

WNP-MPR-mip-mesh 22 Mobile IPv6 – working principles ♦ Differences to MIPv4 » No ForeignAgent » Registration signalling (HomeAddress  CareOfAddress ) – Sent as an IPv6 extension header  Mobility Header – Binding relations ( HomeAddress  CareOfAddress ) recorded also in the CNs ♦ Binding messages » BindingUpdate – MN informs HA/CN of its CareOfAddress » BindingAcknowledgement – Received by MN. Confirms BindingUpdate » BindingRefreshRequest – Sent by HA/CN. Requests MN to refresh binding

WNP-MPR-mip-mesh 23 Binding ♦ MN moves to a visited network – MN auto-configures new address  COA – COA network prefix == prefix of the visited network – MN request the registration of COA in HA MN sends IPv6 packet with BindingUpdate (extension header) – HA registers MN and replies with BindingAcknowledgment ♦ Tunnel MN - HA – HA, in home networks  Intercepts packet to MN  Sends packet to COA ; by tunnel – MN  Sends packet in tunnel to HA – Tunnel terminates in the MN

WNP-MPR-mip-mesh 24 CoA autoconfiguration, in the visited network ♦ MN » Listens RouterAdvertisment messages – In mobility routers  up to 50 msg/s – Obtains network prefix » Builds address in the visited network, the CareOfAddress Routing Prefix MAC address ♦ DHCPv6 may be used by MN to obtain CoA

WNP-MPR-mip-mesh 25 Route optimization ♦ When MN receives a tunnelled packet » it sends BindingUpdate to CN ♦ HomeAddress  CareOfAddress binding – also known at the CN ♦ Then, packets are exchanged directly between MN e CN

WNP-MPR-mip-mesh 26 Route optimization ♦ IPv6 packets in direction CN  MN » CN – Before sending a packet to MN, reads its Bindings cache – Is there is no entry  packet sent as usual – If there is an entry  Sends packet to CareOfAddress (destination address = CareOfAddress )  Includes in the packet a RoutingHeade r having 2 hops (list of addresses to be visited) – 1º hop  CareOfAddress; 2º hop  MN HomeAddress » MN – Receives packet in CareOfAddress – Forwards packet to itself (MN home address) ♦ IPv6 packets in the MN  CN direction – Source address = CareOfAddress – Inclusion of DestinationHeader with information about HomeAddress – CN replaces HomeAddress in the packet source address so that the socket structure may contain the correct information  HomeAddress

WNP-MPR-mip-mesh 27 Routing Header – Packet sent from S to D, passing by I1, I2, I3 As the packet travels from S to I1: Source Address = S Hdr Ext Len = 6 Destination Address = I1 Segments Left = 3 Address[1] = I2 Address[2] = I3 Address[3] = D As the packet travels from I1 to I2: Source Address = S Hdr Ext Len = 6 Destination Address = I2 Segments Left = 2 Address[1] = I1 Address[2] = I3 Address[3] = D As the packet travels from I2 to I3: Source Address = S Hdr Ext Len = 6 Destination Address = I3 Segments Left = 1 Address[1] = I1 Address[2] = I2 Address[3] = D As the packet travels from I3 to D: Source Address = S Hdr Ext Len = 6 Destination Address = D Segments Left = 0 Address[1] = I1 Address[2] = I2 Address[3] = I3