Transcript tunnels
Sideseadmed (IRT0040) loeng 5/2010 Avo [email protected] 1 Client, Public IPv6 address 1 IMS with IPv6 Multi-country/Multi-operator SIP-connectivity network SIP Prox y SIP Signaling: A’s address = Public IPv6 Addr 1 SIP Prox y Public IP-routing domain (inter-operator connections) Media from B to A: Sent to Public IPv6 Addr 1 Client, Public IPv6 address 2 2 Terminology (1) Home Agent (HA) HN Foreign Agent (FA) FN Mobile Host (MH) 3 Terminology (2) • Similar to cellular. • Mobile Node (MN or MH): node changing its PoA. • Correspondent Host (CH). • Home Network (HN) and Foreign Network (FN). 4 Terminology (3) • Mobility Agents: – Home Agent (HA): router on MN’s HN that tunnels datagrams to MH when away and keeps MH’s current location info. – Foreign Agent (FA): router on foreign network; delivers datagrmas to MH while on FN. • Home Address (HoA) and Care-of Address (CoA): – HoA: MH’s permanent address on HN. – CoA: MH’s temporary address on FN. 5 Mobile-IP: Basic Operation • MH normally uses its home address HoA. • When MH visits a foreign network, – Registration with FA. • Discover mobile agent and CoA. – Registration with HA. • Binding update (HoA -> CoA). • Communicating with MN: use HoA. • HA forwards packet from HoA to CoA. 6 Discovering Agents Agents periodically beacon advertisements 7 Agent Discovery • Agent advertisement (beaconing): – Mobile agent broadcast agent advertisement at regular intervals (“I am here”). • Agent solicitation: – MH can poll (“anyone here?”). – Mobile agent responds to poll. 8 Discovering Agents MH polls; agent responds. 9 Agent Advertisement • Allow for the detection of mobility agents. • Follows ICMP router advertisement message. • Let the MH know whether the agent is a HA, or a FA. • List one or more available care-of addresses. • Inform the MN about special features provided by FA. – Example: Alternative encapsulation techniques, header compression. 10 Registration 11 Registering • When away, MH registers its CoA with HA (binding update). • Binding: (HoA->CoA) – Binding has a lifetime. • Registration process – – – – – MH sends a registration request with CoA. HA authenticates request. HA approves or disapproves the request. HA adds necessary information to its routing table. HA sends registration reply back to MH. 12 Tunneling • HA tunnels datagrams destined to MH when MH is away. – Datagrams sent to MH, intercepted by HA and tunneled to its CoA. • Tunnel terminates at MH CoA (either the MH or the FA). 13 Tunneling SRC Tunneled Data Packet HA keeps binding between MH and FA 14 Encapsulation • Tunneling requires encapsulation. – Sending the original packet (CH->MH) in another packet (HA->CoA). • Default encapsulation mechanism: – IP-within-IP (tunnel). – Tunnel header: new IP header inserted by the tunnel source (home agent). – Destination IP: CoA 15 Mobile IP Basic Operation • Entities – Mobile host, home agent, foreign agent, corresponding host • Discovering Care-of Addresses – Agent advertisements • Registering Care-of Address – Security • Tunneling to Care-of Address – IP-within-IP encapsulation 16 Tunneling in Mobile IP 17 Mobile IPv6 • Mobility support in IPv6 (RFC 3775) • Mobile node (MN) is a mobile device with an IPv6 home address • Correspondent node (CN) is a computer with which mobile node communicates using its home address. • Home Agent (HA) helps MN to manage its mobility: – Mobile node can always be reached at its home address, regardless of its point of attachment (care-of address) to the Internet. – Connections made with home address survive movement between different IP networks. 18 Mobile IPv6 addressing • IP addresses act as both an identifier for a node and as a locator. • Mobile IPv6 separates the identity, home address of mobile node from its locator, known as care-of address (CoA). • Without Mobile IPv6 MN can not use its home address for sending and receiving packets when it is outside its home network. • Mobile IPv6 uses IP-IP tunneling to create a virtual network between its CoA and HA, so that MN always appears to be in its home network. 19 Reverse Tunneling • IPv6 in IPv6 tunnel is used for delivering traffic to and from home address of MN via HA. Tunnel IPv6 hdr (CoA –HA) IPv6 hdr (HoA-CN) Data • HA uses proxy neighbor discovery to redirect packets on home link destined to home address of MN to its own link layer address. • HA keeps track of the care-of address of MN to deliver packets to MN. 20 Mobile IPv6 operation Tunnel Binding Ack. Proxy ND for HoA Binding Update Router Advertisement Router solicitation MN forms Care-of address 21 Route in Mobile IPv6 • Tunneling of traffic between MN and CN via home agent is not efficient. – HA is a potential bottleneck – Extra routing hop increases network latency • Route optimization (RO) allows MN and CN to communicate directly • MN sends a BU to CN. • MN and CN use home address option and routing header, type 2 to send packets to each other. • Route optimization is secured using return routability protocol. 22 Mobile IPv6 Implementations • Windows – MS Research implementation MN, CN, HA – MS CN implementation for Win XP – Elmic software: embedded MN • Linux – MIPL (Helsinki University of Technology): MN/CN/HA – Elmic software: embedded MN • Symbian: MN • Cisco: HA • Nokia: HA 23 Mobile IPv6 extensions • Localized mobility management – Hierarchical Mobile IPv6 – Fast Mobile IPv6 • Context transfer to new router: Context transfer protocol • Early discovery of new router: Candidate access router discovery protocol 24 Network Mobility 25 NEMO (RFC 3963) Operation Network a:: Network b:: IP IP tunnel Network a:1:: 26 IPv4 Mobility vs IPv6 Mobility function IPv4 (RFC3344) IPv6 (RFC 3775) addressing 32 bit addresses 128 bit addresses Home address One home address A globally routable Home Address (HoA)and a link local HoA Care-of-Address Via agent discovery, Stateless Address DHCP or manual Autoconfig, DHCP config manual config or 27 IPv4 Mobility vs IPv6 Mobility function IPv4 (RFC 3344) IPv6 (RFC 3775) Movement detection Agent Discovery through Foreign Agent IPv6 Router Discovery CoA (Care of Address) Foreign Agent CoA CoA’s are ALL coand co-located CoA located. No Foreign Agents needed Dynamic Home Agent Address Discovery (DHAAD) Directed broadcast. Anycast addressing. Returns separate Returns a single replies from all HA’s reply to the MN to the MN (Mobile Node) 28 IPv4 Mobility vs IPv6 Mobility function IPv4 (RFC 3344) IPv6 (RFC 3775) Data packet delivery Tunnel routing to MN Tunnel routing and source routing with IPv6 routing headers Decapsulation of data packets sent to MN’s CoA Foreign Agent decapsulates MN itself decapsulates Link layer neighbour address discovery ARP IPv6 neighbour discovery; decoupled from any given link layer. 29 Lingid http://en.wikipedia.org/wiki/Mobile_IP http://tools.ietf.org/html/rfc3344 http://en.wikipedia.org/wiki/Mobile_IP http://en.wikipedia.org/wiki/Mobility_manage ment http://www.iec.org/online/tutorials/tmn/ 30 Mobile IP http://www.ietf.org/rfc/rfc3344.txt?number=3 344 http://www.ietf.org/rfc/rfc3775.txt?number=3 775 http://www.hznet.de/ipv6/mipv6-intro.pdf http://www.ipv6.org.uk/workshop/slides/ipv6_ workshop2_module3_final_animated.ppt 31 Mobile IPv6 • Mobile IPv6: RFC 3775 • Securing Mobile IPv6 MN-HA signaling: RFC 3776 • Hierarchical MIPv6: RFC 4140 • Fast Mobile IPv6: RFC 4068 • Context transfer protocol: RFC 4067 • Candidate access router discovery protocol: RFC 4068 • Network Mobility (NEMO) Basic Support Protocol: RFC 3963 32