1 sideseadmed (irt0040) loeng 5/2010 avo [email protected]
TRANSCRIPT
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IMS with IPv6Multi-country/Multi-operator
SIP-connectivity network
Client, Public IPv6 address 1Client, Public IPv6 address 2
PublicIP-routing domain
(inter-operatorconnections)
SIP Proxy
SIP Proxy
SIP Signaling:A’s address = Public IPv6 Addr 1
Media from B to A:Sent to Public IPv6 Addr 1
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Terminology (1)
Home Agent (HA)
Mobile Host (MH)
Foreign Agent (FA)
HN FN
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Terminology (2)
• Similar to cellular.
• Mobile Node (MN or MH): node changing its PoA.
• Correspondent Host (CH).
• Home Network (HN) and Foreign Network (FN).
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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.
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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.
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Discovering Agents
Agents periodically beaconadvertisements
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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.
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Discovering Agents
MH polls; agent responds.
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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.
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Registration
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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.
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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).
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Tunneling
Tunneled Data Packet
HA keeps bindingbetween MH and FA
SRC
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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
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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
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Tunneling in Mobile IP
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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.
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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.
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Reverse Tunneling• IPv6 in IPv6 tunnel is used for delivering
traffic to and from home address of MN via HA.
• 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.
Tunnel IPv6 hdr (CoA –HA) IPv6 hdr (HoA-CN) Data
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Mobile IPv6 operation
Foreign Network
Home Network
Access Router
Home Agent
Mobile Node
Router solicitation
Binding Update
Proxy ND for HoABinding Ack.
Tunnel
Router Advertisement
MN forms Care-of address
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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.
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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
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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
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Network Mobility
On-Board Network
PAN
Internet
Onboard Network
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On-Board Network
Mobile Router
Access Router
Internet
Server
Home Network
Home Agent
NEMO (RFC 3963) Operation
IP IP tunnel
Network a:1::
Network a::
Network b::
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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, DHCP or manual config
Stateless Address Autoconfig, DHCP manual config or
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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 and co-located CoA
CoA’s are ALL co-located. No Foreign Agents needed
Dynamic Home Agent Address Discovery (DHAAD)
Directed broadcast. Returns separate replies from all HA’s to the MN (Mobile Node)
Anycast addressing. Returns a single reply to the MN
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IPv4 Mobility vs IPv6 Mobility
function IPv4 (RFC 3344) IPv6 (RFC 3775)Data packet delivery to MN
Tunnel routing 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.
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Lingidhttp://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_management
http://www.iec.org/online/tutorials/tmn/
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Mobile IPhttp://www.ietf.org/rfc/rfc3344.txt?number=3344
http://www.ietf.org/rfc/rfc3775.txt?number=3775
http://www.hznet.de/ipv6/mipv6-intro.pdf
http://www.ipv6.org.uk/workshop/slides/ipv6_workshop2_module3_final_animated.ppt
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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