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Dynamic Tunnel Management Protocol for IPv4 Traversal of IPv6 Mobile Network. Jaehoon Jeong Protocol Engineering Center, ETRI paul@etri.re.kr http://www.nemo.6ants.net/. VTC 2004 Fall. Contents. Motivation Network Mobility (NEMO) Related Work Main Idea Mobile Router in NEMO
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Dynamic Tunnel Management Protocolfor IPv4 Traversal of IPv6 Mobile Network Jaehoon Jeong Protocol Engineering Center, ETRI paul@etri.re.kr http://www.nemo.6ants.net/ VTC 2004 Fall
Contents • Motivation • Network Mobility (NEMO) • Related Work • Main Idea • Mobile Router in NEMO • Service Scenarios in IPv6 NEMO • Auto-switching b/w WLAN & CDMA • IPv4 Datagram Layout forIPv6-in-IPv4 Tunnel Management • Testbed for IPv6 NEMO • Conclusion
Motivation • Network Mobility (NEMO) Basic Support protocol • Object of NEMO • NEMO allows a mobile network reachable in the Internet through Mobile IPv6 Extension. • NEMO is being developed at IETF NEMO working group • Limitation of Current NEMO Protocol • NEMO supports network mobility only in IPv6 Internet through bi-directional tunneling between Mobile Router (MR) and Home Agent (HA). • Goal of This Paper • Support of IPv4 Traversal of IPv6 Mobile Network in the current Internet that consists nearly of IPv4 networks.
Network Mobility (NEMO) – 1/2 • Role of NEMO Protocol • Session Continuity of Mobile Network Node (MNN) • Connectivity of MNN • Reachability of MNN • Location Management • Key Idea of NEMO • HA forwards data packets destined for Mobile Network. • HA maintains the forwarding information related to Mobile Network Prefix(es).
Network Mobility (NEMO) – 2/2 • Management of Mobile Network Prefix • Binding Update of Implicit Mode • Binding Update of Explicit Mode • Dynamic Routing Protocols • Refer to NEMO draft for detailed information • draft-ietf-nemo-basic-support-03.txt
Related Work • Vertical Handover based on L2 Triggers • Vertical Handover • Handover between different kinds of physical networks • L2 Trigger • An event that occurs at the Link Layer that is forwarded to the upper layer, i.e., Layer 3. • Five L2 triggers were proposed: • Link Up, Link Down, Source Trigger, Target Trigger or Mobile Trigger • L2 Hint • Information that can be optionally transported with an L2 trigger • LINK-TYPE: CDMA, GPRS or WLAN • Applicability of L2 Triggers • Support of IPv4 Traversal of IPv6 Mobile Network • From WLAN to CDMA, From CDMA to WLAN
Main Idea • Assumption • Every WLAN subnet is IPv6 network. • Mobile router can connect to the IPv4 Internet through CDMA interface. • Maintenance of IPv6 Connectivity through IPv6-in-IPv4 Tunnel • When mobile router becomes detached from IPv6 WLAN, • it connects to IPv4 CDMA network and • it sets up an IPv6-in-IPv4 tunnel for IPv6 connectivity between its home agent and itself.
Mobile Router in NEMO • IPv6 Mobile Router • It has two IEEE 802.11g and one CDMA interfaces • IEEE 802.11g Interfaces • One is used as Ingress Interface and the other as Egress Interface. • 802.11g supports bandwidth up to 54 Mbps. • It uses the 2.4 Ghz frequency for greater range. • CDMA(1x EV-DO) Interface • It is used as Egress Interface. • CDMA 1xEV provide a peak rate data throughput of 2.4 Mbps. • 1x EV-DO of SKT provides actual speed of either 115 or 234 Kbps per one user. • It uses a spectrally efficient 1.25 MHz channel.
Service Scenarios in IPv6 NEMO • NEMO should be able to maintain IPv6 connectivity b/w MNN & CN under a variety of environments;
Scenario 1 :IPv6 Mobile Network connected to IPv6 Access Network
Scenario 2 :IPv6 Mobile Network moving into IPv4 Access Network
Auto-switching b/w WLAN & CDMA • Switching Criteria • Signal strength from WLAN AP • MR prefers WLAN to CDMA. • Whenever WLAN is available, MR uses it rather than CDMA. • IPv4 Address Allocation during IPv4 Traverse • IPv4 Address should be allocated for MR’s egress interface through PPP’s IPCP (IP Control Protocol). • IPv4 address should be public address.
Roaming in IPv4 CDMA • CDMA Connection Setup • AAA Procedure in Linux • IPv4 Address Allocation from PPP • This address is used as Care-of Addres (CoA) of MIPv6. • When should MR set up CDMA session? • Option 1 : Always from boot of MR • Option 2 : When WLAN is not available, MR starts to set up the session. • Delay due to AAA procedure, IPv4 address allocation and IPv6-over-IPv4 tunnel setup • Management of IPv6-over-IPv4 Tunnel b/w HA & MR • MIPv6’s Binding Update message is delivered to HA through IPv4 datagram. • CDMA’s IPv4 address is represented as IPv4-Mapped IPv6 Address Format and delivered to HA through Alternative Care-of Address in Binding Update Message.
IPv4 Datagram Layout forIPv6-in-IPv4 Tunnel Management Dynamic Tunnel Management Protocol (DTMP) Message Format CDMA Interface’s IPv4 Addressrepresented as IPv4-Mapped IPv6 Address
Testbed for IPv6 NEMO • We used NEMO Basic Support Protocol for IPv6 Mobile Network. • For controlling network configuration, • We control Tx and Rx power of IEEE 802.11g NIC. • Also, we use MAC-filtering to filter out packets in other link. • We implemented IPv6 Wireless Mobile Router based on embedded linux for testing Dynamic Tunnel Management (DTMP) Protocol.
Experiment of DTMP inNEMO Testbed IPv6 Wireless Mobile Router Test of DTMP
Conclusion • Policy for Fast Deployment of NEMO • Current Status • The current Internet consists mostly of IPv4 networks. • Cellular networks (e.g., CDMA and GPRS) can be used as backup channel. • Dynamic Tunnel Management Protocol (DTMP) • DTMP can support IPv4 Traversal of IPv6 Mobile Network in the current Internet. • Future Work • We will enhance our movement detection mechanism in order to minimize packet loss and delay of handover.