Network Mobility Thierry Ernst Keio University ernst@sfc.wide.ad.jp 1 Thierry Ernst - Nautilus6.org - September 2004
IP-layer Mobility: Host Mobility and Network Mobility Address Requirements for IPv6 nodes: Must be topologically correct Each interface must have an address formed after the prefix advertised on the link where it is attached IP-layer Mobility BR BR Change of point of attachment = change of IP subnet Change of IP subnet = change of the routing Prefix1::id_MN Prefix1::id_MN directive AR Prefix1 Prefix1 Prefix1::id_MR Prefix1::id_MR HA MN MN Prefix2::id_MR Prefix2::id_MR Prefix2::id_MN Prefix2::id_MN AR AR Prefix2 Prefix2 Prefix1.1::id_MR Prefix1.1::id_MR Prefix1.1::id_MR Prefix1.1::id_MR MN MN Prefix1.1::id_MR Prefix1.1::id_MR 2 Thierry Ernst - Nautilus6.org - September 2004
IP-layer Mobility: Network Mobility Support IETF NEMO Basic Support: draft-ietf-nemo-basic- ✗ support Goal: Session Maintenance ✗ Initialisation ✗ NEMO-prefix identifes all nodes in the mobile network BR BR ✗ MR_HoA: MR's egress interface on home link ✗ Movement to Foreign Link MR retains HoA ✗ MR obtains CoA on its visited link AR HomeLink: P1/48 HomeLink: P1/48 ✗ MR-HoA: P1::id_MR MR-HoA: P1::id_MR CoA is bound to NEMO-prefix, not HoA ✗ HA MNNs retain their initial addresses ✗ MR-CoA: P2::id_MR MR-CoA: P2::id_MR AR AR ForeignLink: P2/64 ForeignLink: P2/64 NEMO-Prefix::id_MR NEMO-Prefix::id_MR NEMO-Prefix::id_MR NEMO-Prefix::id_MR MNNs MNNs NEMO-Prefix::id_MR NEMO-Prefix::id_MR 3 Thierry Ernst - Nautilus6.org - September 2004
IETF NEMO Basic Support: draft-ietf-nemo-basic-support Assumption: All MNNs have an address on NEMO-Prefix CoA bound to NEMO-Prefix Registration Registration with HA: NEMO-prefix-> MR' CoA instead of MR's HoA-> MR's CoA HA records a network-specific route instead of host-specific Bidirectional tunnel between MR and HA Prefix 1/60 ->Prefix2::/128 (MRCoA) HA Internet Prefix P1/48 MR S:MR D:HA NEMO-Prefix AR Prefix P2/64 NEMO-Prefix P1/60 MR NEMO-Prefix P1/60 4 Thierry Ernst - Nautilus6.org - September 2004
IETF NEMO Basic Support: draft-ietf-nemo-basic-support Routing Encapsulation between HA and MR in BOTH directions Not optimal solution, but guarantee mobile networks are supported with minimal effort S:CN D:LFN Prefix 1/60 ->MR CoA HA Internet P1/48 AR S:HA D:MR-CoA S:CN D:LFN P2/64 MR NEMO-Prefix P1/60 S:CN D:LFN 5 Thierry Ernst - Nautilus6.org - September 2004
Benefit of network mobility support over host mobility support The vehicle changes its point of attachment to the Internet Host Mobility: each node maintains Internet access Each host must perform Mobile IPv6 Network Mobility: only the mobile router (MR) maintains Internet access Standards IPv6 nodes can be located behind the MR: no mobility support Host Mobility Support Network Mobility Support (Mobile IPv6) (NEMO Basic Support) 6 Thierry Ernst - Nautilus6.org - September 2004
NEMO vs MANET A NEMO can be made of MANET nodes MNNs in the NEMO can be MANET nodes e.g.: the train (NEMO) and the passengers (MANET nodes) A MANET can be made of NEMOs MANET nodes are MRs each with a network behind e.g.: a car is a MANET router, with an embedded NEMO behind the MR HA_Renault HomeLink: P_RenaulRoad/64 AR Road-side ForeignLink: P_Road/64 MR_CoA:P_Road::id_MR P_Renault_1::id_MR 7 Thierry Ernst - Nautilus6.org - September 2004
NEMO Issues 8 Thierry Ernst - Nautilus6.org - September 2004
NEMO Basic Support Issue: Nested Mobility Cost of multiple encapsulation Packet size ; Packet Fragmentation (PMTU) HA2 HA1 Latency CN Internet MR2 Processing overhead at MR, HA Extremely sub-optimal routing (Pin Ball routing) AR LFN Sol investigated in: MR1 draft-ng-nemo-access-router-option-00.txt draft-thubert-nemo-reverse-routing-header- 01.txt Others MR2 LFN 9 Thierry Ernst - Nautilus6.org - September 2004
NEMO Basic Support & Multihoming Requirement R12 draft-ietf-nemo-requirements-02.txt NEMO Basic Support must allow the mobile network To connect to the Internet via several access networks To switch to the best available technology Multihoming A mobile network connected to the Internet via several interfaces 1 Mobile Router with heterogeneous access medias More than 1 Mobile Router Cases: Multiple MRs Internet Multiple HAs AR AR AR Multiple NEMO-prefixes MR MR Multiple MRs Multiple interfaces Result: Multiple CoAs Multiple HoAs 10 Thierry Ernst - Nautilus6.org - September 2004
NEMO Basic Support & Multihoming: draft-ietf-nemo-multihoming-issues Benefits of multihoming: Ubiquitous access, Redundancy Flexibility, via distinct physical medium or access networks Load Sharing. Load Balacing Bi-casting Problem: Multihoming introduces new issues: Multiple NEMO-Prefixes: Source address selection Multiple MR: MR selection / redirection to other MR Nested and multihoming Issues are not NEMO-specific, but it's more important to solve those issues in the NEMO context because mobile networks are more likely to be multihomed than fixed networks.Taxonomy Taxonomy: X: Number of Mobile Routers (#MRs) Y: Number of Home Agents (#HA) Z: Number of NEMO-Prefixes advertised in the mobile network Total: 8 cases Not all are useful 11 Thierry Ernst - Nautilus6.org - September 2004
NEMO Basic Support & Multihoming: Issues Tunnel re-establisment: MR dynamically change its tunnel entry interface when its egress link fails Obtain CoA from other MRs when egress link fails Re-establish bi-directional tunnel using this new CoA Issue: MR need to detect the presence of other MRs having alternate routes in its local network: Possibility: listen for RA with LifeTime!=0 Possible routing loop when both MRs' egress link fail HA-2 HA-1 HA-2 HA-1 HA-2 HA-1 HA-2 HA-1 Internet Internet Internet Internet X X Obtain Obtain CoA CoA MR-2 MR-2 MR-1 MR-1 MR-2 MR-2 MR-1 MR-1 MNN-2 MNN-2 Re-establish tunnel Re-establish tunnel RA(LifeTime!=0) RA(LifeTime!=0) MNN-1 MNN-1 MNN-2 MNN-2 MNN-1 MNN-1 12 Thierry Ernst - Nautilus6.org - September 2004
NEMO Basic Support & Multihomed: Case (1MR,1Ha,1P) MR has Multiple Egress Interfaces, 1 CoA associated with each e.g.: laptop ✗ Goal: To maintain bidirectional tunnel over each inferface Binding Cache Binding Cache HoA HoA CoA CoA HA HA 1::1 1::1 2::1 2::1 1::2 3::1 1::2 3::1 Routing Table Routing Table Internet Internet Dest Dest Next Hop Next Hop 1:1::/96 1:1::/96 1::1 1::1 MR MR 802.11 Interface 802.11 Interface GPRS Interface GPRS Interface CoA=2::1, HoA=1::1 CoA=2::1, HoA=1::1 CoA=3::1, HoA=1::2 CoA=3::1, HoA=1::2 Prefix=1:1::/96 Prefix=1:1::/96 MNN-1 MNN-1 MNN-2 MNN-2 Addr=1:1::1 Addr=1:1::1 Addr=1:1::2 Addr=1:1::2 13 Thierry Ernst - Nautilus6.org - September 2004
NEMO Basic Support & Multihomed: Case (1MR,1Ha,1P) For Redundancy: Efficient link failure detection mechanism For Load-Sharing: Ability to register several CoAs for a prefix and to exchange priority level for each CoA For Policy-routing: Exchange preference with MR and HAMR has Multiple Egress Interfaces, 1 CoA associated with each Binding Cache Binding Cache HoA HoA CoA CoA HA HA 1::1 1::1 2::1 2::1 1::2 3::1 1::2 3::1 Routing Table Routing Table Internet Internet Dest Dest Next Hop Next Hop 1:1::/96 1:1::/96 1::1 1::1 MR MR 802.11 Interface 802.11 Interface GPRS Interface GPRS Interface CoA=2::1, HoA=1::1 CoA=2::1, HoA=1::1 CoA=3::1, HoA=1::2 CoA=3::1, HoA=1::2 Prefix=1:1::/96 Prefix=1:1::/96 MNN-1 MNN-1 MNN-2 MNN-2 Addr=1:1::1 Addr=1:1::1 Addr=1:1::2 Addr=1:1::2 14 Thierry Ernst - Nautilus6.org - September 2004
NEMO Basic Support & Multihomed: Case (1MR,nHA,1P) Multiple Egress Interfaces, Different HAs e.g.: distinct serive providers Bi-directional tunnels must be established between each (MR,HAy) Binding Cache Binding Cache Binding Cache Binding Cache HoA HoA CoA CoA HoA HoA CoA CoA HA-1 HA-2 HA-2 HA-1 1::1 1::1 3::1 3::1 2::1 2::1 4::1 4::1 Routing Table Routing Table Routing Table Routing Table Internet Internet Dest Next Hop Dest Dest Next Hop Next Hop Dest Next Hop 2:1::/96 2::1 1:1::/96 1::1 2:1::/96 2::1 1:1::/96 1::1 MR MR 802.11 Interface 802.11 Interface GPRS Interface GPRS Interface CoA=3::1, HoA=1::1 CoA=3::1, HoA=1::1 CoA=4::1, HoA=2::1 CoA=4::1, HoA=2::1 Prefix=1:1::/96, 2:1::/96 Prefix=1:1::/96, 2:1::/96 Addr=1:1::2 Addr=1:1::2 Addr=1:1::1 Addr=1:1::1 MNN-1 MNN-2 MNN-1 MNN-2 Or 2:1::2 Or 2:1::2 Or 2:1::1 Or 2:1::1 15 Thierry Ernst - Nautilus6.org - September 2004
NEMO Basic Support & Multihomed: Case (nMR,1HA,1P) Multiple MRs, Single HA e.g.: PAN Bi-directional tunnels must be established between each (Mrx,HA) MR must be selected by MNNs Just use router selection mechanisms Binding Cache Binding Cache HoA HoA CoA CoA HA HA 1::1 1::1 2::1 2::1 1::2 1::2 3::1 3::1 Routing Table Routing Table Internet Internet Dest Dest Next Hop Next Hop 1:1::/96 1:1::/96 ??? ??? CoA=3::1 CoA=3::1 CoA=2::1 CoA=2::1 HoA=1::2 HoA=1::2 HoA=1::1 HoA=1::1 MR-2 MR-2 MR-1 MR-1 Prefix=1:1::/96 Prefix=1:1::/96 Prefix=1:1::/96 Prefix=1:1::/96 MNN-1 MNN-2 MNN-1 MNN-2 Addr=1:1::2 Addr=1:1::2 Addr=1:1::1 Addr=1:1::1 16 Thierry Ernst - Nautilus6.org - September 2004
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