Transcript PowerPoint Presentation - Split Scenario Bootstrapping

Booting up on the Home Link
MEXT WG, IETF 71
Vijay Devarapalli ([email protected])
(draft-devarapalli-mext-mipv6-home-link-01)
Presented by
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Use of Mobile IPv6 in SDOs
• A few SDOs are adopting the use of Mobile IPv6 in their
next generation architectures
• The architectures are being designed to make it appear
to the MN that it is attached to the home link over certain
access networks
– Limited bandwidth
– Desire to avoid Mobile IPv6 tunneling overhead
• A point-to-point link is typically used between the MN
and the HA to create a single hop home link
– GTP, IPsec, PMIPv6 are used to create the point-to-point links
– Neighbor discovery is not run on some of these p2p links
• Booting up in the home link needs to be analyzed in
more detail for this home link operation
– Returning home over the p2p links is not considered here
Bootstrapping
• Bootstrapping depends on the IKEv2 exchange and
BU/BAck exchange between the MN and the HA
– IPv6 Home Address bootstrapped through IKEv2
– DS-MIPv6 IPv4 HoA bootstrapped through BU/Back exchange
– NEMO Mobile Network Prefixes are bootstrapped through
BU/BAck exchange
– MONAMI6 Flow filters are exchanged using BU/BAck
• A RFC 3775-compliant MN does not have to initiate an
IKEv2 exchange or send a BU when it discovers it is
attached to the home link
– The IKEv2 exchange is typically done when the BU is about to
be sent
– The MN does not send BU until it discovers it is on the visited
link
Home Link detection
• Home link detection in RFC 3775 is based on
receiving router advertisements from the home
agent
• Neighbor discovery is not possible on certain
p2p links
– IPsec tunnels
• Even in the generic case RFC 3775, if the MN is
not aware of its home prefix, router
advertisements cannot tell the MN it is at home
• Home link detection may require at the minimum
an IKEv2 exchange with the home agent even
when the mobile node is on the home link
Forwarding at the Home Agent
• When a packet for the MN’s HoA arrives at the
home agent, it needs to forward the packet to
the corresponding point-to-point link
• It is not clear how this state – MN IP address to
corresponding p2p link – is created on the HA
– Might vary with each type of point-to-point link
• Neighbor discovery is typically not run over
these point-to-point links for the HA to create the
forwarding state
• Forwarding entries at the home agent for NEMO
mobile network prefixes not created until a
binding update from mobile router is received
Home Address management on the MN
• When attached to p2p links, the mobile node
configures addresses using the link specific
mechanisms
• The addresses are assigned to the interface that
correspond to the p2p link on the mobile node
• When the mobile node moves away from the
home link,
– It needs to treat those addresses as home addresses
(IPv4 and IPv6)
– Move the addresses to the Mobile IPv6 virtual
interface
Service Selection Option
• The Service Selection option may be used by
the MN to indicate to the HA which service it
wants in the BU
– RFC 5149
• Without the BU sent on the home link, the MN
cannot indicate the service it wants
• The Service selection option may be included in
the lower layer messages (that are used to set
up the p2p links)
– But the service selection option may not be the same,
could be for just getting “access”
Possible Solution #1
• Describe how the mobile node boots up over the home
link works with existing mechanisms
– IKEv2 exchange from home link to detect home link attachment
• MIP6_HOME_PREFIX attribute (RFC 5026) must be implemented
– Configure DS-MIPv6 IPv4 HoA using IKEv2 or DHCP over p2p
links
– Configure NEMO mobile network prefixes using DHCPv6 prefix
delegation
– Specify additional behavior for the home agent and MN to
associate addresses configured using p2p link-specific
mechanisms as home address(es)
– Setup up routing for mobile network prefixes even though
DHCPv6 prefix delegation is used
• HA must be a DHCPv6 relay agent
– Service selection included in the p2p link setup messages or the
IKEv2 exchange with the home agent
– Leave out flow filter exchange when the mobile node boots up
on the home link
Possible Solution #2
• The MN sends a binding update when it attaches to the home link
over the point-to-point link
• A new flag in the BU to indicate that the BU is being sent from the
home link
– The HA confirms this in the Binding Ack
– Mobile IP tunnel is not created
– State created on the HA mapping the home address to the appropriate
p2p tunnel
• Packets for the home address would then be routed over the p2p link
– Any other configuration information like the DS-MIPv6 IPv4 home
address, NEMO MNP is obtained in this BU/BAck exchange
– Service selection option and flow filters are conveyed in the BU
• No modifications to RFC 3775
– This would be an optional extension to be used only by those mobile
nodes which attach to home link via p2p links
– Configurable on the mobile node
Next Steps
• Should MEXT address this?
• Do we develop a new solution (BU with
special flag) or describe how it is
supposed to be done with existing
protocols and bootstrapping mechanisms?
• Do we want the same bootstrapping
mechanisms used irrespective of whether
the mobile node boots up on the home or
the visited link?