Utilizing Home and Away Interfaces Simultaneously

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Utilizing Home and Away Interfaces Simultaneously

• 66th IETF at Montreal, Quebec, Canada
• Benjamin Koh
• Keigo Aso

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Contents

• Problem
• Possible Operations
• Network based solution
• Mobile Node based solution
• Conclusion

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Problem

• When a MN IF returns home, it cannot use both of
  its interfaces for flows.
• If it uses home link, the mobile node MUST
  de-register all the bindings
• The preferences in HA set by the MN before the
  movement is not available any more.
• If it uses interfaces attached to foreign links,
  the mobile node disables the interface attached
  to the home link
• draft-ietf-monami6-multiplecoa-00.txt
• To use home and foreign links simultaneously, the
  home agent can set up another link other than
  home link and uses the link for the mobile node
  to return virtually to home network. The detail
  can be found in Figure 7.
• No emulation details given (Just a figure)
• Contradiction with earlier text in Section 3.3
• When the mobile node returns home, there are two
  situations, since the Home Agent defends the
  mobile node's Home Address by using the proxy
  neighbor advertisement. It is impossible to
  utilize all the interfaces when one interface is
  attached to the home link and the others are
  attached to foreign links.

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Network based solution

• Operation 1
• HA advertises prefix to make the home link appear
  to be the foreign link.
• MCoA-MN considers HA Link to be a foreign link
• MIPv6-MN and MCoA-MN can never perform the
  returning home procedure (always away)

• Operation 2
• HA advertises 2 prefixes.
• Home Link prefix
• Foreign Link prefix
• MCoA-MN can choose prefix to configure
• MIPv6-MN should always select Home Link prefix
• Default behaviour?

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Mobile Node based solution
----
CN ---
---------
---- ------ Internet ----------
HA ---------
-- CoA2
Home Link --------
----------- MCoA MN
---- --------
CoA1 ------- MN
Home Link
---- CoA -------------------------
---

• Operation
• MCoA-MN uses a CoA formed by the home prefix in
  the home network.
• MIPv6-MN performs the returning home procedure.

• Advantage
• No changes to operation of MIPv6-MN (can use own
  home address).
• MCoA-MN can select to return home or not.

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Conclusion

• Both solutions keep backward compatibility with
  Mobile IPv6.
• Network based solution may hinder normal
  operations of a Mobile IPv6 node
• Recommendation for changes to MCoA draft
• Slight text changes to section 3.3 (for
  simultaneous usage of both home and foreign
  interfaces)
• Add supplementary text to Figure 7 describing
  detailed operation of solution(s)