Basic Socket API Extensions for LIN6 EndtoEnd Multihome

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Basic Socket API Extensions for LIN6 End-to-End
Multi-home
- draft-arifumi-lin6-multihome-api-00.txt -

• Arifumi Matsumoto
• Kenji Fujikawa
• Yasuo Okabe
• Kyoto University, JAPAN

July. 14, 2003 IETF 57th
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Proposal Overview

• Host-based multi-home in application layer
• Multi-home support has to be achieved in
  transport or upper layers, we believe
• Based on a mobile protocol LIN6 for
  address-aquirement, notification and registration
• Based on loc/id model for simplicity
• Specifications of extended Socket API
• To manipulate multiple addresses from application

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What is LIN6 ?/ For what ?

• LIN6Location Independent Network Architecture
  for IPv6
• 88 model Divide an IPv6 address into 2 parts
• Upper 8bytes Location Id.(Locator)
• Lower 8bytes Node Id.(Identifier)
• Identify each connection only by Node Id.
• Address-acquirement, notification, registration
  in a secure manner

Node Id.Global unique
IPv6
Location Id.
8byte
8byte
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E2E Multi-home with LIN6(1/2)

• E2E multi-home has an affinity to loc/id
• End node knows each others locators through LIN6
  protocol

Loc1ID-A lt-gt Loc2ID-B
Host-A
ISP1
Loc1ID-A
ISP2
Loc2ID-B
Host-B
Internet
Loc3ID-B
ISP3
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E2E Multi-home with LIN6(2/2)

• The mere change of locator can avoid connection
  down even when a line gets in trouble
• Its simple each connection is identified by Id.

Host-A
ISP1
Dst. ID-B
ISP2
Internet
Dst. ID-A
ISP3
Host-B
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What to do ?

• Existing Socket APIs cannot handle multiple
  dst/src addresses for one connection
• Prepare APIs to manipulate locators
• API to make a multi-home ready socket
• API to change dst./src. locator while connection
  is established
• API to get locators of Corresponding Node

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APIs for Multi-home

• socket(AF_ALIN6)
• Make a special socket to handle multiple
  addresses
• LIN6 socket identifies each connection using only
  lower 8 bytes
• getaddrinfo2()
• Acquires corresponding node(CN)s locators
• Queries Location Agent and gets CNs latest
  locators
• getsockopt()/setsockopt()
• Get/Change the dst/src locator of a connected
  socket
• When connection error is detected, another
  locator can be used

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Example Program
struct addrinfo2 ai_family
ai_socktype ai_addr .. ai_ntloc
ai_tloc ..
struct addrinfo2 hints, res, res2 getaddrinfo2(
hoge.com,http,hints,res) / get
addresses?make connection / for(con0con!1res
-gtai_next!NULL resres-gtai_next) sock
socket(res-gtai_family, res-gtai_socktype,
res-gtai_protocol) if (res-gtai_family
AF_ALIN6) for (con0,i0iltres-gtai_ntloci
) if (connect(sock, res-gtai_tloci,
res-gtai_addrlen)0) con 1 else
connect(sock, res-gtai_addr, res-gtai_addrlen)
void sig_urg(int signo) / error signal
handling / setsockopt(sock,IPPROTO_IPV6,FOREIGN
LOCATOR, res-gtai_tloci,
sizeof(struct lin6_prefix))
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Conclusion

• Weve developed a running implementation of our
  APIs
• To re-make all the application with these APIs
  isnt realistic
• For TCP, multi-home support can be done in TCP
  layer just like SCTP.
• For UDP, multi-home support has to be done in
  App. layer using our APIs.
• As a future work,
• We develop multi-home support extension to TCP.

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MIAKO Project

• MIAKO(Mobile Internet Access in KyotO)
• http//www.miako.net/
• The World Largest Wireless IPv4/IPv6 dual-stack
  Access Network
• About 200 Access Points
• About 4000 Users
• IPv6 multi-home support is now in progress

Oh! Yes, Lets go to Kyoto !!
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End-to-End Multihoming

• draft-ohta-e2e-multihoming-03.txt
• Multihoming not by intelligent routing protocols
  but by a pair of end-system
• Multiple addresses for a node
• Transport or upper layers manipulate addresses.
• No change is
• necessary for routers

ISP1
Router adv.
Loc1ID
Internet
End-node
Loc2ID
ISP2
Router adv.