Path%20type%20support%20for%20NSIS%20signaling%20<draft-sanda-nsis-path-type-03.txt>

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Path type support for NSIS signalingltdraft-sanda-
nsis-path-type-03.txtgt
Takako Sanda, Toyoki Ue, Hong Cheng IETF64 9
November, 2005
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Motivation Goal

• Background Communication nodes sometimes use
  multiple paths for one session, e.g.
• Node with multiple interfaces multiple data
  paths for one session
• Mobile IP triangular path and optimized path
• Requirement QNE needs extra knowledge to treat
  these paths in case of route change
• Goal address the issue in NSIS mobility support

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Problem statement -- Mobile Node with Multiple
Interface case --

• MN is using two interfaces (s, t) for one session
  to communicate with CN.
• When QoS states are installed, Session ID (SID)
  is the same for two paths but Flow IDs are
  different
• When an interface t performs handover ((1) -gt
  (2)), Path2 should be replaced to Path3, but
  Path1 should be kept.
• How can CRN know which path should be released?

(1)
(2)
CN
CN
Path1
Path2
Path1
Path2
SID XFlow ID A
QNE1
QNE1
SID XFlow ID B
SID XFlow ID A
SID XFlow ID B
Path3
Nw1
Nw2
Nw1
Nw2
SID XFlow ID C
AR1
AR2
AR1
AR2
AR3
s
t
s
t
MN
MN
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Problem statement -- Mobile IP case --

• Triangular route (path1) is used first and then
  optimized route (path2) is used
• The state for triangular path may need to be kept
  (as reduced mode), because it would be re-used
• when optimized path is aborted
• When MN performs handover
• How can CRNs recognize that path2 is optimized
  route?
• When MN performs handover, state for new paths
  will be installed
• How can CRNs know which path should be released?

(1)
(2)
QNE3
HA
QNE4
CN
CN
QNE3
HA
QNE4
Path1
Path1
Path2
QNE2
Path2
QNE2
Path4
QNE1
QNE1
Path3
AR1
AR1
AR2
MN
MN
MN
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Requirements for handling multiple paths

• In order to handle multiple paths for one
  session, the signaling identifiers must be able
  to show
• Different relationship between different paths
• Between co-existing paths
• Between old path and new path
• Dependency of each path (e.g. for MIP case)

After Path5, Path4 needs to be reduced
Dependency Path4 triangular path Path5
optimized path
After Path3, Path2 needs to be released
(1)
(2)
CN
QNE3
HA
QNE4
CN
Path1
Path2
Path4
QNE1
Path5
QNE2
Path7
Path3
Nw1
Nw2
QNE1
Path6
AR2
AR1
AR1
AR2
AR3
s
t
MN
MN
Relationship betw. co-existing paths
Relationship betw. old and new paths
MN
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Possible Solutions

• Preparing dedicated parameter for showing path
  type, i.e. Path Type ID

• Alternative Solutions
• Allocating different Session IDs
• Using intra session binding

Difficult to carry dependency
(1)
(2)
CN
QNE3
HA
QNE4
CN
Path1
Path2
Path4
QNE1
Path5
QNE2
Path7
Path3
Nw1
Nw2
QNE1
Path6
AR2
AR1
AR1
AR2
AR3
s
t
MN
MN
MN
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Next Step and Open Issue

• Should this problem be included in NSIS mobility
  support?
• Is more improvement useful?
• Other possible scenarios?