Routing Extensions to Support Network Elements with Switching Constraint

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Routing Extensions to Support Network Elements
with Switching Constraint
draft-imajuku-ccamp-rtg-switching-constraint-01.t
xt

• Wataru Imajuku imajuku.wataru_at_lab.ntt.co.jp
• Yoshiaki Sone sone.yoshiaki_at_lab.ntt.co.jp
• Itaru Nishioka i-nishioka_at_cb.jp.nec.com

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Objective of This Draftand Related Studies

• Objective of This Draft
• Provides routing scheme of Lambda LSPs in the
  networks
• specifically having constraint in TE-Link
  Selectivity
• Related Documents
• RFC4054
• Discusses Signaling Impairment in transparent
  optical networks
• draft-ashwood-ccamp-gmpls-constraint-reqts-0x.txt
  (Expired)
• Proposes to advertise abstract link information
  of the network having optical constraint
• draft-shiba-ccamp-gmpls-lambda-labels-01.txt
• Proposed bit-map advertisement of status of
  wavelength label
• draft-rabbat-ccamp-gmpls-lambda-labels-00.txt
• Signaling extensions to directly assign
  Wavelength of Lambda LSPs in non or limited
  wavelength convertible networks
• Handles constraint in Label Selectivity

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New Problem Statementsin This Draft

• Constraint in TE Link Selectivity
• Sharp market rise of
• reconfigurable optical add/drop multiplexers
  (ROADMs)
• ROADM has constraint in TE-Link Selectivity
• ROADM has two groups of tributary ports,
• connectable only for East or West NNI
• GMPLS routers or other GMPLS capable nodes should
• take into account the constraint of TE Link
  Selectivity.

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TE Link Selectivity in ROADMs
ROADM
NNI Link (West)
NNI Link (East)
Add Switches
Drop Switches
West Bound Bi-Directional LSP
East Bound Bi-Directional LSP
Drop Switches
Add Switches
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
West Bound Tributary Port Group
East Bound Tributary Port Group
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Example of ROADM Ring

• LSPs in ROADM Rings
• LSPs from West Tributary Ports are terminated at
  East Tributary Ports
• This is also true for the case of vice versa.
• Label Allocation
• Approach 1 Routing Solve Label Allocation
  (Bit-map advertisement)
• (draft-shiba-ccamp-gmpls-lambda-labels-01
  .txt)
• Approach 2 Signaling Solve Label Allocation
  (Label Set Null Upstream)

IP Router B
IP Router B
TE-Link of Tributary-E
TE-Link of Tributary-W
NNI-E
NNI-W
NNI-W
NNI-E
TE-Link of Tributary-W
TE-Link of Tributary-E
IP Router A
IP Router A
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Necessity of Extension

• In addition to bit-map information of wavelength
  status, information of TE-Link Selectivity is
  necessary
• Indispensable in multi-ring, ROADM/OXC hybrid
  networks

OXC
ROADM X
Tributary-E
Tributary-W
Tributary-W
Ingress
Egress
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Possible GMPLS Routing Extensions

• Advertise
• Selectable and/or Un-selectable TE-Link lists
  from advertised TE-Link
• Sub-TLV Type TBD
• Length variable
• Name Selectable/Un-Selectable Link Local
  Identifier

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Next Action

• Receiving feed back from several persons, now
  authors feel necessity of an analysis draft with
  the different view of RFC4054.
• Model network architecture having constraint in
  wavelength selectivity and/or TE-Link selectivity
• Analyze signaling procedure to establish LSPs in
  such networks
• Analyze the minimum set of routing and signaling
  extensions
• Thanks Akira Nagata and Akira Chugo (Fujitsu) for
  giving us valuable feed back.