Hybrid Mesh-Ring Optical Networks and Their Routing Consideration

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• Hybrid Mesh-Ring Optical Networks and Their
  Routing Consideration
• Sorrento Networks, Inc.
• Dan Guo
• James Fu
• Leah Zhang
• Nasir Ghani

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High hope for optical meshes

• Mesh
• Efficient Flexible
• Viable in technology
• (from vendors eye)
• OXC
• Routing OSPF extension
• Signaling RSVP-TE extension/GMPLS
• We need look from customers eye!

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Reality checking

• Many customers want to start with Rings
• More comfortable with rings
• Migrate from SONET Rings to optical Rings
• OAM-P issues.
• Customers want reliability
• Rings self-healing robust / fast (lt50ms)
• APS ? O-APS on Optical Rings
• Protection on mesh ?!

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Hybrid Mesh-Ring

• We feel hybrid mesh-ring is more adequate
• Rings with mesh links added
• Rings connected by a mesh
• Even on a mesh, we may want
• to prevision rings for premium traffic
• Open architecture
• Facilitate the migration from rings to meshes!

Migration will be a long process!
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Important Issues

• Slight different routing on mesh-ring
• Topology discovery
• Path computation
• Can we get a path passing ring links only?
• Different light-path requests
• May simplify protection restoration
• Extension for optical rings
• Extension for hybrid mesh-rings.

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OSPF and Opaque LSA

• Extend OSPF for new attributes
• Specify ring links
• A ring link may belong to multiple rings
• Rings are identified by Types and ID
• Ring property TLV
• Ring type BLSR, UPSR, BWPSR.
• Ring ID

Type
Ring ID
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More works to follow

• We hope to see more interests from others.
• More works on Hybrid Mesh-Ring
• Inter-operatability among vendors
• Provision of light-paths across multiple rings
• Fast protection in hybrid mesh-ring.

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Next step

• Recommend IP over Optical WG to initiate the
  study
• Carriers requirement on hybrid mesh-ring
  architecture
• Special issues about routing/signaling/protection.