I-TAG

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I-TAG
A multiplexing tag forservice instance
scalingin Provider Bridged Networks Mick
Seaman mick_seaman_at_ieee.org
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I-TAG

• Purpose
• Architecture
• Format
• Context

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ITAG Purpose

• Allow upto 220 service instances in a PBN
• Particularly to address the E-LINE reqmt
• Use for E-LAN, E-TREE optional/as reqd(more
  later on benefits of choice)
• Leverages existing solutions
• Complements .1Q, .1ad, .1D
• GVRP, GMRP
• No major new protocols required for scaling

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ITAG Architecture

• I-tagging systems are end-stations on a
  provider backbone or core network.
• The backbone can be either bridged (.1D) or
  virtual bridged (.1Q /.1ad)
• If backbone is .1Q then tagging, detagging
  (ingress and egress) rules are exactly as they
  are today
• Tag can be added/not added and tag value
  dependent on frame C-VID just as for dual bridge
  model in .1Q
• ltltsee Paul Bottorffs slides from Monday for
  diagramgtgt

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I-TAG Format (1)

• I-TAG EtherType (16 bits)
• I-TAG TCI (Tag Control Info, i.e. version,
  flags8 bits)
• PRI/DE (priority, drop eligible 4 bits)
• SID (Service Instance ID 20 bits)
• User DA (Destn. Address of conveyed frame 48
  bits)
• User SA (Source Address of conveyed frame 48
  bits)
• 16 128 bits total

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I-TAG Format (2)
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I-TAG Context