OTN physical topology

1
OTN physical topology
B
C
A
D
E
F
F
OTU2/Och
2
OTN virtual topology
B
C
A
D
E
F
F
OTU2/Och
ODU1/ODU2
3
Why virtual topology?

• Not congruent with the parent topology (physical
  or virtual)
• Different qualities (protection, transparency)
• Sets limits on resources allowed to be used by
  intended clients
• CP routing should allow an easy way to constrain
  client ODUs to one or more virtual topologies

4
OTN virtual topology
B
C
A
D
E
F
F
OTU2/Och
ODU1/ODU2
5
Why RFC4203 ISCD sub-TLV?

• Exists and is used already, designed to be used
  in multi-layer environments
• Technology independent
• Sufficient
• Switching capability virt. topology ID
• OTN_LO, OTN_HO, OTN_SHO, etc. (maximum 5)
• Flexible
• allows advertising different signals and
  LSP bandwidths per role

6
FA problem

• FA links depend on their parents, grand parents,
  etc.
• Complex SRLG configuration is required