ASON routing implementation and testing ASON routing extensions

1
ASON routing implementation and testing ASON
routing extensions

• IETF 76 Hiroshima Nov09
• L. Ong (Ciena)
• lyong_at_ciena.com

2
Draft on ASON Routing Testing Experience

• CCAMP work on ASON Routing is Experimental
• No standard codepoints have been allocated
• OIF has experimented with similar extensions
• Transport-only instance of OSPF (no IP routing)
• Advertising reachable local address prefixes
• Advertising local/remote TE router IDs for
  scoping of routing information (Li/Pi mapping)
• Details in draft-ong-gmpls-ason-routing-exper-00.t
  xt
• OIF would like to see this work on Standards
  Track
• Contribution provides input on testing of similar
  extensions
• Tested at interops since 2003, most recently 2007
  2009
• At least 7 independent implementations each time
• OIF extensions are offered for CCAMP use
• Can these extensions be adopted directly?
  Running code
• Will experience help to move work to Standards
  Track?

3
OIF Bandwidth advertisement extension

• OIF ISCD extension
• Combines advertisement of bandwidth for multiple
  signal types in one ISCD
• Advertises separate availability per signal type
• Why
• Standard signal types are placed along specific
  boundaries
• Availability for new connections at STS-3c/VC-4
  or STS-12c/VC-4-4 depends on position of occupied
  timeslots
• Cannot be determined from total unreserved bytes
  per second
• Combination is more efficient than separate ISCD
  or LSA per signal type
• Most link attributes are common across signal
  types, combining reduces duplication
• Although these are layers in ITU-T sense, they
  share the same switching matrix

4
Draft on Extended Routing Functions

• Follow up on previous liaison providing requested
  detail
• Layer-scoped Link Attributes
• Layer VC-3, VC-4
• Connections available at a particular layer
• Attributes (e.g., metric) that differ for a layer
• Local Connection Type
• CP or TCP (switch or terminate)
• Within layer, not multilayer/adaptation-related
• Looking for better solution than ISCD/IACD
• NSAP format Local Node Prefix
• In addition to IPv4 and IPv6 formats
• New draft submitted with more detail
• draft-theillaud-gmpls-ason-routing-add-fcts-01.txt

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Layer-scoped link attributes

• G.7715.1 specifies a set of link characteristics
  specific to a particular layer network
• Most of these attributes would be common across
  layer networks supported by a particular link
• However, OIF members believe that some attributes
  may take different values for different TDM
  layers, esp
• Link available bandwidth
• TE metric
• Possibly others such as administrative group
• Therefore, the ability to support advertisement
  of common attributes on a per link basis but also
  to allow some attributes to be scoped to a layer
  would be highly useful

6
Layer-scoped link attributes potential solutions

• Advertising multiple TE LSAs for a given link,
  the LSA itself scoping the attributes
• Is this allowed by GMPLS protocol?
• Is this an efficient mechanism?
• New sub-TLV allowing to scope some attributes to
  a specific layer
• Proposed in the draft, see draft for details

7
Link associated local connection type

• Section 4.1 in draft-ietf-ccamp-gmpls-ason-routing
  -ospf-09.txt proposes to rely on the ISCD(s)
  advertised by each link endpoints, to infer the
  link local connection type
• Inferring the local connection type from ISCDs is
  not sufficient
• See example
• An explicit local connection type parameter is
  desirable
• detailed proposed extension contained in the draft

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Backup
9
Link Characteristics
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Link associated local connection type
Node1
Node2

• Switching functions
• HO VC-4
• HO VC-3

• Switching functions
• LO VC-3

• For this link, both nodes would advertise the
  same ISCD for the VC-3 layer. Node 1 would in
  addition advertise an ICSD for the VC-4 layer.
• A path computation entity would believe that a HO
  VC-3 connection can be set up across this link,
  while it cannot
• Node2 terminates both HO VC-4 and HO VC-3
  layers
• Node2 can switch a LO VC-3 layer (from a
  terminated HO VC-4 signal)

11
Thanks to contributors

• Richard Graveman (Department of Defense)
• Hans-Martin Foisel (Deutsche Telekom)
• Thierry Marcot (France Telecom)
• Evelyne Roch (Nortel Networks)
• Jonathan Sadler (Tellabs)
• Yoshiaki Sone (NTT Corporation)
• Takehiro Tsuritani (KDDI RD Laboratories)
• Xihua Fu (ZTE)