Use Cases of
Information Distribution over GRASP
(draft-liu-anima-grasp-distribution-03)
Bing Liu (speaker), Sheng Jiang
@Anima WG, ietf97, November 2016
1
Reminder: Distribution Scenarios
• Whole Domain Distribution
– One node distributes the message to all neighbors.
– Normal GRASP Flood behavior
• Selective Distribution (Today’s discussion focus)
– One node distributes the message to the
neighbors matching a/a set of conditions
• Incremental Distribution
– The distribution only goes to the nodes that newly
get online.
– This might mostly happen between neighbors.
2
Reminder: Selective Flooding Mechanism
• Selective flooding criteria
– Matching condition: a set of matching rules (e.g. "Device
role=IPRAN_RSG")
– Matching object: the object that the match condition
would be applied to. (e.g., the node itself or its neighbors)
– Action: what behavior the node needs to do when the
matching object matches or failed the matching condition.
(e.g., forwarding or discarding the distributed message)
• Node behavior
1) The distribution initial node Includes the Selecting Criteria
in the distribution message.
2) The receiving node does the matching indicated by the
Selecting Flooding Criteria
3
Use Case #1 for Selective Distribution
• Selected flooding in hierarchical
network
– E.g. IPRAN as the figure shows
– Large amount of access gateways
(CSG), but limited aggregation
gateways (ASG) and core network
gateways (RSG)
– Some information is not necessary to
flood to the CSGs. (E.g. a network
policy of VPN mechanisms selection)
• Selective flooding criteria
– Matching condition:
• Role=RSG or ASG
RSG
Ring
ASG
Ring
CSG
Ring
CSG
Ring
ASG
Ring
CSG
Ring
CSG
Chain
– Matching object:
• Neighbor devices
– Action:
• If Match=True, forward the
flood message to the neighbor
• If Match=False, discard the
flood message to the neighbor
CSG
Ring
CSG
Chain
4
Use Case #2 for Selective Distribution
• Selected flooding within a
deterministic path
– E.g. flood within a MPLS LSP
– The LSP has been set up
– One node distributes the information
to all the LSRs of the LSP. (e.g. adjust
the reserved bandwidth)
• Selective flooding criteria
– Matching condition:
• vpn-instance=WCDMA-VPN
– Matching object:
• interfaces
– Action:
• If Match=True, forward the flood
message to the interface
• If Match=False, discard the flood
message to the interface
5
Use Case #3 for Selective Distribution
• Selected flooding for ACP set
up
– ACP topology should align with the
physical topology as much as possible
– An Anima-Enabled switch should not
forwarding the ACP discovery to the
nodes attached to it
Node 1
Node 2
(a switch)
• Selective flooding criteria
– Matching condition:
• Role=switch
– Matching object:
• self
– Action:
• If Match=True, discard the flood
message (or M_Discovery )
• If Match=False, continue the flood
– Node 1 only builds ACP with Node 2
– Node 2 builds ACP with the attached
nodes respectively
6
Semantic Definition of Selective Criteria
• It’s challenging to sort out a unified model
which can contain miscellaneous semantics
• Case by case approach?
– Figure out the important semantics currently
needed (e.g. the 3 use cases)
– Allowing private semantic among a domain
7
Comments?
Thank you!
IETF97, Seoul
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