1. TAPI Topology & Connectivity Enhancements Proposal for v3.0
Karthik Sethuraman, NEC
Aug 13, 2019
*animated

2. TAPI 2.2 v/s RFC8345 Topology Models: Simplified View
Composition (YANG list)
Aggregation (YANG leafref + require_instance=true)
Association (YANG leafref + require_instance=false)
Augment (YANG augment + uses + container)
Augment (YANG augment + uses)
TapiContext (ROOT)
Augment
TopologyContext
Networks (ROOT)
Topology
Network
Link
Link
Node
Node
NodeEdgePoint
TerminationPoint
2..* 2
Tapi 2.2 Topology
RFC 8345 Topology
* all TAPI & RFC 8345 associations not shown

3. TAPI 3.0 & RFC8345 Topology Models: Merge Proposal – opt1
Composition (YANG list)
Aggregation (YANG leafref + require_instance=true)
Association (YANG leafref + require_instance=false)
Augment (YANG augment + uses + container)
Augment (YANG augment + uses)
TapiContext (ROOT)
Augment
TopologyContext
Networks (ROOT)
Augment
TopologyContext
Topology
Network
Augment
Topology
Link
Link
Augment
Link
Node
Node
Augment
Node
NodeEdgePoint
TerminationPoint
Augment
NodeEdgePoint
2..* 2
2..*
Tapi 2.2 Topology
RFC 8345 Topology
Tapi 3.0 Topology
* all TAPI & RFC 8345 associations not shown

4. TAPI 3.0 & RFC8345 Topology Models: Merge Proposal – opt2
Composition (YANG list)
Aggregation (YANG leafref + require_instance=true)
Association (YANG leafref + require_instance=false)
Augment (YANG augment + uses + container)
Augment (YANG augment + uses)
TapiContext (ROOT)
Augment
TopologyContext
Networks (ROOT)
Augment
TopologyContext
Topology
Network
Augment
Topology
Link
Link
Augment
Link
Node
Node
Augment
Node
NodeEdgePoint
TerminationPoint
Augment
NodeEdgePoint
2..* 2
Tapi 2.2 Topology
RFC 8345 Topology
Tapi 3.0 Topology
* all TAPI & RFC 8345 associations not shown

5. Topology & Connectivity Concepts

6. Recursive Node & Topology aspects of Forwarding Domain
Node aspect of FD
Topology aspect of FD
Observer 01 A
FD (Node)
Node Edge Point
Link
01.1
Service Interface Point
FD (Topology)
Mapping
TAPI Context N
Context appears as a Topology N of one Node A and SIPs (off-network relationships/Links) 02 01 A
01.1 C
Node-A appears a Topology of
Nodes B & C and Link B-C
C.3
C.4
C.1
C.2 11 14 16 17 18 12 13 15
04`
01``
01`
01.n
Node-C appears a Topology of Nodes C.1-C.4 & Links between them 04 B
02.1 03 C
02`
02.n

7. Recursive Connectivity & Topology aspects of Forwarding
Node aspect of FD
Topology aspect of FD
Observer 01 A
FD (Node)
Node Edge Point
Link
01.1
Service Interface Point
FD (Topology)
Mapping
Connection Topology
Connection
Connection End Point
TAPI Context
Top-level “Network” Connection A N 02 01 A
01.1 C
Connection A appears a route of
Connections B,C and Link B-C
C.3
C.4
C.1
C.2 11 14 16 17 18 12 13 15
04`
01``
Connection C
appears as a route of Connections C.1,C.3,C.4 & in-between Links
01`
01.n 04 B
02.1 C 03
02`
02.n

8. TAPI Topology & Connectivity Instances Tree view (example1)
Topology w/ Connectivity N N
Topology A 01
Node
Connection Topology
Connection
Node Edge Point
Connection End Point
Reference/Pointer
Composition A A A 01 01 01 02 02 02 A A B B B 02 02 02 02 03 03 03 03 C C C 01 01 01
Node A&C Topologies always needs to be fully expanded to access NEPs 01, 02 04 04 04 C C C1 C1 C1 01 01 01 01 11 11 11 10 12 11 C3 C3 C2 13 13 13 12 14 14 14 13 C4 C4 C4 04 04 04 04 18 18 18 05

9. example1: Single-level Topology, Network-Node (Single) abstraction
Node Edge Point 01 A
Node
Reference (pointer)
Link
Topology
Node Encapsulates Topology
Service Interfc Point
Connection End Point
Connection End Point Reference (pointer)
Connection
Connectivity Service
Single Node abstraction – for simple TAPI applications/clients that does not want to concern itself with Network topology & routing
Ability to expose top-level “Network” Connection only – No way to represent top-level Connection’s route or its lower-level decomposed “cross” connections
Node Topology A 01 02 01 02
TAPI Context

10. example2: Single-level Topology, Network abstraction
Node Edge Point 01 A
Node
Reference (pointer)
Link
Topology
Node Encapsulates Topology
Service Interfc Point
Connection End Point
Connection End Point Reference (pointer)
Connection
Connectivity Service
Probably not an very useful example, although allowed by TAPI model – serves as a base for following 2 practical sub-cases
Exposes “Cross” Connections only – NO top-level Node or top-level “Network” Connection or its Connection-topology/route
C.1.1 21
C.1.3 01 01 26 10 22 02
C.1.2 25 23 24 11
C.3 08
C.4 B 06 05 04 03 02 07 12
C.2.1 31 32 33
C.2.3 36
C.2.2
Network Topology 13 34 35
TAPI Context

11. example2a: Single-level Topology, Network abstraction with implicit Node
Node Edge Point 01 A
Node
Reference (pointer)
Link
Topology
Node Encapsulates Topology
Service Interfc Point
Connection End Point
Connection End Point Reference (pointer)
Connection
Connectivity Service
Implicit Top-level Singe Node (and its encapsulated Topology)
Provides ability to expose top-level “Network” Connection and its Connection-topology/route as well as it decomposed lower-level “Cross” Connections
Top-level Connection is NOT bounded by an explicit Node, while lower-level connections have a bounding Node
C.1.1
C.1.3 01 21 01 26 10 22 02
C.1.2 25 23 24 11
C.3 08
C.4 B 06 05 04 03 02 07 12
C.2.1 31 32 33
C.2.3 36
C.2.2
Network Topology 13 34 35
TAPI Context

12. example2b: Single-level Topology, Network abstraction /w multi-level implicit Nodes
Node Edge Point 01 A
Node
Reference (pointer)
Link
Topology
Node Encapsulates Topology
Service Interfc Point
Connection End Point
Connection End Point Reference (pointer)
Connection
Connectivity Service
A variation of example 2a – but with multiple levels of Implicit Nodes (and their encapsulated Topology hierarchy)
Provides ability to expose top-level “Network” Connection and its Connection-topology/route as well as multiple levels of Connection decomposition
Top-level Connection as well as intermediate-level connections are NOT bounded by an explicit Node, while lowest-level connections have a bounding Node
C.1.1
C.1.3 01 21 01 26 10 22 02
C.1.2 25 23 24 B 11
C.3 08
C.4 03 02 06 05 04 07 12
C.2.1 31 32 33
C.2.3 36
C.2.2
Network Topology 13 34 35
TAPI Context

13. example3: 2-level Topology, (explicit) Node + Network abstraction
Node Edge Point 01 A
Node
Reference (pointer)
Link
Topology
Node Encapsulates Topology
Service Interfc Point
Connection End Point
Connection End Point Reference (pointer)
Connection
Connectivity Service
This abstraction emerges from example 2a, with distinction of an Explicit bounding Node for “Network” Connection which allows for clean representation of forwarding capability prior to setting up of connectivity
Provides ability to expose top-level “Network” Connection and its Connection-topology/route as well as its decomposed lower-level “Cross” Connections
All Connections are bounded by an explicit Node
Node Topology A 01 02 01 02
Network Topology
C.1.1
C.1.3 01 21 26 10 22
C.1.2 25 23 24 11
C.3 08
C.4 B 06 05 04 03 02 07 12
C.2.1 31 32 33
C.2.3 36
C.2.2 13 34 35
TAPI Context

14. example4: Multi-level Partitioning Topology abstraction
Node Edge Point 01 A
Node
Reference (pointer)
Link
Topology
Node Encapsulates Topology
Service Interfc Point
Connection End Point
Connection End Point Reference (pointer)
Connection
Connectivity Service
Node Topology 01 A 02 01 02
Topology exposes Boundary NEPS 04 03 C B 02 01 01 04 03 02
Topology A
Node aggregates NEPs exposed by Encapsulated Topology
Topology C 02 01 01
C.1 01
C.4 10 05 04 04 11
C.3 08
C.2 12 06 07 13
C.1.1 01 21
C.1.3 26 10 10 01 22
C.1.2 25
Topology C.1 23 24
Emerges from example 2b - with distinction of multiple levels of Explicit Nodes (and their encapsulated Topology hierarchy)
Provides ability to expose multi-level Connections, each bounded by an explicit Node 11 11 12 12
Topology C.2
C.2.1 31 32 33
C.2.2
C.2.3 36 13 34 13
TAPI Context 35