Multiple applications writing into table 0 (directly or through an Ingress Manager function)
Flow conflict detection mechanisms do not allow for any overlap between flows
Overlap (or rather refinement) should be allowed using priorities to disambiguate:
1. e.g. packets on in_port with certain DMAC to application A, all the rest to application B
How can a generic Ingress Manager ensure that there is no semantic conflict between the flows if the simple non-overlap criterion is not sufficient?

Genius Proposal

Generic Functions for Multi-Network Service Support

Any ODL application can use these to achieve at minimum interference-free co-existence with other applications using the services
Provide support for co-operation between applications with the minimal amount of design-time coordination and hard-coded dependencies
Use APIs to move design-time coordination to run-time
1. Generic infrastructure APIs to avoid direct coupling where possible
2. Direct inter-application (client-server) APIs where necessary for stronger coupling
Factor out commonly used functions into shared services to avoid duplication & waste of resources, e.g.
1. Overlay Tunnel Manager
2. ID manager
3. MD-SAL Util

Models generic interfaces as attachment point for applications
1. Supports Hierarchy of: Port, VLAN, VXLAN Trunk, VXLAN VNI, GRE Tunnel, ...
2. Extendible to arbitrary other types of interfaces (virtual link, VPN interface, …)
3. Interface ID/tag system wide unique identifier in control/data plane.
4. Ingress interface tag stored in metadata

Handles ingress de-capsulation and de-multiplexing
1. Owns table 0 (and possibly additional tables needed for demultiplexing of interfaces)
2. Application bind to interfaces through API and register application-specific instructions/actions to be added to the interfaces ingress flow entry (e.g. write metadata, goto table)
3. Each bound service is assigned to a separate interface handle, no risk of interference on ingress traffic

South bound protocol agnostic
1. Ability to plug in different south bound renderers
2. Provides tunnel monitoring services
3. Handles egress encapsulation and output, service processing priority

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