Forwarding and Control Element Separation (forces)

Last modified: 2015-03-24

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Description of Working Group:

The ForCES working group has created a framework, requirements, a solution protocol, a logical function block library, and other associated documents in support of Forwarding and Control Element Separation.

Drawing on the experience gained from developing the standards and from many efforts using this architecture, the ForCES working group is now working on a set of additions to the model, the protocol, and the libraries.

The following 5 work items are the chartered tasks of this working group:

o Extensions to Model and Protocol

This work is to address a set of extensions to the base model and protocol resulting in updates to RFCs 5810 and 5812. This effort will produce 2 Standards Track documents (one for the model and another for the protocol).

The model extensions will:
1. Allow compound metadata
2. Allow optional default values for datatypes
3. Allow optional access-type for datatypes inside complex components
4. Define new base type: Bitmap
5. Define new events to monitor states.

The protocol extensions will:
1. Support table range query
2. Support table append
3. Define additional return codes to reduce ambiguity
4. Define data packing rule for bitmap datatype.

o Inter-FE Connectivity

ForCES processing is often spread across multiple Forwarding Elements (FEs). The original framework identified the interface between FEs as the "Fi" reference point. Protocol and Logical Function Block (LFB) mechanisms to carry metadata across the Fi interface are needed. This effort will produce a standards track document defining the protocol on the wire to address this need, and the LFBs used to represent the Interfaces for sending and receiving such information. It is expected that this work will draw heavily on existing protocol and LFB definitions.

o Parallelization

An FE can implement an LFB chain with parallelization, but the currently-defined mechanism has no means to represent when synchronization is needed, or to allow the CE to specify where it believes such parallelism is useful. This work item will produce a single standards track document to improve the handling of this case.

o Subsidiary Management

Deployment experience has demonstrated the value of using ForCES to control the Forwarding Element Manager (FEM) by creating an LFB to represent its function using the same encoding rules as for any other LFB. This allows it to be controlled by the same Control Element (CE). This work item assumes the presence of an initially booted FE whose configuration could then be updated at runtime via an FEM LFB for runtime config purposes (e.g., by adding a new CE and its associated IP address). This work item can also be useful in addressing control of virtual FEs where individual FEM Managers can be addressed to control the creation, configuration, and resource assignment of such virtual FEs within a physical FE. This work would result in a standards track LFB FEM library RFC.

In addition to the specific work items listed above, the working group will allow discussions and review work of how to use ForCES to model topics of interest to Network Function Virtualization, I2RS, or OpenFlow. It is understood that the primary responsibility for such documents lives with other working groups, individual contributions, or other standards bodies.

Goals and Milestones

Submit requirements document to IESG
Submit framework document to IESG
Submit forwarding element functional model document to IESG
Submit formal definition of controlled objects in functional model
Submit protocol selection/definition document to IESG
Request for Publication of Standards Track document specifying model changes
Request for Publication of Standards Track document specifying protocol changes
Feb 2014
Request for publication of Subsidiary management LFB
Mar 2014
Request for publication of Inter-FE LFB
Request for publication of parallelization LFBs
Apr 2014
Recharter or shutdown

Request for Comments


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