2.6.2 Forwarding and Control Element Separation (forces)

NOTE: This charter is a snapshot of the 76th IETF Meeting in Hiroshima, Japan. It may now be out-of-date.

Last Modified: 2008-11-17


Patrick Droz <dro@zurich.ibm.com>
Jamal Hadi Salim <hadi@mojatatu.com>

Routing Area Director(s):

Ross Callon <rcallon@juniper.net>
Adrian Farrel <adrian.farrel@huawei.com>

Routing Area Advisor:

Ross Callon <rcallon@juniper.net>

Mailing Lists:

General Discussion: forces@peach.ease.lsoft.com
To Subscribe: listserv@peach.ease.lsoft.com
In Body: (un)subscribe forces
Archive: http://www.ietf.org/mail-archive/web/forces/

Description of Working Group:

The emergence of off-the-shelf network processor devices that
the fast path or forwarding plane in network devices such as routers,
along with the appearance of a new generation of third party
routing, and other router control plane software, has created the need
for standard mechanisms to allow these components to be combined into
functional wholes. ForCES aims to define a framework and associated
mechanisms for standardizing the exchange of information between the
logically separate functionality of the control plane, including
entities such as routing protocols, admission control, and signaling,
and the forwarding plane, where per-packet activities such as packet
forwarding, queuing, and header editing occur. By defining a set
of standard mechanisms for control and forwarding separation, ForCES
will enable rapid innovation in both the control and forwarding
A standard separation mechanism allows the control and forwarding
planes to innovate in parallel while maintaining interoperability.

The products of this working group will be:

o A set of requirements for mechanisms to logically
  separate the control and data forwarding planes of
  an IP network element (NE)

o An applicability statement for the ForCES model
  and protocol

o Informational RFCs as necessary documenting current
  approaches to the functional model and controlled
  objects therein

o An architectural framework defining the entities
  comprising a ForCES network element and identifying
  the interactions between them.

o A description of the functional model of a
  Forwarding Element

o A formal definition of the controlled objects in the
  functional model of a forwarding element. This
  includes IP forwarding, IntServ and DiffServ QoS. An
  existing specification language shall be used for
  this task.

o Specification of IP-based protocol for transport of the
  controlled objects. When the control and forwarding devices
  are separated beyond a single hop, ForCES will make use of an
  existing  RFC2914 compliant L4 protocol with adequate reliability,
  security and congestion control (e.g. TCP, SCTP) for transport

The main focus area of the working group will be control and
forwarding separation for IP forwarding devices where the
control and forwarding elements are in close (same room/small
number of hops) or very close (same box/one hop) proximity. Other
scenarios will be considered but at not the main focus of the
work. The functional model of the forwarding element will include
QoS (DiffServ and IntServ) capabilities of modern networking
devices such as routers.  In order to minimize the effort to
integrate forwarding elements and control elements, a mechanism
for auto discovery and capability information exchange will form
an integral part of the standardized interface.

ForCES will coordinate with other standards bodies and working
groups as appropriate. Examples of such bodies include IETF/GSMP,
IETF/Megaco, the Network Processing Forum (NPF), the Multiservice
Switching Forum (MSF), IEEE P1520, and SoftSwitch. ForCES will
review relevant protocol efforts such as GSMP and Megaco and will
extend or reuse them if appropriate. If protocol reuse is
accepted as satisfactory for fulfilling the ForCES requirements
then ForCES may recharter to adopt specific deliverables around
the selected protocol.

Goals and Milestones:

Done  Submit requirements document to IESG
Done  Submit framework document to IESG
Done  Submit forwarding element functional model document to IESG
Mar 2005  Submit formal definition of controlled objects in functional model
Done  Submit protocol selection/definition document to IESG
Mar 2009  Submit applicability statement to IESG


  • draft-ietf-forces-applicability-07.txt
  • draft-ietf-forces-model-16.txt
  • draft-ietf-forces-protocol-22.txt
  • draft-ietf-forces-mib-10.txt
  • draft-ietf-forces-sctptml-08.txt
  • draft-ietf-forces-interoperability-04.txt
  • draft-ietf-forces-implementation-report-00.txt
  • draft-ietf-forces-implementation-experience-00.txt

    Request For Comments:

    RFC3549 I Linux Netlink as an IP Services Protocol
    RFC3654 I Requirements for Separation of IP Control and Forwarding
    RFC3746 I Forwarding and Control Element Separation (ForCES) Framework

    Meeting Minutes


    Agenda etc
    WG Status
    SCTP update
    Implementation Report
    Implementation Experience
    tcpdump howto