Forwarding and Control Element Separation (forces) -------------------------------------------------- Charter Last Modified: 2008-08-21 Current Status: Active Working Group Chair(s): Patrick Droz Jamal Hadi Salim Routing Area Director(s): Ross Callon David Ward Routing Area Advisor: Ross Callon 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 implement the fast path or forwarding plane in network devices such as routers, along with the appearance of a new generation of third party signaling, 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 planes. 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 purposes. 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 Mar 2005 Submit applicability statement to IESG Done Submit protocol selection/definition document to IESG Internet-Drafts: Posted Revised I-D Title ------ ------- -------------------------------------------- Aug 2003 Oct 2008 ForCES Forwarding Element Model Sep 2004 Oct 2008 ForCES Protocol Specification Jan 2006 Sep 2008 ForCES MIB Nov 2007 Jul 2008 SCTP based TML (Transport Mapping Layer) for ForCES protocol Request For Comments: RFC Stat Published Title ------- -- ----------- ------------------------------------ RFC3549 I Jul 2003 Linux Netlink as an IP Services Protocol RFC3654 I Dec 2003 Requirements for Separation of IP Control and Forwarding RFC3746 I Apr 2004 Forwarding and Control Element Separation (ForCES) Framework