MPLS-TP BFD for CC-CV proactive and RDI functionalities

	draft-fulignoli-mpls-tp-bfd-cv-proactive-and-rdi-01.txt
	draft-boutros-mpls-tp-cc-cv-00.txt
	MPLS WG, 75th IETF - Stockholm, Sweden

Authors

	Annamaria Fulignoli (Ericsson)
	Sami Boutros (Cisco Systems )
	Martin Vigoureux (Alcatel-Lucent)

Goals of draft

	Extend BFD for proactive Connection Verification and Reverse Defect Indication
	Remain Backwards Compatible
	Specify Interoperability

Requirements

	Continuity Check: monitors the integrity of the continuity of the path;
	Connectivity Verification: monitors the integrity of the routing of the path between sink and source
			Detect unintended connectivity (e.g. mismerging or misconnection)
	RDI: enable an End Point to report a fault or defect condition that it detects on a PW, LSP or Section
	MUST operate proactively for:
		bidirectional and unidirectional p2p
		unidirectional p2mp connection

 Overview

	CC and RDI are supported by base BFD
		RDI is simply a mapping of specific BFD diagnostics
	Open Issue: There are scenarios where CC/CV may not be running and RDI must be sent
	MPLS-TP specifies constraints on default configuration for timer values and detect multiplier
	No changes to the BFD state machine
	Operating mode is Asynchronous

Proposed Solution Overview

	Two modes of operation
		CC
			Existing ACH codepoint (0x0007) - BFD w/o IP/UDP
			Supports CC & RDI
		CV
			New ACH codepoint
			Supports CV & RDI
				Implicit CC
		Both apply to PWs, MPLS LSPs (including tandem connection monitoring), and sections

CV Mode

	New ACH codepoint
	Header contains the Source MEP Identifier (unique per transport path)
		Session will not come up if the expected MEP-ID is not received
	The BFD control packet format is identical to CC mode
	The BFD session is declared Down if an unexpected MEP identifier is received (mis-connectivity defect)

Default Behavior both CC and CV mode

	BFD timer values are set as follows
		The configured packet transmission is carried in “Desired Min TX Interval field”
		Timer and detect multiplier re-negotiation is optional and disabled by default
		Active Role is default, passive is optional
		Bidirectional p2p settings:
			“Required Min RX Interval field”  MUST be the same as “Desired Min TX Interval field”
		Unidirectional p2p and p2mp session MUST set the “Required Min RX Interval field“ to 0
	The session will NOT reach UP if expected timers values and detect multiplier are not the same

Next Steps

	Resolve open issues
	Merge the 2 drafts to draft-asm-mpls-tp-bfd-cc-cv and ask for workgroup adoption..

QUESTIONS ?