< draft-ietf-manet-dlep-multi-hop-extension-06.txt		draft-ietf-manet-dlep-multi-hop-extension-06_BB.txt >
	Network Working Group B. Cheng		Network Working Group B. Cheng
	Internet-Draft MIT Lincoln Laboratory		Internet-Draft MIT Lincoln Laboratory
	Intended status: Standards Track L. Berger, Ed.		Intended status: Standards Track L. Berger, Ed.
	Expires: September 12, 2019 LabN Consulting, L.L.C.		Expires: October 11, 2019 LabN Consulting, L.L.C.
	March 11, 2019		April 9, 2019
	DLEP Multi-Hop Forwarding Extension		DLEP Multi-Hop Forwarding Extension
	draft-ietf-manet-dlep-multi-hop-extension-06		draft-ietf-manet-dlep-multi-hop-extension-06
	Abstract		Abstract
	This document defines an extension to the DLEP protocol that enables		This document defines an extension to the DLEP protocol that enables
	the reporting and control of Multi-Hop Forwarding by DLEP capable		the reporting and control of Multi-Hop Forwarding by DLEP capable
	modems.		modems.
	skipping to change at page 1, line 33 ¶		skipping to change at page 1, line 33 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at https://datatracker.ietf.org/drafts/current/.		Drafts is at https://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on September 12, 2019.		This Internet-Draft will expire on October 11, 2019.
	Copyright Notice		Copyright Notice
	Copyright (c) 2019 IETF Trust and the persons identified as the		Copyright (c) 2019 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 2, line 32 ¶		skipping to change at page 2, line 32 ¶
	6. References . . . . . . . . . . . . . . . . . . . . . . . . . 9		6. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
	6.1. Normative References . . . . . . . . . . . . . . . . . . 9		6.1. Normative References . . . . . . . . . . . . . . . . . . 9
	6.2. Informative References . . . . . . . . . . . . . . . . . 10		6.2. Informative References . . . . . . . . . . . . . . . . . 10
	Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 10		Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 10
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
	1. Introduction		1. Introduction
	The Dynamic Link Exchange Protocol (DLEP) is defined in [RFC8175].		The Dynamic Link Exchange Protocol (DLEP) is defined in [RFC8175].
	It provides the exchange of link related control information between		It provides the exchange of link related control information between
	DLEP peers. DLEP peers are comprised of a modem and a router. DLEP		a modem and its DLEP peer router. DLEP defines a base set of
	defines a base set of mechanisms as well as support for possible		mechanisms as well as support for possible extensions. This document
	extensions. This document defines one such extension.		defines one such extension.
	Some modem technologies support mobile ad hoc network (MANET)		Some modem technologies support mobile ad hoc network (MANET)
	forwarding where connectivity to destinations is provided via		forwarding where connectivity to destinations is provided via
	forwarding in intermediate modems. This document refers to		forwarding in intermediate modems. This document refers to
	forwarding by intermediate modems as 'multi-hop forwarding'. example		forwarding by intermediate modems as 'multi-hop forwarding'. example
	using . DLEP Destination messages can be used to report such		using {Missing text?}. DLEP Destination messages can be used to
	reachable destinations, see [RFC8175], but do not provide any		report such reachable destinations, see [RFC8175], but do not provide
	information related to the number or capacity of the hops. The		any information related to the number or capacity of the hops. The
	extension defined in this document enables modems to inform routers		extension defined in this document enables modems to inform routers
	when multi-hop forwarding is being used, and routers to request that		when multi-hop forwarding is being used, and routers to request that
	modems change multi-hop forwarding behavior. The extension defined		modems change multi-hop forwarding behavior. The extension defined
	in this document is referred to as "Multi-Hop Forwarding", where each		in this document is referred to as "Multi-Hop Forwarding", where each
	modem that transmits/sends data to reach a particular destination is		modem that transmits/sends data to reach a particular destination is
	counted as a hop.		counted as a hop.
	It is important to note that the use of the hop control mechanism		It is important to note that the use of the hop control mechanism
	defined in this can result in connectivity changes and even loss of		defined in this document can result in connectivity changes and even
	the ability to reach one or more destinations. The defined mechanism		loss of the ability to reach one or more destinations. The defined
	will report such connectivity changes, but the details of what a		mechanism will report such connectivity changes, but the details of
	router does or how it reacts to such are out scope of this document.		what a router does or how it reacts to such are out scope of this
			document.
	This document defines a new DLEP Extension Type Value in Section 2		This document defines a new DLEP Extension Type Value in Section 2
	which is used to indicate the use of the extension, and three new		which is used to indicate the use of the extension, and three new
	DLEP Data Items in Section 3.		DLEP Data Items in Section 3.
	1.1. Key Words		1.1. Key Words
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and		"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
	"OPTIONAL" in this document are to be interpreted as described in BCP		"OPTIONAL" in this document are to be interpreted as described in BCP
	skipping to change at page 3, line 37 ¶		skipping to change at page 3, line 38 ¶
	The Multi-Hop Forwarding Extension Type Value is TBA1, see Section 5.		The Multi-Hop Forwarding Extension Type Value is TBA1, see Section 5.
	3. Extension Data Items		3. Extension Data Items
	Three data items are defined by this extension. The Hop Count Data		Three data items are defined by this extension. The Hop Count Data
	Item is used by a modem to provide the number of modem hops traversed		Item is used by a modem to provide the number of modem hops traversed
	to reach a particular destination. The Hop Control Data Item is used		to reach a particular destination. The Hop Control Data Item is used
	by a router to request that a modem alter connectivity to a		by a router to request that a modem alter connectivity to a
	particular destination. The Suppress Forwarding Data Item is used by		particular destination. The Suppress Forwarding Data Item is used by
	a router to request that a modem disable multi-hop forwarding on		a router to request that a modem disable multi-hop forwarding on
	either a device or destination basis.		either a device or destination basis. {It's inadvisable to define a
			term that does not mean what you intend it to mean: "Suppress Multi-
			Hop" would be better.}
	3.1. Hop Count		3.1. Hop Count
	The Hop Count Data Item is used by a modem to indicate the number of		The Hop Count Data Item is used by a modem to indicate the number of
	modem that transmits/sends data to reach a particular destination,		modems that transmit/send data to reach a particular destination,
	i.e., hops, between the modem and a specific destination. In other		i.e., hops, between the modem and a specific destination. In other
	words, each hop represents a transmission and the number of hops is		words, each hop represents a transmission and the number of hops is
	equal to the number of transmissions required to go from a router		equal to the number of transmissions required to go from a router
	connected modem to the destination's connected modem. The minimum		connected modem to the destination's connected modem. The minimum
	number of hops is 1, which represents transmission to destinations		number of hops is 1, which represents transmission to destinations
	that are directly reachable via the router's locally connected modem.		that are directly reachable via the router's locally connected modem.
	The data item also contains an indication of when a destination which		The data item also contains an indication of whether a destination
	currently has a hop count of greater than one (1) could be made		which currently has a hop count of greater than one (1) could be made
	directly reachable by a modem, e.g., by re-aiming an antenna.		directly reachable by a modem, e.g., by re-aiming an antenna.
	The Hop Count Data Item SHOULD be carried in the Destination Up,		The Hop Count Data Item SHOULD be carried in the Destination Up,
	Destination Update, Destination Announce Response, and Link		Destination Update, Destination Announce Response, and Link
	Characteristics Response Messages when the Hop Count to a destination		Characteristics Response Messages when the Hop Count to a destination
	is greater than one (1).		is greater than one (1). {Does this 'when >1' clause apply to all 4
			messages, or just Link Characteristic Response messages?}
	A router receiving a Hop Count Data Item can use this information in		A router receiving a Hop Count Data Item can use this information in
	its forwarding and routing decisions, and specific use is out of		its forwarding and routing decisions, and specific use is out of
	scope of this document. The absence of the Hop Count Data Item MUST		scope of this document. The absence of the Hop Count Data Item MUST
	be interpreted by the router as a Hop Count value of one (1).		be interpreted by the router as a Hop Count value of one (1).
	The format of the Hop Count Data Item is:		The format of the Hop Count Data Item is:
	0 1 2 3		0 1 2 3
	0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1		0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	skipping to change at page 5, line 11 ¶		skipping to change at page 5, line 12 ¶
	reach the destination indicated in the message. The special value		reach the destination indicated in the message. The special value
	of 255 (0xFF) is used to indicate that the number of hops is an		of 255 (0xFF) is used to indicate that the number of hops is an
	unknown number greater than one (1). This field MUST contain a		unknown number greater than one (1). This field MUST contain a
	value of at least one (1) if the associated destination is		value of at least one (1) if the associated destination is
	reachable.		reachable.
	A value of zero (0) is used to indicate that processing of a Hop		A value of zero (0) is used to indicate that processing of a Hop
	Control action, see Section 3.2, has resulted in the destination		Control action, see Section 3.2, has resulted in the destination
	no longer being reachable. A zero value MUST NOT be used in any		no longer being reachable. A zero value MUST NOT be used in any
	message other then a Link Characteristics Response Message.		message other then a Link Characteristics Response Message.
			{Contradicts earlier requirement: "Hop Count Data Item SHOULD be
			carried in ... Link Characteristics Response messages when the Hop
			Count to a destination is greater than one (1)"}
	3.2. Hop Control		3.2. Hop Control
	The Hop Control Data Item is used by a router to request a change in		The Hop Control Data Item is used by a router to request a change in
	connectivity to a particular destination, or in multi-hop processing		connectivity to a particular destination, or in multi-hop processing
	on a device wide basis. A router can request multi-hop reachable		on a device-wide basis. A router can request that a multi-hop
	destination be changed to a single hop. A router can also indicate		reachable destination be changed to a single hop. A router can also
	that the modem terminates a previous direct connectivity request to a		indicate that the modem terminates a previous direct connectivity
	particular destination.		request to a particular destination.
	The Hop Control Data Item MAY be carried in a Session Update Message		The Hop Control Data Item MAY be carried either in a Session Update
	sent by a router when the control applies to the whole device, or a		Message sent by a router when the control applies to the whole
	Link Characteristics Request Message when the control applies to a		device, or a Link Characteristics Request Message when the control
	particular destination.		applies to a particular destination.
	A modem that receives the Hop Control Data Item in a Link		A modem that receives the Hop Control Data Item in a Link
	Characteristics Request Message SHOULD take whatever actions are		Characteristics Request Message SHOULD take whatever actions are
	needed to make the change indicated by the data item for the		needed to make the change indicated by the data item for the
	associated destination MAC address. Once the change is made, fails		associated destination MAC address. Once the change is made, fails
	or is rejected, the modem MUST respond with a Link Characteristics		or is rejected, the modem MUST respond with a Link Characteristics
	Response Message containing an updated Hop Count Data Item. Note		Response Message containing an updated Hop Count Data Item. Note
	that other destinations can be impacted as a result of the change and		that other destinations can be impacted as a result of the change and
	such changes are reported in Destination Down and Destination Update		such changes are reported in Destination Down and Destination Update
	Messages. The modem MUST notify the router of each destination that		Messages. The modem MUST notify the router of each destination that
	is not identified in the Link Characteristics Response Message and is		is not identified in the Link Characteristics Response Message and is
	no longer reachable via a Destination Down Message. The modem MUST		no longer reachable via a Destination Down Message. The modem MUST
	also notify the router of each destination that is not identified in		also notify the router of each destination that is not identified in
	the Link Characteristics Response Message and has a changed Hop Count		the Link Characteristics Response Message and has a changed Hop Count
	impacted via a Destination Update Message.		impacted via a Destination Update Message.
	Failures may occur for multiple reasons, for example, the		Failures may occur for multiple reasons, for example, the
	transmission characteristics of the link don't support the one-hop		transmission characteristics of the link don't support the one-hop
	connection at the time of the request. Requests may be rejected by		connection at the time of the request. Requests might be rejected by
	local policy.		local policy.
	A modem that receives the Hop Control Data Item in a Session Update		A modem that receives the Hop Control Data Item in a Session Update
	Message SHOULD take whatever actions are needed to make the change		Message SHOULD take whatever actions are needed to make the change
	indicated by the data item for all known destinations. Once the		indicated by the data item for all known destinations. Once the
	change is made, or fails or is rejected, the modem MUST respond with		change is made, or fails or is rejected, the modem MUST respond with
	a Session Update Response Message with an appropriate Status Code.		a Session Update Response Message with an appropriate Status Code.
	Destination specific impact resulting from the processing of a Hop		Destination specific impact resulting from the processing of a Hop
	Control Data Item in a Session Update Message is provided via		Control Data Item in a Session Update Message is provided via
	Destination Down and Destination Update Messages. The modem MUST		Destination Down and Destination Update Messages. The modem MUST
	skipping to change at page 6, line 28 ¶		skipping to change at page 6, line 32 ¶
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Data Item Type: TBA3		Data Item Type: TBA3
	Length: 2		Length: 2
	Hop Control Actions:		Hop Control Actions:
	An unsigned 16-bit value with the following meaning:		An unsigned 16-bit value with the following meaning:
	+-------+---------------------+		+-------+-----------------------------------------------------+
	| Value | Action |		| Value | Action |
	+-------+---------------------+		+-------+-----------------------------------------------------+
	| 0 | Reset |		| 0 | Reset |
	| | |		| | |
	| 1 | Terminate |		| 1 | Terminate |
	| | |		| | |
	| 2 | Direct Connection |		| 2 | Direct Connection |
	| | |		| | |
	| 3 | Suppress Forwarding |		| 3 | Suppress Forwarding {Consider "Suppress Multi-Hop"} |
	+-------+---------------------+		+-------+-----------------------------------------------------+
	Table 1: Hop Control Actions Values		Table 1: Hop Control Actions Values
	3.2.1. Reset		3.2.1. Reset
	The Reset Action requests that the default behavior be restored.		The Reset Action requests that the default behavior be restored.
	When received in a Session Update Message message, a modem MUST clear		When received in a Session Update Message message, a modem MUST clear
	all control actions that have previously been processed on a device		all control actions that have previously been processed on a device
	wide basis, and revert to its configured behavior. When received in		wide basis, and revert to its configured behavior. When received in
	a Link Characteristics Request Message, a modem MUST clear all		a Link Characteristics Request Message, a modem MUST clear all
	skipping to change at page 7, line 17 ¶		skipping to change at page 7, line 20 ¶
	The Terminate Action is only valid on a per destination basis and		The Terminate Action is only valid on a per destination basis and
	MUST NOT be sent in a Session Update Message message. It indicates		MUST NOT be sent in a Session Update Message message. It indicates
	that a direct connection is no longer needed with the destination		that a direct connection is no longer needed with the destination
	identified in the message. This request has no impact for multi-hop		identified in the message. This request has no impact for multi-hop
	destinations and may fail even in a single hop case, i.e. can result		destinations and may fail even in a single hop case, i.e. can result
	in the Hop Count to the destination not being impacted by the		in the Hop Count to the destination not being impacted by the
	processing of the request.		processing of the request.
	3.2.3. Direct Connection		3.2.3. Direct Connection
	The Direct Connection is only valid on a per destination basis and		The Direct Connection Action is only valid on a per destination basis
	MUST NOT be sent in a Session Update Message message. It indicates		and MUST NOT be sent in a Session Update Message message. It
	that the modem SHOULD attempt to establish a direct connection with		indicates that the modem SHOULD attempt to establish a direct
	the destination identified in the message. This action SHOULD only		connection with the destination identified in the message. This
	be sent for destinations for which the Hop Count is greater than 1		action SHOULD only be sent for destinations for which the Hop Count
	and has the P-Bit set in the previously received Hop Count Data Item.		is greater than 1 and has the P-Bit set in the previously received
	Results of the request for the destination identified in the message		Hop Count Data Item. Results of the request for the destination
	are provided as described above.		identified in the message are provided as described above.
	3.2.4. Suppress Forwarding		3.2.4. Suppress Forwarding
	The Suppress Forwarding Action is used by a router to indicate to its		The Suppress Forwarding Action is used by a router to indicate to its
	peer that multi-hop forwarding performed by the modem is to be		peer that multi-hop forwarding performed by the modem is to be
	suppressed. A router may request that multi-hop forwarding may be		suppressed. A router can request that multi-hop forwarding is
	suppressed on a device wide or destination specific basis.		suppressed on a device wide or destination specific basis.
	A modem which receives the Suppress Forwarding Data Item in a Session		A modem that receives the Suppress Forwarding Data Item in a Session
	Update Message MUST suppress multi-hop forwarding on a device wide		Update Message MUST suppress multi-hop forwarding on a device wide
	basis. This means that data traffic originating from the modem's		basis. This means that data traffic originating from the modem's
	peer router SHALL only be sent by the modem to destinations that are		peer router SHALL only be sent by the modem to destinations that are
	one modem hop away, and that any data traffic received by the modem		one modem hop away, and that any data traffic received by the modem
	from another modem that is not destined to the peer router SHALL be		from another modem that is not destined to the peer router SHALL be
	dropped. Impact to destination hop counts are provided to the router		dropped. The impact on destination hop counts is provided to the
	by the modem as described above.		router by the modem as described above.
	A modem which receives the Suppress Forwarding Data Item in a Link		A modem that receives the Suppress Forwarding Data Item in a Link
	Characteristics Request Message MUST suppress multi-hop forwarding		Characteristics Request Message MUST suppress multi-hop forwarding
	for only the destination indicated in the message. This means that		for only the destination indicated in the message. This means that
	data traffic originating from the modem's peer router SHALL be sent		data traffic originating from the modem's peer router SHALL be sent
	by the modem to the destination indicated in the Link Characteristics		by the modem to the destination indicated in the Link Characteristics
	Request Message only when it is one modem hop away. Notably, data		Request Message only when it is one modem hop away. Notably, data
	traffic received by the modem from another modem can be forwarded by		traffic received by the modem from another modem can be forwarded by
	the modem per its normal processing. Results are provided as		the modem per its normal processing. Results are provided as
	described above.		described above.
	4. Security Considerations		4. Security Considerations
End of changes. 19 change blocks.
	52 lines changed or deleted		59 lines changed or added
This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/