draft-werner-nsis-natfw-nslp-statemachine-04.txt		draft-werner-nsis-natfw-nslp-statemachine-03.txt
	NSIS C. Werner		NSIS C. Werner
	Internet-Draft N. Steinleitner, Ed.		Internet-Draft X. Fu
	Expires: September 6, 2007 X. Fu		Expires: December 27, 2006 Univ. Goettingen
	Univ. Goettingen
	H. Tschofenig		H. Tschofenig
	Siemens		Siemens
	C. Aoun		C. Aoun
	ENST		ENST
	March 5, 2007		N. Steinleitner, Ed.
			Univ. Goettingen
			June 25, 2006
	NAT/FW NSLP State Machine		NAT/FW NSLP State Machine
	draft-werner-nsis-natfw-nslp-statemachine-04.txt		draft-werner-nsis-natfw-nslp-statemachine-03.txt
	Status of this Memo		Status of this Memo
	By submitting this Internet-Draft, each author represents that any		By submitting this Internet-Draft, each author represents that any
	applicable patent or other IPR claims of which he or she is aware		applicable patent or other IPR claims of which he or she is aware
	have been or will be disclosed, and any of which he or she becomes		have been or will be disclosed, and any of which he or she becomes
	aware will be disclosed, in accordance with Section 6 of BCP 79.		aware will be disclosed, in accordance with Section 6 of BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF), its areas, and its working groups. Note that		Task Force (IETF), its areas, and its working groups. Note that
	skipping to change at page 1, line 39		skipping to change at page 1, line 40
	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."
	The list of current Internet-Drafts can be accessed at		The list of current Internet-Drafts can be accessed at
	http://www.ietf.org/ietf/1id-abstracts.txt.		http://www.ietf.org/ietf/1id-abstracts.txt.
	The list of Internet-Draft Shadow Directories can be accessed at		The list of Internet-Draft Shadow Directories can be accessed at
	http://www.ietf.org/shadow.html.		http://www.ietf.org/shadow.html.
	This Internet-Draft will expire on September 6, 2007.		This Internet-Draft will expire on December 27, 2006.
	Copyright Notice		Copyright Notice
	Copyright (C) The IETF Trust (2007).		Copyright (C) The Internet Society (2006).
	Abstract		Abstract
	This document describes the state machines for the NSIS Signaling		This document describes the state machines for the NSIS Signaling
	Layer Protocol for Network Address Translation/Firewall signaling		Layer Protocol for Network Address Translation/Firewall signaling
	(NAT/FW NSLP). A set of state machines for NAT/FW NSLP entities at		(NAT/FW NSLP). A set of state machines for NAT/FW NSLP entities at
	different locations of a signaling path are presented in order to		different locations of a signaling path are presented in order to
	illustrate how NAT/FW NSLP may be implemented.		illustrate how NAT/FW NSLP may be implemented.
	Table of Contents		Table of Contents
	skipping to change at page 2, line 27		skipping to change at page 2, line 28
	6. State machine for the NAT/FW NI/NR+ . . . . . . . . . . . . . 9		6. State machine for the NAT/FW NI/NR+ . . . . . . . . . . . . . 9
	7. State machine for the NAT/FW NF . . . . . . . . . . . . . . . 11		7. State machine for the NAT/FW NF . . . . . . . . . . . . . . . 11
	8. State machine for the NAT/FW NR/NI+ . . . . . . . . . . . . . 15		8. State machine for the NAT/FW NR/NI+ . . . . . . . . . . . . . 15
	9. Security Considerations . . . . . . . . . . . . . . . . . . . 18		9. Security Considerations . . . . . . . . . . . . . . . . . . . 18
	10. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 18		10. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 18
	11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 18		11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 18
	12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18		12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18
	13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18		13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
	13.1. Normative References . . . . . . . . . . . . . . . . . . . 18		13.1. Normative References . . . . . . . . . . . . . . . . . . . 18
	13.2. Informative References . . . . . . . . . . . . . . . . . . 18		13.2. Informative References . . . . . . . . . . . . . . . . . . 18
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20
	Intellectual Property and Copyright Statements . . . . . . . . . . 21		Intellectual Property and Copyright Statements . . . . . . . . . . 21
	1. Introduction		1. Introduction
	This document describes the state machines for NAT/FW NSLP [1],		This document describes the state machines for NAT/FW NSLP [1],
	trying to show how NAT/FW NSLP can be implemented to support its		trying to show how NAT/FW NSLP can be implemented to support its
	deployment. The state machines described in this document are		deployment. The state machines described in this document are
	illustrative of how the NAT/FW NSLP protocol defined in [1] may be		illustrative of how the NAT/FW NSLP protocol defined in [1] may be
	implemented for the first NAT/FW NSLP node in the signaling path,		implemented for the first NAT/FW NSLP node in the signaling path,
	intermediate NAT/FW NSLP nodes with Firewall and/or NAT		intermediate NAT/FW NSLP nodes with Firewall and/or NAT
	skipping to change at page 3, line 24		skipping to change at page 3, line 24
	Where there are differences [1] are authoritative. The state		Where there are differences [1] are authoritative. The state
	machines are informative only. Implementations may achieve the same		machines are informative only. Implementations may achieve the same
	results using different methods.		results using different methods.
	The messages used in the NAT/FW NSLP protocol can be summarized as		The messages used in the NAT/FW NSLP protocol can be summarized as
	follows:		follows:
	Requesting message Responding message		Requesting message Responding message
	------------------------+---------------------------		------------------------+---------------------------
	CREATE |RESPONSE		CREATE |RESPONSE
	EXT |RESPONSE		REA |RESPONSE
			TRACE |RESPONSE
	RESPONSE |NONE		RESPONSE |NONE
	NOTIFY |NONE		NOTIFY |NONE
	------------------------+---------------------------		------------------------+---------------------------
	We describe a set of state machines for different roles of entities		We describe a set of state machines for different roles of entities
	running NAT/FW NSLP to illustrate how NAT/FW NSLP may be implemented.		running NAT/FW NSLP to illustrate how NAT/FW NSLP may be implemented.
	2. Terminology		2. Terminology
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	skipping to change at page 6, line 36		skipping to change at page 6, line 38
	= Assignment action. The value of the expression to the right of		= Assignment action. The value of the expression to the right of
	the operator is assigned to the variable to the left of the		the operator is assigned to the variable to the left of the
	operator. Where this operator is used to define multiple		operator. Where this operator is used to define multiple
	assignments, e.g., a = b = X the action causes the value of the		assignments, e.g., a = b = X the action causes the value of the
	expression following the right-most assignment operator to be		expression following the right-most assignment operator to be
	assigned to all of the variables that appear to the left of the		assigned to all of the variables that appear to the left of the
	right-most assignment operator.		right-most assignment operator.
	! Logical NOT operator.		! Logical NOT operator.
	&& Logical AND operator.		&& Logical AND operator.
	|| Logical OR operator.		|| Logical OR operator.
	if...then... Conditional action. If the Boolean expression		if...then... Conditional action. If the Boolean expression following
	following the if evaluates to TRUE, then the action following the		the if evaluates to TRUE, then the action following the then is
	then is executed.		executed.
	{ statement 1, ... statement N } Compound statement. Braces are		{ statement 1, ... statement N } Compound statement. Braces are used
	used to group statements that are executed together as if they		to group statements that are executed together as if they were a
	were a single statement.		single statement.
	!= Inequality. Evaluates to TRUE if the expression to the left of		!= Inequality. Evaluates to TRUE if the expression to the left of
	the operator is not equal in value to the expression to the right.		the operator is not equal in value to the expression to the right.
	== Equality. Evaluates to TRUE if the expression to the left of the		== Equality. Evaluates to TRUE if the expression to the left of the
	operator is equal in value to the expression to the right.		operator is equal in value to the expression to the right.
	> Greater than. Evaluates to TRUE if the value of the expression to		> Greater than. Evaluates to TRUE if the value of the expression to
	the left of the operator is greater than the value of the		the left of the operator is greater than the value of the
	expression to the right.		expression to the right.
	<= Less than or equal to. Evaluates to TRUE if the value of the		<= Less than or equal to. Evaluates to TRUE if the value of the
	expression to the left of the operator is either less than or		expression to the left of the operator is either less than or
	equal to the value of the expression to the right.		equal to the value of the expression to the right.
	++ Increment the preceding integer operator by 1.		++ Increment the preceding integer operator by 1.
	5. Common Rules		5. Common Rules
	Throughout the document we use terms defined in the [1], such as NI,		Throughout the document we use terms defined in the [1], such as NI,
	NF, NR, CREATE, EXT or RESPONSE.		NF, NR, CREATE, REA or RESPONSE.
	5.1. Common Procedures		5.1. Common Procedures
	tx_CREATE(): Transmit a CREATE message		tx_CREATE(): Transmit a CREATE message
	tx_CREATE(LIFETIME>0): Transmit CREATE message with lifetime object		tx_CREATE(LIFETIME>0): Transmit CREATE message with lifetime object
	greater than 0 for session creation.		greater than 0 for session creation.
	tx_CREATE(LIFETIME=0): Transmit CREATE message with lifetime object		tx_CREATE(LIFETIME=0): Transmit CREATE message with lifetime object
	explicitly set to 0 for session deletion.		explicitly set to 0 for session deletion.
	tx_RESPONSE(code,type): Transmit RESPONSE message with specified		tx_RESPONSE(code,type): Transmit RESPONSE message with specified code
	code (SUCCESS or ERROR) and result type (related to a specific		(SUCCESS or ERROR) and result type (related to a specific request
	request type message: CREATE or EXT). A code or result type may		type message: CREATE or REA). A code or result type may be
	be omitted, typically when forwarding received RESPONSE messages.		omitted, typically when forwarding received RESPONSE messages.
	tx_EXT(): Transmit a EXT message		tx_REA(): Transmit a REA message
	rx_RESPONSE(code, type): Evaluates to TRUE if a RESPONSE message has		rx_RESPONSE(code, type): Evaluates to TRUE if a RESPONSE message has
	been received with the specified code (SUCCESS or ERROR) and		been received with the specified code (SUCCESS or ERROR) and
	result type (related to a specific request type message: CREATE or		result type (related to a specific request type message: CREATE or
	EXT). If the code or type is omitted, any received RESPONSE		REA). If the code or type is omitted, any received RESPONSE
	message which is only matching the given code or type will		message which is only matching the given code or type will
	evaluate this procedure to TRUE.		evaluate this procedure to TRUE.
	rx_CREATE(): Evaluates to TRUE if a CREATE message has been		rx_CREATE(): Evaluates to TRUE if a CREATE message has been received.
	received.
	rx_CREATE(Lifetime > 0): Evaluates to TRUE if a CREATE message with		rx_CREATE(Lifetime > 0): Evaluates to TRUE if a CREATE message with
	lifetime object greater than 0 has been received.		lifetime object greater than 0 has been received.
	rx_CREATE(Lifetime == 0): Evaluates to TRUE if a CREATE message with		rx_CREATE(Lifetime == 0): Evaluates to TRUE if a CREATE message with
	lifetime object explicitly set to 0 has been received.		lifetime object explicitly set to 0 has been received.
	rx_EXT(): Evaluates to TRUE if a EXT message has been received.		rx_REA(): Evaluates to TRUE if a REA message has been received.
	rx_EXT(Lifetime > 0): Evaluates to TRUE if a EXT message with		rx_REA(Lifetime > 0): Evaluates to TRUE if a REA message with
	lifetime object greater than 0 has been received.		lifetime object greater than 0 has been received.
	rx_EXT(Lifetime == 0): Evaluates to TRUE if a EXT message with		rx_REA(Lifetime == 0): Evaluates to TRUE if a REA message with
	lifetime object explicitly set to 0 has been received.		lifetime object explicitly set to 0 has been received.
	CHECK_AA(): Checks Authorization and Authentication of the received		CHECK_AA(): Checks Authorization and Authentication of the received
	message. Evaluates to TRUE if the check is successful, otherwise		message. Evaluates to TRUE if the check is successful, otherwise
	it evaluates to FALSE. This check is performed on all received		it evaluates to FALSE. This check is performed on all received
	messages hence it will only be shown within the state machine when		messages hence it will only be shown within the state machine when
	the check has failed. This CHECK_AA also MAY include a local		the check has failed. This CHECK_AA also MAY include a local
	policy check for the received message.		policy check for the received message.
	CreateSession(): Installs all session related states, variables,		CreateSession(): Installs all session related states, variables,
	bindings, policies.		bindings, policies.
	DeleteSession(): Removes all session related states, variables,		DeleteSession(): Removes all session related states, variables,
	bindings, policies.		bindings, policies.
	CreatePinhole(): Installs a pinhole for the new session.		CreatePinhole(): Installs a pinhole for the new session.
	DeletePinhole(): Removes a previously installed pinhole.		DeletePinhole(): Removes a previously installed pinhole.
	CreateReservations(): Creates a matching based on the MRI and open		CreateReservations(): Creates a matching based on the MRI and open
	pinholes for the signaling traffic.		pinholes for the signaling traffic.
	DeleteReservations(): Deletes previously installed matchings and		DeleteReservations(): Deletes previously installed matchings and
	pinholes for the signaling traffic.		pinholes for the signaling traffic.
	CreateBinding(): Creates a public/private network translation		CreateBinding(): Creates a public/private network translation binding
	binding on a NAT device for the requesting entity.		on a NAT device for the requesting entity.
	DeleteBinding(): Deletes a previously created a public/private		DeleteBinding(): Deletes a previously created a public/private
	network translation binding on a NAT device for the requesting		network translation binding on a NAT device for the requesting
	entity.		entity.
	StartTimer(identifier): This procedure starts a timer with a certain		StartTimer(identifier): This procedure starts a timer with a certain
	timespan, which is up to the specific implementation. The		timespan, which is up to the specific implementation. The
	parameter 'identifier' identifies this timer uniquely. Any		parameter 'identifier' identifies this timer uniquely. Any
	subsequent StartTimer(identifier), StopTimer(identifier),		subsequent StartTimer(identifier), StopTimer(identifier),
	(identifier)_TIMEOUT refer to the same timer labeled x. This		(identifier)_TIMEOUT refer to the same timer labeled x. This
	timer is required to time the lifetime of state, which means that		timer is required to time the lifetime of state, which means that
	when it times out, it indicates the current machine state should		when it times out, it indicates the current machine state should
	be left or its validation has expired. This procedure starts the		be left or its validation has expired. This procedure starts the
	timer 'identifier'. If a timer with the same 'identifier' has		timer 'identifier'. If a timer with the same 'identifier' has
	already been started and not yet stopped, the timer is now stopped		already been started and not yet stopped, the timer is now stopped
	and restarted. After the timer has timed out, the procedure		and restarted. After the timer has timed out, the procedure
	(identifier)_TIMEOUT evaluates to TRUE. The timer does not		(identifier)_TIMEOUT evaluates to TRUE. The timer does not
	restart automatically, but must be started again with a		restart automatically, but must be started again with a
	StartTimer(identifier). Used identifier are STATE, REFRESH,		StartTimer(identifier). Used identifier are STATE, REFRESH,
	CREATE, EXT or RESPONSE.		CREATE, REA or RESPONSE.
	StopTimer(identifier): This procedure stops the timer labeled		StopTimer(identifier): This procedure stops the timer labeled
	'identifier'. If it has already been stopped, this procedure has		'identifier'. If it has already been stopped, this procedure has
	no effect. If the timer has already timed out, this procedure		no effect. If the timer has already timed out, this procedure
	removes the timeout-state from the timer 'identifier', so		removes the timeout-state from the timer 'identifier', so
	subsequent calls to (identifier)_TIMEOUT evaluate to FALSE. A		subsequent calls to (identifier)_TIMEOUT evaluate to FALSE. A
	timeout cannot occur until the timer 'identifier' has been		timeout cannot occur until the timer 'identifier' has been
	(re-)started.		(re-)started.
	(identifier)_TIMEOUT: This procedure evaluates to TRUE if the		(identifier)_TIMEOUT: This procedure evaluates to TRUE if the
	(identifier)-timer has timed out and indicates a state lifetime		(identifier)-timer has timed out and indicates a state lifetime
	expiration. This procedure cannot evaluate to TRUE if the timer		expiration. This procedure cannot evaluate to TRUE if the timer
	has been stopped. Used timers are STATE_TIMEOUT, REFRESH_TIMEOUT,		has been stopped. Used timers are STATE_TIMEOUT, REFRESH_TIMEOUT,
	CREATE_TIMEOUT, EXT_TIMEOUT or RESPONSE_TIMEOUT.		CREATE_TIMEOUT, REA_TIMEOUT or RESPONSE_TIMEOUT.
	tg_CREATE: External trigger to send a CREATE message (typically		tg_CREATE: External trigger to send a CREATE message (typically
	triggered by the application).		triggered by the application).
	tg_TEARDOWN: External trigger to delete a previously created session		tg_TEARDOWN: External trigger to delete a previously created session
	(typically triggered by the application)		(typically triggered by the application)
	tg_EXT: External trigger to send a EXT message towards an		tg_REA: External trigger to send a REA message towards an
	opportunistic address (typically triggered by the application)		opportunistic address (typically triggered by the application)
	tg_CREATE_PROXY: Internal trigger to send a CREATE message (used in		tg_CREATE_PROXY: Internal trigger to send a CREATE message (used in
	proxy mode, triggered by corresponding NAT/FW NSLP session).		proxy mode, triggered by corresponding NAT/FW NSLP session).
	tg_TEARDOWN_PROXY: Internal trigger to delete a previously created		tg_TEARDOWN_PROXY: Internal trigger to delete a previously created
	session (used in proxy mode, triggered by corresponding NAT/FW		session (used in proxy mode, triggered by corresponding NAT/FW
	NSLP session).		NSLP session).
	5.2. Common Variables		5.2. Common Variables
	IS_EDGE: Boolean flag which evaluates to TRUE if the node is on the		IS_EDGE: Boolean flag which evaluates to TRUE if the node is on the
	network edge, otherwise it evaluates to FALSE.		network edge, otherwise it evaluates to FALSE.
	IS_PUBLICSIDE: Boolean flag which evaluates to TRUE if the (CREATE-		IS_PUBLICSIDE: Boolean flag which evaluates to TRUE if the (CREATE-
	or EXT-) message has been received on the public side of the		or REA-) message has been received on the public side of the
	network.		network.
	CREATE(LIFETIME): Gets the value of the LIFETIME object in the		CREATE(LIFETIME): Gets the value of the LIFETIME object in the CREATE
	CREATE message.		message.
	counter(CREATE): Denotes the current number of retries of CREATE		counter(CREATE): Denotes the current number of retries of CREATE
	message which has been re-transmitted due to previous		message which has been re-transmitted due to previous
	RESPONSE_ERROR message. If the number of counter(CREATE) equals		RESPONSE_ERROR message. If the number of counter(CREATE) equals
	the value of counterLimit(CREATE), the current session creation		the value of counterLimit(CREATE), the current session creation
	attempt is aborted and the application is being notified.		attempt is aborted and the application is being notified.
	counter(EXT): Denotes the current number of retries of EXT message		counter(REA): Denotes the current number of retries of REA message
	which has been re-transmitted due to previous RESPONSE_ERROR		which has been re-transmitted due to previous RESPONSE_ERROR
	message. If the number of counter(EXT) equals the value of		message. If the number of counter(REA) equals the value of
	counterLimit(EXT), the current session creation attempt is aborted		counterLimit(REA), the current session creation attempt is aborted
	and the application is being notified.		and the application is being notified.
	5.3. Constants		5.3. Constants
	counterLimit(CREATE): Contains the maximum number of retransmission		counterLimit(CREATE): Contains the maximum number of retransmission
	attempts of a CREATE message after it is aborted and the		attempts of a CREATE message after it is aborted and the
	application is being notified.		application is being notified.
	counterLimit(EXT): Contains the maximum number of retransmission		counterLimit(REA): Contains the maximum number of retransmission
	attempts of a EXT message after it is aborted and the application		attempts of a REA message after it is aborted and the application
	is being notified.		is being notified.
	6. State machine for the NAT/FW NI/NR+		6. State machine for the NAT/FW NI/NR+
	This section presents the state machine for the NSIS initator which		This section presents the state machine for the NSIS initator which
	is capable of NAT/FW NSLP signaling.		is capable of NAT/FW NSLP signaling.
	-----------		-----------
	State: INITIALIZE		State: INITIALIZE
	-----------		-----------
	skipping to change at page 12, line 14		skipping to change at page 12, line 14
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	-----------		-----------
	State: IDLE		State: IDLE
	Entry: DeleteSession();		Entry: DeleteSession();
	Exit : CreateSession();		Exit : CreateSession();
	-----------		-----------
	Condition Action State		Condition Action State
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	(rx_EXT) && (IS_PUBLICSIDE) |tx_RESPONSE(ERROR, EXT); | IDLE		(rx_REA) && (IS_PUBLICSIDE) |tx_RESPONSE(ERROR, REA); | IDLE
	| |		| |
	(rx_CREATE(Lifetime > 0)) |tx_CREATE(); | CREATE_		(rx_CREATE(Lifetime > 0)) |tx_CREATE(); | CREATE_
	| | WAITRESP		| | WAITRESP
	| |		| |
	((rx_EXT) && (!IS_EDGE) |tx_EXT(); | NONEDGE_		((rx_REA) && (!IS_EDGE) |tx_REA(); | NONEDGE_
	&& (!IS_PUBLICSIDE)) | | EXT		&& (!IS_PUBLICSIDE)) | | REA
	| |		| |
	((rx_EXT) && (IS_EDGE) |tx_RESPONSE(SUCCESS,EXT); | EDGE_EXT		((rx_REA) && (IS_EDGE) |tx_RESPONSE(SUCCESS,REA); | EDGE_REA
	&& (!IS_PUBLICSIDE)) |tx_CREATE; |		&& (!IS_PUBLICSIDE)) |tx_CREATE; |
	|if(proxy_object) then |		|if(proxy_object) then |
	| (tg_CREATE_PROXY);|		| (tg_CREATE_PROXY);|
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	-----------		-----------
	State: CREATE_WAITRESP		State: CREATE_WAITRESP
	Entry: StartTimer(STATE);		Entry: StartTimer(STATE);
	Exit : StopTimer(STATE);		Exit : StopTimer(STATE);
	-----------		-----------
	skipping to change at page 13, line 5		skipping to change at page 13, line 5
	|ReportAsyncEvent(); |		|ReportAsyncEvent(); |
	| |		| |
	STATE_TIMEOUT |tx_RESPONSE(ERROR,CREATE); | IDLE		STATE_TIMEOUT |tx_RESPONSE(ERROR,CREATE); | IDLE
	|ReportAsyncEvent(); |		|ReportAsyncEvent(); |
	| |		| |
	(rx_CREATE(Lifetime == 0)) |tx_CREATE(Lifetime=0); | IDLE		(rx_CREATE(Lifetime == 0)) |tx_CREATE(Lifetime=0); | IDLE
	| |		| |
	rx_RESPONSE(SUCCESS,CREATE) |tx_RESPONSE(SUCCESS,CREATE); | SESSION		rx_RESPONSE(SUCCESS,CREATE) |tx_RESPONSE(SUCCESS,CREATE); | SESSION
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	-----------		-----------
	State: NONEDGE_EXT		State: NONEDGE_REA
	Entry: StartTimer(EXT);		Entry: StartTimer(REA);
	CreateReservations();		CreateReservations();
	Exit : StopTimer(EXT);		Exit : StopTimer(REA);
	DeleteReservations();		DeleteReservations();
	-----------		-----------
	Condition Action State		Condition Action State
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	(rx_EXT(Lifetime > 0)) |StopTimer(EXT); | NONEDGE_		(rx_REA(Lifetime > 0)) |StopTimer(REA); | NONEDGE_
	|StartTimer(EXT); | EXT		|StartTimer(REA); | REA
	|tx_EXT(); |		|tx_REA(); |
	| |		| |
	rx_RESPONSE(SUCCESS, EXT) |tx_RESPONSE(SUCCESS,EXT); | NONEDGE_		rx_RESPONSE(SUCCESS, REA) |tx_RESPONSE(SUCCESS,REA); | NONEDGE_
	| | EXT		| | REA
	| |		| |
	rx_RESPONSE(ERROR, EXT) |tx_RESPONSE(ERROR,EXT); | IDLE		rx_RESPONSE(ERROR, REA) |tx_RESPONSE(ERROR,REA); | IDLE
	|ReportAsyncEvent(); |		|ReportAsyncEvent(); |
	| |		| |
	(rx_EXT(Lifetime == 0)) |tx_EXT(Lifetime=0); | IDLE		(rx_REA(Lifetime == 0)) |tx_REA(Lifetime=0); | IDLE
	|ReportAsyncEvent(); |		|ReportAsyncEvent(); |
	| |		| |
	EXT_TIMEOUT |ReportAsyncEvent(); | IDLE		REA_TIMEOUT |ReportAsyncEvent(); | IDLE
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	-----------		-----------
	State: EDGE_EXT		State: EDGE_REA
	Entry: StartTimer(EXT);		Entry: StartTimer(REA);
	CreateReservations();		CreateReservations();
	Exit : StopTimer(EXT);		Exit : StopTimer(REA);
	DeleteReservations();		DeleteReservations();
	-----------		-----------
	Condition Action State		Condition Action State
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	(rx_EXT(Lifetime > 0)) |StopTimer(EXT); | EDGE_EXT		(rx_REA(Lifetime > 0)) |StopTimer(REA); | EDGE_REA
	|StartTimer(EXT); |		|StartTimer(REA); |
	|tx_RESPONSE(SUCCESS, EXT); |		|tx_RESPONSE(SUCCESS, REA); |
	| |		| |
	(rx_EXT(Lifetime == 0)) |tx_EXT(Lifetime=0); | IDLE		(rx_REA(Lifetime == 0)) |tx_REA(Lifetime=0); | IDLE
	|ReportAsyncEvent(); |		|ReportAsyncEvent(); |
	|if(proxy_mode) then |		|if(proxy_mode) then |
	| (tg_TEARDOWN_PROXY);|		| (tg_TEARDOWN_PROXY);|
	| |		| |
	EXT_TIMEOUT |ReportAsyncEvent(); | IDLE		REA_TIMEOUT |ReportAsyncEvent(); | IDLE
	|if(proxy_mode) then |		|if(proxy_mode) then |
	| (tg_TEARDOWN_PROXY);|		| (tg_TEARDOWN_PROXY);|
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	-----------		-----------
	State: SESSION		State: SESSION
	Entry: StartTimer(CREATE)		Entry: StartTimer(CREATE)
	CreatePinhole();		CreatePinhole();
	CreateBinding();		CreateBinding();
	Exit : StopTimer(RESPONSE);		Exit : StopTimer(RESPONSE);
	StopTimer(CREATE);		StopTimer(CREATE);
	DeletePinhole();		DeletePinhole();
	DeleteBinding();		DeleteBinding();
	-----------		-----------
	Condition Action State		Condition Action State
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	RESPONSE_TIMEOUT |StopTimer(RESPONSE); | SESSION		RESPONSE_TIMEOUT |StopTimer(RESPONSE); | SESSION
	|tx_RESPONSE(ERROR,CREATE); |		|tx_RESPONSE(ERROR,CREATE); |
	| |		| |
	(rx_EXT(Lifetime > 0)) |StopTimer(CREATE); | SESSION		(rx_REA(Lifetime > 0)) |StopTimer(CREATE); | SESSION
	|StartTimer(RESPONSE); |		|StartTimer(RESPONSE); |
	|tx_CREATE(); |		|tx_CREATE(); |
	| |		| |
	rx_RESPONSE(SUCCESS,CREATE) |StopTimer(RESPONSE); | SESSION		rx_RESPONSE(SUCCESS,CREATE) |StopTimer(RESPONSE); | SESSION
	|StartTimer(CREATE); |		|StartTimer(CREATE); |
	|tx_RESPONSE(SUCCESS,CREATE); |		|tx_RESPONSE(SUCCESS,CREATE); |
	| |		| |
	CREATE_TIMEOUT |ReportAsyncEvent(); | IDLE		CREATE_TIMEOUT |ReportAsyncEvent(); | IDLE
	| |		| |
	(rx_EXT(Lifetime == 0)) |tx_CREATE(Lifetime=0); | IDLE		(rx_REA(Lifetime == 0)) |tx_CREATE(Lifetime=0); | IDLE
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	8. State machine for the NAT/FW NR/NI+		8. State machine for the NAT/FW NR/NI+
	This section presents the state machines for the NSIS responder which		This section presents the state machines for the NSIS responder which
	is capable of NSLP NAT/FW signaling.		is capable of NSLP NAT/FW signaling.
	-----------		-----------
	State: INITIALIZE		State: INITIALIZE
	-----------		-----------
	skipping to change at page 16, line 14		skipping to change at page 16, line 14
	-----------		-----------
	State: IDLE		State: IDLE
	Entry: DeleteSession();		Entry: DeleteSession();
	Exit : CreateSession();		Exit : CreateSession();
	-----------		-----------
	Condition Action State		Condition Action State
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	(rx_CREATE) && !(CHECK_AA())|tx_RESPONSE(ERROR,CREATE); | IDLE		(rx_CREATE) && !(CHECK_AA())|tx_RESPONSE(ERROR,CREATE); | IDLE
	| |		| |
	tg_EXT |tx_EXT(); | EXT_		tg_REA |tx_REA(); | REA_
	| | WAITRESP		| | WAITRESP
	| |		| |
	(rx_EXT(Lifetime > 0)) |tx_RESPONSE(SUCCESS,CREATE); | SESSION		(rx_REA(Lifetime > 0)) |tx_RESPONSE(SUCCESS,CREATE); | SESSION
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	-----------		-----------
	State: EXT_WAITRESP		State: REA_WAITRESP
	Entry: ResetCounter(EXT);		Entry: ResetCounter(REA);
	StartTimer(RESPONSE);		StartTimer(RESPONSE);
	Exit : StopTimer(RESPONSE);		Exit : StopTimer(RESPONSE);
	-----------		-----------
	Condition Action State		Condition Action State
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	RESPONSE_TIMEOUT && |counter(EXT)++; | EXT_		RESPONSE_TIMEOUT && |counter(REA)++; | REA_
	(counter(EXT) < |StartTimer(RESPONSE); | WAITRESP		(counter(REA) < |StartTimer(RESPONSE); | WAITRESP
	counterLimit(EXT)) |tx_EXT(); |		counterLimit(REA)) |tx_REA(); |
	| |		| |
	rx_RESPONSE(SUCCESS,EXT) |ReportAsyncEvent(); | EXT		rx_RESPONSE(SUCCESS,REA) |ReportAsyncEvent(); | REA
	| |		| |
	RESPONSE_TIMEOUT && |ReportAsyncEvent(); | IDLE		RESPONSE_TIMEOUT && |ReportAsyncEvent(); | IDLE
	(counter(EXT) == | |		(counter(REA) == | |
	counterLimit(EXT)) | |		counterLimit(REA)) | |
	| |		| |
	rx_RESPONSE(ERROR,EXT) |ReportAsyncEvent(); | IDLE		rx_RESPONSE(ERROR,REA) |ReportAsyncEvent(); | IDLE
	| |		| |
	tg_TEARDOWN |tx_EXT(Lifetime=0); | IDLE		tg_TEARDOWN |tx_REA(Lifetime=0); | IDLE
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	-----------		-----------
	State: EXT		State: REA
	Entry: ResetCounter(EXT);		Entry: ResetCounter(REA);
	StartTimer(REFRESH);		StartTimer(REFRESH);
	Exit : StopTimer(RESPONSE);		Exit : StopTimer(RESPONSE);
	StopTimer(REFRESH);		StopTimer(REFRESH);
	-----------		-----------
	Condition Action State		Condition Action State
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	RESPONSE_TIMEOUT && |counter(EXT)++; | EXT		RESPONSE_TIMEOUT && |counter(REA)++; | REA
	(counter(EXT) < |StartTimer(RESPONSE); |		(counter(REA) < |StartTimer(RESPONSE); |
	counterLimit(EXT)) |tx_EXT(); |		counterLimit(REA)) |tx_REA(); |
	| |		| |
	rx_RESPONSE(SUCCESS,EXT) |StartTimer(REFRESH); | EXT		rx_RESPONSE(SUCCESS,REA) |StartTimer(REFRESH); | REA
	|StopTimer(RESPONSE); |		|StopTimer(RESPONSE); |
	|ResetCounter(EXT); |		|ResetCounter(REA); |
	| |		| |
	REFRESH_TIMEOUT |tx_EXT(); | EXT		REFRESH_TIMEOUT |tx_REA(); | REA
	|StartTimer(RESPONSE); |		|StartTimer(RESPONSE); |
	| |		| |
	RESPONSE_TIMEOUT && |ReportAsyncEvent(); | IDLE		RESPONSE_TIMEOUT && |ReportAsyncEvent(); | IDLE
	(counter(EXT) == | |		(counter(REA) == | |
	counterLimit(EXT)) | |		counterLimit(REA)) | |
	| |		| |
	rx_RESPONSE(ERROR,EXT) |ReportAsyncEvent(); | IDLE		rx_RESPONSE(ERROR,REA) |ReportAsyncEvent(); | IDLE
	| |		| |
	tg_TEARDOWN |tx_EXT(Lifetime=0); | IDLE		tg_TEARDOWN |tx_REA(Lifetime=0); | IDLE
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	-----------		-----------
	State: SESSION		State: SESSION
	Entry: StartTimer(STATE);		Entry: StartTimer(STATE);
	Exit : StopTimer(STATE);		Exit : StopTimer(STATE);
	-----------		-----------
	Condition Action State		Condition Action State
	----------------------------+-----------------------------+----------		----------------------------+-----------------------------+----------
	skipping to change at page 18, line 38		skipping to change at page 18, line 38
	12. Acknowledgments		12. Acknowledgments
	The authors would like to thank Martin Stiemerling for his valuable		The authors would like to thank Martin Stiemerling for his valuable
	comments and discussions.		comments and discussions.
	13. References		13. References
	13.1. Normative References		13.1. Normative References
	[1] Stiemerling, M., "NAT/Firewall NSIS Signaling Layer Protocol		[1] Stiemerling, M., "NAT/Firewall NSIS Signaling Layer Protocol
	(NSLP)", draft-ietf-nsis-nslp-natfw-13 (work in progress),		(NSLP)", draft-ietf-nsis-nslp-natfw-11 (work in progress),
	October 2006.		April 2006.
	[2] Bradner, S., "Key words for use in RFCs to Indicate Requirement		[2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
	Levels", March 1997.		Levels", March 1997.
	13.2. Informative References		13.2. Informative References
	[3] Fajardo, V., "State Machines for Protocol for Carrying		[3] Fajardo, V., "State Machines for Protocol for Carrying
	Authentication for Network Access (PANA)",		Authentication for Network Access (PANA)",
	draft-ietf-pana-statemachine-04 (work in progress), May 2006.		draft-ietf-pana-statemachine-04 (work in progress), May 2006.
	skipping to change at page 19, line 29		skipping to change at page 20, line 16
	Constantin Werner		Constantin Werner
	University of Goettingen		University of Goettingen
	Telematics Group		Telematics Group
	Lotzestr. 16-18		Lotzestr. 16-18
	Goettingen 37083		Goettingen 37083
	Germany		Germany