draft-ietf-speermint-architecture-00.txt		draft-ietf-speermint-architecture-01.txt
	Network Working Group R.Penno (Editor)		Speermint Working Group R.Penno (Editor)
	Internet Draft Juniper Networks		Internet Draft Juniper Networks
	Expires: February 2007 August 8, 2006		Expires: March 2007 September 18, 2006
	SPEERMINT Peering Architecture		SPEERMINT Peering Architecture
	draft-ietf-speermint-architecture-00		draft-ietf-speermint-architecture-01
	Status of this Memo		Status of this Memo
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	aware have been or will be disclosed, and any of which he or she		aware have been or will be disclosed, and any of which he or she
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	BCP 79.		BCP 79.
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	skipping to change at page 1, line 37		skipping to change at page 1, line 37
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	This Internet-Draft will expire on November 2006.		This Internet-Draft will expire on November 2006.
	Abstract		Abstract
	This document defines a SPEERMINT peering reference architecture, its		This document defines the SPEERMINT peering architecture, its
	functional components and peering interface functions.		functional components and peering interface functions.
	Conventions used in this document		Conventions used in this document
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
	document are to be interpreted as described in [RFC2119]		document are to be interpreted as described in [1]
	Table of Contents		Table of Contents
	1. Introduction...................................................2		1. Introduction...................................................2
	2. Network Context................................................3		2. Network Context................................................3
	3. Procedures.....................................................5		3. Procedures.....................................................5
	4. Reference SPEERMINT Architecture...............................5		4. Reference SPEERMINT Architecture...............................5
	5. Peer Function Examples.........................................6		5. Peer Function Examples.........................................7
	5.1. The Location Function (LF) of an Initiating Provider......7		5.1. The Location Function (LF) of an Initiating Provider......7
	5.1.1. Target address analysis..............................7		5.1.1. Target address analysis..............................7
	5.1.2. User ENUM Lookup.....................................7		5.1.2. User ENUM Lookup.....................................8
	5.1.3. Carrier ENUM lookup..................................8		5.1.3. Carrier ENUM lookup..................................8
	5.1.4. Routing Table........................................8		5.1.4. Routing Table........................................8
	5.1.5. SIP DNS Resolution...................................8		5.1.5. SIP DNS Resolution...................................8
	5.1.6. SIP Redirect Server..................................9		5.1.6. SIP Redirect Server..................................9
	5.2. The Location Function (LF) of a Receiving Provider........9		5.2. The Location Function (LF) of a Receiving Provider........9
	5.2.1. Publish ENUM records.................................9		5.2.1. Publish ENUM records.................................9
	5.2.2. Publish SIP DNS records..............................9		5.2.2. Publish SIP DNS records..............................9
	5.3. Policy Function (PF)......................................9		5.3. Policy Function (PF)......................................9
	5.3.1. TLS.................................................10		5.3.1. TLS.................................................11
	5.3.2. IPSec...............................................11		5.3.2. IPSec...............................................11
	5.3.3. Subscribe Notify....................................11		5.3.3. Subscribe Notify....................................11
	5.4. Signaling Function (SF)..................................11		5.4. Signaling Function (SF)..................................11
	5.5. Media Function (MF)......................................12		5.5. Media Function (MF)......................................12
	6. Call Control and Media Control Deployment Options.............12		6. Call Control and Media Control Deployment Options.............12
	7. Security Considerations.......................................13		7. Security Considerations.......................................13
	8. IANA Considerations...........................................14		8. IANA Considerations...........................................14
	9. Conclusions...................................................14		9. Acknowledgments...............................................14
	10. Acknowledgments..............................................14
	Author's Addresses...............................................15		Author's Addresses...............................................15
	11. References...................................................15		10. References...................................................15
	11.1. Normative References....................................15		10.1. Normative References....................................15
	11.2. Informative References..................................17		10.2. Informative References..................................16
	Intellectual Property Statement..................................18		Intellectual Property Statement..................................17
	Disclaimer of Validity...........................................19		Disclaimer of Validity...........................................18
	Copyright Statement..............................................19		Copyright Statement..............................................18
	Acknowledgment...................................................19		Acknowledgment...................................................18
	1. Introduction		1. Introduction
	The objective of this document is to define a reference peering		The objective of this document is to define a reference peering
	architecture in the context of Session PEERing for Multimedia		architecture in the context of Session PEERing for Multimedia
	INTerconnect (SPEERMINT). In this process, we define a peering		INTerconnect (SPEERMINT). In this process, we define the peering
	reference architecture, its functional components, and peering		reference architecture (reference, for short), its functional
	interface functions from the perspective of a real-time		components, and peering interface functions from the perspective of a
	communications (Voice and Multimedia) IP Service provider network.		real-time communications (Voice and Multimedia) IP Service provider
			network.
	This reference architecture allows the interconnection of two service		This architecture allows the interconnection of two service providers
	providers in layer 5 peering as defined in the SPEERMINT Requirements		in layer 5 peering as defined in the SPEERMINT Requirements [13] and
	[2] and Terminology [1] documents for the purpose SIP-based voice and		Terminology [12] documents for the purpose SIP-based voice and
	multimedia traffic.		multimedia traffic.
	IP Layer peering is outside the scope of SPEERMINT at this time;		Layer 3 peering is outside the scope of this document. Hence, the
	thus, we do not include them in the SPEEMINT Peering Architecture.		figures in this document do not show routers so that the focus is on
	Note that IP Routers are not shown in the subsequent figures so that		Layer 5 protocol aspects.
	the focus is on Layer 5 protocol aspects.
	This document uses terminology defined in the SPEERMINT Terminology		This document uses terminology defined in the SPEERMINT Terminology
	document [1].		document [12].
	2. Network Context		2. Network Context
	Figure 1 shows an example network context. Two SIP providers can form		Figure 1 shows an example network context. Two SIP providers can form
	a Layer 5 peer over either the public Internet or private Layer 3		a Layer 5 peer over either the public Internet or private Layer 3
	networks. In addition, two or more providers may form a SIP (Layer 5)		networks. In addition, two or more providers may form a SIP (Layer 5)
	federation [1][9] on either the public Internet or private Layer 3		federation [17] on either the public Internet or private Layer 3
	networks. This document does not make any assumption whether the SIP		networks. This document does not make any assumption whether the SIP
	providers directly peer to each other or through Layer 3 transit		providers directly peer to each other or through Layer 3 transit
	network as per use case of [7].		network as per use case of [16].
	Note that Figure 1 allows for the following potential SPEERMINT		Note that Figure 1 allows for the following potential SPEERMINT
	peering scenarios:		peering scenarios:
	o Enterprise to Enterprise across the public Internet		o Enterprise to Enterprise across the public Internet
	o Enterprise to Service Provider across the public Internet		o Enterprise to Service Provider across the public Internet
	o Service Provider to Service Provider across the public Internet		o Service Provider to Service Provider across the public Internet
	skipping to change at page 4, line 5		skipping to change at page 4, line 5
	o Service Provider to Service Provider across a private Layer 3		o Service Provider to Service Provider across a private Layer 3
	network		network
	The members of a federation may jointly use a set of functions such		The members of a federation may jointly use a set of functions such
	as location peering function, application function, subscriber		as location peering function, application function, subscriber
	database function, SIP proxies, and/or functions that synthesize		database function, SIP proxies, and/or functions that synthesize
	various SIP and non-SIP based applications. Similarly, two providers		various SIP and non-SIP based applications. Similarly, two providers
	may jointly use a set of peering functions. The federation functions		may jointly use a set of peering functions. The federation functions
	or the peering functions can be either public or private.		or the peering functions can be either public or private.
	+------------------+		+-------------------+
	| Public |		| Public |
	| Peering Function |		| Peering Function |
	| or |		| or |
	| Public |		| Public |
	|Federation Function|		|Federation Function|
	+------------------+		+-------------------+
	|		|
	-----		-----
	+-----------+ / \ +-----------+		+-----------+ / \ +-----------+
	|Enterprise | -- -- |Enterprise |		|Enterprise | -- -- |Enterprise |
	|Provider A |-----------/ \-----------|Provider B |		|Provider A |-----------/ \-----------|Provider B |
	+-----------+ -- -- +-----------+		+-----------+ -- -- +-----------+
	/ Public \		/ Public \
	| Internet |		| Internet |
	\ (Layer 3) /		\ (Layer 3) /
	+-----------+ -- -- +-----------+		+-----------+ -- -- +-----------+
	skipping to change at page 4, line 40		skipping to change at page 4, line 40
	|Provider E |-----------/ \-----------|Provider F |		|Provider E |-----------/ \-----------|Provider F |
	+-----------+ -- Service -- +-----------+		+-----------+ -- Service -- +-----------+
	/ Provider \		/ Provider \
	| Private |		| Private |
	\ Network /		\ Network /
	+-----------+ -- (Layer 3) -- +-----------+		+-----------+ -- (Layer 3) -- +-----------+
	|Service |-----------\ /-----------|Service |		|Service |-----------\ /-----------|Service |
	|Provider G | -- -- |Provider H |		|Provider G | -- -- |Provider H |
	+-----------+ \____/ +-----------+		+-----------+ \____/ +-----------+
	|		|
	+------------------+		+-------------------+
	| Private |		| Private |
	| Peering Function |		| Peering Function |
	| or |		| or |
	|Federation Function|		|Federation Function|
	+------------------+		+-------------------+
	Figure 1: SPEERMINT Network Context		Figure 1: SPEERMINT Network Context
	3. Procedures		3. Procedures
	This document assumes that a call from an end user in the initiating		This document assumes that a call from an end user in the initiating
	peer goes through the following steps to establish a call to an end		peer goes through the following steps to establish a call to an end
	user in the receiving peer:		user in the receiving peer:
	. the analysis of a target address,		1. The analysis of a target address.
	. the discovery of the receiving peering point		a. If the target address represents an intra-VSP resource,
	address,		we go directly to step 4.
	. the enforcement of authentication and other policy,		2. the discovery of the receiving peering point address,
	. the discovery of end user address,		3. the enforcement of authentication and other policy,
	. the routing of SIP messages,		4. the discovery of end user address,
	. the session establishment,		5. the routing of SIP messages,
	. the transfer of media,		6. the session establishment,
	. and the session termination.		7. the transfer of media,
			8. and the session termination.
	4. Reference SPEERMINT Architecture		4. Reference SPEERMINT Architecture
	Figure 2 depicts the SPEERMINT reference architecture and logical		Figure 2 depicts the SPEERMINT architecture and logical functions
	functions that form the peering between two SIP service providers I		that form the peering between two SIP service providers I and R,
	and R, where I is the Initiating peer and R is the Receiving peer.		where I is the Initiating peer and R is the Receiving peer.
	+----+		+------+
	| LF |		| DNS, |
	------- +----+ -------		| Db, |
			| etc |
			------- +------+ -------
	/ \ | | / \		/ \ | | / \
	| LF---+ +---LF |		| LF---+ +---LF |
	| | | |		| | | |
	| PF-----------PF |		| PF----------PF |
	| | | |		| | | |
	| SIP SF-----------SF SIP |		| SIP SF----------SF SIP |
	| Service | | Service |		| Service | | Service |
	|Provider MF---------MF Provider|		|Provider MF----------MF Provider|
	| I | | R |		| I | | R |
	| | | |		| | | |
	| | | |		| | | |
	\ / \ /		\ / \ /
	------- -------		------- -------
	Figure 2: Reference SPEERMINT Architecture		Figure 2: Reference SPEERMINT Architecture
	The procedures presented in Chapter 3 are implemented by a set of		The procedures presented in Chapter 3 are implemented by a set of
	peering functions:		peering functions:
	o Location Function (LF): Purpose is to develop call routing data		o Location Function (LF): Purpose is to develop call routing data
	(CRD) by discovering the Signaling Function (SF), Policy Function		(CRD) by discovering the Signaling Function (SF), Policy Function
	(PF), and end user's reachable host (IP address and port).		(PF), and end user's reachable host (IP address and port).
	o Policy Function (PF): Purpose is to perform authentication and to		o Policy Function (PF): Purpose is to perform authentication and to
	exchange policy parameters to be used by the SF.		exchange policy parameters to be used by the SF. The data acquired
			through the policy function can provide input to the LF, SF or MF
			functions. Therefore the policy function can happen multiple times
			(through multiple methods) during the procedures used to establish
			a call.
	o Signaling Function (SF): Purpose is to perform routing of SIP		o Signaling Function (SF): Purpose is to perform routing of SIP
	messages, to optionally perform termination and re-initiation of		messages, to optionally perform termination and re-initiation of
	call, to optionally implement security and policies on SIP		call, to optionally implement security and policies on SIP
	messages, and to assist in discovery/exchange of parameters to be		messages, and to assist in discovery/exchange of parameters to be
	used by the Media Function (MF).		used by the Media Function (MF).
	o Media Function (MF): Purpose is to perform media related function		o Media Function (MF): Purpose is to perform media related function
	such as media transcoding and media security implementation		such as media transcoding and media security implementation
	between two SIP providers.		between two SIP providers.
	The intention of defining these functions is to provide a framework		The intention of defining these functions is to provide a framework
	for design segmentation and allow each one to evolve separately.		for design segmentation and allow each one to evolve separately.
	5. Peer Function Examples		5. Peer Function Examples
	This section describes the peering functions in more detail and		This section describes the peering functions in more detail and
	provides some examples on the role they would play in a SIP call in a		provides some examples on the role they would play in a SIP call in a
	Layer 5 peering scenario.		Layer 5 peering scenario.
	Some of the information in the chapter is taken from [4].		Some of the information in the chapter is taken from [14].
	5.1. The Location Function (LF) of an Initiating Provider		5.1. The Location Function (LF) of an Initiating Provider
	Purpose is to develop call routing data (CRD) [1] by discovering the		Purpose is to develop call routing data (CRD) [12] by discovering
	Signaling Function (SF), Policy Function (PF), and end user's		the Signaling Function (SF), Policy Function (PF), and end user's
	reachable host (IP address and host). The LF of an Initiating		reachable host (IP address and host). The LF of an Initiating
	provider analyzes target address and discovers the next hop		provider analyzes target address and discovers the next hop
	signaling function (SF) in a peering relationship using DNS, SIP		signaling function (SF) in a peering relationship using DNS, SIP
	Redirect Server, or a functional equivalent database.		Redirect Server, or a functional equivalent database.
	5.1.1. Target address analysis		5.1.1. Target address analysis
	When the initiating provider receives a request to communicate, the		When the initiating provider receives a request to communicate, the
	initiating provider analyzes the target state data to determine		initiating provider analyzes the target state data to determine
	whether the call needs to be terminated internal or external to its		whether the call needs to be terminated internal or external to its
	skipping to change at page 7, line 33		skipping to change at page 7, line 39
	consult any manner of private data sources to make this		consult any manner of private data sources to make this
	determination.		determination.
	If the target address does not represent a resource inside the		If the target address does not represent a resource inside the
	initiating peer's administrative domain or federation of domains, the		initiating peer's administrative domain or federation of domains, the
	initiating provider resolves the call routing data by using the		initiating provider resolves the call routing data by using the
	Location Function (LF). Examples of the LF are the functions of ENUM,		Location Function (LF). Examples of the LF are the functions of ENUM,
	Routing Table, SIP DNS, and SIP Redirect Server.		Routing Table, SIP DNS, and SIP Redirect Server.
	If the request to communicate is for an im: or pres: URI type, the		If the request to communicate is for an im: or pres: URI type, the
	initiating peer follows the procedures in [RFC3861]. If the highest		initiating peer follows the procedures in [8]. If the highest
	priority supported URI scheme is sip: or sips:, the initiating peer		priority supported URI scheme is sip: or sips:, the initiating peer
	skips to SIP DNS resolution in Section 5.1.5. Likewise, if the target		skips to SIP DNS resolution in Section 5.1.5. Likewise, if the target
	address is already a sip: or sips: URI in an external domain, the		address is already a sip: or sips: URI in an external domain, the
	initiating peer skips to SIP DNS resolution in Section 5.1.5.5.1.5.		initiating peer skips to SIP DNS resolution in Section 5.1.5.
	If the target address corresponds to a specific E.164 address, the		If the target address corresponds to a specific E.164 address, the
	peer may need to perform some form of number plan mapping according		peer may need to perform some form of number plan mapping according
	to local policy. For example, in the United States, a dial string		to local policy. For example, in the United States, a dial string
	beginning "011 44" could be converted to "+44", or in the United		beginning "011 44" could be converted to "+44", or in the United
	Kingdom "00 1" could be converted to "+1". Once the peer has an		Kingdom "00 1" could be converted to "+1". Once the peer has an
	E.164 address, it can use ENUM.		E.164 address, it can use ENUM.
	5.1.2. User ENUM Lookup		5.1.2. User ENUM Lookup
	If an external E.164 address is the target, the initiating peer		If an external E.164 address is the target, the initiating peer
	consults the public "User ENUM" rooted at e164.arpa, according to the		consults the public "User ENUM" rooted at e164.arpa, according to the
	procedures described in RFC 3761. The peer MUST query for the		procedures described in RFC 3761. The peer MUST query for the
	"E2U+sip" enumservice as described in RFC 3674 [11], but MAY check		"E2U+sip" enumservice as described in RFC 3764 [11], but MAY check
	for other enumservices. The initiating peer MAY consult a cache or		for other enumservices. The initiating peer MAY consult a cache or
	alternate representation of the ENUM data rather than actual DNS		alternate representation of the ENUM data rather than actual DNS
	queries. Also, the peer MAY skip actual DNS queries if the		queries. Also, the peer MAY skip actual DNS queries if the
	initiating peer is sure that the target address country code is not		initiating peer is sure that the target address country code is not
	represented in e164.arpa. If a sip: or sips: URI is chosen the peer		represented in e164.arpa. If a sip: or sips: URI is chosen the peer
	skips to Section 5.1.5.		skips to Section 5.1.5.
	If an im: or pres: URI is chosen for based on an "E2U+im" [10] or		If an im: or pres: URI is chosen for based on an "E2U+im" [10] or
	"E2U+pres" [RFC3953] enumserver, the peer follows the procedures for		"E2U+pres" [9] enumserver, the peer follows the procedures for
	resolving these URIs to URIs for specific protocols such a SIP or		resolving these URIs to URIs for specific protocols such a SIP or
	XMPP as described in the previous section.		XMPP as described in the previous section.
	5.1.3. Carrier ENUM lookup		5.1.3. Carrier ENUM lookup
	Next the initiating peer checks for a carrier-of-record in a carrier		Next the initiating peer checks for a carrier-of-record in a carrier
	ENUM domain according to the procedures described in [11]. As in the		ENUM domain according to the procedures described in [12]. As in the
	previous step, the peer MAY consult a cache or alternate		previous step, the peer MAY consult a cache or alternate
	representation of the ENUM data in lieu of actual DNS queries. The		representation of the ENUM data in lieu of actual DNS queries. The
	peer first checks for records for the "E2U+sip" enumservice, then for		peer first checks for records for the "E2U+sip" enumservice, then for
	the "E2U+pstn" enumservice as defined in [12]. If a terminal record		the "E2U+pstn" enumservice as defined in [21]. If a terminal record
	is found with a sip: or sips: URI, the peer skips to Section 5.1.5,		is found with a sip: or sips: URI, the peer skips to Section 5.1.5,
	otherwise the peer continues processing according to the next		otherwise the peer continues processing according to the next
	section.		section.
	5.1.4. Routing Table		5.1.4. Routing Table
	If there is no user ENUM records and the initiating peer cannot		If there is no user ENUM records and the initiating peer cannot
	discover the carrier-of-record or if the initiating peer cannot reach		discover the carrier-of-record or if the initiating peer cannot reach
	the carrier-of-record via SIP peering, the initiating peer still		the carrier-of-record via SIP peering, the initiating peer still
	needs to deliver the call to the PSTN or reject the call. Note that		needs to deliver the call to the PSTN or reject the call. Note that
	the initiating peer MAY still sends the call to another provider for		the initiating peer MAY still sends the call to another provider for
	PSTN gateway termination by prior arrangement using a routing table.		PSTN gateway termination by prior arrangement using a routing table.
	If so, the initiating peer rewrites the Request-URI to address the		If so, the initiating peer rewrites the Request-URI to address the
	gateway resource in the target provider's domain and MAY forward the		gateway resource in the target provider's domain and MAY forward the
	request on to that provider using the procedures described in the		request on to that provider using the procedures described in the
	remainder of these steps.		remainder of these steps.
	5.1.5. SIP DNS Resolution		5.1.5. SIP DNS Resolution
	Once a sip: or sips: in an external domain is selected as the target,		Once a sip: or sips: in an external domain is selected as the target,
	the initiating peer uses the procedures described in [RFC3263]		the initiating peer uses the procedures described in [4] Section 4.
	Section 4. To summarize the RFC 3263 procedure: unless these are
	explicitly encoded in the target URI, a transport is chosen using		To summarize the RFC 3263 procedure: unless these are explicitly
	NAPTR records, a port is chosen using SRV records, and an address is		encoded in the target URI, a transport is chosen using NAPTR records,
	chosen using A or AAAA records. Note that these are queries of		a port is chosen using SRV records, and an address is chosen using A
	records in the global DNS.		or AAAA records. Note that these are queries of records in the
			global DNS.
			It is worth mentioning that the PF can override the default RFC 3263
			procedure. That may be based on learned routes (via SUBSCRIBE), or
			federation announcements.
	5.1.6. SIP Redirect Server		5.1.6. SIP Redirect Server
	A SIP Redirect Server may help in resolving current address of a		A SIP Redirect Server may help in resolving current address of a
	mobile target address.		mobile target address.
	5.2. The Location Function (LF) of a Receiving Provider		5.2. The Location Function (LF) of a Receiving Provider
	5.2.1. Publish ENUM records		5.2.1. Publish ENUM records
	skipping to change at page 9, line 30		skipping to change at page 9, line 40
	5.2.2. Publish SIP DNS records		5.2.2. Publish SIP DNS records
	To receive peer requests, the receiving peer MUST insure that it		To receive peer requests, the receiving peer MUST insure that it
	publishes appropriate NAPTR, SRV, and address (A and/or AAAA) records		publishes appropriate NAPTR, SRV, and address (A and/or AAAA) records
	in the global DNS that resolve an appropriate transport, port, and		in the global DNS that resolve an appropriate transport, port, and
	address to a relevant SIP server.		address to a relevant SIP server.
	5.3. Policy Function (PF)		5.3. Policy Function (PF)
	Policy function is optional. The purpose of policy function is to		The purpose of policy function is to perform authentication and to
	perform authentication and to exchange peering policy capabilities to		exchange peering policy capabilities to be used by the signaling
	be used by the signaling function.		function. The policy function can happen multiple times (through
			multiple methods) during the procedures used to establish a call and
			the data acquired as a result can provide input to the LF, SF or MF
			functions.
			Policy data can come through DNS NAPTR resolution as shown in [18]
			and/or a SIP peering event package [22].
	The policy capabilities should be specified through well defined XML		The policy capabilities should be specified through well defined XML
	schemas. These policies define the capabilities of each peer and its		schemas. These policies define the capabilities of each peer and its
	devices used for peering. For example, the following capabilities		devices used for peering. For example, the following capabilities
	could be exchanged through the policy function:		could be exchanged through the policy function:
	o Adjacency (Next hop network attributes)		o Adjacency (Next hop network attributes)
	o If there are many adjacent proxies to use, the choice could be		o If there are many adjacent proxies to use, the choice could be
	based on:		based on:
	skipping to change at page 10, line 25		skipping to change at page 10, line 41
	o Inflow Traffic Restriction (not call-by-call)		o Inflow Traffic Restriction (not call-by-call)
	o For maintenance actions		o For maintenance actions
	o For congestion management		o For congestion management
	o How can a carrier prevent upstream networks from submitting		o How can a carrier prevent upstream networks from submitting
	calls for certain destinations in overload		calls for certain destinations in overload
	The Policy function can be implemented by method such as described in
	[6] as subscribe-notify.
	The authentication policy function can be implemented by TLS (as		The authentication policy function can be implemented by TLS (as
	described in (5.3.1), IPSec or any other method that meet the		described in (5.3.1), IPSec or any other method that meet the
	security needs to a specific deployment.		security needs to a specific deployment.
	Editor's Note: This section will be updated based on the progress on		Editor's Note: This section will be updated based on the progress on
	the SPEERMINT policy document.		the SPEERMINT policy document.
	5.3.1. TLS		5.3.1. TLS
	Once a transport, port, and address are found, the initiating peer		Once a transport, port, and address are found, the initiating peer
	skipping to change at page 11, line 19		skipping to change at page 11, line 34
	handshake.		handshake.
	5.3.2. IPSec		5.3.2. IPSec
	Editor's Note: will be described later.		Editor's Note: will be described later.
	5.3.3. Subscribe Notify		5.3.3. Subscribe Notify
	Policy function may also be optionally implemented by dynamic		Policy function may also be optionally implemented by dynamic
	subscribe, notify, and exchange of policy information and feature		subscribe, notify, and exchange of policy information and feature
	information among providers.		information among providers [22].
	5.4. Signaling Function (SF)		5.4. Signaling Function (SF)
	The purpose of signaling function is to perform routing of SIP		The purpose of signaling function is to perform routing of SIP
	messages, to optionally perform termination and re-initiation of a		messages, to optionally perform termination and re-initiation of a
	call, to optionally implement security and policies on SIP messages,		call, to optionally implement security and policies on SIP messages,
	and to assist in discovery/exchange of parameters to be used by the		and to assist in discovery/exchange of parameters to be used by the
	Media Function (MF).		Media Function (MF).
	The routing of SIP messages are performed by SIP proxies. The		The routing of SIP messages are performed by SIP proxies. The
	skipping to change at page 11, line 42		skipping to change at page 12, line 9
	Optionally, a SF may perform additional functions such as Session		Optionally, a SF may perform additional functions such as Session
	Admission Control, SIP Denial of Service protection, SIP Topology		Admission Control, SIP Denial of Service protection, SIP Topology
	Hiding, SIP header normalization, and SIP security, privacy and		Hiding, SIP header normalization, and SIP security, privacy and
	encryption.		encryption.
	The signaling function can also process SDP payloads for media		The signaling function can also process SDP payloads for media
	information such as media type, bandwidth, and type of codec; then,		information such as media type, bandwidth, and type of codec; then,
	communicate this information to the media function. Signaling		communicate this information to the media function. Signaling
	function may optionally communicate with network layer to pass Layer		function may optionally communicate with network layer to pass Layer
	3 related policies [GATE]		3 related policies [10]
	Signaling Function supports the following RFCs as per SPEERMINT
	Requirement document [2]:
	o SF MUST support the core SIP RFCs defined in SIP Hitchhikers
	Guide [5].
	o SF MUST support SDP related RFCs: the Session
	Description Protocol (SDP) [RFC2327], and the Offer/Answer
	mechanism with SDP [RFC3264].
	o SF SHOULD support: Reliability of Provisional
	Responses in SIP - PRACK [RFC3262], the SIP UPDATE method (for
	e.g. for codec changes during a session) [RFC3311], the Reason
	header field [RFC3326].
	5.5. Media Function (MF)		5.5. Media Function (MF)
	Examples of the media function is to transform voice payload from one		Examples of the media function is to transform voice payload from one
	coding (e.g., G.711) to another (e.g., EvRC), media relaying, media		coding (e.g., G.711) to another (e.g., EvRC), media relaying, media
	security, privacy, and encryption.		security, privacy, and encryption.
	Editor's Note: This section will be further updated.		Editor's Note: This section will be further updated.
	6. Call Control and Media Control Deployment Options		6. Call Control and Media Control Deployment Options
	skipping to change at page 13, line 24		skipping to change at page 13, line 24
	| | MF |<~~~~\(Option)|~~~~| MF | |		| | MF |<~~~~\(Option)|~~~~| MF | |
	| +----+ . \ / . +----+ |		| +----+ . \ / . +----+ |
	| | . \__ _/ . | |		| | . \__ _/ . | |
	\_________ / . . \________ _/		\_________ / . . \________ _/
	---------- ----------		---------- ----------
	--- Signal (SIP)		--- Signal (SIP)
	~~~ Bearer (RTP/IP)		~~~ Bearer (RTP/IP)
	... Scope of peering		... Scope of peering
	Figure 3: Decomposed v. Composed Peering		Figure 3: Decomposed v. Collapsed Peering
	The advantage of composed peering architecture is that one-element		The advantage of a collapsed peering architecture is that one-element
	solves all peering issues. Disadvantage examples of this architecture		solves all peering issues. Disadvantage examples of this architecture
	are single point failure, bottle neck, and complex scalability.		are single point failure, bottle neck, and complex scalability.
	In a decomposed model, SF and MF are implemented in separate peering		In a decomposed model, SF and MF are implemented in separate peering
	logical elements. Signaling functions are implemented in a proxy and		logical elements. Signaling functions are implemented in a proxy and
	media functions are implemented in another logical element. The		media functions are implemented in another logical element. The
	scaling of signaling versus scaling of media may differ between		scaling of signaling versus scaling of media may differ between
	applications. Decomposing allows each to follow a separate migration		applications. Decomposing allows each to follow a separate migration
	path.		path.
	skipping to change at page 14, line 19		skipping to change at page 14, line 19
	relationships, should be standardized within the IETF. These		relationships, should be standardized within the IETF. These
	standardized methods may enable capabilities such as dynamic peering		standardized methods may enable capabilities such as dynamic peering
	relationships across publicly maintained interconnections.		relationships across publicly maintained interconnections.
	TODO: Address RFC-3552 BCP items.		TODO: Address RFC-3552 BCP items.
	8. IANA Considerations		8. IANA Considerations
	There are no IANA considerations at this time.		There are no IANA considerations at this time.
	9. Conclusions		9. Acknowledgments
	The proposed peering reference architecture decomposes the peering
	interface into a set of well defined functions. Such an arrangement
	allows each function to the specified and evolved separately.
	10. Acknowledgments
	The working group thanks Sohel Khan for his initial architecture		The working group thanks Sohel Khan for his initial architecture
	draft that helped to initiate work on this draft.		draft that helped to initiate work on this draft.
	A significant portion of this draft is taken from [4] with permission		A significant portion of this draft is taken from [14] with
	from the author R. Mahy. The other important contributor is Otmar		permission from the author R. Mahy. The other important contributor
	Lendl.		is Otmar Lendl.
	Author's Addresses		Author's Addresses
	Mike Hammer		Mike Hammer
	Cisco Systems		Cisco Systems
	13615 Dulles Technology Drive		13615 Dulles Technology Drive
	Herndon, VA 20171		Herndon, VA 20171
	USA		USA
	Email: mhammer@cisco.com		Email: mhammer@cisco.com
	skipping to change at page 15, line 43		skipping to change at page 15, line 43
	USA		USA
	Email: rpenno@juniper.net		Email: rpenno@juniper.net
	Adam Uzelac		Adam Uzelac
	Global Crossing		Global Crossing
	1120 Pittsford Victor Road		1120 Pittsford Victor Road
	PITTSFORD, NY 14534		PITTSFORD, NY 14534
	USA		USA
	Email: adam.uzelac@globalcrossing.com		Email: adam.uzelac@globalcrossing.com
	11. References		10. References
	11.1. Normative References
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119, March 1997.
	[RFC2327] Handley, M. and V. Jacobson, "SDP: Session Description		10.1. Normative References
	Protocol", RFC 2327, April 1998.
	[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for		[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
	specifying the location of services (DNS SRV)", RFC 2782,		Levels", BCP 14, RFC 2119, March 1997.
	February 2000.
	[RFC2915] Mealling, M. and R. Daniel, "The Naming Authority Pointer		[2] Mealling, M. and R. Daniel, "The Naming Authority Pointer
	(NAPTR) DNS Resource Record", RFC 2915, September 2000.		(NAPTR) DNS Resource Record", RFC 2915, September 2000.
	[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,		[3] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
	A., Peterson, J., Sparks, R., Handley, M., and E.		Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP:
	Schooler, "SIP: Session Initiation Protocol", RFC 3261,		Session Initiation Protocol", RFC 3261, June 2002.
	June 2002.
	[RFC3262] Rosenberg, J. and H. Schulzrinne, "Reliability of
	Provisional Responses in Session Initiation Protocol
	(SIP)", RFC 3262, June 2002.
	[RFC3263] Rosenberg, J. and H. Schulzrinne, "Session Initiation
	Protocol (SIP): Locating SIP Servers", RFC 3263,
	June 2002.
	[RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
	with Session Description Protocol (SDP)", RFC 3264,
	June 2002.
	[RFC3311] Rosenberg, J., "The Session Initiation Protocol (SIP)
	UPDATE Method", RFC 3311, October 2002.
	[RFC3326] Schulzrinne, H., Oran, D., and G. Camarillo, "The Reason
	Header Field for the Session Initiation Protocol (SIP)",
	RFC 3326, December 2002.
	[RFC3546] Blake-Wilson, S., Nystrom, M., Hopwood, D., Mikkelsen, J.,
	and T. Wright, "Transport Layer Security (TLS)
	Extensions", RFC 3546, June 2003.
	[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.
	Jacobson, "RTP: A Transport Protocol for Real-Time
	Applications", STD 64, RFC 3550, July 2003.
	[RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control		[4] Rosenberg, J. and H. Schulzrinne, "Session Initiation Protocol
	Protocol Extended Reports (RTCP XR)", RFC 3611,		(SIP): Locating SIP Servers", RFC 3263, June 2002.
	November 2003.
	[RFC3764] Peterson, J., "enumservice registration for Session		[5] Blake-Wilson, S., Nystrom, M., Hopwood, D., Mikkelsen, J., and
	Initiation Protocol (SIP) Addresses-of-Record", RFC 3764,		T. Wright, "Transport Layer Security (TLS) Extensions", RFC
	April 2004.		3546, June 2003.
	[RFC3824] Peterson, J., Liu, H., Yu, J., and B. Campbell, "Using		[6] Schulzrinne, H., Casner, S., Frederick, R., and V. Jacobson,
	E.164 numbers with the Session Initiation Protocol (SIP)",		"RTP: A Transport Protocol for Real-Time Applications", STD 64,
	RFC 3824, June 2004.		RFC 3550, July 2003.
	[RFC3861] Peterson, J., ''Address Resolution for Instant Messaging		[7] Peterson, J., Liu, H., Yu, J., and B. Campbell, "Using E.164
	and Presence'',RFC 3861, August 2004.		numbers with the Session Initiation Protocol (SIP)", RFC 3824,
			June 2004.
	[RFC3951] Andersen, S., Duric, A., Astrom, H., Hagen, R., Kleijn,		[8] Peterson, J., "Address Resolution for Instant Messaging and
	W., and J. Linden, "Internet Low Bit Rate Codec (iLBC)",		Presence",RFC 3861, August 2004.
	RFC 3951, December 2004.
	[RFC3952] Duric, A. and S. Andersen, "Real-time Transport Protocol		[9] Peterson, J., "Telephone Number Mapping (ENUM) Service
	(RTP) Payload Format for internet Low Bit Rate Codec		Registration for Presence Services", RFC 3953, January 2005.
	(iLBC) Speech", RFC 3952, December 2004.
	[RFC3953] Peterson, J., "Telephone Number Mapping (ENUM) Service		[10] ETSI TS 102 333: " Telecommunications and Internet converged
	Registration for Presence Services", RFC 3953, January		Services and Protocols for Advanced Networking (TISPAN); Gate
	2005.		control protocol".
	[GATE] ETSI TS 102 333: " Telecommunications and Internet		[11] Peterson, J., "enumservice registration for Session Initiation
	converged Services and Protocols for Advanced Networking		Protocol (SIP) Addresses-of-Record", RFC 3764, April 2004.
	(TISPAN); Gate control protocol".
	11.2. Informative References		10.2. Informative References
	[1] Meyer, D., "SPEERMINT Terminology", draft-ietf-speermint-		[12] Meyer, D., "SPEERMINT Terminology", draft-ietf-speermint-
	terminology-01 (work in progress), May 2006.		terminology-04 (work in progress), May 2006.
	[2] Mule, J-F., ''SPEERMINT Requirements for SIP-based VoIP		[13] Mule, J-F., "SPEERMINT Requirements for SIP-based VoIP
	Interconnection'', draft-ietf-speermint-requirements-00.txt,		Interconnection", draft-ietf-speermint-requirements-00.txt,
	June 2006.		June 2006.
	[3] Hilt, V., Camarillo, G., and J. Rosenberg, "A Framework for		[14] Mahy, R., "A Minimalist Approach to Direct Peering", draft-
	Session Initiation Protocol (SIP) Session Policies", draft-
	ietf-sipping-session-policy-framework-00 (work in progress)
	[4] Mahy, R., ''A Minimalist Approach to Direct Peering'', draft-
	mahy-speermint-direct-peering-00.txt, June 19, 2006.		mahy-speermint-direct-peering-00.txt, June 19, 2006.
	[5] Rosenberg, J., "A Hitchhikers Guide to the Session Initiation		[15] Penno, R., et al., "SPEERMINT Routing Architecture Message
	Protocol (SIP)", February 2006.		Flows", draft-ietf-speermint-flows-00.txt", August 2006.
	[6] Penno, R., et al., ''SPEERMINT Routing Architecture Message
	Flows'', draft-ietf-speermint-message-flows-00.txt'', August
	2006.
	[7] Lee, Y., ''Session Peering Use Case for Cable'', draft-lee-		[16] Lee, Y., "Session Peering Use Case for Cable", draft-lee-
	speermint-use-case-cable-00.txt, June, 2006.		speermint-use-case-cable-00.txt, June, 2006.
	[8] Houri, A., et al., ''RTC Provisioning Requirements'', draft-		[17] Houri, A., et al., "RTC Provisioning Requirements", draft-
	houri-speermint-rtc-provisioning-reqs-00.txt, June, 2006.		houri-speermint-rtc-provisioning-reqs-00.txt, June, 2006.
	[9] Habler, M., et al., ''A Federation based VOIP Peering		[18] Habler, M., et al., "A Federation based VOIP Peering
	Architecture'', draft-lendl-speermint-federations-01.txt, June		Architecture", draft-lendl-speermint-federations-03.txt,
	2006.		September 2006.
	[10] Mahy, R., "A Telephone Number Mapping (ENUM) Service		[19] Mahy, R., "A Telephone Number Mapping (ENUM) Service
	Registration for Instant Messaging (IM) Services", draft-ietf-		Registration for Instant Messaging (IM) Services", draft-ietf-
	enum-im-service-00 (work in progress), March 2006.		enum-im-service-00 (work in progress), March 2006.
	[11] Haberler, M. and R. Stastny, "Combined User and Carrier ENUM in		[20] Haberler, M. and R. Stastny, "Combined User and Carrier ENUM in
	the e164.arpa tree", draft-haberler-carrier-enum-02 (work in		the e164.arpa tree", draft-haberler-carrier-enum-02 (work in
	progress), March 2006.		progress), March 2006.
	[12] Livingood, J. and R. Shockey, "IANA Registration for an		[21] Livingood, J. and R. Shockey, "IANA Registration for an
	Enumservice Containing PSTN Signaling Information", draft-ietf-		Enumservice Containing PSTN Signaling Information", draft-ietf-
	enum-pstn-04 (work in progress), May 2006.		enum-pstn-04 (work in progress), May 2006.
			[22] Penno, R., Malas D., and Melampy, P., "A Session Initiation
			Protocol (SIP) Event package for Peering", draft-penno-sipping-
			peering-package-00 (work in progress), September 2006.
	Intellectual Property Statement		Intellectual Property Statement
	The IETF takes no position regarding the validity or scope of any		The IETF takes no position regarding the validity or scope of any
	Intellectual Property Rights or other rights that might be claimed to		Intellectual Property Rights or other rights that might be claimed to
	pertain to the implementation or use of the technology described in		pertain to the implementation or use of the technology described in
	this document or the extent to which any license under such rights		this document or the extent to which any license under such rights
	might or might not be available; nor does it represent that it has		might or might not be available; nor does it represent that it has
	made any independent effort to identify any such rights. Information		made any independent effort to identify any such rights. Information
	on the procedures with respect to rights in RFC documents can be		on the procedures with respect to rights in RFC documents can be
	found in BCP 78 and BCP 79.		found in BCP 78 and BCP 79.
End of changes. 76 change blocks.
	194 lines changed or deleted		146 lines changed or added
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