draft-ietf-p2psip-disco-00.txt		draft-ietf-p2psip-disco-01.txt
	Network Working Group A. Knauf		Network Working Group A. Knauf
	Internet-Draft T C. Schmidt, Ed.		Internet-Draft T. Schmidt, Ed.
	Intended status: Standards Track HAW Hamburg		Intended status: Standards Track HAW Hamburg
	Expires: April 12, 2013 G. Hege		Expires: January 13, 2014 G. Hege
	daviko GmbH		daviko GmbH
	M. Waehlisch		M. Waehlisch
	link-lab & FU Berlin		link-lab & FU Berlin
	October 9, 2012		July 12, 2013
	A RELOAD Usage for Distributed Conference Control (DisCo)		A RELOAD Usage for Distributed Conference Control (DisCo)
	draft-ietf-p2psip-disco-00		draft-ietf-p2psip-disco-01
	Abstract		Abstract
	This document defines a RELOAD Usage for Distributed Conference		This document defines a RELOAD Usage for Distributed Conference
	Control (DisCo) with SIP. DisCo preserves conference addressing		Control (DisCo) with SIP. DisCo preserves conference addressing
	through a single SIP URI by splitting its semantic of identifier and		through a single SIP URI by splitting its semantic of identifier and
	locator using a new Kind data structure. Conference members are		locator using a new Kind data structure. Conference members are
	enabled to select conference controllers based on proximity awareness		enabled to select conference controllers based on proximity awareness
	and to recover from failures of individual resource instances. DisCo		and to recover from failures of individual resource instances. DisCo
	proposes call delegation to balance the load at focus peers.		proposes call delegation to balance the load at focus peers.
	Status of this Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	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 http://datatracker.ietf.org/drafts/current/.		Drafts is at http://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
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	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 April 12, 2013.		This Internet-Draft will expire on January 13, 2014.
	Copyright Notice		Copyright Notice
	Copyright (c) 2012 IETF Trust and the persons identified as the		Copyright (c) 2013 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
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://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
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5		2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
	3. Overview of DisCo . . . . . . . . . . . . . . . . . . . . . . 6		3. Overview of DisCo . . . . . . . . . . . . . . . . . . . . . . 4
	3.1. Reference Scenario . . . . . . . . . . . . . . . . . . . . 6		3.1. Reference Scenario . . . . . . . . . . . . . . . . . . . 4
	3.2. Initiating a Distributed Conference . . . . . . . . . . . 7		3.2. Initiating a Distributed Conference . . . . . . . . . . . 6
	3.3. Joining a Conference . . . . . . . . . . . . . . . . . . . 8		3.3. Joining a Conference . . . . . . . . . . . . . . . . . . 6
	3.4. Conference State Synchronization . . . . . . . . . . . . . 9		3.4. Conference State Synchronization . . . . . . . . . . . . 7
	3.5. Call delegation . . . . . . . . . . . . . . . . . . . . . 10		3.5. Call delegation . . . . . . . . . . . . . . . . . . . . . 8
	3.6. Resilience . . . . . . . . . . . . . . . . . . . . . . . . 10		3.6. Resilience . . . . . . . . . . . . . . . . . . . . . . . 8
	3.7. Topology Awareness . . . . . . . . . . . . . . . . . . . . 10		3.7. Topology Awareness . . . . . . . . . . . . . . . . . . . 8
	4. RELOAD Usage for Distributed Conference Control . . . . . . . 11		4. RELOAD Usage for Distributed Conference Control . . . . . . . 8
	4.1. Shared Resource DisCo-Registration . . . . . . . . . . . . 11		4.1. Shared Resource DisCo-Registration . . . . . . . . . . . 9
	4.2. Kind Data Structure . . . . . . . . . . . . . . . . . . . 11		4.2. Kind Data Structure . . . . . . . . . . . . . . . . . . . 9
	4.3. Variable Conference Identifier . . . . . . . . . . . . . . 12		4.3. Variable Conference Identifier . . . . . . . . . . . . . 10
	4.4. Conference Creation . . . . . . . . . . . . . . . . . . . 12		4.4. Conference Creation . . . . . . . . . . . . . . . . . . . 10
	4.5. Advertising Focus Ability . . . . . . . . . . . . . . . . 13		4.5. Advertising Focus Ability . . . . . . . . . . . . . . . . 11
	4.6. Determining Coordinates . . . . . . . . . . . . . . . . . 14		4.6. Determining Coordinates . . . . . . . . . . . . . . . . . 12
	4.7. Proximity-aware Conference Participation . . . . . . . . . 14		4.7. Proximity-aware Conference Participation . . . . . . . . 12
	4.8. Configuration Document Extension . . . . . . . . . . . . . 16		4.8. Configuration Document Extension . . . . . . . . . . . . 14
	5. Conference State Synchronization . . . . . . . . . . . . . . . 18		5. Conference State Synchronization . . . . . . . . . . . . . . 15
	5.1. Event Package Overview . . . . . . . . . . . . . . . . . . 18		5.1. Event Package Overview . . . . . . . . . . . . . . . . . 15
	5.2. <distributed-conference> . . . . . . . . . . . . . . . . . 20		5.2. <distributed-conference> . . . . . . . . . . . . . . . . 16
	5.3. <version-vector>/<version> . . . . . . . . . . . . . . . . 20		5.3. <version-vector>/<version> . . . . . . . . . . . . . . . 17
	5.4. <conference-description> . . . . . . . . . . . . . . . . . 21		5.4. <conference-description> . . . . . . . . . . . . . . . . 18
	5.5. <focus> . . . . . . . . . . . . . . . . . . . . . . . . . 22		5.5. <focus> . . . . . . . . . . . . . . . . . . . . . . . . . 18
	5.5.1. <focus-state> . . . . . . . . . . . . . . . . . . . . 23		5.5.1. <focus-state> . . . . . . . . . . . . . . . . . . . . 19
	5.5.2. <users>/<user> . . . . . . . . . . . . . . . . . . . . 23		5.5.2. <users>/<user> . . . . . . . . . . . . . . . . . . . 20
	5.5.3. <relations>/<relation> . . . . . . . . . . . . . . . . 24		5.5.3. <relations>/<relation> . . . . . . . . . . . . . . . 20
	5.6. Distribution of Change Events . . . . . . . . . . . . . . 24		5.6. Distribution of Change Events . . . . . . . . . . . . . . 21
	5.7. Translation to Conference-Info Event Package . . . . . . . 25		5.7. Translation to Conference-Info Event Package . . . . . . 22
	5.7.1. <conference-info> . . . . . . . . . . . . . . . . . . 26		5.7.1. <conference-info> . . . . . . . . . . . . . . . . . . 22
	5.7.2. <conference-description> . . . . . . . . . . . . . . . 26		5.7.2. <conference-description> . . . . . . . . . . . . . . 23
	5.7.3. <host-info> . . . . . . . . . . . . . . . . . . . . . 26		5.7.3. <host-info> . . . . . . . . . . . . . . . . . . . . . 23
	5.7.4. <conference-state> . . . . . . . . . . . . . . . . . . 26		5.7.4. <conference-state> . . . . . . . . . . . . . . . . . 23
	5.7.5. <users>/<user> . . . . . . . . . . . . . . . . . . . . 27		5.7.5. <users>/<user> . . . . . . . . . . . . . . . . . . . 24
	5.7.6. <sidebars-by-ref>/<sidebars-by-value> . . . . . . . . 27		5.7.6. <sidebars-by-ref>/<sidebars-by-value> . . . . . . . . 24
	6. Distributed Conference Control with SIP . . . . . . . . . . . 28		6. Distributed Conference Control with SIP . . . . . . . . . . . 24
	6.1. Call delegation . . . . . . . . . . . . . . . . . . . . . 28		6.1. Call delegation . . . . . . . . . . . . . . . . . . . . . 24
	6.2. Conference Access . . . . . . . . . . . . . . . . . . . . 29		6.2. Conference Access . . . . . . . . . . . . . . . . . . . . 26
	6.3. Media Negotiation and Distribution . . . . . . . . . . . . 30		6.3. Media Negotiation and Distribution . . . . . . . . . . . 26
	6.3.1. Offer/Answer . . . . . . . . . . . . . . . . . . . . . 30		6.3.1. Offer/Answer . . . . . . . . . . . . . . . . . . . . 26
	6.3.2. New Peers Joining . . . . . . . . . . . . . . . . . . 31		6.3.2. New Peers Joining . . . . . . . . . . . . . . . . . . 27
	6.4. Restructuring a Conference . . . . . . . . . . . . . . . . 31		6.4. Restructuring a Conference . . . . . . . . . . . . . . . 27
	6.4.1. On Graceful Leave . . . . . . . . . . . . . . . . . . 31		6.4.1. On Graceful Leave . . . . . . . . . . . . . . . . . . 27
	6.4.2. On Unexpected Leave . . . . . . . . . . . . . . . . . 32		6.4.2. On Unexpected Leave . . . . . . . . . . . . . . . . . 28
	7. DisCo Kind Definition . . . . . . . . . . . . . . . . . . . . 33		7. DisCo Kind Definition . . . . . . . . . . . . . . . . . . . . 28
	8. XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . . 34		8. XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . 29
	9. Relax NG Grammar . . . . . . . . . . . . . . . . . . . . . . . 38		9. Relax NG Grammar . . . . . . . . . . . . . . . . . . . . . . 32
	10. Security Considerations . . . . . . . . . . . . . . . . . . . 39		10. Security Considerations . . . . . . . . . . . . . . . . . . . 33
	10.1. Trust Aspects . . . . . . . . . . . . . . . . . . . . . . 39		10.1. Trust Aspects . . . . . . . . . . . . . . . . . . . . . 33
	11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 40		11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 33
	12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 41		12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 33
	13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 42		13. References . . . . . . . . . . . . . . . . . . . . . . . . . 33
	13.1. Normative References . . . . . . . . . . . . . . . . . . . 42		13.1. Normative References . . . . . . . . . . . . . . . . . . 33
	13.2. Informative References . . . . . . . . . . . . . . . . . . 43		13.2. Informative References . . . . . . . . . . . . . . . . . 34
	Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 44		Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 35
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 46		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 36
	1. Introduction		1. Introduction
	This document describes a RELOAD Usage for distributed conference		This document describes a RELOAD Usage for distributed conference
	control (DisCo) in a tightly coupled model with SIP [RFC3261]. The		control (DisCo) in a tightly coupled model with SIP [RFC3261]. The
	Usage provides self-organizing and scalable signaling that allows		Usage provides self-organizing and scalable signaling that allows
	RELOAD peers, clients and plain SIP user agents to participate in a		RELOAD peers, clients and plain SIP user agents to participate in a
	managed P2P conference. DisCo defines the following functions:		managed P2P conference. DisCo defines the following functions:
	o A SIP protocol scheme for distributed conference control		o A SIP protocol scheme for distributed conference control
	skipping to change at page 7, line 5		skipping to change at page 5, line 31
	conference from the storing peer. In contrast to this, the user		conference from the storing peer. In contrast to this, the user
	agent E receives the conference URI not by RELOAD mechanisms, but		agent E receives the conference URI not by RELOAD mechanisms, but
	resolves the ID and joins the conference by plain SIP negotiation.		resolves the ID and joins the conference by plain SIP negotiation.
	Focus peers maintain a SIP signaling relation among each other used		Focus peers maintain a SIP signaling relation among each other used
	for notification messages that synchronize the conference focus		for notification messages that synchronize the conference focus
	peers' knowledge about the entire conference state. Additionally,		peers' knowledge about the entire conference state. Additionally,
	focus peers can transfer calls to each other by a call delegation		focus peers can transfer calls to each other by a call delegation
	mechanism.		mechanism.
	+-------------------+ +------------------+		+-------------------+ +------------------+
	|Access Control List| |DisCo-Registration|		|Access Control List| |DisCo-Registration|
	+-------------------+ +------------------+		+-------------------+ +------------------+
	\ /		\ /
	+-------+		+-------+
	|Storing|		|Storing|
	# # # # # # # # # # | Peer | # # # # # # # # # #		# # # # # # # # # # | Peer | # # # # # # # # # #
	# | SP | #		# | SP | #
	# +-------+ #		# +-------+ #
	# #		# #
	# #		# #
	# #		# #
	+----+ +----+		+----+ +----+
	|Peer| \ RELOAD Instance |Peer|		|Peer| \ RELOAD Instance |Peer|
	| C | \ | D |		| C | \ | D |
	+----+ \ +----+		+----+ \ +----+
	# SIP #		# SIP #
	# \ #		# \ #
	# \ #		# \ #
	# +-------+ +-------+ #(		# +-------+ +-------+ #(
	# | Focus | | Focus | # )		# | Focus | | Focus | # )
	# # | Peer | # # # # # # # # # # # | Peer | # # (		# # | Peer | # # # # # # # # # # # | Peer | # # (
	| A | <===Conf.Events/====> | B | )		| A | <===Conf.Events/====> | B | )
	+-------+ Call delegation +-------+ Overlay		+-------+ Call delegation +-------+ Overlay
	/ \ Comm.		/ \ Comm.
	/ \ (		/ \ (
	SIP SIP )		SIP SIP )
	/ \ (		/ \ (
	/ \ )		/ \ )
	+----------+ +--------+		+----------+ +--------+
	|User Agent| | Client |		|User Agent| | Client |
	| E | | F |		| E | | F |
	+----------+ +--------+		+----------+ +--------+
	Figure 1: Reference Scenario: Focus peers A,B maintain a distributed		Figure 1: Reference Scenario: Focus peers A,B maintain a distributed
	conference		conference
	3.2. Initiating a Distributed Conference		3.2. Initiating a Distributed Conference
	To create a conference the initiating user agent announces itself as		To create a conference the initiating user agent announces itself as
	a focus for the conference. It stores its own contact information		a focus for the conference. It stores its own contact information
	(Node-ID) as a DisCo-Registration Kind (cf. Figure 2) in the RELOAD		(Node-ID) as a DisCo-Registration Kind (cf. Figure 2) in the RELOAD
	overlay. The hashed conference URI is used as the Resource-ID. This		overlay. The hashed conference URI is used as the Resource-ID. This
	skipping to change at page 9, line 5		skipping to change at page 6, line 45
	used to send an INVITE to the conference applying the chosen focus as		used to send an INVITE to the conference applying the chosen focus as
	the contact. The selection of the focus peer can optionally be based		the contact. The selection of the focus peer can optionally be based
	on proximity information if available.		on proximity information if available.
	A conference member proposes itself as a focus for subsequent		A conference member proposes itself as a focus for subsequent
	participants by adding its Node-ID to the DisCo-Registration stored		participants by adding its Node-ID to the DisCo-Registration stored
	under the conference URI in the RELOAD overlay. The decision whether		under the conference URI in the RELOAD overlay. The decision whether
	a peer announces as a focus incorporates bandwidth, power, and other		a peer announces as a focus incorporates bandwidth, power, and other
	constraints, but details are beyond the scope of this document.		constraints, but details are beyond the scope of this document.
	Alice RELOAD Bob		Alice RELOAD Bob
	(initiating peer) (joining peer)		(initiating peer) (joining peer)
	--------------------------------------------------------------------		--------------------------------------------------------------------
	| | |		| | |
	| Alice stores her mapping to register a conference |		| Alice stores her mapping to register a conference |
	| Store mapping(ConfURI, Alice) | |		| Store mapping(ConfURI, Alice) | |
	|------------------------------>| |		|------------------------------>| |
	| Bob requests the list of potential focus peers |		| Bob requests the list of potential focus peers |
	| | Lookup ConfURI |		| | Lookup ConfURI |
	| |<------------------------------|		| |<------------------------------|
	| | Result list of conf. focus |		| | Result list of conf. focus |
	| |------------------------------>|		| |------------------------------>|
	| | |		| | |
	| Bob establishes transport connection to Alice |		| Bob establishes transport connection to Alice |
	| AppAttach |		| AppAttach |
	|<--------------------------------------------------------------|		|<--------------------------------------------------------------|
	| AppAttach |		| AppAttach |
	|-------------------------------------------------------------->|		|-------------------------------------------------------------->|
	| INVITE |		| INVITE |
	|<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|		|<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
	| OK |		| OK |
	|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|		|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
	| ACK |		| ACK |
	|<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|		|<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
	| Media |		| Media |
	|<=============================================================>|		|<=============================================================>|
	| | |		| | |
	| Bob stores his mapping to become a focus peer too |		| Bob stores his mapping to become a focus peer too |
	| | Store mapping(ConfURI, Bob) |		| | Store mapping(ConfURI, Bob) |
	| |<------------------------------|		| |<------------------------------|
	| | |		| | |
	Figure 2: DisCo Usage generic Call Flow		Figure 2: DisCo Usage generic Call Flow
	3.4. Conference State Synchronization		3.4. Conference State Synchronization
	Each focus of a conference maintains signaling connections to its		Each focus of a conference maintains signaling connections to its
	related participants independently from other conference controllers.		related participants independently from other conference controllers.
	This distributed conference design effects that the entire SIP		This distributed conference design effects that the entire SIP
	conference state is jointly held by all focus peers. In DisCo, state		conference state is jointly held by all focus peers. In DisCo, state
	synchronization is based on a SIP specific event notifications		synchronization is based on a SIP specific event notifications
	skipping to change at page 11, line 43		skipping to change at page 9, line 40
	cooperatively control the conference. Additionally, each DisCo-		cooperatively control the conference. Additionally, each DisCo-
	Registration provides the coordinate value, which indicates the		Registration provides the coordinate value, which indicates the
	relative network position of the focus peers.		relative network position of the focus peers.
	The data structure uses the RELOAD dictionary type. The dictionary		The data structure uses the RELOAD dictionary type. The dictionary
	key MUST be the Node-ID of the focus peer that is associated with the		key MUST be the Node-ID of the focus peer that is associated with the
	dictionary entry. This allows a focus peer to update only its own		dictionary entry. This allows a focus peer to update only its own
	mapping. The DisCo data structure of type DisCoRegistration is		mapping. The DisCo data structure of type DisCoRegistration is
	constructed as follows:		constructed as follows:
	struct {		struct {
	/* This field is optional, see documentation */		/* This field is optional, see documentation */
	ResourceNameExtension res_name_ext;		ResourceNameExtension res_name_ext;
	opaque coordinate<0..2^16-1>;		opaque coordinate<0..2^16-1>;
	NodeId node_id;		NodeId node_id;
	} DisCoRegistration;		} DisCoRegistration;
	The DisCoRegistration structure is composed of the following values:		The DisCoRegistration structure is composed of the following values:
	res_name_ext: This field can contain the conference URI. It meets		res_name_ext: This field can contain the conference URI. It meets
	the requirement for the USER-CHAIN-ACL access policy defined in		the requirement for the USER-CHAIN-ACL access policy defined in
	[I-D.knauf-p2psip-share] to enable variable resource names.		[I-D.knauf-p2psip-share] to enable variable resource names.
	coordinate: This field contains a topological descriptor that		coordinate: This field contains a topological descriptor that
	indicates the relative position of the peer in the network. To		indicates the relative position of the peer in the network. To
	support different algorithms the coordinate field is represented		support different algorithms the coordinate field is represented
	skipping to change at page 13, line 8		skipping to change at page 11, line 8
	Section 4.3) and an ACL referring to the DisCo-Registration Kind-ID.		Section 4.3) and an ACL referring to the DisCo-Registration Kind-ID.
	If DisCo registrations and ACL Kinds from previous conferences are		If DisCo registrations and ACL Kinds from previous conferences are
	still existing there are two options. First, if conference creator		still existing there are two options. First, if conference creator
	is aware of the indexes from previous ACL Kinds, it refreshes the		is aware of the indexes from previous ACL Kinds, it refreshes the
	root item of this ACL and stores its registration as focus peer as		root item of this ACL and stores its registration as focus peer as
	DisCo-Registration Kind. Second, If the creator is unaware of		DisCo-Registration Kind. Second, If the creator is unaware of
	indexes, it fetches all Access List Kinds to determine the index of		indexes, it fetches all Access List Kinds to determine the index of
	the root item.		the root item.
	Alice Peer1 Overlay PeerN Storing Peer		Alice Peer1 Overlay PeerN Storing Peer
	-------------------------------------------------------------		-------------------------------------------------------------
	| StatReq Res:Conf-URI | |		| StatReq Res:Conf-URI | |
	|------------>|----------->|----------->|----------->|		|------------>|----------->|----------->|----------->|
	| StatAns | | |		| StatAns | | |
	|<------------|<-----------|<-----------|<-----------|		|<------------|<-----------|<-----------|<-----------|
	| StoreReq Res:Conf-URI Kinds:DisCo, Access-List |		| StoreReq Res:Conf-URI Kinds:DisCo, Access-List |
	|------------>|----------->|----------->|----------->|		|------------>|----------->|----------->|----------->|
	| StoreAns | | |		| StoreAns | | |
	|<------------|<-----------|<-----------|<-----------|		|<------------|<-----------|<-----------|<-----------|
	| | | | |		| | | | |
	Figure 3: Initial creation of a Distributed Conference		Figure 3: Initial creation of a Distributed Conference
	Optionally the conference initiator (or any active focus) MAY store		Optionally the conference initiator (or any active focus) MAY store
	an additional RELOAD SIP-Registration in the overlay		an additional RELOAD SIP-Registration in the overlay
	[I-D.ietf-p2psip-sip] or even at a standard SIP registrar [RFC3261]		[I-D.ietf-p2psip-sip] or even at a standard SIP registrar [RFC3261]
	under a URI for which it has write permission. This allows DisCo-		under a URI for which it has write permission. This allows DisCo-
	unaware or even legacy SIP user agents to participate in the		unaware or even legacy SIP user agents to participate in the
	conference. Those registrations SHOULD always point to a currently		conference. Those registrations SHOULD always point to a currently
	active focus, who is prepared to accept legacy user agents. The user		active focus, who is prepared to accept legacy user agents. The user
	skipping to change at page 15, line 6		skipping to change at page 13, line 8
	1. Resolution of the conference identifier.		1. Resolution of the conference identifier.
	2. Establishment of of transport connection.		2. Establishment of of transport connection.
	3. SIP signaling to join a conference.		3. SIP signaling to join a conference.
	Figure 4 and the following specifications give a more detailed view		Figure 4 and the following specifications give a more detailed view
	on the joining procedure.		on the joining procedure.
	Bob Peer1 Overlay PeerN Storing Peer Alice		Bob Peer1 Overlay PeerN Storing Peer Alice
	--------------------------------------------------------------		--------------------------------------------------------------
	| StatReq Res:Conf-URI | | |		| StatReq Res:Conf-URI | | |
	|--------->|--------->|--------->|--------->| |		|--------->|--------->|--------->|--------->| |
	| |StatAns | | | |		| |StatAns | | | |
	|<---------|<---------|<---------|<---------| |		|<---------|<---------|<---------|<---------| |
	| FetchReq Res:Conf-URI Kind:DisCo,ACL | |		| FetchReq Res:Conf-URI Kind:DisCo,ACL | |
	|--------->|--------->|--------->|--------->| |		|--------->|--------->|--------->|--------->| |
	| |FetchAns | | | |		| |FetchAns | | | |
	|<---------|<---------|<---------|<---------| |		|<---------|<---------|<---------|<---------| |
	| | | | | |		| | | | | |
	| Bob calculates Alice as closest Focus | |		| Bob calculates Alice as closest Focus | |
	| | | | | |		| | | | | |
	| |AppAttach application:5060 | |		| |AppAttach application:5060 | |
	|--------->|--------->|--------->|--------->|--------->|		|--------->|--------->|--------->|--------->|--------->|
	| |AppAttach application:5060 | |		| |AppAttach application:5060 | |
	|<---------|<---------|<---------|<---------|<---------|		|<---------|<---------|<---------|<---------|<---------|
	| | | | | |		| | | | | |
	|<-------------------ICE Checks----------------------->|		|<-------------------ICE Checks----------------------->|
	| | | | | |		| | | | | |
	| | INVITE sip:Alice | |		| | INVITE sip:Alice | |
	|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|		|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
	| | 200 OK | | |		| | 200 OK | | |
	|<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|		|<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
	| | ACK | | |		| | ACK | | |
	|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|		|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
	| | | | | |		| | | | | |
	Figure 4: Participation of a Distributed Conference		Figure 4: Participation of a Distributed Conference
	1. The joining peer MAY determine its own coordinate value (if		1. The joining peer MAY determine its own coordinate value (if
	used).		used).
	2. The joining peer sends a StatReq message to obtain all indexes of		2. The joining peer sends a StatReq message to obtain all indexes of
	the Access Control List (ACL) Kinds stored.		the Access Control List (ACL) Kinds stored.
	3. The joining peer sends a FetchReq message for the DisCo and ACL		3. The joining peer sends a FetchReq message for the DisCo and ACL
	skipping to change at page 19, line 5		skipping to change at page 15, line 38
	5.1. Event Package Overview		5.1. Event Package Overview
	The 'distributed-conference' event package is designed to convey		The 'distributed-conference' event package is designed to convey
	information about roles and relations of the conference participants.		information about roles and relations of the conference participants.
	Conference controllers obtain the global state of the conference and		Conference controllers obtain the global state of the conference and
	use this information for load balancing or conference restructuring		use this information for load balancing or conference restructuring
	mechanisms in case of a focus failure. Figure Figure 5 gives a		mechanisms in case of a focus failure. Figure Figure 5 gives a
	general overview of the document hierarchy.		general overview of the document hierarchy.
	distributed-conference		distributed-conference
	|		|
	|-- version-vector		|-- version-vector
	| |-- version		| |-- version
	| |-- version		| |-- version
	|		|
	|-- conference-description		|-- conference-description
	|		|
	|-- focus		|-- focus
	| |-- focus-state		| |-- focus-state
	| | |-- user-count		| | |-- user-count
	| | |-- coordinate		| | |-- coordinate
	| | |-- maximum-user-count		| | |-- maximum-user-count
	| | |-- active		| | |-- active
	| | |-- locked		| | |-- locked
	| | |-- conf-uris		| | |-- conf-uris
	| | |-- available-media		| | |-- available-media
	| |		| |
	| |-- users		| |-- users
	| | |-- user		| | |-- user
	| | | |-- endpoint		| | | |-- endpoint
	| | | | |-- media		| | | | |-- media
	| | | | |-- call-info		| | | | |-- call-info
	| |		| |
	| |-- relations		| |-- relations
	| | |-- relation		| | |-- relation
	|-- focus		|-- focus
	| |-- ...		| |-- ...
	Figure 5: Overview of the event package for distributed conferences		Figure 5: Overview of the event package for distributed conferences
	The document structure is designed to allow concurrent change events		The document structure is designed to allow concurrent change events
	at several focus peers. To prevent race conditions each focus peer		at several focus peers. To prevent race conditions each focus peer
	has exclusive writing permission to the 'focus' sub element that		has exclusive writing permission to the 'focus' sub element that
	describes itself. It is achieved by a unique mapping from a focus		describes itself. It is achieved by a unique mapping from a focus
	peer to its XML element using the 'Element Keys' mechanisms for		peer to its XML element using the 'Element Keys' mechanisms for
	partial notification [RFC4575](sections 4.4-5.). A focus peer is		partial notification [RFC4575](sections 4.4-5.). A focus peer is
	only allowed to update or change that <focus> sub element, whose		only allowed to update or change that <focus> sub element, whose
	skipping to change at page 26, line 27		skipping to change at page 23, line 19
	events of remote focus peer.		events of remote focus peer.
	5.7.2. <conference-description>		5.7.2. <conference-description>
	The <conference-description> element exists in both event packages,		The <conference-description> element exists in both event packages,
	conference-info and distributed-conference. Thus, the following		conference-info and distributed-conference. Thus, the following
	elements are seamlessly translatable: <keywords>, <display-text>,		elements are seamlessly translatable: <keywords>, <display-text>,
	<subject>, <free-text> and <service-uris>.		<subject>, <free-text> and <service-uris>.
	The sub elements <conf-uris>, <maximum-user-count> and <available-		The sub elements <conf-uris>, <maximum-user-count> and <available-
	media> in conference-info have there counterparts below the		media> in conference-info have there counterparts below the \focus
	\focus\focus-state element of the distributed-conference event		\focus-state element of the distributed-conference event package.
	package. Each describes a local state of a focus peer in the		Each describes a local state of a focus peer in the conference.
	conference. Hence, the intersection of every disco.<conf-uris>,		Hence, the intersection of every disco.<conf-uris>, disco.<available-
	disco.<available-media> and the sum over each disco.<maximum-user-		media> and the sum over each disco.<maximum-user-count> element of
	count> element of each disco.<focus> element in distributed-		each disco.<focus> element in distributed-conference, specifies the
	conference, specifies the content of the corresponding conference-		content of the corresponding conference-info elements.
	info elements.
	5.7.3. <host-info>		5.7.3. <host-info>
	According to [RFC4575] the ci.<host-info> element contains		According to [RFC4575] the ci.<host-info> element contains
	information about the entity hosting the conference. For		information about the entity hosting the conference. For
	participants in a distributed conference, the hosting entity is their		participants in a distributed conference, the hosting entity is their
	focus peer. Thus, the ci.<host-info> element contains information		focus peer. Thus, the ci.<host-info> element contains information
	about a focus peer.		about a focus peer.
	5.7.4. <conference-state>		5.7.4. <conference-state>
	The ci.<conference-state> element allows subscribers obtain		The ci.<conference-state> element allows subscribers obtain
	information about overall state of a conference. Its sub elements		information about overall state of a conference. Its sub elements ci
	ci.<user-count>, ci.<active> and ci.<locked> are reused as sub		.<user-count>, ci.<active> and ci.<locked> are reused as sub elements
	elements of \focus\focus-state to describe the local state of a focus		of \focus\focus-state to describe the local state of a focus peer in
	peer in a distributed conference. The translation rules from the		a distributed conference. The translation rules from the
	distributed-conference to the conference-info event package are the		distributed-conference to the conference-info event package are the
	following:		following:
	<user-count>: The sum over each value of the disco.<user-count>		<user-count>: The sum over each value of the disco.<user-count>
	element defines the corresponding ci.<user-count>.		element defines the corresponding ci.<user-count>.
	<active>: The boolean ci.<active> element is the logical		<active>: The boolean ci.<active> element is the logical
	concatenation over all disco.<active> elements by an OR-operator.		concatenation over all disco.<active> elements by an OR-operator.
	<locked> The boolean ci.<locked> element is the logical		<locked> The boolean ci.<locked> element is the logical
	skipping to change at page 33, line 9		skipping to change at page 28, line 39
	6.4.2. On Unexpected Leave		6.4.2. On Unexpected Leave
	If an unexpected leave is detected by a participant (e.g. missing		If an unexpected leave is detected by a participant (e.g. missing
	signaling and/or media packets) it MUST repeat the joining procedure		signaling and/or media packets) it MUST repeat the joining procedure
	as described in Section 4.7.		as described in Section 4.7.
	7. DisCo Kind Definition		7. DisCo Kind Definition
	This section formally defines the DisCo kind.		This section formally defines the DisCo kind.
	Name		Name
	DISCO-REGISTRATION		DISCO-REGISTRATION
	Kind IDs		Kind IDs
	The Resource name DISCO-REGISTRATION Kind-ID is the AoR of the		The Resource name DISCO-REGISTRATION Kind-ID is the AoR of the
	conference. The data stored is the DisCoRegistrationData, that		conference. The data stored is the DisCoRegistrationData, that
	contains the Node-ID of a peer acting as a focus for the		contains the Node-ID of a peer acting as a focus for the
	conference and optionally a coordinates value describing a		conference and optionally a coordinates value describing a
	peer's relative network position.		peer's relative network position.
	Data Model		Data Model
	The data model for the DISCO-REGISTRATION Kind-ID is dictionary.		The data model for the DISCO-REGISTRATION Kind-ID is dictionary.
	The dictionary key is the Node-ID of the peer action as focus.		The dictionary key is the Node-ID of the peer action as focus.
	Access Control		Access Control
	USER-CHAIN-ACL		USER-CHAIN-ACL
	The data stored for the Kind-ID DISCO-REGISTRATION is of type		The data stored for the Kind-ID DISCO-REGISTRATION is of type
	DisCoRegistration. It contains a "coordinates" value, that describes		DisCoRegistration. It contains a "coordinates" value, that describes
	the peers relative network position and the Node-ID of the registered		the peers relative network position and the Node-ID of the registered
	focus peer.		focus peer.
	8. XML Schema		8. XML Schema
	The XML schema for the event package for distributed conferences is:		The XML schema for the event package for distributed conferences is:
	skipping to change at page 38, line 5		skipping to change at page 32, line 30
	<xs:complexType name="relation-type">		<xs:complexType name="relation-type">
	<xs:simpleContent>		<xs:simpleContent>
	<xs:extension base="xs:string">		<xs:extension base="xs:string">
	<xs:attribute name="entity" type="xs:anyURI"/>		<xs:attribute name="entity" type="xs:anyURI"/>
	<xs:anyAttribute namespace="##other" processContents="lax"/>		<xs:anyAttribute namespace="##other" processContents="lax"/>
	</xs:extension>		</xs:extension>
	</xs:simpleContent>		</xs:simpleContent>
	</xs:complexType>		</xs:complexType>
	</xs:schema>		</xs:schema>
			Figure 7
	9. Relax NG Grammar		9. Relax NG Grammar
	The grammar for the Landmark configuration document extension is:		The grammar for the Landmark configuration document extension is:
	<!--		<!--
	LANDMARKS ELEMENT		LANDMARKS ELEMENT
	-->		-->
	parameter &= element landmarks {		parameter &= element landmarks {
	attribute version { xsd:int }		attribute version { xsd:int }
	<!--		<!--
	LANDMARK-HOST ELEMENT		LANDMARK-HOST ELEMENT
	-->		-->
	element landmark-host {		element landmark-host {
	attribute address { xsd:string },		attribute address { xsd:string },
	attribute port { xsd:int }		attribute port { xsd:int }
	}*		}*
	}?		}?
			Figure 8
	10. Security Considerations		10. Security Considerations
	10.1. Trust Aspects		10.1. Trust Aspects
	TODO		TODO
	11. IANA Considerations		11. IANA Considerations
	TODO: register Kind-ID code point at the IANA		TODO: register Kind-ID code point at the IANA
	skipping to change at page 42, line 12		skipping to change at page 33, line 31
	David Bryan, Toerless Eckert, Lothar Grimm, Cullen Jennings, Peter		David Bryan, Toerless Eckert, Lothar Grimm, Cullen Jennings, Peter
	Musgrave, Joerg Ott, Peter Pogrzeba, Brian Rosen, and Jan Seedorf.		Musgrave, Joerg Ott, Peter Pogrzeba, Brian Rosen, and Jan Seedorf.
	13. References		13. References
	13.1. Normative References		13.1. Normative References
	[I-D.ietf-p2psip-base]		[I-D.ietf-p2psip-base]
	Jennings, C., Lowekamp, B., Rescorla, E., Baset, S., and		Jennings, C., Lowekamp, B., Rescorla, E., Baset, S., and
	H. Schulzrinne, "REsource LOcation And Discovery (RELOAD)		H. Schulzrinne, "REsource LOcation And Discovery (RELOAD)
	Base Protocol", draft-ietf-p2psip-base-22 (work in		Base Protocol", draft-ietf-p2psip-base-26 (work in
	progress), July 2012.		progress), February 2013.
	[I-D.knauf-p2psip-share]		[I-D.knauf-p2psip-share]
	Knauf, A., Hege, G., Schmidt, T., and M. Waehlisch, "A		Knauf, A., Hege, G., Schmidt, T., and M. Waehlisch, "A
	Usage for Shared Resources in RELOAD (ShaRe)",		Usage for Shared Resources in RELOAD (ShaRe)", draft-
	draft-knauf-p2psip-share-03 (work in progress),		knauf-p2psip-share-03 (work in progress), April 2012.
	April 2012.
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119, March 1997.		Requirement Levels", BCP 14, RFC 2119, March 1997.
	[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,		[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
	A., Peterson, J., Sparks, R., Handley, M., and E.		A., Peterson, J., Sparks, R., Handley, M., and E.
	Schooler, "SIP: Session Initiation Protocol", RFC 3261,		Schooler, "SIP: Session Initiation Protocol", RFC 3261,
	June 2002.		June 2002.
	[RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model		[RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
	with Session Description Protocol (SDP)", RFC 3264,		with Session Description Protocol (SDP)", RFC 3264, June
	June 2002.		2002.
	[RFC3265] Roach, A., "Session Initiation Protocol (SIP)-Specific		[RFC3265] Roach, A., "Session Initiation Protocol (SIP)-Specific
	Event Notification", RFC 3265, June 2002.		Event Notification", RFC 3265, June 2002.
	[RFC3515] Sparks, R., "The Session Initiation Protocol (SIP) Refer		[RFC3515] Sparks, R., "The Session Initiation Protocol (SIP) Refer
	Method", RFC 3515, April 2003.		Method", RFC 3515, April 2003.
	[RFC4574] Levin, O. and G. Camarillo, "The Session Description		[RFC4574] Levin, O. and G. Camarillo, "The Session Description
	Protocol (SDP) Label Attribute", RFC 4574, August 2006.		Protocol (SDP) Label Attribute", RFC 4574, August 2006.
	[RFC4575] Rosenberg, J., Schulzrinne, H., and O. Levin, "A Session		[RFC4575] Rosenberg, J., Schulzrinne, H., and O. Levin, "A Session
	Initiation Protocol (SIP) Event Package for Conference		Initiation Protocol (SIP) Event Package for Conference
	State", RFC 4575, August 2006.		State", RFC 4575, August 2006.
	[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data		[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
	Encodings", RFC 4648, October 2006.		Encodings", RFC 4648, October 2006.
	[RFC5245] Rosenberg, J., "Interactive Connectivity Establishment		[RFC5245] Rosenberg, J., "Interactive Connectivity Establishment
	(ICE): A Protocol for Network Address Translator (NAT)		(ICE): A Protocol for Network Address Translator (NAT)
	Traversal for Offer/Answer Protocols", RFC 5245,		Traversal for Offer/Answer Protocols", RFC 5245, April
	April 2010.		2010.
	13.2. Informative References		13.2. Informative References
	[I-D.ietf-p2psip-concepts]		[I-D.ietf-p2psip-concepts]
	Bryan, D., Willis, D., Shim, E., Matthews, P., and S.		Bryan, D., Willis, D., Shim, E., Matthews, P., and S.
	Dawkins, "Concepts and Terminology for Peer to Peer SIP",		Dawkins, "Concepts and Terminology for Peer to Peer SIP",
	draft-ietf-p2psip-concepts-04 (work in progress),		draft-ietf-p2psip-concepts-04 (work in progress), October
	October 2011.		2011.
	[I-D.ietf-p2psip-sip]		[I-D.ietf-p2psip-sip]
	Jennings, C., Lowekamp, B., Rescorla, E., Baset, S., and		Jennings, C., Lowekamp, B., Rescorla, E., Baset, S.,
	H. Schulzrinne, "A SIP Usage for RELOAD",		Schulzrinne, H., and T. Schmidt, "A SIP Usage for RELOAD",
	draft-ietf-p2psip-sip-07 (work in progress), January 2012.		draft-ietf-p2psip-sip-09 (work in progress), February
			2013.
	[RFC4353] Rosenberg, J., "A Framework for Conferencing with the		[RFC4353] Rosenberg, J., "A Framework for Conferencing with the
	Session Initiation Protocol (SIP)", RFC 4353,		Session Initiation Protocol (SIP)", RFC 4353, February
	February 2006.		2006.
	[landmarks-infocomm02]		[landmarks-infocomm02]
	Ratnasamy, Handley, Karp, and Shenker, "Topologically-		Ratnasamy, ., Handley, ., Karp, ., and . Shenker,
	Aware Overlay Construction and Server Selection", Proc. of		"Topologically-Aware Overlay Construction and Server
	21st Annual Joint Conference of the IEEE Computer and		Selection", Proc. of 21st Annual Joint Conference of the
	Communications Societies (INFOCOM '02) pp. 1190-1199,		IEEE Computer and Communications Societies (INFOCOM '02)
	2002.		pp. 1190-1199, 2002.
	[timestamps-acsc88]		[timestamps-acsc88]
	Fidge, C., "Timestamps in Message-Passing Systems that		Fidge, C., "Timestamps in Message-Passing Systems that
	Preserve the Partial Ordering", Proceedings of 11th		Preserve the Partial Ordering", Proceedings of 11th
	Australian Computer Science Conference, pp. 56-66,		Australian Computer Science Conference, pp. 56-66,
	February 1988.		February 1988.
	Appendix A. Change Log		Appendix A. Change Log
	The following changes have been made from version		The following changes have been made from version draft-knauf-p2psip-
	draft-knauf-p2psip-disco-04.		disco-04.
	1. Editorial improvements.		1. Editorial improvements.
	2. Updated references.		2. Updated references.
	The following changes have been made from version		The following changes have been made from version draft-knauf-p2psip-
	draft-knauf-p2psip-disco-03.		disco-03.
	1. Adapted mechanisms for storing DisCo-Registrations to new		1. Adapted mechanisms for storing DisCo-Registrations to new
	requirements of Shared Resources draft [I-D.knauf-p2psip-share]		requirements of Shared Resources draft [I-D.knauf-p2psip-share]
	The following changes have been made from version		The following changes have been made from version draft-knauf-p2psip-
	draft-knauf-p2psip-disco-02.		disco-02.
	1. DisCo-Registration uses now only the USER-CHAIN-ACL access		1. DisCo-Registration uses now only the USER-CHAIN-ACL access
	control policy.		control policy.
	2. Adapted mechanisms for storing DisCo-Registrations to new		2. Adapted mechanisms for storing DisCo-Registrations to new
	requirements of Shared Resources draft [I-D.knauf-p2psip-share]		requirements of Shared Resources draft [I-D.knauf-p2psip-share]
	The following changes have been made from version		The following changes have been made from version draft-knauf-p2psip-
	draft-knauf-p2psip-disco-01.		disco-01.
	1. The conference registration is now based on the Shared Resources		1. The conference registration is now based on the Shared Resources
	draft [I-D.knauf-p2psip-share]:		draft [I-D.knauf-p2psip-share]:
	* DisCo-Registration Kind now meets the requirements for ShaRe.		* DisCo-Registration Kind now meets the requirements for ShaRe.
	* Conference creation procedure now uses the ShaRe Access List.		* Conference creation procedure now uses the ShaRe Access List.
	* Replaced USER-CHAIN-MATCH access policy for DisCo-		* Replaced USER-CHAIN-MATCH access policy for DisCo-
	Registration. Now uses USER-CHAIN-ACL or USER-PATTERN-MATCH.		Registration. Now uses USER-CHAIN-ACL or USER-PATTERN-MATCH.
	skipping to change at page 45, line 7		skipping to change at page 36, line 7
	element.		element.
	4. Added a 'node-id' attribute to the event package XML <focus>		4. Added a 'node-id' attribute to the event package XML <focus>
	element.		element.
	5. Added a 'coordinate' child element to the event package XML		5. Added a 'coordinate' child element to the event package XML
	<focus> element.		<focus> element.
	6. Corrected typos/wording		6. Corrected typos/wording
	The following changes have been made from version		The following changes have been made from version draft-knauf-p2psip-
	draft-knauf-p2psip-disco-00.		disco-00.
	1. Updated references.		1. Updated references.
	2. Corrected typos.		2. Corrected typos.
	3. New Section: Conference State Synchronization		3. New Section: Conference State Synchronization
	4. XML Event Package for Distributed Conferences		4. XML Event Package for Distributed Conferences
	5. New mechanism for generating chained conference certificates		5. New mechanism for generating chained conference certificates
	skipping to change at page 46, line 15		skipping to change at page 36, line 37
	Authors' Addresses		Authors' Addresses
	Alexander Knauf		Alexander Knauf
	HAW Hamburg		HAW Hamburg
	Berliner Tor 7		Berliner Tor 7
	Hamburg D-20099		Hamburg D-20099
	Germany		Germany
	Phone: +4940428758067		Phone: +4940428758067
	Email: alexanderknauf@gmail.com		Email: alexanderknauf@gmail.com
	URI:
	Thomas C. Schmidt		Thomas C. Schmidt
	HAW Hamburg		HAW Hamburg
	Berliner Tor 7		Berliner Tor 7
	Hamburg D-20099		Hamburg D-20099
	Germany		Germany
	Email: schmidt@informatik.haw-hamburg.de		Email: schmidt@informatik.haw-hamburg.de
	URI: http://inet.cpt.haw-hamburg.de/members/schmidt		URI: http://inet.cpt.haw-hamburg.de/members/schmidt
	Gabriel Hege		Gabriel Hege
	daviko GmbH		daviko GmbH
	Am Borsigturm 50		Am Borsigturm 50
	Berlin D-13507		Berlin D-13507
	Germany		Germany
	Phone: +493043004344		Phone: +493043004344
	Email: hege@daviko.com		Email: hege@daviko.com
	URI:
	Matthias Waehlisch		Matthias Waehlisch
	link-lab & FU Berlin		link-lab & FU Berlin
	Hoenower Str. 35		Hoenower Str. 35
	Berlin D-10318		Berlin D-10318
	Germany		Germany
	Email: mw@link-lab.net		Email: mw@link-lab.net
	URI: http://www.inf.fu-berlin.de/~waehl		URI: http://www.inf.fu-berlin.de/~waehl
End of changes. 38 change blocks.
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