draft-ietf-p2psip-sip-21.txt   rfc7904.txt 
P2PSIP C. Jennings Internet Engineering Task Force (IETF) C. Jennings
Internet-Draft Cisco Request for Comments: 7904 Cisco
Intended status: Standards Track B. Lowekamp Category: Standards Track B. Lowekamp
Expires: October 29, 2016 Skype ISSN: 2070-1721 Skype
E. Rescorla E. Rescorla
RTFM, Inc. RTFM, Inc.
S. Baset S. Baset
IBM
H. Schulzrinne H. Schulzrinne
Columbia University Columbia University
T. Schmidt, Ed. T. Schmidt, Ed.
HAW Hamburg HAW Hamburg
April 27, 2016 October 2016
A SIP Usage for RELOAD A SIP Usage for REsource LOcation And Discovery (RELOAD)
draft-ietf-p2psip-sip-21
Abstract Abstract
This document defines a SIP Usage for REsource LOcation And Discovery This document defines a SIP Usage for REsource LOcation And Discovery
(RELOAD). The SIP Usage provides the functionality of a SIP proxy or (RELOAD). The SIP Usage provides the functionality of a SIP proxy or
registrar in a fully-distributed system and includes a lookup service registrar in a fully distributed system and includes a lookup service
for Address of Records (AORs) stored in the overlay. It also defines for Address of Records (AORs) stored in the overlay. It also defines
Globally Routable User Agent URIs (GRUUs) that allow the Globally Routable User Agent URIs (GRUUs) that allow the
registrations to map an AOR to a specific node reachable through the registrations to map an AOR to a specific node reachable through the
overlay. After such initial contact of a peer, the RELOAD AppAttach overlay. After such initial contact of a Peer, the RELOAD AppAttach
method is used to establish a direct connection between nodes through method is used to establish a direct connection between nodes through
which SIP messages are exchanged. which SIP messages are exchanged.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on October 29, 2016. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7904.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 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
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publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 34 skipping to change at page 3, line 7
modifications of such material outside the IETF Standards Process. modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other it for publication as an RFC or to translate it into languages other
than English. than English.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. Registering AORs in the Overlay . . . . . . . . . . . . . . . 6 3. Registering AORs in the Overlay . . . . . . . . . . . . . . . 6
3.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 6 3.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2. Data Structure . . . . . . . . . . . . . . . . . . . . . 6 3.2. Data Structure . . . . . . . . . . . . . . . . . . . . . 7
3.3. Access Control . . . . . . . . . . . . . . . . . . . . . 8 3.3. Access Control . . . . . . . . . . . . . . . . . . . . . 9
3.4. Overlay Configuration Document Extension . . . . . . . . 9 3.4. Overlay Configuration Document Extension . . . . . . . . 10
4. Looking up an AOR . . . . . . . . . . . . . . . . . . . . . . 10 4. Looking Up an AOR . . . . . . . . . . . . . . . . . . . . . . 11
4.1. Finding a Route to an AOR . . . . . . . . . . . . . . . . 10 4.1. Finding a Route to an AOR . . . . . . . . . . . . . . . . 11
4.2. Resolving an AOR . . . . . . . . . . . . . . . . . . . . 11 4.2. Resolving an AOR . . . . . . . . . . . . . . . . . . . . 12
5. Forming a Direct Connection . . . . . . . . . . . . . . . . . 11 5. Forming a Direct Connection . . . . . . . . . . . . . . . . . 12
5.1. Setting Up a Connection . . . . . . . . . . . . . . . . . 11 5.1. Setting Up a Connection . . . . . . . . . . . . . . . . . 12
5.2. Keeping a Connection Alive . . . . . . . . . . . . . . . 12 5.2. Keeping a Connection Alive . . . . . . . . . . . . . . . 13
6. Using GRUUs . . . . . . . . . . . . . . . . . . . . . . . . . 12 6. Using GRUUs . . . . . . . . . . . . . . . . . . . . . . . . . 13
7. SIP-REGISTRATION Kind Definition . . . . . . . . . . . . . . 13 7. SIP-REGISTRATION Kind Definition . . . . . . . . . . . . . . 14
8. Security Considerations . . . . . . . . . . . . . . . . . . . 14 8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
8.1. RELOAD-Specific Issues . . . . . . . . . . . . . . . . . 14 8.1. RELOAD-Specific Issues . . . . . . . . . . . . . . . . . 14
8.2. SIP-Specific Issues . . . . . . . . . . . . . . . . . . . 14 8.2. SIP-Specific Issues . . . . . . . . . . . . . . . . . . . 15
8.2.1. Fork Explosion . . . . . . . . . . . . . . . . . . . 14 8.2.1. Fork Explosion . . . . . . . . . . . . . . . . . . . 15
8.2.2. Malicious Retargeting . . . . . . . . . . . . . . . . 15 8.2.2. Malicious Retargeting . . . . . . . . . . . . . . . . 15
8.2.3. Misuse of AORs . . . . . . . . . . . . . . . . . . . 15 8.2.3. Misuse of AORs . . . . . . . . . . . . . . . . . . . 15
8.2.4. Privacy Issues . . . . . . . . . . . . . . . . . . . 15 8.2.4. Privacy Issues . . . . . . . . . . . . . . . . . . . 16
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
9.1. Data Kind-ID . . . . . . . . . . . . . . . . . . . . . . 15 9.1. Data Kind-ID . . . . . . . . . . . . . . . . . . . . . . 16
9.2. XML Name Space Registration . . . . . . . . . . . . . . . 16 9.2. XML Namespace Registration . . . . . . . . . . . . . . . 16
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 10.1. Normative References . . . . . . . . . . . . . . . . . . 16
11.1. Normative References . . . . . . . . . . . . . . . . . . 16 10.2. Informative References . . . . . . . . . . . . . . . . . 18
11.2. Informative References . . . . . . . . . . . . . . . . . 18 Appendix A. Third-Party Registration . . . . . . . . . . . . . . 19
Appendix A. Third Party Registration . . . . . . . . . . . . . . 18 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 19
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 18
B.1. Changes since draft-ietf-p2psip-sip-09 . . . . . . . . . 19
B.2. Changes since draft-ietf-p2psip-sip-08 . . . . . . . . . 19
B.3. Changes since draft-ietf-p2psip-sip-07 . . . . . . . . . 19
B.4. Changes since draft-ietf-p2psip-sip-06 . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20
1. Introduction 1. Introduction
REsource LOcation And Discovery (RELOAD) [RFC6940] specifies a peer- REsource LOcation And Discovery (RELOAD) [RFC6940] specifies a peer-
to-peer (P2P) signaling protocol for the general use on the Internet. to-peer (P2P) signaling protocol for general use on the Internet.
This document defines a SIP Usage of RELOAD that allows SIP [RFC3261] This document defines a SIP Usage of RELOAD that allows SIP [RFC3261]
user agents (UAs) to establish peer-to-peer SIP (or SIPS) sessions user agents (UAs) to establish peer-to-peer SIP (or SIPS) sessions
without the requirement for permanent proxy or registration servers, without the requirement for a permanent proxy or registration
e.g., a fully distributed telephony service. This service servers, e.g., a fully distributed telephony service. This service
transparently supports SIP addressing including telephone numbers. transparently supports SIP addressing including telephone numbers.
In such a network, the RELOAD overlay itself performs the In such a network, the RELOAD overlay itself performs the
registration and rendezvous functions ordinarily associated with such registration and rendezvous functions ordinarily associated with such
servers. servers.
The SIP Usage involves two basic functions. The SIP Usage involves two basic functions:
Registration: SIP UAs can use the RELOAD data storage functionality Registration: SIP UAs can use the RELOAD data storage functionality
to store a mapping from their address-of-record (AOR) to their to store a mapping from their Address of Record (AOR) to their
Node-ID in the overlay, and to retrieve the Node-ID of other UAs. Node-ID in the overlay and to retrieve the Node-ID of other UAs.
Rendezvous: Once a SIP UA has identified the Node-ID for an AOR it Rendezvous: Once a SIP UA has identified the Node-ID for an AOR it
wishes to call, it can use the RELOAD message routing system to wishes to call, it can use the RELOAD message routing system to
set up a direct connection for exchanging SIP messages. set up a direct connection for exchanging SIP messages.
Mappings are stored in the SipRegistration Resource Record defined in Mappings are stored in the SipRegistration Resource Record defined in
this document. All operations required to perform a SIP registration this document. All operations required to perform a SIP registration
or rendezvous are standard RELOAD protocol methods. or rendezvous are standard RELOAD protocol methods.
For example, Bob registers his AOR, "bob@dht.example.com", for his For example, Bob registers his AOR, "bob@dht.example.com", for his
Node-ID "1234". When Alice wants to call Bob, she queries the Node-ID "1234". When Alice wants to call Bob, she queries the
overlay for "bob@dht.example.com" and receives Node-ID "1234" in overlay for "bob@dht.example.com" and receives Node-ID "1234" in
return. She then uses the overlay routing to establish a direct return. She then uses the overlay routing to establish a direct
connection with Bob and can directly transmit a standard SIP INVITE. connection with Bob and can directly transmit a standard SIP INVITE.
In detail, this works along the following steps. In detail, this works along the following steps:
1. Bob, operating Node-ID "1234", stores a mapping from his AOR to 1. Bob, operating Node-ID "1234", stores a mapping from his AOR to
his Node-ID in the overlay by applying a Store request for his Node-ID in the overlay by applying a Store request for
"bob@dht.example.com -> 1234". "bob@dht.example.com -> 1234".
2. Alice, operating Node-ID "5678", decides to call Bob. She 2. Alice, operating Node-ID "5678", decides to call Bob. She
retrieves Node-ID "1234" by performing a Fetch request on retrieves Node-ID "1234" by performing a Fetch request on
"bob@dht.example.com". "bob@dht.example.com".
3. Alice uses the overlay to route an AppAttach message to Bob's 3. Alice uses the overlay to route an AppAttach message to Bob's
peer (ID "1234"). Bob responds with his own AppAttach and they Peer (ID "1234"). Bob responds with his own AppAttach and they
set up a direct connection, as shown in Figure 1. Note that set up a direct connection, as shown in Figure 1. Note that
mutual Interactive Connectivity Establishment (ICE) checks are mutual Interactive Connectivity Establishment (ICE) checks are
invoked automatically from AppAttach message exchange. invoked automatically from the AppAttach message exchange.
Overlay Overlay
Alice Peer1 ... PeerN Bob Alice Peer1 ... PeerN Bob
(5678) (1234) (5678) (1234)
------------------------------------------------- -------------------------------------------------
AppAttach -> AppAttach ->
AppAttach -> AppAttach ->
AppAttach -> AppAttach ->
AppAttach -> AppAttach ->
<- AppAttach <- AppAttach
skipping to change at page 4, line 42 skipping to change at page 5, line 25
<- AppAttach <- AppAttach
<- AppAttach <- AppAttach
<------------------ ICE Checks -----------------> <------------------ ICE Checks ----------------->
INVITE -----------------------------------------> INVITE ----------------------------------------->
<--------------------------------------------- OK <--------------------------------------------- OK
ACK --------------------------------------------> ACK -------------------------------------------->
<------------ ICE Checks for media -------------> <------------ ICE Checks for media ------------->
<-------------------- RTP ----------------------> <-------------------- RTP ---------------------->
Figure 1: Connection setup in P2P SIP using the RELOAD overlay Figure 1: Connection Setup in P2P SIP Using the RELOAD Overlay
It is important to note that here the only role of RELOAD is to set It is important to note that the only role of RELOAD in this example
up the direct SIP connection between Alice and Bob. As soon as the is to set up the direct SIP connection between Alice and Bob. As
ICE checks complete and the connection is established, ordinary SIP soon as the ICE checks complete and the connection is established,
or SIPS is used. In particular, the establishment of the media ordinary SIP or SIPS is used. In particular, the establishment of
channel for a phone call happens via the usual SIP mechanisms, and the media channel for a phone call happens via the usual SIP
RELOAD is not involved. Media never traverses the overlay. After mechanisms, and RELOAD is not involved. Media never traverses the
the successful exchange of SIP messages, call peers run ICE overlay. After the successful exchange of SIP messages,
connectivity checks for media. communicating Peers run ICE connectivity checks for media.
In addition to mappings from AORs to Node-IDs, the SIP Usage also In addition to mappings from AORs to Node-IDs, the SIP Usage also
allows mappings from AORs to other AORs. This enables an indirection allows mappings from AORs to other AORs. This enables an indirection
useful for call forwarding. For instance, if Bob wants his phone useful for call forwarding. For instance, if Bob wants his phone
calls temporarily forwarded to Charlie, he can store the mapping calls temporarily forwarded to Charlie, he can store the mapping
"bob@dht.example.com -> charlie@dht.example.com". When Alice wants "bob@dht.example.com -> charlie@dht.example.com". When Alice wants
to call Bob, she retrieves this mapping and can then fetch Charlie's to call Bob, she retrieves this mapping and can then fetch Charlie's
AOR to retrieve his Node-ID. These mechanisms are described in AOR to retrieve his Node-ID. These mechanisms are described in
Section 3. Section 3.
Alternatively, Globally Routable User Agent URIs (GRUUs) [RFC5627] Alternatively, Globally Routable User Agent URIs (GRUUs) [RFC5627]
can be used for directly accessing peers. They are handled via a can be used for directly accessing Peers. They are handled via a
separate mechanism, as described in Section 6. separate mechanism, as described in Section 6.
Concepts used in this document can be extended to include tel URIs
[RFC3966], but this will require further specifications to ensure
semantic interoperability of implementations.
The SIP Usage for RELOAD addresses a fully distributed deployment of The SIP Usage for RELOAD addresses a fully distributed deployment of
session-based services among overlay peers. This RELOAD usage may be session-based services among overlay Peers. This RELOAD Usage may be
relevant in a variety of environments, including a highly regulated relevant in a variety of environments, including a tightly controlled
environment of a "single provider" that admits parties using AORs environment of a single provider that admits parties using AORs with
with domains from controlled namespace(s) only, or an open, multi- domains from controlled namespace(s) only, or an open, multi-party
party infrastructure that liberally allows a registration and infrastructure that liberally allows a registration and rendezvous
rendezvous for various or any domain namespace. It is noteworthy in for various or any domain namespace. It is noteworthy in this
this context that - in contrast to regular SIP - domain names play no context that -- in contrast to regular SIP -- domain names play no
role in routing to a proxy server. Once connectivity to an overlay role in routing to a proxy server. Once connectivity to an overlay
is given, any name registration can be technically processed. is given, the technology allows any name registration, possibly
constrained by overlay domain restrictions.
2. Terminology 2. Terminology
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 RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
We use the terminology and definitions from Concepts and Terminology We use the terminology and definitions from "Concepts and Terminology
for Peer to Peer SIP [I-D.ietf-p2psip-concepts] and the RELOAD Base for Peer-to-Peer SIP (P2PSIP)" [RFC7890] and the RELOAD Base Protocol
Protocol [RFC6940] extensively in this document. [RFC6940] extensively in this document.
In addition, term definitions from SIP [RFC3261] apply to this memo. In addition, terms defined by SIP [RFC3261] apply to this memo. The
The term AOR is the SIP "Address of Record" used to identify a user term AOR is the SIP "Address of Record" used to identify a user in
in SIP. For example, alice@example.com could be the AOR for Alice. SIP. For example, "alice@example.com" could be the AOR for Alice.
For the purposes of this specification, an AOR is considered not to For the purposes of this specification, an AOR is considered not to
include the scheme (e.g. sip:) as the AOR needs to match the include the scheme (e.g., sip:), as the AOR needs to match the
rfc822Name in the X509v3 certificates [RFC5280]. It is worth noting rfc822Name in the X.509 v3 certificates [RFC5280]. It is worth
that SIP and SIPS are distinguished in P2PSIP by the Application-ID. noting that SIP and SIPS are distinguished in P2PSIP by the
Application-ID.
3. Registering AORs in the Overlay 3. Registering AORs in the Overlay
3.1. Overview 3.1. Overview
In ordinary SIP, a UA registers the user's AOR and its network In ordinary SIP, a UA registers the user's AOR and its network
location with a registrar. In RELOAD, this registrar function is location with a registrar. In RELOAD, this registrar function is
provided by the overlay as a whole. To register its location, a provided by the overlay as a whole. To register its location, a
RELOAD peer stores a SipRegistration Resource Record under its own RELOAD peer stores a SipRegistration Resource Record under its own
AOR using the SIP-REGISTRATION Kind, which is formally defined in AOR using the SIP-REGISTRATION Kind, which is formally defined in
Section 7. Note that the registration lifetime known from the Section 7. Note that the registration lifetime known from the
regular SIP REGISTER method is inherited from the lifetime attribute regular SIP REGISTER method is inherited from the lifetime attribute
of the basic RELOAD StoredData structure (see Section 7 in of the basic RELOAD StoredData structure (see Section 7 in
[RFC6940]). [RFC6940]).
A RELOAD overlay MAY restrict the storage of AORs. Namespaces (i.e., A RELOAD overlay MAY restrict the storage of AORs. Namespaces (i.e.,
the right hand side of the AOR) that are supported for registration the right-hand side of the AOR) that are supported for registration
and lookup can be configured for each RELOAD deployment as described and lookup can be configured for each RELOAD deployment as described
in Section 3.4. in Section 3.4.
As a simple example, consider Alice with AOR "alice@dht.example.org" As a simple example, consider Alice with an AOR
at Node-ID "1234". She might store the mapping "alice@dht.example.org" at Node-ID "1234". She might store the
"alice@dht.example.org -> 1234" telling anyone who wants to call her mapping "alice@dht.example.org -> 1234" telling anyone who wants to
to contact node "1234". call her to contact node "1234".
RELOAD peers can store two kinds of SIP mappings, RELOAD peers can store two kinds of SIP mappings,
o from an AOR to a destination list (a single Node-ID is just a o from an AOR to a destination list (a single Node-ID is just a
trivial destination list), or trivial destination list), or
o from an AOR to another AOR. o from one AOR to another.
The meaning of the first kind of mapping is "in order to contact me, The meaning of the first kind of mapping is "in order to contact me,
form a connection with this peer." The meaning of the second kind of form a connection with this Peer." The meaning of the second kind of
mapping is "in order to contact me, dereference this AOR". The mapping is "in order to contact me, dereference this AOR". The
latter allows for forwarding. For instance, if Alice wants her calls latter allows for forwarding. For instance, if Alice wants her calls
to be forwarded to her secretary, Sam, she might insert the following to be forwarded to her secretary, Sam, she might insert the following
mapping "alice@dht.example.org -> sam@dht.example.org". mapping, "alice@dht.example.org -> sam@dht.example.org".
3.2. Data Structure 3.2. Data Structure
This section defines the SipRegistration Resource Record as follows: This section defines the SipRegistration Resource Record as follows:
enum { sip_registration_uri(1), sip_registration_route(2), enum {
(255) } SipRegistrationType; sip_registration_uri(1),
sip_registration_route(2),
(255)
} SipRegistrationType;
select (SipRegistration.type) { select (SipRegistration.type) {
case sip_registration_uri: case sip_registration_uri:
opaque uri<0..2^16-1>; opaque uri<0..2^16-1>;
case sip_registration_route: case sip_registration_route:
opaque contact_prefs<0..2^16-1>; opaque contact_prefs<0..2^16-1>;
Destination destination_list<0..2^16-1>; Destination destination_list<3..2^16-1>;
/* This type can be extended */ /* This type can be extended */
} SipRegistrationData; } SipRegistrationData;
struct { struct {
SipRegistrationType type; SipRegistrationType type;
uint16 length; uint16 length;
SipRegistrationData data; SipRegistrationData data;
} SipRegistration; } SipRegistration;
The contents of the SipRegistration Resource Record are: The contents of the SipRegistration Resource Record are:
type type
skipping to change at page 8, line 7 skipping to change at page 8, line 29
data data
the registration data the registration data
o If the registration is of type "sip_registration_uri", then the o If the registration is of type "sip_registration_uri", then the
contents are an opaque string containing the AOR. contents are an opaque string containing the AOR.
o If the registration is of type "sip_registration_route", then the o If the registration is of type "sip_registration_route", then the
contents are an opaque string containing the registrant's contact contents are an opaque string containing the registrant's contact
preferences and a destination list for the peer. preferences and a destination list for the Peer.
The callee expresses its capabilities within the contact preferences The callee expresses its capabilities within the contact preferences
as specified in [RFC3840]. It encodes a media feature set comprised as specified in [RFC3840]. It encodes a media feature set comprised
of its capabilities as a contact predicate, i.e., a string of feature of its capabilities as a contact predicate, i.e., a string of feature
parameters that appear as part of the Contact header field. Feature parameters that appear as part of the Contact header field. Feature
parameters are derived from the media feature set syntax of [RFC2533] parameters are derived from the media feature set syntax of [RFC2533]
(see also [RFC2738]) as described in [RFC3840]. (see also [RFC2738]) as described in [RFC3840].
This encoding covers all SIP User Agent capabilities, as defined in This encoding covers all SIP User Agent capabilities, as defined in
[RFC3840] and registered in the SIP feature tag registration tree. [RFC3840] and registered in the SIP feature tag registration tree.
In particular, a callee can indicate that it prefers contact via a In particular, a callee can indicate that it prefers contact via a
particular SIP scheme - SIP or SIPS - by using one of the following particular SIP scheme -- SIP or SIPS -- by using one of the following
contact_prefs attribute: contact_prefs attributes:
(sip.schemes=SIP) (sip.schemes=SIP)
(sip.schemes=SIPS) (sip.schemes=SIPS)
RELOAD explicitly supports multiple registrations for a single AOR. RELOAD explicitly supports multiple registrations for a single AOR.
The registrations are stored in a Dictionary with Node-IDs as the The registrations are stored in a dictionary with Node-IDs as the
dictionary keys. Consider, for instance, the case where Alice has dictionary keys. Consider, for instance, the case where Alice has
two peers: two Peers:
o her desk phone (1234) o her desk phone (1234)
o her cell phone (5678) o her cell phone (5678)
Alice might store the following in the overlay at resource Alice might store the following in the overlay at resource
"alice@dht.example.com". "alice@dht.example.com":
o A SipRegistration of type "sip_registration_route" with dictionary o a SipRegistration of type "sip_registration_route" with dictionary
key "1234" and value "1234". key "1234" and value "1234", both referring to Node-IDs
o A SipRegistration of type "sip_registration_route" with dictionary o a SipRegistration of type "sip_registration_route" with dictionary
key "5678" and value "5678". key "5678" and value "5678"
Note that this structure explicitly allows one Node-ID to forward to Note that this structure explicitly allows one Node-ID to forward to
another Node-ID. For instance, Alice could set calls to her desk another Node-ID. For instance, Alice could set calls to her desk
phone to ring at her cell phone by storing a SipRegistration of type phone to ring at her cell phone by storing a SipRegistration of type
"sip_registration_route" with dictionary key "1234" and value "5678". "sip_registration_route" with a dictionary key "1234" and a value
"5678".
3.3. Access Control 3.3. Access Control
In order to prevent hijacking or other misuse, registrations are In order to prevent hijacking or other misuse, registrations are
subject to access control rules. Two kinds of restrictions apply: subject to access control rules. Two kinds of restrictions apply:
o A Store is permitted only for AORs with domain names that fall o A Store is permitted only for AORs with domain names that fall
into the namespaces supported by the RELOAD overlay instance. into the namespaces supported by the RELOAD Overlay Instance.
o Storing requests are performed according to the USER-NODE-MATCH o Storing requests are performed according to the USER-NODE-MATCH
access control policy of RELOAD. access control policy of RELOAD.
Before issuing a Store request to the overlay, any peer SHOULD verify Before issuing a Store request to the overlay, any Peer SHOULD verify
that the AOR of the request is a valid Resource Name with respect to that the AOR of the request is a valid Resource Name with respect to
its domain name and the namespaces defined in the overlay its domain name and the namespaces defined in the overlay
configuration document (see Section 3.4). configuration document (see Section 3.4).
Before a Store is permitted, the storing peer MUST check that: Before a Store is permitted, the Storing Peer MUST check that:
o The AOR of the request is a valid Resource Name with respect to o The AOR of the request is a valid Resource Name with respect to
the namespaces defined in the overlay configuration document. the namespaces defined in the overlay configuration document.
o The certificate contains a username that is a SIP AOR which hashes o The certificate contains a username that is a SIP AOR that hashes
to the Resource-ID it is being stored at. to the Resource-ID it is being stored at.
o The certificate contains a Node-ID that is the same as the o The certificate contains a Node-ID that is the same as the
dictionary key it is being stored at. dictionary key it is being stored at.
If any of these checks fail, the request MUST be rejected with an If any of these checks fail, the request MUST be rejected with an
Error_Forbidden error. Error_Forbidden error.
Note that these rules permit Alice to forward calls to Bob without Note that these rules permit Alice to forward calls to Bob without
his permission. However, they do not permit Alice to forward Bob's his permission. However, they do not permit Alice to forward Bob's
calls to her. See Section 8.2.2 for additional descriptions. calls to her. See Section 8.2.2 for additional details.
3.4. Overlay Configuration Document Extension 3.4. Overlay Configuration Document Extension
The use of a SIP-enabled overlay MAY be restricted to users with AORs The use of a SIP-enabled overlay MAY be restricted to users with AORs
from specific domains. When deploying an overlay service, providers from specific domains. When deploying an overlay service, providers
can decide about these use case scenarios by defining a set of can implement such restrictions by defining a set of namespaces for
namespaces for admissible domain names. This section extends the admissible domain names. This section extends the overlay
overlay configuration document by defining new elements for patterns configuration document by defining new elements for patterns that
that describe a corresponding domain name syntax. describe a corresponding domain name syntax.
A RELOAD overlay can be configured to accept store requests for any A RELOAD overlay can be configured to accept store requests for any
AOR, or to apply domain name restrictions. To apply restrictions, AOR, or to apply domain name restrictions. To apply restrictions,
the overlay configuration document needs to contain a <domain- the overlay configuration document needs to contain a <domain-
restrictions> element. The <domain-restrictions> element serves as a restrictions> element. The <domain-restrictions> element serves as a
container for zero to multiple <pattern> sub-elements. A <pattern> container for zero to multiple <pattern> sub-elements. A <pattern>
element MAY be present if the "enable" attribute of its parent element MAY be present if the "enable" attribute of its parent
element is set to true. Each <pattern> element defines a pattern for element is set to true. Each <pattern> element defines a pattern for
constructing admissible resource names. It is of type xsd:string and constructing admissible resource names. It is of type xsd:string and
interpreted as a regular expression according to "POSIX Extended interpreted as a regular expression according to "POSIX Extended
Regular Expression" (see the specifications in [IEEE-Posix]). Regular Expression" (see the specifications in [IEEE-Posix]).
Encoding of the domain name adheres to the restricted ASCII character
Encoding of the domain name complies to the restricted ASCII set without character escaping as defined in Section 19.1 of
character set without character escaping as defined in Section 19.1 [RFC3261].
of [RFC3261].
Inclusion of a <domain-restrictions> element in an overlay Inclusion of a <domain-restrictions> element in an overlay
configuration document is OPTIONAL. If the element is not included, configuration document is OPTIONAL. If the element is not included,
the default behavior is to accept any AOR. If the element is the default behavior is to accept any AOR. If the element is
included and the "enable" attribute is not set or set to false, the included and the "enable" attribute is not set or set to false, the
overlay MUST only accept AORs that match the domain name of the overlay MUST only accept AORs that match the domain name of the
overlay. If the element is included and the "enable" attribute is overlay. If the element is included and the "enable" attribute is
set to true, the overlay MUST only accept AORs that match patterns set to true, the overlay MUST only accept AORs that match patterns
specified in the <domain-restrictions> element. specified in the <domain-restrictions> element.
Example of Domain Patterns: Example of Domain Patterns:
dht\.example\.com dht\.example\.com
.*\.my\.example .*\.my\.example
In this example, any AOR will be accepted that is either of the form In this example, any AOR will be accepted that is either of the form
<user>@dht.example.com, or ends with the domain "my.example". <user>@dht.example.com, or ends with the domain "my.example".
The Relax NG Grammar for the AOR Domain Restriction reads: The RELAX NG grammar for the AOR Domain Restriction reads:
# AOR DOMAIN RESTRICTION URN SUB-NAMESPACE # AOR DOMAIN RESTRICTION URN SUB-NAMESPACE
namespace sip = "urn:ietf:params:xml:ns:p2p:config-base:sip" namespace sip = "urn:ietf:params:xml:ns:p2p:config-base:sip"
# AOR DOMAIN RESTRICTION ELEMENT # AOR DOMAIN RESTRICTION ELEMENT
Kind-parameter &= element sip:domain-restriction { Kind-parameter &= element sip:domain-restriction {
attribute enable { xsd:boolean } attribute enable { xsd:boolean }
# PATTERN ELEMENT # PATTERN ELEMENT
element sip:pattern { xsd:string }* element sip:pattern { xsd:string }*
}? }?
4. Looking up an AOR 4. Looking Up an AOR
4.1. Finding a Route to an AOR 4.1. Finding a Route to an AOR
A RELOAD user, member of an overlay, who wishes to call another user A RELOAD user, member of an overlay, who wishes to call another user
with given AOR SHALL proceed in the following way. with a given AOR SHALL proceed in the following way:
AOR is GRUU? If the AOR is a GRUU for this overlay, the callee can AOR is a GRUU? If the AOR is a GRUU for this overlay, the callee can
be contacted directly as described in Section 6. be contacted directly as described in Section 6.
AOR domain is hosted in overlay? If the domain part of the AOR AOR domain is hosted in overlay? If the domain part of the AOR
matches a domain pattern configured in the overlay, the user can matches a domain pattern configured in the overlay, the user can
continue to resolve the AOR in this overlay. The user MAY choose continue to resolve the AOR in this overlay. The user MAY choose
to query the DNS service records to search for additional support to query the DNS service records to search for additional support
of this domain name. of this domain name.
AOR domain not supported by overlay? If the domain part of the AOR AOR domain not supported by overlay? If the domain part of the AOR
is not supported in the current overlay, the user might query the is not supported in the current overlay, the user might query the
skipping to change at page 11, line 27 skipping to change at page 12, line 8
AOR inaccessible? If all of the above contact attempts fail, the AOR inaccessible? If all of the above contact attempts fail, the
call fails. call fails.
The procedures described above likewise apply when nodes are The procedures described above likewise apply when nodes are
simultaneously connected to several overlays. simultaneously connected to several overlays.
4.2. Resolving an AOR 4.2. Resolving an AOR
A RELOAD user that has discovered a route to an AOR in the current A RELOAD user that has discovered a route to an AOR in the current
overlay SHALL execute the following steps. overlay SHALL execute the following steps:
1. Perform a Fetch for Kind SIP-REGISTRATION at the Resource-ID 1. Perform a Fetch for Kind SIP-REGISTRATION at the Resource-ID
corresponding to the AOR. This Fetch SHOULD NOT indicate any corresponding to the AOR. This Fetch SHOULD NOT indicate any
dictionary keys, so that it will fetch all the stored values. dictionary keys, so that it will fetch all the stored values.
2. If any of the results of the Fetch are non-GRUU AORs, then repeat 2. If any of the results of the Fetch are non-GRUU AORs, then repeat
step 1 for that AOR. step 1 for that AOR.
3. Once only GRUUs and destination lists remain, the peer removes 3. Once only GRUUs and destination lists remain, the Peer removes
duplicate destination lists and GRUUs from the list and initiates duplicate destination lists and GRUUs from the list and initiates
SIP or SIPS connections to the appropriate peers as described in SIP or SIPS connections to the appropriate Peers as described in
the following sections. If there are also external AORs, the the following sections. If there are also external AORs, the
peer follows the appropriate procedure for contacting them as Peer follows the appropriate procedure for contacting them as
well. well.
5. Forming a Direct Connection 5. Forming a Direct Connection
5.1. Setting Up a Connection 5.1. Setting Up a Connection
Once the peer has translated the AOR into a set of destination lists, Once the Peer has translated the AOR into a set of destination lists,
it then uses the overlay to route AppAttach messages to each of those it then uses the overlay to route AppAttach messages to each of those
peers. The "application" field MUST be either 5060 to indicate SIP Peers. The "application" field MUST be either 5060 to indicate SIP
or 5061 for using SIPS. If certificate-based authentication is in or 5061 to indicate SIPS. If certificate-based authentication is in
use, the responding peer MUST present a certificate with a Node-ID use, the responding Peer MUST present a certificate with a Node-ID
matching the terminal entry in the destination list. Otherwise, the matching the terminal entry in the destination list. Otherwise, the
connection MUST NOT be used and MUST be closed. Note that it is connection MUST NOT be used and MUST be closed. Note that it is
possible that the peers already have a RELOAD connection mutually possible that the Peers already have a RELOAD connection mutually
established. This MUST NOT be used for SIP messages unless it is a established. This MUST NOT be used for SIP messages unless it is a
SIP connection. A previously established SIP connection MAY be used SIP connection. A previously established SIP connection MAY be used
for a new call. for a new call.
Once the AppAttach succeeds, the peer sends plain or (D)TLS encrypted Once the AppAttach succeeds, the Peer sends plain or (D)TLS-encrypted
SIP messages over the connection as in normal SIP. A caller MAY SIP messages over the connection as in normal SIP. A caller MAY
choose to contact the callee using SIP or SIPS, but SHOULD follow a choose to contact the callee using SIP or SIPS, but SHOULD follow a
preference indicated by the callee in its contact_prefs attribute preference indicated by the callee in its contact_prefs attribute
(see Section 3.2). A callee MAY choose to listen on both SIP and (see Section 3.2). A callee MAY choose to listen on both SIP and
SIPS ports and accept calls from either SIP scheme, or select a SIPS ports and accept calls from either SIP scheme, or select a
single one. However, a callee that decides to accept SIPS calls, single one. However, a callee that decides to accept SIPS calls
only, SHOULD indicate its choice by setting the corresponding only, SHOULD indicate its choice by setting the corresponding
attribute in its contact_prefs. It is noteworthy that according to attribute in its contact_prefs. It is noteworthy that, according to
[RFC6940] all overlay links are built on (D)TLS secured transport. [RFC6940], all overlay links are built on (D)TLS-secured transport.
While hop-wise encrypted paths do not prevent the use of plain SIP,
SIPS requires protection of all links that may include client links
(if present) and endpoint certificates.
SIP messages carry the SIP URIs of actual overlay endpoints (e.g., SIP messages carry the SIP URIs of actual overlay endpoints (e.g.,
"sip:alice@dht.example.com") in the Via and Contact headers, while "sip:alice@dht.example.com") in the Via and Contact headers, while
the communication continues via the RELOAD connection. However, a UA the communication continues via the RELOAD connection. However, a UA
can redirect its communication path by setting an alternate Contact can redirect its communication path by setting an alternate Contact
header field like in ordinary SIP. header field like in ordinary SIP.
5.2. Keeping a Connection Alive 5.2. Keeping a Connection Alive
In many cases, RELOAD connections will traverse NATs and Firewalls In many cases, RELOAD connections established from ICE [RFC5245]
that maintain states established from ICE [RFC5245] negotiations. It negotiations will traverse stateful NATs and firewalls. It is the
is the responsibility of the Peers to provide sufficiently frequent responsibility of the Peers to send messages with a frequency
traffic to keep NAT and Firewall states present and the connection sufficient to maintain the necessary state in these NATs and
alive. Keepalives are a mandatory component of ICE (see Section 10 firewalls and thus keep the connection alive. Keepalives are a
of [RFC5245]) and no further operations are required. Applications mandatory component of ICE (see Section 10 of [RFC5245]) and no
that want to assure maintenance of sessions individually need to further operations are required. Applications that want to assure
follow regular SIP means. Accordingly, a SIP Peer MAY apply keep- maintenance of sessions individually need to follow regular SIP
alive techniques in agreement with its transport binding as defined means. Accordingly, a SIP Peer MAY apply keep-alive techniques in
in Section 3.5 of [RFC5626]. agreement with its transport binding as defined in Section 3.5 of
[RFC5626].
6. Using GRUUs 6. Using GRUUs
Globally Routable User Agent URIs (GRUUs) [RFC5627] have been Globally Routable User Agent URIs (GRUUs) [RFC5627] have been
designed to allow direct routing to a specific UA instance without designed to allow direct routing to a specific UA instance without
the need for dereferencing by a domain-specific SIP proxy function. the need for dereferencing by a domain-specific SIP proxy function.
The concept is transferred to RELOAD overlays as follows. GRUUs in The concept is transferred to RELOAD overlays as follows. GRUUs in
RELOAD are constructed by embedding a base64-encoded destination list RELOAD are constructed by embedding a base64-encoded destination list
in the "gr" URI parameter of the GRUU. The base64 encoding is done in the "gr" URI parameter of the GRUU. The base64 encoding is done
with the alphabet specified in table 1 of [RFC4648] with the with the alphabet specified in Table 1 of [RFC4648] with the
exception that ~ is used in place of =. exception that "~" is used in place of "=".
Example of a RELOAD GRUU: Example of a RELOAD GRUU:
alice@example.com;gr=MDEyMzQ1Njc4OTAxMjM0NTY3ODk~ alice@example.com;gr=MDEyMzQ1Njc4OTAxMjM0NTY3ODk~
GRUUs do not require to store data in the Overlay Instance. Rather GRUUs do not require storing data in the Overlay Instance. Rather,
when a peer needs to route a message to a GRUU in the same P2P when a Peer needs to route a message to a GRUU in the same P2P
overlay, it simply uses the destination list and connects to that overlay, it simply uses the destination list and connects to that
peer. Because a GRUU contains a destination list, it can have the Peer. Because a GRUU contains a destination list, it can have the
same contents as a destination list stored elsewhere in the resource same contents as a destination list stored elsewhere in the resource
dictionary. dictionary.
Anonymous GRUUs [RFC5767] are constructed analogously, but require Anonymous GRUUs [RFC5767] are constructed analogously, but require
either that the enrollment server issues a different Node-ID for each either that the enrollment server issues a different Node-ID for each
anonymous GRUU required, or that a destination list be used that anonymous GRUU required, or that a destination list be used that
includes a peer that compresses the destination list to stop the includes a Peer that compresses the destination list to stop the
Node-ID from being revealed. Node-ID from being revealed.
7. SIP-REGISTRATION Kind Definition 7. SIP-REGISTRATION Kind Definition
This section defines the SIP-REGISTRATION Kind. This section defines the SIP-REGISTRATION Kind.
Name SIP-REGISTRATION Name: SIP-REGISTRATION
Kind IDs The Resource Name for the SIP-REGISTRATION Kind-ID is the Kind IDs: The Resource Name for the SIP-REGISTRATION Kind-ID is the
AOR of the user as specified in Section 2. The data stored is a AOR of the user as specified in Section 2. The data stored is a
SipRegistration, which can contain either another URI or a SipRegistration, which can contain either another URI or a
destination list to the peer which is acting for the user. destination list to the Peer that is acting for the user.
Data Model The data model for the SIP-REGISTRATION Kind-ID is Data Model: The data model for the SIP-REGISTRATION Kind-ID is a
dictionary. The dictionary key is the Node-ID of the storing dictionary. The dictionary key is the Node-ID of the Storing
peer. This allows each peer (presumably corresponding to a single Peer. This allows each Peer (presumably corresponding to a single
device) to store a single route mapping. device) to store a single route mapping.
Access Control USER-NODE-MATCH. Note that this matches the SIP AOR Access Control: USER-NODE-MATCH. Note that this matches the SIP AOR
against the rfc822Name in the X509v3 certificate. The rfc822Name against the rfc822Name in the X.509 v3 certificate. The
does not include the scheme so that the "sip:" prefix needs to be rfc822Name does not include the scheme so that the "sip:" prefix
removed from the SIP AOR before matching. Escaped characters ('%' needs to be removed from the SIP AOR before matching. Escaped
encoding) in the SIP AOR also need to be decoded prior to matching characters ('%' encoding) in the SIP AOR also need to be decoded
(see [RFC3986]). prior to matching (see [RFC3986]).
Data stored under the SIP-REGISTRATION Kind is of type Data stored under the SIP-REGISTRATION Kind is of type
SipRegistration. This comes in two varieties: SipRegistration, containing one of two data types:
sip_registration_uri sip_registration_uri
a URI which the user can be reached at. A URI that the user can be reached at.
sip_registration_route sip_registration_route
a destination list which can be used to reach the user's peer. A destination list that can be used to reach the user's Peer.
8. Security Considerations 8. Security Considerations
8.1. RELOAD-Specific Issues 8.1. RELOAD-Specific Issues
This Usage for RELOAD does not define new protocol elements or This Usage for RELOAD does not define new protocol elements or
operations. Hence no new threats arrive from message exchanges in operations. Hence, no new threats arrive from message exchanges in
RELOAD. RELOAD.
This document introduces an AOR domain restriction function that must This document introduces an AOR domain restriction function that must
be surveyed by the storing peer. A misconfigured or malicious peer be compared against the registration attempt by the Storing Peer. A
could cause frequent rejects of illegitimate storing requests. misconfigured or malicious Peer could cause frequent rejects of
However, domain name control relies on a lightweight pattern matching illegitimate storing requests. However, domain name control relies
and can be processed prior to validating certificates. Hence no on a lightweight pattern matching and can be processed prior to
extra burden is introduced for RELOAD peers beyond loads already validating certificates. Hence, no extra burden is introduced for
present in the base protocol. RELOAD peers beyond loads already present in the base protocol.
8.2. SIP-Specific Issues 8.2. SIP-Specific Issues
8.2.1. Fork Explosion 8.2.1. Fork Explosion
Because SIP includes a forking capability (the ability to retarget to Because SIP includes a forking capability (the ability to retarget to
multiple recipients), fork bombs (i.e., attacks using SIP forking to multiple recipients), fork bombs (i.e., attacks using SIP forking to
amplify the effect on the intended victims) are a potential DoS amplify the effect on the intended victims) are a potential DoS
concern. However, in the SIP usage of RELOAD, fork bombs are a much concern. However, in the SIP Usage of RELOAD, fork bombs are a much
lower concern than in a conventional SIP Proxy infrastructure, lower concern than in a conventional SIP Proxy infrastructure,
because the calling party is involved in each retargeting event. It because the calling party is involved in each retargeting event. It
can therefore directly measure the number of forks and throttle at can therefore directly measure the number of forks and throttle at
some reasonable number. some reasonable number.
8.2.2. Malicious Retargeting 8.2.2. Malicious Retargeting
Another potential DoS attack is for the owner of an attractive AOR to To launch a DoS attack, the owner of a popular AOR could retarget all
retarget all calls to some victim. This attack is common to SIP and calls to the victim. This attack is common to SIP and is difficult
difficult to ameliorate without requiring the target of a SIP to ameliorate without requiring the target of a SIP registration to
registration to authorize all stores. The overhead of that authorize all stores. The overhead of that requirement would be
requirement would be excessive and in addition there are good use excessive and, in addition, there are good use cases for retargeting
cases for retargeting to a peer without its explicit cooperation. to a Peer without its explicit cooperation.
8.2.3. Misuse of AORs 8.2.3. Misuse of AORs
A RELOAD overlay and enrollment service that liberally accept A RELOAD overlay and enrollment service that liberally accepts
registrations for AORs of domain names unrelated to the overlay registrations for AORs of domain names unrelated to the overlay
instance and without further authorisation, eventually store presence instance and without further authorization could store presence state
state for misused AORs. An attacker could hijack names, register a for AORs without the consent of the owner of the AOR. An attacker
bogus presence and attract calls dedicated to a victim that resides could hijack names, register a bogus presence, and attract calls
within or outside the Overlay Instance. dedicated to a victim that resides within or outside the Overlay
Instance.
A hijacking of AORs can be mitigated by restricting the name spaces A hijacking of AORs can be mitigated by restricting the name spaces
admissible in the Overlay Instance, or by additional verification admissible in the Overlay Instance, or by additional verification
actions of the enrollment service. To prevent an (exclusive) routing actions of the enrollment service. To prevent an (exclusive) routing
to a bogus registration, a caller can in addition query the DNS (or to a bogus registration, a caller can in addition query the DNS (or
other discovery services at hand) to search for an alternative other discovery services at hand), search for an alternative presence
presence of the callee in another overlay or a normal SIP of the callee in another overlay or a SIP infrastructure using
infrastructure. [RFC3263] for name resolution.
8.2.4. Privacy Issues 8.2.4. Privacy Issues
All RELOAD SIP registration data is visible to all nodes in the All RELOAD SIP registration data is visible to all nodes in the
overlay. Location privacy can be gained from using anonymous GRUUs. overlay. Location privacy can be gained from using anonymous GRUUs.
Methods of providing anonymity or deploying pseudonyms exist, but are Methods of providing anonymity or deploying pseudonyms exist, but are
beyond the scope of this document. beyond the scope of this document.
9. IANA Considerations 9. IANA Considerations
9.1. Data Kind-ID 9.1. Data Kind-ID
IANA shall register the following code point in the "RELOAD Data IANA has registered the following code point in the "RELOAD Data
Kind-ID" Registry (cf., [RFC6940]) to represent the SIP-REGISTRATION Kind-ID" Registry (cf., [RFC6940]) to represent the SIP-REGISTRATION
Kind, as described in Section 7. [NOTE TO IANA/RFC-EDITOR: Please Kind, as described in Section 7.
replace RFC-AAAA with the RFC number for this specification in the
following list.]
+---------------------+------------+----------+ +---------------------+------------+-----------+
| Kind | Kind-ID | RFC | | Kind | Kind-ID | Reference |
+---------------------+------------+----------+ +---------------------+------------+-----------+
| SIP-REGISTRATION | 1 | RFC-AAAA | | SIP-REGISTRATION | 0x1 | RFC 7904 |
+---------------------+------------+----------+ +---------------------+------------+-----------+
9.2. XML Name Space Registration 9.2. XML Namespace Registration
This document registers the following URI for the config XML This document registers the following URI for the config XML
namespace in the IETF XML registry defined in [RFC3688] namespace in the IETF XML registry defined in [RFC3688]:
URI: urn:ietf:params:xml:ns:p2p:config-base:sip URI: urn:ietf:params:xml:ns:p2p:config-base:sip
Registrant Contact: The IESG Registrant Contact: The IESG
XML: N/A, the requested URI is an XML namespace XML: N/A; the requested URI is an XML namespace
10. Acknowledgments
This document was generated in parts from initial drafts and
discussions in the early specification phase of the P2PSIP base
protocol. Significant contributions (in alphabetical order) were
from David A. Bryan, James Deverick, Marcin Matuszewski, Jonathan
Rosenberg, and Marcia Zangrilli, which is gratefully acknowledged.
Additional thanks go to all those who helped with ideas, discussions,
and reviews, in particular (in alphabetical order) Roland Bless,
Michael Chen, Alissa Cooper, Marc Petit-Huguenin, Brian Rosen, Meral
Shirazipour, and Matthias Waehlisch.
11. References 10. References
11.1. Normative References 10.1. Normative References
[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, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC6940] Jennings, C., Lowekamp, B., Ed., Rescorla, E., Baset, S., [RFC6940] Jennings, C., Lowekamp, B., Ed., Rescorla, E., Baset, S.,
and H. Schulzrinne, "REsource LOcation And Discovery and H. Schulzrinne, "REsource LOcation And Discovery
(RELOAD) Base Protocol", RFC 6940, DOI 10.17487/RFC6940, (RELOAD) Base Protocol", RFC 6940, DOI 10.17487/RFC6940,
January 2014, <http://www.rfc-editor.org/info/rfc6940>. January 2014, <http://www.rfc-editor.org/info/rfc6940>.
skipping to change at page 18, line 6 skipping to change at page 18, line 17
Initiation Protocol (SIP)", RFC 5626, Initiation Protocol (SIP)", RFC 5626,
DOI 10.17487/RFC5626, October 2009, DOI 10.17487/RFC5626, October 2009,
<http://www.rfc-editor.org/info/rfc5626>. <http://www.rfc-editor.org/info/rfc5626>.
[RFC5627] Rosenberg, J., "Obtaining and Using Globally Routable User [RFC5627] Rosenberg, J., "Obtaining and Using Globally Routable User
Agent URIs (GRUUs) in the Session Initiation Protocol Agent URIs (GRUUs) in the Session Initiation Protocol
(SIP)", RFC 5627, DOI 10.17487/RFC5627, October 2009, (SIP)", RFC 5627, DOI 10.17487/RFC5627, October 2009,
<http://www.rfc-editor.org/info/rfc5627>. <http://www.rfc-editor.org/info/rfc5627>.
[IEEE-Posix] [IEEE-Posix]
"IEEE Standard for Information Technology - Portable IEEE, "International Standard - Information technology
Operating System Interface (POSIX) - Part 2: Shell and Portable Operating System Interface (POSIX) Base
Utilities (Vol. 1)", IEEE Std 1003.2-1992, ISBN Specifications, Issue 7", ISO/IEC/IEEE 9945:2009,
1-55937-255-9, January 1993. DOI 10.1109/IEEESTD.2009.5393893, September 2009.
11.2. Informative References 10.2. Informative References
[I-D.ietf-p2psip-concepts] [RFC3263] Rosenberg, J. and H. Schulzrinne, "Session Initiation
Bryan, D., Matthews, P., Shim, E., Willis, D., and S. Protocol (SIP): Locating SIP Servers", RFC 3263,
Dawkins, "Concepts and Terminology for Peer to Peer SIP", DOI 10.17487/RFC3263, June 2002,
draft-ietf-p2psip-concepts-09 (work in progress), April <http://www.rfc-editor.org/info/rfc3263>.
2016.
[RFC3966] Schulzrinne, H., "The tel URI for Telephone Numbers",
RFC 3966, DOI 10.17487/RFC3966, December 2004,
<http://www.rfc-editor.org/info/rfc3966>.
[RFC7890] Bryan, D., Matthews, P., Shim, E., Willis, D., and S.
Dawkins, "Concepts and Terminology for Peer-to-Peer SIP
(P2PSIP)", RFC 7890, DOI 10.17487/RFC7890, June 2016,
<http://www.rfc-editor.org/info/rfc7890>.
[RFC5767] Munakata, M., Schubert, S., and T. Ohba, "User-Agent- [RFC5767] Munakata, M., Schubert, S., and T. Ohba, "User-Agent-
Driven Privacy Mechanism for SIP", RFC 5767, Driven Privacy Mechanism for SIP", RFC 5767,
DOI 10.17487/RFC5767, April 2010, DOI 10.17487/RFC5767, April 2010,
<http://www.rfc-editor.org/info/rfc5767>. <http://www.rfc-editor.org/info/rfc5767>.
[I-D.ietf-p2psip-share] [SHARE] Knauf, A., Schmidt, T., Hege, G., and M. Waehlisch, "A
Knauf, A., Schmidt, T., Hege, G., and M. Waehlisch, "A Usage for Shared Resources in RELOAD (ShaRe)", Work in
Usage for Shared Resources in RELOAD (ShaRe)", draft-ietf- Progress, draft-ietf-p2psip-share-08, March 2016.
p2psip-share-08 (work in progress), March 2016.
Appendix A. Third Party Registration
In traditional SIP, the mechanism of a third party registration
(i.e., an assistant acting for a boss, changing users register a
role-based AOR, ...) is defined in Section 10.2 of [RFC3261]. This
is a REGISTER which uses the URI of the third-party in its From
header and cannot be translated directly into a P2PSIP registration,
because only the owner of the certificate can store a SIP-
REGISTRATION in a RELOAD overlay.
A way to implement third party registration is by using the extended
access control mechanism USER-CHAIN-ACL defined in
[I-D.ietf-p2psip-share]. Creating a new Kind "SIP-3P-REGISTRATION"
that is ruled by USER-CHAIN-ACL allows the owner of the certificate
to delegate the right for registration to individual third parties.
In this way, original SIP functionality can be regained without
weakening the security control of RELOAD.
Appendix B. Change Log
B.1. Changes since draft-ietf-p2psip-sip-09
o Added subsection on keepalive
o Updated references
B.2. Changes since draft-ietf-p2psip-sip-08
o Added the handling of SIPS
o Specified use of Posix regular expressions in configuration
document
o Added IANA registration for namespace
o Editorial polishing
o Updated and extended references
B.3. Changes since draft-ietf-p2psip-sip-07
o Cleared open issues
o Clarified use cases after WG discussion
o Added configuration document extensions for configurable domain
names
o Specified format of contact_prefs
o Clarified routing to AORs
o Extended security section
o Added Appendix on Third Party Registration Appendix A. Third-Party Registration
o Added IANA code points Non-peer-to-peer SIP defines third-party registration (e.g., an
assistant acting for a manager or a changing set of users registering
under a role-based AOR) in Section 10.2 of [RFC3261]. This is a
REGISTER that uses the URI of the third party in its From header and
cannot be translated directly into a P2PSIP registration because only
the owner of the certificate can store a SIP-REGISTRATION in a RELOAD
overlay.
o Editorial polishing Third-party registration can be implemented by using the extended
access control mechanism USER-CHAIN-ACL defined in [SHARE]. Creating
a new Kind "SIP-3P-REGISTRATION" that is ruled by USER-CHAIN-ACL
allows the owner of the certificate to delegate the right for
registration to individual third parties. This way, the SIP third-
party registration functionality can be regained without weakening
the security controls of RELOAD.
o Updated and extended references Acknowledgments
B.4. Changes since draft-ietf-p2psip-sip-06 This document was generated in parts from initial drafts and
discussions in the early specification phase of the P2PSIP base
protocol. We gratefully acknowledge the significant contributions
made by (in alphabetical order) David A. Bryan, James Deverick,
Marcin Matuszewski, Jonathan Rosenberg, and Marcia Zangrilli.
o Added Open Issue Additional thanks go to all those who helped with ideas, discussions,
and reviews, in particular (in alphabetical order) Roland Bless,
Michael Chen, Alissa Cooper, Marc Petit-Huguenin, Brian Rosen, Meral
Shirazipour, and Matthias Waehlisch.
Authors' Addresses Authors' Addresses
Cullen Jennings Cullen Jennings
Cisco Cisco
170 West Tasman Drive 170 West Tasman Drive
MS: SJC-21/2 MS: SJC-21/2
San Jose, CA 95134 San Jose, CA 95134
USA United States of America
Phone: +1 408 421-9990 Phone: +1 408 421-9990
Email: fluffy@cisco.com Email: fluffy@cisco.com
Bruce B. Lowekamp Bruce B. Lowekamp
Skype Skype
Palo Alto, CA Palo Alto, CA
USA United States of America
Email: bbl@lowekamp.net Email: bbl@lowekamp.net
Eric Rescorla Eric Rescorla
RTFM, Inc. RTFM, Inc.
2064 Edgewood Drive 2064 Edgewood Drive
Palo Alto, CA 94303 Palo Alto, CA 94303
USA United States of America
Phone: +1 650 678 2350 Phone: +1 650 678 2350
Email: ekr@rtfm.com Email: ekr@rtfm.com
Salman A. Baset Salman A. Baset
Columbia University IBM T. J. Watson Research Center
1214 Amsterdam Avenue 1101 Kitchawan Road
New York, NY Yorktown Heights, NY 10598
USA United States of America
Email: sabaset@us.ibm.com
Email: salman@cs.columbia.edu
Henning Schulzrinne Henning Schulzrinne
Columbia University Columbia University
1214 Amsterdam Avenue 1214 Amsterdam Avenue
New York, NY New York, NY 10027
USA United States of America
Email: hgs@cs.columbia.edu Email: hgs@cs.columbia.edu
Thomas C. Schmidt (editor) Thomas C. Schmidt (editor)
HAW Hamburg HAW Hamburg
Berliner Tor 7 Berliner Tor 7
Hamburg 20099 Hamburg 20099
Germany Germany
Email: t.schmidt@haw-hamburg.de Email: t.schmidt@haw-hamburg.de
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