draft-ietf-ecrit-data-only-ea-10.txt   draft-ietf-ecrit-data-only-ea-11.txt 
ECRIT B. Rosen ECRIT B. Rosen
Internet-Draft NeuStar, Inc. Internet-Draft NeuStar, Inc.
Intended status: Standards Track H. Schulzrinne Intended status: Standards Track H. Schulzrinne
Expires: February 12, 2016 Columbia U. Expires: September 2, 2016 Columbia U.
H. Tschofenig H. Tschofenig
August 11, 2015 ARM Limited
R. Gellens
March 1, 2016
Data-Only Emergency Calls Data-Only Emergency Calls
draft-ietf-ecrit-data-only-ea-10.txt draft-ietf-ecrit-data-only-ea-11.txt
Abstract Abstract
RFC 6443 'Framework for Emergency Calling Using Internet Multimedia' RFC 6443 'Framework for Emergency Calling Using Internet Multimedia'
describes how devices use the Internet to place emergency calls and describes how devices use the Internet to place emergency calls and
how Public Safety Answering Points (PSAPs) can handle Internet how Public Safety Answering Points (PSAPs) handle Internet multimedia
multimedia emergency calls natively. The exchange of multimedia emergency calls natively. The exchange of multimedia traffic for
traffic typically involves a SIP session establishment starting with emergency services involves a SIP session establishment starting with
a SIP INVITE that negotiates various parameters for that session. a SIP INVITE that negotiates various parameters for that session.
In some cases, however, the transmission of application data is In some cases, however, the transmission of application data is all
everything that is needed. Examples of such environments include a that is needed. Examples of such environments include alerts issued
temperature sensors issuing alerts, or vehicles sending crash data. by a temperature sensor, burglar alarm, or chemical spill sensor.
Often these alerts are conveyed as one-shot data transmissions. Often these alerts are conveyed as one-shot data transmissions.
These type of interactions are called 'data-only emergency calls'. These type of interactions are called 'data-only emergency calls'.
This document describes a container for the data based on the Common This document describes a container for the data based on the Common
Alerting Protocol (CAP) and its transmission using the SIP MESSAGE Alerting Protocol (CAP) and its transmission using the SIP MESSAGE
transaction. transaction.
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.
skipping to change at page 1, line 46 skipping to change at page 1, line 48
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
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 12, 2016. This Internet-Draft will expire on September 2, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 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
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
skipping to change at page 2, line 40 skipping to change at page 2, line 40
5.1. 425 (Bad Alert Message) Response Code . . . . . . . . . . 9 5.1. 425 (Bad Alert Message) Response Code . . . . . . . . . . 9
5.2. The AlertMsg-Error Header Field . . . . . . . . . . . . . 9 5.2. The AlertMsg-Error Header Field . . . . . . . . . . . . . 9
6. Updates to the CAP Message . . . . . . . . . . . . . . . . . 11 6. Updates to the CAP Message . . . . . . . . . . . . . . . . . 11
7. Call Backs . . . . . . . . . . . . . . . . . . . . . . . . . 11 7. Call Backs . . . . . . . . . . . . . . . . . . . . . . . . . 11
8. Handling Large Amounts of Data . . . . . . . . . . . . . . . 11 8. Handling Large Amounts of Data . . . . . . . . . . . . . . . 11
9. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 9. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
10. Security Considerations . . . . . . . . . . . . . . . . . . . 15 10. Security Considerations . . . . . . . . . . . . . . . . . . . 15
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
11.1. Registration of the 'application/emergencyCall.cap+xml' 11.1. Registration of the 'application/emergencyCall.cap+xml'
MIME type . . . . . . . . . . . . . . . . . . . . . . . 17 MIME type . . . . . . . . . . . . . . . . . . . . . . . 17
11.2. IANA Registration of Additional Data Block . . . . . . . 18 11.2. IANA Registration of 'cap' Additional Data Block . . . . 18
11.3. IANA Registration for 425 Response Code . . . . . . . . 18 11.3. IANA Registration for 425 Response Code . . . . . . . . 18
11.4. IANA Registration of New AlertMsg-Error Header Field . . 19 11.4. IANA Registration of New AlertMsg-Error Header Field . . 19
11.5. IANA Registration for the SIP AlertMsg-Error Codes . . . 19 11.5. IANA Registration for the SIP AlertMsg-Error Codes . . . 19
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 20 12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 20
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 20
13.1. Normative References . . . . . . . . . . . . . . . . . . 20 13.1. Normative References . . . . . . . . . . . . . . . . . . 20
13.2. Informative References . . . . . . . . . . . . . . . . . 21 13.2. Informative References . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction 1. Introduction
RFC 6443 [RFC6443] describes how devices use the Internet to place RFC 6443 [RFC6443] describes how devices use the Internet to place
emergency calls and how Public Safety Answering Points (PSAPs) can emergency calls and how Public Safety Answering Points (PSAPs) handle
handle Internet multimedia emergency calls natively. The exchange of Internet multimedia emergency calls natively. The exchange of
multimedia traffic typically involves a SIP session establishment multimedia traffic for emergency services involves a SIP session
starting with a SIP INVITE that negotiates various parameters for establishment starting with a SIP INVITE that negotiates various
that session. parameters for that session.
In some cases, however, there is only application data to be conveyed In some cases, however, there is only application data to be conveyed
from the end devices to a PSAP or some other intermediary. Examples from the end devices to a PSAP or an intermediary. Examples of such
of such environments includes sensors issuing alerts, or vehicles environments includes sensors issuing alerts, or vehicles sending
sending crash data. These messages may be one-shot alerts to crash data. These messages may be one-shot alerts to emergency
emergency authorities and do not require establishment of a session. authorities and do not require establishment of a session. These
These type of interactions are called 'data-only emergency calls'. type of interactions are called 'data-only emergency calls'. In this
In this document, we use the term "call" so that similarities between document, we use the term "call" so that similarities between data-
full sessions with interactive media can be exploited. only (non-interactive) alerts and sessions with interactive media are
more obvious.
Data-only emergency calls are similar to regular emergency calls in Data-only emergency calls are similar to regular emergency calls in
the sense that they require the emergency indications, emergency call the sense that they require the emergency indications, emergency call
routing functionality and may even have the same location routing functionality and may even have the same location
requirements. However, the communication interaction will not lead requirements. However, the communication interaction will not lead
to the exchange of interactive media, that is, Real-Time Protocol to the exchange of interactive media, that is, Real-Time Protocol
packets, such as voice, video data or real-time text. packets, such as voice, video data or real-time text.
The Common Alerting Protocol (CAP) [cap] is a document format for The Common Alerting Protocol (CAP) [cap] is a document format for
exchanging emergency alerts and public warnings. CAP is mainly used exchanging emergency alerts and public warnings. CAP is mainly used
for conveying alerts and warnings between authorities and from for conveying alerts and warnings between authorities and from
authorities to citizen/individuals. This document is concerned with authorities to citizen/individuals. This document is concerned with
citizen to authority "alerts", where the alert is sent without any citizen to authority "alerts", where the alert is a call without any
interactive media. interactive media.
This document describes a method of including a CAP message in a SIP This document describes a method of including a CAP message in a SIP
transaction, either by value (CAP message is in the body of the transaction, either by value (the CAP message is in the body of the
message, using a CID) or by reference (A URI is included in the message, using a CID) or by reference (a URI is included in the
message, which when dereferenced returns the CAP message) by defining message, which when dereferenced returns the CAP message) by defining
it as a block of "additional data" as defined in it as a block of "additional data" as defined in
[I-D.ietf-ecrit-additional-data]. The additional data mechanism is [I-D.ietf-ecrit-additional-data]. The additional data mechanism is
also used to send alert specific data beyond that available in the also used to send alert specific data beyond that available in the
CAP message. This document also describes how a SIP MESSAGE CAP message. This document also describes how a SIP MESSAGE
[RFC3428] transaction can be used to send a data-only call. [RFC3428] transaction can be used to send a data-only call.
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].
3. Architectural Overview 3. Architectural Overview
This section illustrates two envisioned usage modes; targeted and This section illustrates two envisioned usage modes: targeted and
location-based emergency alert routing. location-based emergency alert routing.
1. Emergency alerts containing only data are targeted to a 1. Emergency alerts containing only data are targeted to an
intermediary recipient responsible for evaluating the next steps. intermediary recipient responsible for evaluating the next steps.
These steps could include: These steps could include:
1. Sending a call containing only data toward a Public Safety 1. Sending a non-interactive call containing only data toward a
Answering Point (PSAP); Public Safety Answering Point (PSAP);
2. Establishing a third-party initiated emergency call towards a 2. Establishing a third-party initiated emergency call towards a
PSAP that could include audio, video, and data. PSAP that could include audio, video, and data.
2. Emergency alerts may be targeted to a Service URN used for IP- 2. Emergency alerts may be targeted to a Service URN used for IP-
based emergency calls where the recipient is not known to the based emergency calls where the recipient is not known to the
originator. In this scenario, the alert may contain only data originator. In this scenario, the alert may contain only data
(e.g., a CAP, Geolocation header and one or more Call-Info (e.g., a CAP, Geolocation header field and one or more Call-Info
headers containing Additional Data header fields containing Additional Data
[I-D.ietf-ecrit-additional-data] in a SIP MESSAGE). [I-D.ietf-ecrit-additional-data] in a SIP MESSAGE).
Figure 1 shows a deployment variant where a sensor, is pre-configured Figure 1 shows a deployment variant where a sensor is pre-configured
(using techniques outside the scope of this document) to issue an (using techniques outside the scope of this document) to issue an
alert to an aggregator that processes these messages and performs alert to an aggregator that processes these messages and performs
whatever steps are necessary to appropriately react on the alert. whatever steps are necessary to appropriately react to the alert.
For example, a security firm may use different sensor inputs to For example, a security firm may use different sensor inputs to
dispatch their security staff to a building they protect or to dispatch their security staff to a building they protect or to
initiate a third-party emergency call. initiate a third-party emergency call.
+------------+ +------------+ +------------+ +------------+
| Sensor | | Aggregator | | Sensor | | Aggregator |
| | | | | | | |
+---+--------+ +------+-----+ +---+--------+ +------+-----+
| | | |
Sensors | Sensors |
skipping to change at page 5, line 29 skipping to change at page 5, line 29
| emergency | emergency
| alert | alert
| 200 (OK) | | 200 (OK) |
|<-----------------------------| |<-----------------------------|
| | | |
| | | |
Figure 1: Targeted Emergency Alert Routing Figure 1: Targeted Emergency Alert Routing
In Figure 2 a scenario is shown whereby the alert is routed using In Figure 2 a scenario is shown whereby the alert is routed using
location information and the Service URN. An emergency services location information and a Service URN. An emergency services
routing proxy (ESRP) may use LoST to determine the next hop proxy to routing proxy (ESRP) may use LoST to determine the next hop proxy to
route the alert message to. A possible receiver is a PSAP and the route the alert message to. A possible receiver is a PSAP and the
recipient of the alert may be call taker. In the generic case, there recipient of the alert may be a call taker. In the generic case,
is very likely no prior relationship between the originator and the there is very likely no prior relationship between the originator and
receiver, e.g. PSAP. A PSAP, for example, is likely to receive and the receiver, e.g., a PSAP. A PSAP, for example, is likely to
accept alerts from entities it cannot authorize. This scenario receive and accept alerts from entities it cannot authorize. This
corresponds more to the classical emergency services use case and the scenario corresponds to the classic emergency services use case and
description in [RFC6881] is applicable. In this use case, the only the description in [RFC6881] is applicable. In this use case, the
difference between an emergency call, and an emergency data-only call only difference between an emergency call and an emergency data-only
is that the former uses INVITE, creates a session and negotiates one call is that the former uses INVITE, creates a session, and
or more media streams, while the latter uses MESSAGE, does not create negotiates one or more media streams, while the latter uses MESSAGE,
a session and does not have media. does not create a session, and does not have media.
+-----------+ +----------+ +-----------+ +----------+
+--------+ | ESRP | | PSAP | +--------+ | ESRP | | PSAP |
| Sensor | | | | | | Sensor | | | | |
+---+----+ +---+-------+ +---+------+ +---+----+ +---+-------+ +---+------+
| | | | | |
Sensors | | Sensors | |
trigger | | trigger | |
emergency | | emergency | |
alert | | alert | |
skipping to change at page 6, line 46 skipping to change at page 6, line 46
|<-------------------| | |<-------------------| |
| | | | | |
| | | | | |
Figure 2: Location-Based Emergency Alert Routing Figure 2: Location-Based Emergency Alert Routing
4. Protocol Specification 4. Protocol Specification
4.1. CAP Transport 4.1. CAP Transport
A CAP message may be sent on the initial message of any SIP A CAP message may be sent in the initial message of any SIP
transaction. However, this document only describes specific behavior transaction. However, this document only addresses sending a CAP
when used with a SIP INVITE that would accompany a normal emergency message in a SIP INVITE that initiates an emergency call, or in a SIP
call and a SIP MESSAGE transaction for a one-shot, data-only MESSAGE transaction for a one-shot, data-only emergency call.
emergency call. Behavior with other transactions is not defined. Behavior with other transactions is not defined.
The CAP message included in a SIP message as an additional-data block The CAP message is included in a SIP message as an additional-data
[I-D.ietf-ecrit-additional-data]. Accordingly, it is introduced to block [I-D.ietf-ecrit-additional-data]. Accordingly, it is
the SIP message with a Call-Info header with a purpose of introduced to the SIP message with a Call-Info header field with a
"emergencyCall.cap". The header may contain a URI that is used by purpose of "emergencyCall.cap". The header field may contain a URI
the recipient (or in some cases, an intermediary) to obtain the CAP that is used by the recipient (or in some cases, an intermediary) to
message. Alternative, the Call-Info header may contain a Content obtain the CAP message. Alternative, the Call-Info header field may
Indirect url [RFC2392] and the CAP message included in the body of contain a Content Indirect url [RFC2392] and the CAP message included
the message. In either case, the CAP message is located in a MIME in the body of the message. In either case, the CAP message is
block. The MIME type is set to 'application/emergencyCall.cap+xml'. located in a MIME block of the type 'application/
emergencyCall.cap+xml'.
If the server does not support the functionality required to fulfill If the SIP server does not support the functionality required to
the request then a 501 Not Implemented MUST be returned as specified fulfill the request then a 501 Not Implemented MUST be returned as
in RFC 3261 [RFC3261]. This is the appropriate response when a UAS specified in RFC 3261 [RFC3261]. This is the appropriate response
does not recognize the request method and is not capable of when a UAS does not recognize the request method and is not capable
supporting it for any user. of supporting it for any user.
The 415 Unsupported Media Type error MUST be returned as specified in The 415 Unsupported Media Type error MUST be returned as specified in
RFC 3261 [RFC3261] if the server is refusing to service the request RFC 3261 [RFC3261] if the SIP server is refusing to service the
because the message body of the request is in a format not supported request because the message body of the request is in a format not
by the server for the requested method. The server MUST return a supported by the server for the requested method. The server MUST
list of acceptable formats using the Accept, Accept-Encoding, or return a list of acceptable formats using the Accept, Accept-
Accept-Language header field, depending on the specific problem with Encoding, or Accept-Language header fields, depending on the specific
the content. problem with the content.
4.2. Profiling of the CAP Document Content 4.2. Profiling of the CAP Document Content
The usage of CAP MUST conform to the specification provided with The usage of CAP MUST conform to the specification provided with
[cap]. For the usage with SIP the following additional requirements [cap]. For usage with SIP the following additional requirements are
are imposed: imposed:
sender: A few sub-categories for putting a value in the <sender> sender: The following restrictions and conditions apply to setting
element have to be considered: the value of the <sender> element:
Originator is a SIP entity, Author indication irrelevant: When Originator is a SIP entity, Author indication irrelevant: When
the alert was created by a SIP-based originator and it is not the alert was created by a SIP-based originator and it is not
useful to be explicit about the author of the alert then the useful to be explicit about the author of the alert, then the
<sender> element MUST be populated with the SIP URI of the user <sender> element MUST be populated with the SIP URI of the user
agent. agent.
Originator is a non-SIP entity, Author indication irrelevant: In Originator is a non-SIP entity, Author indication irrelevant:
case that the alert was created by a non-SIP based entity and When the alert was created by a non-SIP based entity and the
the identity of this original sender wants to be preserved then identity of this original sender is to be preserved, then this
this identity MUST be placed into the <sender> element. In identity MUST be placed into the <sender> element. In this
this category the it is not useful to be explicit about the situation it is not useful to be explicit about the author of the
author of the alert. The specific type of identity being used alert. The specific type of identity being used will depend on
will depends on the technology being used by the original the technology used by the original originator.
originator.
Author indication relevant: In case the author is different from Author indication relevant: When the author is different from the
the actual originator of the message and this distinction actual originator of the message and this distinction should be
should be preserved then the <sender> element MUST NOT contain preserved, then the <sender> element MUST NOT contain the SIP URI
the SIP URI of the user agent. of the user agent.
incidents: The <incidents> element MUST be present. This incident incidents: The <incidents> element MUST be present. This incident
identifier MUST be chosen in such a way that it is unique for a identifier MUST be chosen in such a way that it is unique for a
given <sender, expires, incidents> combination. Note that the given <sender, expires, incidents> combination. Note that the
<expires> element is optional and may not be present. <expires> element is optional and may not be present.
scope: The value of the <scope> element MAY be set to "Private" if scope: The value of the <scope> element MAY be set to "Private" if
the alert is not meant for public consumption. The <addresses> the alert is not meant for public consumption. The <addresses>
element is, however, not used by this specification since the element is, however, not used by this specification since the
message routing is performed by SIP and the respective address message routing is performed by SIP and the respective address
information is already available in other SIP headers. Populating information is already available in other SIP header fields.
information twice into different parts of the message may lead to Populating information twice into different parts of the message
inconsistency. may lead to inconsistency.
parameter: The <parameter> element MAY contain additional parameter: The <parameter> element MAY contain additional
information specific to the sendor. information specific to the sendor.
area: It is RECOMMENDED to omit this element when constructing a area: It is RECOMMENDED to omit this element when constructing a
message. In case that the CAP message already contained an <area> message. If the CAP message already contains an <area> element,
element then the specified location information SHOULD be copied then the specified location information SHOULD be copied into the
into the PIDF-LO structure of the 'geolocation' header. PIDF-LO structure of the 'geolocation' header field.
4.3. Sending a Data-Only Emergency Call 4.3. Sending a Data-Only Emergency Call
A data-only emergency call is sent using a SIP MESSAGE transaction A data-only emergency call is sent using a SIP MESSAGE transaction
with a CAP URI or body as described above in a manner similar to how with a CAP URI or body as described above in a manner similar to how
an emergency call with interactive media is sent, as described in an emergency call with interactive media is sent, as described in
[RFC6881]. The MESSAGE transaction does not create a session or send [RFC6881]. The MESSAGE transaction does not create a session nor
media, but otherwise, the header content of the transaction, routing, send media, but otherwise, the header content of the transaction,
and processing of data-only calls are the same as those of other routing, and processing of data-only calls are the same as those of
emergency calls. other emergency calls.
5. Error Handling 5. Error Handling
This section defines a new error response code and a header field for This section defines a new error response code and a header field for
additional information. additional information.
5.1. 425 (Bad Alert Message) Response Code 5.1. 425 (Bad Alert Message) Response Code
This SIP extension creates a new location-specific response code, This SIP extension creates a new location-specific response code,
defined as follows, defined as follows:
425 (Bad Alert Message) 425 (Bad Alert Message)
The 425 response code is a rejection of the request due to its The 425 response code is a rejection of the request due to its
included alert content, indicating that it was malformed or not included alert content, indicating that it was malformed or not
satisfactory for the recipient's purpose. satisfactory for the recipient's purpose.
A SIP intermediary can also reject an alert it receives from a UA A SIP intermediary can also reject an alert it receives from a UA
when it understands that the provided alert is malformed. when it understands that the provided alert is malformed.
Section 5.2 describes an AlertMsg-Error header field with more Section 5.2 describes an AlertMsg-Error header field with more
details about what was wrong with the alert message in the request. details about what was wrong with the alert message in the request.
This header field MUST be included in the 425 response. This header field MUST be included in the 425 response.
It is only appropriate to generate a 425 response when the responding It is only appropriate to generate a 425 response when the responding
entity has no other information in the request that are usable by the entity has no other information in the request that is usable by the
responder. responder.
A 425 response code MUST NOT be sent in response to a request that A 425 response code MUST NOT be sent in response to a request that
lacks an alert message entirely, as the user agent in that case may lacks an alert message, as the user agent in that case may not
not support this extension at all. support this extension.
A 425 response is a final response within a transaction, and MUST NOT A 425 response is a final response within a transaction, and MUST NOT
terminate an existing dialog. terminate an existing dialog.
5.2. The AlertMsg-Error Header Field 5.2. The AlertMsg-Error Header Field
The AlertMsg-Error header provides additional information about what The AlertMsg-Error header field provides additional information about
was wrong with the original request. In some cases the provided what was wrong with the original request. In some cases the provided
information will be used for debugging purposes. information will be used for debugging purposes.
The AlertMsg-Error header field has the following ABNF [RFC5234]: The AlertMsg-Error header field has the following ABNF [RFC5234]:
message-header /= AlertMsg-Error message-header /= AlertMsg-Error
; (message-header from 3261) ; (message-header from 3261)
AlertMsg-Error = "AlertMsg-Error" HCOLON AlertMsg-Error = "AlertMsg-Error" HCOLON
ErrorValue ErrorValue
ErrorValue = error-code ErrorValue = error-code
*(SEMI error-params) *(SEMI error-params)
error-code = 1*3DIGIT error-code = 1*3DIGIT
error-params = error-code-text error-params = error-code-text
/ generic-param ; from RFC3261 / generic-param ; from RFC3261
error-code-text = "code" EQUAL quoted-string ; from RFC3261 error-code-text = "code" EQUAL quoted-string ; from RFC3261
HCOLON, SEMI, and EQUAL are defined in RFC3261 [RFC3261]. DIGIT is HCOLON, SEMI, and EQUAL are defined in RFC3261 [RFC3261]. DIGIT is
defined in RFC5234 [RFC5234]. defined in RFC5234 [RFC5234].
The AlertMsg-Error header field MUST contain only one ErrorValue to The AlertMsg-Error header field MUST contain only one ErrorValue to
indicate what was wrong with the alert payload the recipient indicate what was wrong with the alert payload the recipient
determined was bad. determined was bad.
The ErrorValue contains a 3-digit error code indicating what was The ErrorValue contains a 3-digit error code indicating what was
wrong with the alert in the request. This error code has a wrong with the alert in the request. This error code has a
corresponding quoted error text string that is human understandable. corresponding quoted error text string that is human understandable.
The text string are OPTIONAL, but RECOMMENDED for human readability, The text string are OPTIONAL, but RECOMMENDED for human readability,
similar to the string phrase used for SIP response codes. That said, similar to the string phrase used for SIP response codes. That said,
the strings are complete enough for rendering to the user, if so the strings are complete enough for rendering to the user, if so
desired. The strings in this document are recommendations, and are desired. The strings in this document are recommendations, and are
not standardized - meaning an operator can change the strings - but not standardized -- meaning an operator can change the strings -- but
MUST NOT change the meaning of the error code. Similar to how RFC MUST NOT change the meaning of the error code. Similar to how RFC
3261 specifies, there MUST NOT be more than one string per error 3261 specifies, there MUST NOT be more than one string per error
code. code.
The AlertMsg-Error header field MAY be included in any response as an The AlertMsg-Error header field MAY be included in any response if an
alert message was in the request part of the same transaction. For alert message was in the request part of the same transaction. For
example, a UA includes an alert in an MESSAGE to a PSAP. The PSAP example, a UA includes an alert in an MESSAGE to a PSAP. The PSAP
can accept this MESSAGE, thus creating a dialog, even though his UA can accept this MESSAGE, thus creating a dialog, even though its UA
determined the alert message contained in the MESSAGE was bad. The determined that the alert message contained in the MESSAGE was bad.
PSAP merely includes an AlertMsg-Error header value in the 200 OK to The PSAP merely includes an AlertMsg-Error header field value in the
the MESSAGE informing the UA that the MESSAGE was accepted but the 200 OK to the MESSAGE, thus informing the UA that the MESSAGE was
alert provided was bad. accepted but the alert provided was bad.
If, on the other hand, the PSAP cannot accept the transaction without If, on the other hand, the PSAP cannot accept the transaction without
a suitable alert message, a 425 response is sent. a suitable alert message, a 425 response is sent.
A SIP intermediary that requires the UA's alert message in order to A SIP intermediary that requires the UA's alert message in order to
properly process the transaction may also sends a 425 with a properly process the transaction may also sends a 425 with an
AlertMsg-Error code. AlertMsg-Error code.
This document defines an initial list of error code ranges for any This document defines an initial list of AlertMsg-Error values for
SIP response, including provisional responses (other than 100 Trying) any SIP response, including provisional responses (other than 100
and the new 425 response. There MUST be no more than one AlertMsg- Trying) and the new 425 response. There MUST be no more than one
Error code in a SIP response. AlertMsg-Error code in a SIP response.
AlertMsg-Error: 100 ; code="Cannot Process the Alert Payload" AlertMsg-Error: 100 ; code="Cannot Process the Alert Payload"
AlertMsg-Error: 101 ; code="Alert Payload was not present or could AlertMsg-Error: 101 ; code="Alert Payload was not present or could
not be found" not be found"
AlertMsg-Error: 102 ; code="Not enough information to determine the AlertMsg-Error: 102 ; code="Not enough information to determine the
purpose of the alert" purpose of the alert"
AlertMsg-Error: 103 ; code="Alert Payload was corrupted" AlertMsg-Error: 103 ; code="Alert Payload was corrupted"
Additionally, if an entity cannot or chooses not to process the alert Additionally, if an entity cannot or chooses not to process the alert
message from a SIP request, a 500 (Server Internal Error) SHOULD be message from a SIP request, a 500 (Server Internal Error) SHOULD be
used with or without a configurable Retry-After header field. used with or without a configurable Retry-After header field.
6. Updates to the CAP Message 6. Updates to the CAP Message
If the sender anticipates that the content of the CAP message may If the sender anticipates that the content of the CAP message may
need to be updated during the lifecycle of the event referred to in need to be updated during the lifecycle of the event referred to in
the message, it may include an update block as defined in the message, it may include an update block as defined in
[I-D.rosen-ecrit-addldata-subnot]. [I-D.rosen-ecrit-addldata-subnot].If the sender includes an update
block and does not have a globally reachable URI, then the UA must
register it's contact with a Registrar, and include a GRUU in in the
update block
7. Call Backs 7. Call Backs
This document does not describe any method for the recipient to call This document does not describe any method for the recipient to call
back the sender of the data-only call. Usually, these alerts are back the sender of a data-only call. Usually, these alerts are sent
sent by automata, and do not have any mechanism to receive calls of by automata, which do not have a mechanism to receive calls of any
any kind. The identifier in the From header may be useful to obtain kind. The identifier in the 'From' header field may be useful to
more information, but any such mechanism is not defined in this obtain more information, but any such mechanism is not defined in
document. The CAP message may contain related contact information this document. The CAP message may contain related contact
for the sender. information for the sender.
8. Handling Large Amounts of Data 8. Handling Large Amounts of Data
It is not atypical for sensor to have large quantities of data that It is not atypical for sensors to have large quantities of data that
they may wish to send. Including large amounts of data in a MESSAGE they may wish to send. Including large amounts of data in a MESSAGE
is not advisable, because SIP entities are usually not equipped to is not advisable, because SIP entities are usually not equipped to
handle very large messages. In such cases, the sender SHOULD make handle very large messages. In such cases, the sender SHOULD make
use of the by-reference mechanisms defined for Additional Data which use of the by-reference mechanisms defined in
involve sending a URI in the Call-Info header and using HTTPS to [I-D.ietf-ecrit-additional-data], which involves making the data
retrieve the data. The CAP message itself can be sent by-reference available via HTTPS (either at the originator or at another entity),
using this mechanism as well as any or all of the Additional Data placing a URI to the data in the 'Call-Info' header field, and the
blocks that may contain sensor-specific data. recipient using HTTPS to retrieve the data. The CAP message itself
can be sent by-reference using this mechanism, as well as any or all
of the Additional Data blocks that may contain sensor-specific data.
9. Example 9. Example
Figure 3 shows a CAP document indicating a BURGLARY alert issued by a Figure 3 shows a CAP document indicating a BURGLARY alert issued by a
sensor called 'sensor1@domain.com'. The location of the sensor can sensor called 'sensor1@domain.com'. The location of the sensor can
be obtained from the attached location information provided via the be obtained from the attached location information provided via the
'geolocation' header contained in the SIP MESSAGE structure. 'geolocation' header field contained in the SIP MESSAGE structure.
Additionally, the sensor provided some data long with the alert Additionally, the sensor provided some data along with the alert
message using proprietary information elements only to be processed message, using proprietary information elements intended only to be
by the receiver, a SIP entity acting as an aggregator. This example processed by the receiver, a SIP entity acting as an aggregator.
reflects the description in Figure 1. This example reflects the description in Figure 1.
MESSAGE sip:aggregator@domain.com SIP/2.0 MESSAGE sip:aggregator@domain.com SIP/2.0
Via: SIP/2.0/TCP sensor1.domain.com;branch=z9hG4bK776sgdkse Via: SIP/2.0/TCP sensor1.domain.com;branch=z9hG4bK776sgdkse
Max-Forwards: 70 Max-Forwards: 70
From: sip:sensor1@domain.com;tag=49583 From: sip:sensor1@domain.com;tag=49583
To: sip:aggregator@domain.com To: sip:aggregator@domain.com
Call-ID: asd88asd77a@1.2.3.4 Call-ID: asd88asd77a@1.2.3.4
Geolocation: <cid:abcdef@domain.com> Geolocation: <cid:abcdef@domain.com>
;routing-allowed=yes ;routing-allowed=yes
Supported: geolocation Supported: geolocation
Accept: application/pidf+xml, application/emergencyCall.cap+xml Accept: application/pidf+xml, application/emergencyCall.cap+xml
CSeq: 1 MESSAGE CSeq: 1 MESSAGE
Call-Info: cid:abcdef2@domain.com;purpose=emergencyCall.cap Call-Info: cid:abcdef2@domain.com;purpose=emergencyCall.cap
Content-Type: multipart/mixed; boundary=boundary1 Content-Type: multipart/mixed; boundary=boundary1
Content-Length: ... Content-Length: ...
--boundary1 --boundary1
Content-Type: application/emergencyCall.cap Content-Type: application/emergencyCall.cap+xml
Content-ID: <abcdef2@domain.com> Content-ID: <abcdef2@domain.com>
Content-Disposition: by-reference;handling=optional Content-Disposition: by-reference;handling=optional
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<alert xmlns="urn:oasis:names:tc:emergency:cap:1.1"> <alert xmlns="urn:oasis:names:tc:emergency:cap:1.1">
<identifier>S-1</identifier> <identifier>S-1</identifier>
<sender>sip:sensor1@domain.com</sender> <sender>sip:sensor1@domain.com</sender>
<sent>2008-11-19T14:57:00-07:00</sent> <sent>2008-11-19T14:57:00-07:00</sent>
<status>Actual</status> <status>Actual</status>
<msgType>Alert</msgType> <msgType>Alert</msgType>
skipping to change at page 15, line 42 skipping to change at page 15, line 47
Figure 4: Example Message conveying an Alert to a PSAP Figure 4: Example Message conveying an Alert to a PSAP
10. Security Considerations 10. Security Considerations
This section discusses security considerations when SIP user agents This section discusses security considerations when SIP user agents
issue emergency alerts utilizing MESSAGE and CAP. Location specific issue emergency alerts utilizing MESSAGE and CAP. Location specific
threats are not unique to this document and are discussed in threats are not unique to this document and are discussed in
[RFC7378] and [RFC6442]. [RFC7378] and [RFC6442].
The ECRIT emergency services architecture [RFC6443] considers The ECRIT emergency services architecture [RFC6443] considers classic
classical individual-to-authority emergency calling and the identity individual-to-authority emergency calling where the identity of the
of the emergency caller does not play a role at the time of the call emergency caller does not play a role at the time of the call
establishment itself, i.e., a response to the emergency call will not establishment itself, i.e., a response to the emergency call does not
depend on the identity of the caller. In case of emergency alerts depend on the identity of the caller. In the case of emergency
generated by devices, like sensors, the processing may be different alerts generated by devices such as sensors, the processing may be
in order to reduce the number of falsely generated emergency alerts. different in order to reduce the number of falsely generated
Alerts may get triggered based on certain sensor input that may have emergency alerts. Alerts may get triggered based on certain sensor
been caused by other factors than the actual occurrence of an alert input that may have been caused by factors other than the actual
relevant event. For example, a sensor may simply be malfunctioning. occurrence of an alert relevant event. For example, a sensor may
simply be malfunctioning. For this reason, not all alert messages
For this purpose not all alert messages are directly sent to a PSAP are directly sent to a PSAP, but rather may be pre-processed by a
but rather may be pre-processed by a separate entity, potentially separate entity, potentially under supervision by a human, to filter
under supervision by a human, to filter alerts and potentially alerts and potentially correlate received alerts with others to
correlate received alerts with others to obtain a larger picture of obtain a larger picture of the ongoing situation.
the ongoing situation.
In any case, for alerts that are initiated by sensors the identity In any case, for alerts initiated by sensors, the identity may play
may play an important role in deciding whether to accept or ignore an an important role in deciding whether to accept or ignore an incoming
incoming alert message. With the scenario shown in Figure 1 it is alert message. With the scenario shown in Figure 1 it is very likely
very likely that only authorized sensor input will be processed. For that only authorized sensor input will be processed. For this
this purpose it needs to be ensured that no alert messages from an reason, it needs to be possible to refuse to accept alert messages
unknown origin are accepted. Two types of information elements can from an unknown origin. Two types of information elements can be
be used for this purpose: used for this purpose:
1. SIP itself provides security mechanisms that allow the 1. SIP itself provides security mechanisms that allow the
verification of the originator's identity. These mechanisms can verification of the originator's identity. These mechanisms can
be re-used, such as P-Asserted-Identity [RFC3325] or SIP Identity be re-used, such as P-Asserted-Identity [RFC3325] or SIP Identity
[RFC4474]. The latter provides a cryptographic assurance while [RFC4474]. The latter provides a cryptographic assurance while
the former relies on a chain of trust model. the former relies on a chain of trust model.
2. CAP provides additional security mechanisms and the ability to 2. CAP provides additional security mechanisms and the ability to
carry additional information about the sender's identity. carry further information about the sender's identity.
Section 3.3.2.1 of [cap] specifies the signing algorithms of CAP Section 3.3.2.1 of [cap] specifies the signing algorithms of CAP
documents. documents.
In addition to the desire to perform identity-based access control In addition to the desire to perform identity-based access control,
the classical communication security threats need to be considered, the classic communication security threats need to be considered,
including integrity protection to prevent forgery and replay of alert including integrity protection to prevent forgery or replay of alert
messages in transit. To deal with replay of alerts a CAP document messages in transit. To deal with replay of alerts, a CAP document
contains the mandatory <identifier>, <sender>, <sent> elements and an contains the mandatory <identifier>, <sender>, <sent> elements and an
optional <expire> element. These attributes make the CAP document optional <expire> element. Together, these elements make the CAP
unique for a specific sender and provide time restrictions. An document unique for a specific sender and provide time restrictions.
entity that has received a CAP message already within the indicated An entity that has already received a CAP message within the
timeframe is able to detect a replayed message and, if the content of indicated timeframe is able to detect a replayed message and, if the
that message is unchanged, then no additional security vulnerability content of that message is unchanged, then no additional security
is created. Additionally, it is RECOMMENDED to make use of SIP vulnerability is created. Additionally, it is RECOMMENDED to make
security mechanisms, such as SIP Identity [RFC4474], to tie the CAP use of SIP security mechanisms, such as SIP Identity [RFC4474], to
message to the SIP message. To provide protection of the entire SIP tie the CAP message to the SIP message. To provide protection of the
message exchange between neighboring SIP entities the usage of TLS is entire SIP message exchange between neighboring SIP entities, the
mandatory. usage of TLS is MANDATORY.
Note that none of the security mechanism in this document protect Note that none of the security mechanism in this document protect
against a compromised sensor sending crafted alerts. against a compromised sensor sending crafted alerts.
11. IANA Considerations 11. IANA Considerations
11.1. Registration of the 'application/emergencyCall.cap+xml' MIME type 11.1. Registration of the 'application/emergencyCall.cap+xml' MIME type
To: ietf-types@iana.org To: ietf-types@iana.org
skipping to change at page 17, line 28 skipping to change at page 17, line 28
Required parameters: (none) Required parameters: (none)
Optional parameters: charset; Indicates the character encoding of Optional parameters: charset; Indicates the character encoding of
enclosed XML. Default is UTF-8 [RFC3629]. enclosed XML. Default is UTF-8 [RFC3629].
Encoding considerations: Uses XML, which can employ 8-bit Encoding considerations: Uses XML, which can employ 8-bit
characters, depending on the character encoding used. See RFC characters, depending on the character encoding used. See RFC
3023 [RFC3023], Section 3.2. 3023 [RFC3023], Section 3.2.
Security considerations: This content type is designed to carry Security considerations: This content type is designed to carry
payloads of the Common Alerting Protocol (CAP). payloads of the Common Alerting Protocol (CAP). RFC XXX [Replace
by the RFC number of this specification] discusses security
considerations for this.
Interoperability considerations: This content type provides a way to Interoperability considerations: This content type provides a way to
convey CAP payloads. convey CAP payloads.
Published specification: RFC XXX [Replace by the RFC number of this Published specification: RFC XXX [Replace by the RFC number of this
specification]. specification].
Applications which use this media type: Applications that convey Applications which use this media type: Applications that convey
alerts and warnings according to the CAP standard. alerts and warnings according to the CAP standard.
Additional information: OASIS has published the Common Alerting Additional information: OASIS has published the Common Alerting
Protocol at http://www.oasis-open.org/committees/ Protocol at http://www.oasis-open.org/committees/
documents.php&wg_abbrev=emergency documents.php&wg_abbrev=emergency
Person and email address to contact for further information: Hannes Person and email address to contact for further information: Hannes
Tschofenig, Hannes.Tschofenig@nsn.com Tschofenig, hannes.tschofenig@gmx.net
Intended usage: Limited use Intended usage: Limited use
Author/Change controller: IETF ECRIT working group Author/Change controller: IETF ECRIT working group
Other information: This media type is a specialization of Other information: This media type is a specialization of
application/xml RFC 3023 [RFC3023], and many of the considerations application/xml RFC 3023 [RFC3023], and many of the considerations
described there also apply to application/cap+xml. described there also apply to application/cap+xml.
11.2. IANA Registration of Additional Data Block 11.2. IANA Registration of 'cap' Additional Data Block
This document registers a new block type in the sub-registry called This document registers a new block type in the sub-registry called
'Additional Data Blocks' defined in [I-D.ietf-ecrit-additional-data]. 'Additional Data Blocks' defined in [I-D.ietf-ecrit-additional-data].
The token is "cap" and the reference is this document. The token is "cap" and the reference is this document.
11.3. IANA Registration for 425 Response Code 11.3. IANA Registration for 425 Response Code
In the SIP Response Codes registry, the following is added In the SIP Response Codes registry, the following is added
Reference: RFC-XXXX (i.e., this document) Reference: RFC-XXXX (i.e., this document)
skipping to change at page 19, line 8 skipping to change at page 19, line 8
Response Code Reference Response Code Reference
------------------------------------------ --------- ------------------------------------------ ---------
Request Failure 4xx Request Failure 4xx
425 Bad Alert Message [this doc] 425 Bad Alert Message [this doc]
This SIP Response code is defined in Section 5. This SIP Response code is defined in Section 5.
11.4. IANA Registration of New AlertMsg-Error Header Field 11.4. IANA Registration of New AlertMsg-Error Header Field
The SIP AlertMsg-error header field is created by this document, with The SIP AlertMsg-error header field is created by this document, with
its definition and rules in Section 5, to be added to the IANA sip- its definition and rules in Section 5, to be added to the IANA
parameters registry with two actions: Session Initiation Protocol (SIP) Parameters registry with two
actions:
1. Update the Header Fields registry with 1. Update the Header Fields registry with
Registry: Registry:
Header Name compact Reference Header Name compact Reference
----------------- ------- --------- ----------------- ------- ---------
AlertMsg-Error [this doc] AlertMsg-Error [this doc]
2. In the portion titled "Header Field Parameters and Parameter 2. In the portion titled "Header Field Parameters and Parameter
Values", add Values", add
Predefined Predefined
Header Field Parameter Name Values Reference Header Field Parameter Name Values Reference
----------------- ------------------- ---------- --------- ----------------- ------------------- ---------- ---------
AlertMsg-Error code yes [this doc] AlertMsg-Error code yes [this doc]
11.5. IANA Registration for the SIP AlertMsg-Error Codes 11.5. IANA Registration for the SIP AlertMsg-Error Codes
This document creates a new registry for SIP, called "AlertMsg-Error This document creates a new registry for SIP, called "AlertMsg-Error
Codes". AlertMsg-Error codes provide reason for the error discovered Codes". AlertMsg-Error codes provide reasons for an error discovered
by recipients, categorized by action to be taken by error recipient. by a recipient, categorized by the action to be taken by the error
The initial values for this registry are shown below. recipient. The initial values for this registry are shown below.
Registry Name: AlertMsg-Error Codes Registry Name: AlertMsg-Error Codes
Reference: [this doc] Reference: [this doc]
Registration Procedures: Specification Required Registration Procedures: Specification Required
Code Default Reason Phrase Reference Code Default Reason Phrase Reference
---- --------------------------------------------------- --------- ---- --------------------------------------------------- ---------
100 "Cannot Process the Alert Payload" [this doc] 100 "Cannot Process the Alert Payload" [this doc]
skipping to change at page 21, line 7 skipping to change at page 21, line 7
<http://www.rfc-editor.org/info/rfc2392>. <http://www.rfc-editor.org/info/rfc2392>.
[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,
DOI 10.17487/RFC3261, June 2002, DOI 10.17487/RFC3261, June 2002,
<http://www.rfc-editor.org/info/rfc3261>. <http://www.rfc-editor.org/info/rfc3261>.
[RFC3428] Campbell, B., Ed., Rosenberg, J., Schulzrinne, H., [RFC3428] Campbell, B., Ed., Rosenberg, J., Schulzrinne, H.,
Huitema, C., and D. Gurle, "Session Initiation Protocol Huitema, C., and D. Gurle, "Session Initiation Protocol
(SIP) Extension for Instant Messaging", RFC 3428, DOI (SIP) Extension for Instant Messaging", RFC 3428,
10.17487/RFC3428, December 2002, DOI 10.17487/RFC3428, December 2002,
<http://www.rfc-editor.org/info/rfc3428>. <http://www.rfc-editor.org/info/rfc3428>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, DOI 10.17487/ Specifications: ABNF", STD 68, RFC 5234,
RFC5234, January 2008, DOI 10.17487/RFC5234, January 2008,
<http://www.rfc-editor.org/info/rfc5234>. <http://www.rfc-editor.org/info/rfc5234>.
[RFC3023] Murata, M., St. Laurent, S., and D. Kohn, "XML Media [RFC3023] Murata, M., St. Laurent, S., and D. Kohn, "XML Media
Types", RFC 3023, DOI 10.17487/RFC3023, January 2001, Types", RFC 3023, DOI 10.17487/RFC3023, January 2001,
<http://www.rfc-editor.org/info/rfc3023>. <http://www.rfc-editor.org/info/rfc3023>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <http://www.rfc-editor.org/info/rfc3629>. 2003, <http://www.rfc-editor.org/info/rfc3629>.
[RFC6442] Polk, J., Rosen, B., and J. Peterson, "Location Conveyance [RFC6442] Polk, J., Rosen, B., and J. Peterson, "Location Conveyance
for the Session Initiation Protocol", RFC 6442, DOI for the Session Initiation Protocol", RFC 6442,
10.17487/RFC6442, December 2011, DOI 10.17487/RFC6442, December 2011,
<http://www.rfc-editor.org/info/rfc6442>. <http://www.rfc-editor.org/info/rfc6442>.
[RFC6881] Rosen, B. and J. Polk, "Best Current Practice for [RFC6881] Rosen, B. and J. Polk, "Best Current Practice for
Communications Services in Support of Emergency Calling", Communications Services in Support of Emergency Calling",
BCP 181, RFC 6881, DOI 10.17487/RFC6881, March 2013, BCP 181, RFC 6881, DOI 10.17487/RFC6881, March 2013,
<http://www.rfc-editor.org/info/rfc6881>. <http://www.rfc-editor.org/info/rfc6881>.
[I-D.ietf-ecrit-additional-data] [I-D.ietf-ecrit-additional-data]
Gellens, R., Rosen, B., Tschofenig, H., Marshall, R., and Gellens, R., Rosen, B., Tschofenig, H., Marshall, R., and
J. Winterbottom, "Additional Data Related to an Emergency J. Winterbottom, "Additional Data Related to an Emergency
Call", draft-ietf-ecrit-additional-data-33 (work in Call", draft-ietf-ecrit-additional-data-37 (work in
progress), July 2015. progress), October 2015.
[I-D.rosen-ecrit-addldata-subnot] [I-D.rosen-ecrit-addldata-subnot]
Rosen, B., "Updating Additional Data related to an Rosen, B., "Updating Additional Data related to an
Emergency Call using Subscribe/ Notify", draft-rosen- Emergency Call using Subscribe/ Notify", draft-rosen-
ecrit-addldata-subnot-01 (work in progress), November ecrit-addldata-subnot-01 (work in progress), November
2013. 2013.
13.2. Informative References 13.2. Informative References
[RFC7378] Tschofenig, H., Schulzrinne, H., and B. Aboba, Ed., [RFC7378] Tschofenig, H., Schulzrinne, H., and B. Aboba, Ed.,
"Trustworthy Location", RFC 7378, DOI 10.17487/RFC7378, "Trustworthy Location", RFC 7378, DOI 10.17487/RFC7378,
December 2014, <http://www.rfc-editor.org/info/rfc7378>. December 2014, <http://www.rfc-editor.org/info/rfc7378>.
[RFC4474] Peterson, J. and C. Jennings, "Enhancements for [RFC4474] Peterson, J. and C. Jennings, "Enhancements for
Authenticated Identity Management in the Session Authenticated Identity Management in the Session
Initiation Protocol (SIP)", RFC 4474, DOI 10.17487/ Initiation Protocol (SIP)", RFC 4474,
RFC4474, August 2006, DOI 10.17487/RFC4474, August 2006,
<http://www.rfc-editor.org/info/rfc4474>. <http://www.rfc-editor.org/info/rfc4474>.
[RFC3325] Jennings, C., Peterson, J., and M. Watson, "Private [RFC3325] Jennings, C., Peterson, J., and M. Watson, "Private
Extensions to the Session Initiation Protocol (SIP) for Extensions to the Session Initiation Protocol (SIP) for
Asserted Identity within Trusted Networks", RFC 3325, DOI Asserted Identity within Trusted Networks", RFC 3325,
10.17487/RFC3325, November 2002, DOI 10.17487/RFC3325, November 2002,
<http://www.rfc-editor.org/info/rfc3325>. <http://www.rfc-editor.org/info/rfc3325>.
[RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton, [RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton,
"Framework for Emergency Calling Using Internet "Framework for Emergency Calling Using Internet
Multimedia", RFC 6443, DOI 10.17487/RFC6443, December Multimedia", RFC 6443, DOI 10.17487/RFC6443, December
2011, <http://www.rfc-editor.org/info/rfc6443>. 2011, <http://www.rfc-editor.org/info/rfc6443>.
Authors' Addresses Authors' Addresses
Brian Rosen Brian Rosen
skipping to change at page 22, line 44 skipping to change at page 22, line 44
Department of Computer Science Department of Computer Science
450 Computer Science Building 450 Computer Science Building
New York, NY 10027 New York, NY 10027
US US
Phone: +1 212 939 7004 Phone: +1 212 939 7004
Email: hgs+ecrit@cs.columbia.edu Email: hgs+ecrit@cs.columbia.edu
URI: http://www.cs.columbia.edu URI: http://www.cs.columbia.edu
Hannes Tschofenig Hannes Tschofenig
Hall in Tirol 6060 ARM Limited
Austria Austria
Email: Hannes.tschofenig@gmx.net Email: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at URI: http://www.tschofenig.priv.at
Randall Gellens
Email: rg+ietf@randy.pensive.org
 End of changes. 68 change blocks. 
204 lines changed or deleted 214 lines changed or added

This html diff was produced by rfcdiff 1.42. The latest version is available from http://tools.ietf.org/tools/rfcdiff/