draft-ietf-sipping-mwi-04.txt   rfc3842.txt 
SIPPING WG R. Mahy Network Working Group R. Mahy
Internet-Draft Cisco Systems, Inc. Request for Comments: 3842 Cisco Systems, Inc.
Expires: May 31, 2004 Dec 2003 Category: Standards Track August 2004
A Message Summary and Message Waiting Indication Event Package for A Message Summary and Message Waiting Indication Event Package for
the Session Initiation Protocol (SIP) the Session Initiation Protocol (SIP)
draft-ietf-sipping-mwi-04.txt
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with This document specifies an Internet standards track protocol for the
all provisions of Section 10 of RFC2026. Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Internet-Drafts are working documents of the Internet Engineering Official Protocol Standards" (STD 1) for the standardization state
Task Force (IETF), its areas, and its working groups. Note that other and status of this protocol. Distribution of this memo is unlimited.
groups may also distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at http://
www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on May 31, 2004.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved. Copyright (C) The Internet Society (2004).
Abstract Abstract
This document describes a SIP event package to carry message waiting This document describes a Session Initiation Protocol (SIP) event
status and message summaries from a messaging system to an interested package to carry message waiting status and message summaries from a
User Agent. messaging system to an interested User Agent.
Table of Contents Table of Contents
1. Conventions . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Conventions . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Background and Appropriateness . . . . . . . . . . . . . . . 3 2. Background and Appropriateness . . . . . . . . . . . . . . . 3
3. Event Package Formal Definition . . . . . . . . . . . . . . 4 3. Event Package Formal Definition . . . . . . . . . . . . . . 4
3.1 Event Package Name . . . . . . . . . . . . . . . . . . . . . 4 3.1. Event Package Name . . . . . . . . . . . . . . . . . . 4
3.2 Event Package Parameters . . . . . . . . . . . . . . . . . . 4 3.2. Event Package Parameters . . . . . . . . . . . . . . . 4
3.3 SUBSCRIBE Bodies . . . . . . . . . . . . . . . . . . . . . . 4 3.3. SUBSCRIBE Bodies . . . . . . . . . . . . . . . . . . . 4
3.4 Subscription Duration . . . . . . . . . . . . . . . . . . . 4 3.4. Subscription Duration. . . . . . . . . . . . . . . . . 4
3.5 NOTIFY Bodies . . . . . . . . . . . . . . . . . . . . . . . 4 3.5. NOTIFY Bodies. . . . . . . . . . . . . . . . . . . . . 4
3.6 Subscriber generation of SUBSCRIBE requests . . . . . . . . 6 3.6. Subscriber Generation of SUBSCRIBE Requests. . . . . . 6
3.7 Notifier processing of SUBSCRIBE requests . . . . . . . . . 6 3.7. Notifier Processing of SUBSCRIBE Requests. . . . . . . 6
3.8 Notifier generation of NOTIFY requests . . . . . . . . . . . 7 3.8. Notifier Generation of NOTIFY Requests . . . . . . . . 7
3.9 Subscriber processing of NOTIFY requests . . . . . . . . . . 7 3.9. Subscriber Processing of NOTIFY Requests . . . . . . . 7
3.10 Handling of Forked Requests . . . . . . . . . . . . . . . . 7 3.10. Handling of Forked Requests. . . . . . . . . . . . . . 7
3.11 Rate of notifications . . . . . . . . . . . . . . . . . . . 7 3.11. Rate of Notifications. . . . . . . . . . . . . . . . . 7
3.12 State Agents and Lists . . . . . . . . . . . . . . . . . . . 8 3.12. State Agents and Lists . . . . . . . . . . . . . . . . 8
3.13 Behavior of a Proxy Server . . . . . . . . . . . . . . . . . 8 3.13. Behavior of a Proxy Server . . . . . . . . . . . . . . 8
4. Examples of Usage . . . . . . . . . . . . . . . . . . . . . 8 4. Examples of Usage . . . . . . . . . . . . . . . . . . . . . 8
4.1 Example Message Flow . . . . . . . . . . . . . . . . . . . . 8 4.1. Example Message Flow . . . . . . . . . . . . . . . . . 8
4.2 Example Usage with Callee Capabilities and Caller 4.2. Example Usage with Callee Capabilities and Caller
Preferences . . . . . . . . . . . . . . . . . . . . . . . . 14 Preferences. . . . . . . . . . . . . . . . . . . . . . 14
5. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . 14 5. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . 14
5.1 New event-package definition . . . . . . . . . . . . . . . . 14 5.1. New Event-Package Definition . . . . . . . . . . . . . 15
5.2 Body Format Syntax . . . . . . . . . . . . . . . . . . . . . 15 5.2. Body Format Syntax . . . . . . . . . . . . . . . . . . 15
6. Security Considerations . . . . . . . . . . . . . . . . . . 15 6. Security Considerations . . . . . . . . . . . . . . . . . . 15
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . 15 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . 16
7.1 SIP Event Package Registration for message-summary . . . . . 16 7.1. SIP Event Package Registration for message-summary . . 16
7.2 MIME Registration for application/simple-message-summary . . 16 7.2. MIME Registration for application/
8. Revision history . . . . . . . . . . . . . . . . . . . . . . 17 simple-message-summary . . . . . . . . . . . . . . . . 16
8.1 Changes from draft-ietf-sipping-mwi-03 . . . . . . . . . . . 17 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 17
8.2 Changes from draft-ietf-sipping-mwi-01 and -02 . . . . . . . 17 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 17
8.3 Changes from draft-ietf-sipping-mwi-00 . . . . . . . . . . . 17 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.4 Changes from draft-mahy-sipping-mwi-00 . . . . . . . . . . . 18 10.1. Normative References . . . . . . . . . . . . . . . . . 17
8.5 Changes from draft-mahy-sip-mwi-01 . . . . . . . . . . . . . 18 10.2. Informational References . . . . . . . . . . . . . . . 18
8.6 Changes from draft-mahy-sip-mwi-00 . . . . . . . . . . . . . 18 11. Author's Address . . . . . . . . . . . . . . . . . . . . . . 18
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 19 12. Full Copyright Statement . . . . . . . . . . . . . . . . . . 19
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 19
Normative References . . . . . . . . . . . . . . . . . . . . 19
Informational References . . . . . . . . . . . . . . . . . . 20
Author's Address . . . . . . . . . . . . . . . . . . . . . . 20
Intellectual Property and Copyright Statements . . . . . . . 21
1. Conventions 1. Conventions
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 [3]. document are to be interpreted as described in BCP 14, RFC 2119 [3].
2. Background and Appropriateness 2. Background and Appropriateness
Messaging Waiting Indication is a common feature of telephone Message Waiting Indication is a common feature of telephone networks.
networks. It typically involves an audible or visible indication It typically involves an audible or visible indication that messages
that messages are waiting, such as playing a special dial tone (which are waiting, such as playing a special dial tone (which in telephone
in telephone networks is called message-waiting dial tone), lighting networks is called message-waiting dial tone), lighting a light or
a light or indicator on the phone, displaying icons or text, or some indicator on the phone, displaying icons or text, or some
combination. combination.
Message-waiting dial tone is similar to but distinct from stutter Message-waiting dial tone is similar to but distinct from stutter
dial tone. Both are defined in GR-506 [12]. dial tone. Both are defined in GR-506 [11].
The methods in the SIP [1] base specification were only designed to The methods in the SIP [1] base specification were only designed to
solve the problem of session initiation for multimedia sessions, and solve the problem of session initiation for multimedia sessions, and
rendezvous. Since Message Waiting Indication is really status rendezvous. Since Message Waiting Indication is really status
information orthogonal to a session, it was not clear how an IP information orthogonal to a session, it was not clear how an IP
telephone acting as a SIP User Agent would implement comparable telephone acting as a SIP User Agent would implement comparable
functionality. Members of the telephony community viewed this as a functionality. Members of the telephony community viewed this as a
shortcoming of SIP. shortcoming of SIP.
Users want the useful parts of the functionality they have using Users want the useful parts of the functionality they have using
traditional analog, mobile, and PBX telephones. It is also desirable traditional analog, mobile, and PBX telephones. It is also desirable
to provide comparable functionality in a flexible way that allows for to provide comparable functionality in a flexible way that allows for
more customization and new features. SIP Specific Event Notification more customization and new features. SIP Specific Event Notification
(RFC 3265 -- SIP Events) [2] is an appropriate mechanism to use in (RFC 3265 -- SIP Events) [2] is an appropriate mechanism to use in
this environment, as it preserves the user mobility and rendezvous this environment, as it preserves the user mobility and rendezvous
features which SIP provides. features which SIP provides.
Using SIP-Specific Event Notification, A Subscriber User Agent Using SIP-Specific Event Notification, a Subscriber User Agent
(typically an IP phone or SIP software User Agent) subscribes to the (typically an IP phone or SIP software User Agent) subscribes to the
status of their messages. A SIP User Agent acting on behalf of the status of their messages. A SIP User Agent acting on behalf of the
user's messaging system then notifies the Subscriber whenever the user's messaging system then notifies the Subscriber each time the
messaging account's messages have changed. (This Notifier could be messaging account's messages have changed. (This Notifier could be
composed with a User Agent that provides a real-time media interface composed with a User Agent that provides a real-time media interface
to send or receive messages, or it could be a standalone entitiy.) to send or receive messages, or it could be a stand-alone entity.)
The Notifier sends a message summary in the body of a NOTIFY, encoded The Notifier sends a message summary in the body of a NOTIFY, encoded
in a new MIME type defined later in this document. A User Agent can in a new MIME type defined later in this document. A User Agent can
also explicitly fetch the current status. also explicitly fetch the current status.
A SIP User Agent MAY subscribe to multiple accounts (distinguished by A SIP User Agent MAY subscribe to multiple accounts (distinguished by
the Request URI). Multiple SIP User Agents MAY subscribe to the same the Request URI). Multiple SIP User Agents MAY subscribe to the same
account. account.
Before any subscriptions or notifications are sent, each interested Before any subscriptions or notifications are sent, each interested
User Agent must be made aware of its messaging notifier(s). This MAY User Agent must be made aware of its messaging notifier(s). This MAY
be manually configured on interested User Agents, manually configured be manually configured on interested User Agents, manually configured
on an appropriate SIP Proxy, or dynamically discovered based on on an appropriate SIP Proxy, or dynamically discovered based on
requested caller preferences [4] and registered callee capabilities requested caller preferences [4] and registered callee capabilities
[5]. (For more information on usage with callee capabilities, see [5]. (For more information on usage with callee capabilities, see
Section 4.2) Section 4.2)
3. Event Package Formal Definition 3. Event Package Formal Definition
3.1 Event Package Name 3.1. Event Package Name
This document defines a SIP Event Package as defined in RFC 3265 [2]. This document defines a SIP Event Package as defined in RFC 3265 [2].
The event-package token name for this package is: The event-package token name for this package is:
"message-summary" "message-summary"
3.2 Event Package Parameters 3.2. Event Package Parameters
This package does not define any event package parameters. This package does not define any event package parameters.
3.3 SUBSCRIBE Bodies 3.3. SUBSCRIBE Bodies
This package does not define any SUBSCRIBE bodies. This package does not define any SUBSCRIBE bodies.
3.4 Subscription Duration 3.4. Subscription Duration
Subscriptions to this event package MAY range from minutes to weeks. Subscriptions to this event package MAY range from minutes to weeks.
Subscriptions in hours or days are more typical and are RECOMMENDED. Subscriptions in hours or days are more typical and are RECOMMENDED.
The default subscription duration for this event package is one hour. The default subscription duration for this event package is one hour.
3.5 NOTIFY Bodies 3.5. NOTIFY Bodies
A simple text-based format is proposed to prevent an undue burden on A simple text-based format is proposed to prevent an undue burden on
low-end user agents, for example, inexpensive IP phones with no low-end user agents, for example, inexpensive IP phones with no
display. Although this format is text-based, it is intended for display. Although this format is text-based, it is intended for
machine consumption only. machine consumption only.
A future extension MAY define other NOTIFY bodies. If no "Accept" A future extension MAY define other NOTIFY bodies. If no "Accept"
header is present in the SUBSCRIBE, the body type defined in this header is present in the SUBSCRIBE, the body type defined in this
document MUST be assumed. document MUST be assumed.
The format specified in this proposal attempts to separate orthogonal The format specified in this proposal attempts to separate orthogonal
attributes of messages as much as possible. Messages are separated attributes of messages as much as possible. Messages are separated
by message-context-class (for example: voice-message, fax-message, by message-context-class (for example: voice-message, fax-message,
pager-message, multimedia-message, text-message, and none); by pager-message, multimedia-message, text-message, and none), by
message status (new and old); and by urgent and non-urgent type. message status (new and old), and urgent and non-urgent type.
The text format begins with a simple status line, and optionally a The text format begins with a simple status line, and optionally a
summary line per message-context-class. Message-context-classes are summary line per message-context-class. Message-context-classes are
defined in [7]. For each message-context-class, the total number of defined in [7]. For each message-context-class, the total number of
new and old messages is reported in the new and old fields. new and old messages is reported in the new and old fields.
In some cases, detailed message summaries are not available. The In some cases, detailed message summaries are not available. The
status line allows messaging systems or messaging gateways to provide status line allows messaging systems or messaging gateways to provide
the traditional boolean message waiting notification. the traditional boolean message waiting notification.
Messages-Waiting: yes Messages-Waiting: yes
If the Request-URI or To header in a message-summary subscription If the Request-URI or To header in a message-summary subscription
corresponds to a group or collection of individual messaging corresponds to a group or collection of individual messaging
accounts, the notifier MUST specify to which account the accounts, the notifier MUST specify to which account the message-
message-summary body corresponds. Note that the account URI MUST NOT summary body corresponds. Note that the account URI MUST NOT be
be delimited with angle brackets ("<" and ">"). delimited with angle brackets ("<" and ">").
Message-Account: sip:alice@example.com Message-Account: sip:alice@example.com
In the example that follows, more than boolean message summary In the example that follows, more than boolean message summary
information is available to the User Agent. There are two new and information is available to the User Agent. There are two new and
four old fax messages. four old fax messages.
Fax-Message: 2/4 Fax-Message: 2/4
After the summary, the format can optionally list a summary count of After the summary, the format can optionally list a summary count of
urgent messages. In the next example there are one new and three old urgent messages. In the next example there are one new and three old
voice messages, none of the new messages are urgent, but one of the voice messages, none of the new messages are urgent, but one of the
old messages is. All counters have a maximum value of 4,294,967,295 old messages is. All counters have a maximum value of 4,294,967,295
((2^32) - 1). Notifiers MUST NOT generate a request with a larger ((2^32) - 1). Notifiers MUST NOT generate a request with a larger
value. Subscribers MUST treat a larger value as 2^32-1. value. Subscribers MUST treat a larger value as 2^32-1.
Voice-Message: 1/3 (0/1) Voice-Message: 1/3 (0/1)
Optionally, after the summary counts, the messaging systems MAY Optionally, after the summary counts, the messaging systems MAY
append RFC 2822 [10]-style message headers, which further describe append RFC 2822 style message headers [9], which further describe
newly added messages. Message headers MUST NOT be included in an newly added messages. Message headers MUST NOT be included in an
initial NOTIFY, as new messages could be essentially unbounded in initial NOTIFY, as new messages could be essentially unbounded in
size. Message headers included in subsequent notifications MUST only size. Message headers included in subsequent notifications MUST only
correspond to messages added since the previous notification for that correspond to messages added since the previous notification for that
subscription. A messaging system which includes message headers in a subscription. A messaging system which includes message headers in a
NOTIFY, MUST provide an administrator configurable mechanism for NOTIFY MUST provide an administrator configurable mechanism to select
selecting which headers are sent. Likely headers for inclusion which headers are sent. Headers likely for inclusion are To, From,
include To, From, Date, Subject, and Message-ID. Note that the Date, Subject, and Message-ID. Note that the formatting of these
formatting of these headers in this body is identical to that of SIP headers in this body is identical to that of SIP extension-headers,
extension-headers, not the (similar) format defined in RFC 2822. not the (similar) format defined in RFC 2822.
Implementations which generate large notifications are reminded to Implementations which generate large notifications are reminded to
follow the message size restrictions for unreliable transports follow the message size restrictions for unreliable transports
articulated in Section 18.1.1 of SIP. articulated in Section 18.1.1 of SIP [1].
Mapping local message state to new/old message status and urgency is Mapping local message state to new/old message status and urgency is
an implementation issue of the messaging system. However, the an implementation issue of the messaging system. However, the
messaging notifier MUST NOT consider a message "old" merely because messaging notifier MUST NOT consider a message "old" merely because
it generated a notification, as this could prevent another it generated a notification, as this could prevent another
subscription from accurately receiving message-summary notifications. subscription from accurately receiving message-summary notifications.
Likewise, the messaging system MAY use any suitable algorithm to Likewise, the messaging system MAY use any suitable algorithm to
determine that a message is "urgent". determine that a message is "urgent".
Messaging systems MAY use any algorithm for determining the Messaging systems MAY use any algorithm for determining the
approporiate message-context-class for a specific message. Systems appropriate message-context-class for a specific message. Systems
which use Internet Mail SHOULD use the contents of the which use Internet Mail SHOULD use the contents of the Message-
Message-Context header [7] (defined in RFC 3458) if present as a hint Context header [7] (defined in RFC 3458) if present as a hint to make
to make a context determination. Note that a composed messaging a context determination. Note that a composed messaging system does
system does not need to support a given context in order to generate not need to support a given context in order to generate
notifications identified with that context. notifications identified with that context.
3.6 Subscriber generation of SUBSCRIBE requests 3.6. Subscriber Generation of SUBSCRIBE Requests
Subscriber User Agents will typically SUBSCRIBE to message summary Subscriber User Agents will typically SUBSCRIBE to message summary
information for a period of hours or days, and automatically attempt information for a period of hours or days, and automatically attempt
to re-SUBSCRIBE well before the subscription is completely expired. to re-SUBSCRIBE well before the subscription is completely expired.
If re-subscription fails, the Subscriber SHOULD periodically retry If re-subscription fails, the Subscriber SHOULD periodically retry
again until a subscription is successful, taking care to backoff to again until a subscription is successful, taking care to backoff to
avoid network congestion. If a subscription has expired, new avoid network congestion. If a subscription has expired, new re-
re-subscriptions MUST use a new Call-ID. subscriptions MUST use a new Call-ID.
The Subscriber SHOULD SUBSCRIBE to that user's message summaries The Subscriber SHOULD SUBSCRIBE to that user's message summaries
whenever a new user becomes associated with the device (a new login). whenever a new user becomes associated with the device (a new login).
The Subscriber MAY also explicitly fetch the current status at any The Subscriber MAY also explicitly fetch the current status at any
time. The subscriber SHOULD renew its subscription immediately after time. The subscriber SHOULD renew its subscription immediately after
a reboot, or when the subscriber's network connectivity has just been a reboot, or when the subscriber's network connectivity has just been
re-established. re-established.
The Subscriber MUST be prepared to receive and process a NOTIFY with The Subscriber MUST be prepared to receive and process a NOTIFY with
new state immediately after sending a new SUBSCRIBE, a SUBSCRIBE new state immediately after sending a new SUBSCRIBE, a SUBSCRIBE
renewal, an unsubscribe, or a fetch; or at any time during the renewal, an unsubscribe, a fetch, or at any other time during the
subscription. subscription.
When a user de-registers from a device (logoff, power down of a When a user de-registers from a device (logoff, power down of a
mobile device, etc.), subscribers SHOULD unsubscribe by sending a mobile device, etc.), subscribers SHOULD unsubscribe by sending a
SUBSCRIBE message with an Expires header of zero. SUBSCRIBE message with an Expires header of zero.
3.7 Notifier processing of SUBSCRIBE requests 3.7. Notifier Processing of SUBSCRIBE Requests
When a SIP Messaging System receives SUBSCRIBE messages with the When a SIP Messaging System receives SUBSCRIBE messages with the
message-summary event-type, it SHOULD authenticate the subscription message-summary event-type, it SHOULD authenticate the subscription
request. If authentication is successful, the Notifier MAY limit the request. If authentication is successful, the Notifier MAY limit the
duration of the subscription to an administrator defined amount of duration of the subscription to an administrator defined amount of
time as described in SIP Events. time as described in SIP Events [2].
3.8 Notifier generation of NOTIFY requests 3.8. Notifier Generation of NOTIFY Requests
Immediately after a subscription is accepted, the Notifier MUST send Immediately after a subscription is accepted, the Notifier MUST send
a NOTIFY with the current message summary information. This allows a NOTIFY with the current message summary information. This allows
the Subscriber to resynchronize its state. This initial the Subscriber to resynchronize its state. This initial
synchronization NOTIFY MUST NOT include the optional RFC 2822 synchronization NOTIFY MUST NOT include the optional RFC 2822 style
[9]-style message headers. message headers [8].
When the status of the messages changes sufficiently for a messaging When the status of the messages changes sufficiently for a messaging
account to change the number of new or old messages, the Notifier account to change the number of new or old messages, the Notifier
SHOULD send a NOTIFY message to all active subscribers to that SHOULD send a NOTIFY message to all active subscribers of that
account. NOTIFY messages sent to subscribers of a group or alias, account. NOTIFY messages sent to subscribers of a group or alias,
MUST contain the message account name in the notification body. MUST contain the message account name in the notification body.
A Messaging System MAY send a NOTIFY with an "Expires" header of "0" A Messaging System MAY send a NOTIFY with an "Expires" header of "0"
and a "Subscription-State" header of "terminated" before a graceful and a "Subscription-State" header of "terminated" before a graceful
shutdown. shutdown.
3.9 Subscriber processing of NOTIFY requests 3.9. Subscriber Processing of NOTIFY Requests
Upon receipt of a valid NOTIFY request, the subscriber SHOULD Upon receipt of a valid NOTIFY request, the subscriber SHOULD
immediately render the message status and summary information to the immediately render the message status and summary information to the
end user in an implementation specific way. end user in an implementation specific way.
The Subscriber MUST be prepared to receive NOTIFYs from different The Subscriber MUST be prepared to receive NOTIFYs from different
Contacts corresponding to the same SUBSCRIBE. (the SUBSCRIBE may Contacts corresponding to the same SUBSCRIBE. (The SUBSCRIBE may
have been forked). have been forked).
3.10 Handling of Forked Requests 3.10. Handling of Forked Requests
Forked requests are allowed for this event type and may install Forked requests are allowed for this event type and may install
multiple subscriptions. The Subscriber MAY render multiple summaries multiple subscriptions. The Subscriber MAY render multiple summaries
which correspond to the same account directly to the user, or MAY corresponding to the same account directly to the user, or MAY merge
merge them as described below. them as described below.
If any of the "Messages-Waiting" status lines report "yes", then the If any of the "Messages-Waiting" status lines report "yes", then the
merged state is "yes"; otherwise the merged state is "no". merged state is "yes"; otherwise the merged state is "no".
The Subscriber MAY merge summary lines in an implementation-specific The Subscriber MAY merge summary lines in an implementation-specific
way if all notifications contain at least one msg-summary line. way if all notifications contain at least one msg-summary line.
3.11 Rate of notifications 3.11. Rate of Notifications
A Notifier MAY choose to hold NOTIFY requests in "quarantine" for a A Notifier MAY choose to hold NOTIFY requests in "quarantine" for a
short administrator-defined period (seconds or minutes) when the short administrator-defined period (seconds or minutes) when the
message status is changing rapidly. Requests in the quarantine which message status is changing rapidly. Requests in the quarantine which
become invalid are replaced by newer notifications, thus reducing the become invalid are replaced by newer notifications, thus reducing the
total volume of notifications. This behavior is encouraged for total volume of notifications. This behavior is encouraged for
implementations with heavy interactive use. Note that timely implementations with heavy interactive use. Note that timely
notification which results in a change of overall state (messages notification resulting in a change of overall state (messages waiting
waiting or not), and notification of newly added messages is probably or not) and notification of newly added messages is probably more
more significant to the end user than a notification of newly deleted significant to the end user than a notification of newly deleted
messages which do not affect the overall message waiting state (e.g. messages which do not affect the overall message waiting state (e.g.,
there are still new messages). there are still new messages).
Notifiers SHOULD NOT generate NOTIFY requests more frequently than Notifiers SHOULD NOT generate NOTIFY requests more frequently than
once per second. once per second.
3.12 State Agents and Lists 3.12. State Agents and Lists
A Subscriber MAY use an "alias" or "group" in the Request-URI of a A Subscriber MAY use an "alias" or "group" in the Request-URI of a
subscription if that name is significant to the messaging system. subscription if that name is significant to the messaging system.
Implementers MAY create a service which consolidates and summarizes Implementers MAY create a service which consolidates and summarizes
NOTIFYs from many Contacts. This document does not preclude NOTIFYs from many Contacts. This document does not preclude
implementations from building state agents which support this event implementations from building state agents which support this event
package. One way to implement such a service is with the event list package. One way to implement such a service is with the event list
extension [11]. extension [10].
3.13 Behavior of a Proxy Server 3.13. Behavior of a Proxy Server
There are no additional requirements on a SIP Proxy, other than to There are no additional requirements on a SIP Proxy, other than to
transparently forward the SUBSCRIBE and NOTIFY methods as required in transparently forward the SUBSCRIBE and NOTIFY methods as required in
SIP. However, Proxies SHOULD allow non-SIP URLs. Proxies and SIP. However, Proxies SHOULD allow non-SIP URLs. Proxies and
Redirect servers SHOULD be able to direct the SUBSCRIBE request to an Redirect servers SHOULD be able to direct the SUBSCRIBE request to an
appropriate messaging notifier User Agent. appropriate messaging notifier User Agent.
4. Examples of Usage 4. Examples of Usage
4.1 Example Message Flow 4.1. Example Message Flow
The examples shown below are for informational purposes only. For a The examples shown below are for informational purposes only. For a
normative description of the event package, please see sections 3 and normative description of the event package, please see sections 3 and
5 of this document. 5 of this document.
In the example call flow below, Alice's IP phone subscribes to the In the example call flow below, Alice's IP phone subscribes to the
status of Alice's messages. Via headers are omitted for clarity. status of Alice's messages. Via headers are omitted for clarity.
Subscriber Notifier Subscriber Notifier
| | | |
skipping to change at page 11, line 23 skipping to change at page 11, line 24
CSeq: 31 NOTIFY CSeq: 31 NOTIFY
Event: message-summary Event: message-summary
Subscription-State: active Subscription-State: active
Content-Type: application/simple-message-summary Content-Type: application/simple-message-summary
Content-Length: 503 Content-Length: 503
Messages-Waiting: yes Messages-Waiting: yes
Message-Account: sip:alice@vmail.example.com Message-Account: sip:alice@vmail.example.com
Voice-Message: 4/8 (1/2) Voice-Message: 4/8 (1/2)
To: <alice@atlanta.com> To: <alice@atlanta.example.com>
From: <bob@biloxi.com> From: <bob@biloxi.example.com>
Subject: carpool tomorrow? Subject: carpool tomorrow?
Date: Sun, 09 Jul 2000 21:23:01 -0700 Date: Sun, 09 Jul 2000 21:23:01 -0700
Priority: normal Priority: normal
Message-ID: 13784434989@vmail.example.com Message-ID: 13784434989@vmail.example.com
To: <alice@example.com> To: <alice@example.com>
From: <cathy-the-bob@example.com> From: <cathy-the-bob@example.com>
Subject: HELP! at home ill, present for me please Subject: HELP! at home ill, present for me please
Date: Sun, 09 Jul 2000 21:25:12 -0700 Date: Sun, 09 Jul 2000 21:25:12 -0700
Priority: urgent Priority: urgent
skipping to change at page 14, line 17 skipping to change at page 14, line 19
SIP/2.0 200 OK SIP/2.0 200 OK
To: <sip:alice@example.com>;tag=78923 To: <sip:alice@example.com>;tag=78923
From: <sip:alice@example.com>;tag=4442 From: <sip:alice@example.com>;tag=4442
Date: Mon, 10 Jul 2000 19:35:08 GMT Date: Mon, 10 Jul 2000 19:35:08 GMT
Call-Id: 1349882@alice-phone.example.com Call-Id: 1349882@alice-phone.example.com
CSeq: 56 NOTIFY CSeq: 56 NOTIFY
Event: message-summary Event: message-summary
Content-Length: 0 Content-Length: 0
4.2 Example Usage with Callee Capabilities and Caller Preferences 4.2. Example Usage with Callee Capabilities and Caller Preferences
The use of callee capabilities is optional but encouraged. If callee The use of callee capabilities is optional but encouraged. If callee
capabilities is used, a messaging notifier MAY REGISTER a Contact capabilities are used, a messaging notifier MAY REGISTER a Contact
with an appropriate methods and events tag as shown in the example with an appropriate methods and events tag as shown in the example
below. To further distinguish itself, the messaging notifier MAY below. To further distinguish itself, the messaging notifier MAY
also REGISTER as a Contact with the actor="msg-taker" tag. An also REGISTER as a Contact with the actor="msg-taker" tag. An
example of this kind of registration follows below. example of this kind of registration follows below.
REGISTER sip:sip3-sj.example.com SIP/2.0 REGISTER sip:sip3-sj.example.com SIP/2.0
To: <sip:alice@example.com> To: <sip:alice@example.com>
From: <sip:alice@example.com>;tag=4442 From: <sip:alice@example.com>;tag=4442
... ...
Contact: <sip:alice@vm13-sj.example.com> Contact: <sip:alice@vm13-sj.example.com>
;actor="msg-taker";methods="SUBSCRIBE" ;actor="msg-taker";methods="SUBSCRIBE"
;automata;events="message-summary" ;automata;events="message-summary"
The following SUBSCRIBE message would find the Contact which The following SUBSCRIBE message would find the Contact which
registered in the example above. registered in the example above.
SUSBCRIBE sip:alice@example.com SIP/2.0 SUBSCRIBE sip:alice@example.com SIP/2.0
... ...
Accept: application/simple-message-summary Accept: application/simple-message-summary
Event: message-summary Event: message-summary
Accept-Contact: *;automata;actor="msg-taker" Accept-Contact: *;automata;actor="msg-taker"
5. Formal Syntax 5. Formal Syntax
The following syntax specification uses the augmented Backus-Naur The following syntax specification uses the augmented Backus-Naur
Form (BNF) as described in RFC-2234 [6]. Form (BNF) as described in RFC 2234 [6].
5.1. New Event-Package Definition
5.1 New event-package definition
This document defines a new event-package with the package name: This document defines a new event-package with the package name:
message-summary message-summary
5.2 Body Format Syntax 5.2. Body Format Syntax
The formal syntax for the application/simple-message-summary MIME The formal syntax for the application/simple-message-summary MIME
type is described below: type is described below. The message-context-class production is
defined in Section 6.2 of RFC 3458 [7]. Note that all productions
described here are case insensitive.
messsage-summary = msg-status-line CRLF message-summary = msg-status-line CRLF
[msg-account CRLF] [msg-account CRLF]
[*(msg-summary-line CRLF)] [*(msg-summary-line CRLF)]
[ *opt-msg-headers ] [ *opt-msg-headers ]
msg-status-line = "Messages-Waiting" HCOLON msg-status msg-status-line = "Messages-Waiting" HCOLON msg-status
msg-status = "yes" / "no" msg-status = "yes" / "no"
msg-account = "Message-Account" HCOLON Account-URI msg-account = "Message-Account" HCOLON Account-URI
Account-URI = SIP-URI / SIPS-URI / absoluteURI Account-URI = SIP-URI / SIPS-URI / absoluteURI
msg-summary-line = message-context-class HCOLON newmsgs SLASH oldmsgs msg-summary-line = message-context-class HCOLON newmsgs SLASH oldmsgs
skipping to change at page 15, line 37 skipping to change at page 15, line 42
newmsgs = msgcount newmsgs = msgcount
oldmsgs = msgcount oldmsgs = msgcount
new-urgentmsgs = msgcount new-urgentmsgs = msgcount
old-urgentmsgs = msgcount old-urgentmsgs = msgcount
msgcount = 1*DIGIT ; MUST NOT exceed 2^32-1 msgcount = 1*DIGIT ; MUST NOT exceed 2^32-1
6. Security Considerations 6. Security Considerations
Message summaries and optional message bodies contain information Message summaries and optional message bodies contain information
which is typically very privacy sensitive. At minimum, subscriptions which is typically very privacy sensitive. At a minimum,
to this event package SHOULD be authenticated and properly subscriptions to this event package SHOULD be authenticated and
authorized. Furthermore, notifications SHOULD be encrypted and properly authorized. Furthermore, notifications SHOULD be encrypted
integrity protected using either end-to-end mechanisms, or the and integrity protected using either end-to-end mechanisms, or the
hop-by-hop protection afforded messages sent to SIPS URIs. hop-by-hop protection afforded messages sent to SIPS URIs.
Additional and privacy security considerations are discussed in Additional and privacy security considerations are discussed in
detail in SIP [1] and SIP Events [2]. detail in SIP [1] and SIP Events [2].
7. IANA Considerations 7. IANA Considerations
7.1 SIP Event Package Registration for message-summary 7.1. SIP Event Package Registration for message-summary
Package name: message-summary Package name: message-summary
Type: package Type: package
Contact: [Mahy] Contact: [Mahy]
Published Specification: This document. Published Specification: This document.
7.2 MIME Registration for application/simple-message-summary 7.2. MIME Registration for application/simple-message-summary
MIME media type name: application MIME media type name: application
MIME subtype name: simple-message-summary MIME subtype name: simple-message-summary
Required parameters: none. Required parameters: none.
Optional parameters: none. Optional parameters: none.
Encoding considerations: This MIME type was designed for Encoding considerations: This MIME type was designed for
skipping to change at page 17, line 4 skipping to change at page 17, line 10
Applications which use this media: The simple-message-summary Applications which use this media: The simple-message-summary
application subtype supports the exchange of message waiting and application subtype supports the exchange of message waiting and
message summary information in SIP networks. message summary information in SIP networks.
Additional information: Additional information:
1. Magic number(s): N/A 1. Magic number(s): N/A
2. File extension(s): N/A 2. File extension(s): N/A
3. Macintosh file type code: N/A
8. Revision history
** Note to the RFC editor: please remove this entire section upon
publication. **
8.1 Changes from draft-ietf-sipping-mwi-03
1. Updated MIME type registration to permit transfer encoding using
any binary-clean encoding.
2. Changed caller preferences and callee capabilities usage to be
consistent with change from msg-server="true" to
actor="msg-taker".
8.2 Changes from draft-ietf-sipping-mwi-01 and -02
1. Updated the caller-preference section (now the callee
capabilities section) to reflect the split of these drafts and
the new tag ;msgserver="true".
2. Added some text in the overview to further clarify how message
notifiers can be composed/decomposed with media processing.
3. Add a pointer to the event-list extension.
8.3 Changes from draft-ietf-sipping-mwi-00
1. Replaced the "media types" concept with message contexts. This is
a better semantic match than what was in the draft before, and
also controls extensibility and change control in a single
document. The list of valid message-context-classes are
voice-message, fax-message, pager-message, multimedia-message,
text-message, and none.
2. Completely updated the syntax to follow that of SIP instead of
the previously more restrictive (and somewhat arbitrary) syntax.
The SIP syntax adds line folding, for example. The optional
message-headers borrow the "extension-header" syntax and explicit
whitespace separators defined in SIP (ex: HCOLON, SLASH).
3. Added a Message-Account field in the body format to provide the
specific account name which corresponds to the notification when
forking or state agents are used with group aliases (or
collections).
4. Changed caller preferences example to exclude methods="SUBSCRIBE"
in the SUBSCRIBE request (removed redundant information).
5. Changed examples to be consistent with IESG recommendations
8.4 Changes from draft-mahy-sipping-mwi-00
1. Updated references and split into normative and informational
2. Removed normative behavior now specified in Events
3. Updated to address the event package sections now specified in
Events.
4. Added the Subscription-State header field to the examples and
removed the Event header field from responses.
5. Removed redundant BNF
6. Simplified text on how to choose the media type. For Internet
Mail, this now references the Message-Context header.
8.5 Changes from draft-mahy-sip-mwi-01
1. This document is now formatted as a SIP Event Package as defined
in Section 4 of RFC 3265 (SIP Events) [2].
2. The event-package name is now "message-summary", to allow for
other bodies to extend the package.
3. The "urgent" token was missing from the BNF.
8.6 Changes from draft-mahy-sip-mwi-00
This draft greatly simplifies and shortens the -00 version.
1. The generic behavior of SUBSCRIBE/NOTIFY is now greatly clarified
in SIP Events [2] and made consistent with PINT and SIP for
presence. This message waiting draft is now consistent with SIP
Events.
2. The XML format has been removed due to lack of immediate 3. Macintosh file type code: N/A
interest. At a future date, similar functionality may be added
as another body definition with an appropriate MIME type.
3. An IANA Considerations section was added to register the new
"application/simple-message-summary" MIME type and the
"simple-message-summary" SIP event package.
4. The "flag-list" was removed due to lack of interest and to
encourage simplicity.
5. Due to synchronization issues, and the recommendation of the VPIM
Working Group, support for message count "deltas" was removed.
6. The Messages-Waiting line in the body is now mandatory.
7. This version of the draft clarifies the role of caller
preferences as optional but encouraged.
8. A set of SMTP-like headers from the triggering messages may now
optionally follow the message summaries, provided that the
resulting NOTIFY on UDP fits in a single datagram.
9. Contributors 8. Contributors
Ilya Slain came up with the initial format of the text body contained Ilya Slain came up with the initial format of the text body contained
in this document. He was previously listed as a co-author, however, in this document. He was previously listed as a co-author, however,
he is no longer reachable. he is no longer reachable.
10. Acknowledgments 9. Acknowledgments
Thanks to Dan Wing, Dave Oran, Bill Foster, Steve Levy, Denise Thanks to Dan Wing, Dave Oran, Bill Foster, Steve Levy, Denise
Caballero-McCann, Jeff Michel, Priti Patil, Satyender Khatter, Bich Caballero-McCann, Jeff Michel, Priti Patil, Satyender Khatter, Bich
Nguyen, Manoj Bhatia, David Williams, and Bryan Byerly of Cisco; Nguyen, Manoj Bhatia, David Williams, and Bryan Byerly of Cisco,
Jonathan Rosenberg and Adam Roach of Dynamicsoft; Eric Burger of Jonathan Rosenberg and Adam Roach of Dynamicsoft, Eric Burger of
Snowshore; Nir Chen of iComverse, and Eric Tremblay of Mediatrix. Snowshore, Nir Chen of Comverse, and Eric Tremblay of Mediatrix.
Normative References 10. References
10.1. Normative References
[1] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., [1] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP: Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP:
Session Initiation Protocol", RFC 3261, June 2002. Session Initiation Protocol", RFC 3261, June 2002.
[2] Roach, A., "Session Initiation Protocol (SIP)-Specific Event [2] Roach, A.B., "Session Initiation Protocol (SIP)-Specific Event
Notification", RFC 3265, June 2002. Notification", RFC 3265, June 2002.
[3] Bradner, S., "Key words for use in RFCs to Indicate Requirement [3] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997. Levels", BCP 14, RFC 2119, March 1997.
[4] Rosenberg, J., Schulzrinne, H. and P. Kyzivat, "Caller [4] Rosenberg, J., Schulzrinne, H., and P. Kyzivat, "Caller
Preferences and Callee Capabilities for the Session Initiation Preferences for the Session Initiation Protocol (SIP)", RFC
Protocol (SIP)", draft-ietf-sip-callerprefs-08 (work in 3841, August 2004.
progress), March 2003.
[5] Rosenberg, J., "Indicating User Agent Capabilities in the [5] Rosenberg, J., Schulzrinne, H., and P. Kyzivat, "Indicating User
Session Initiation Protocol (SIP)", Agent Capabilities in the Session Initiation Protocol (SIP)",
draft-ietf-sip-callee-caps-00 (work in progress), June 2003. RFC 3840, August 2004.
[6] Crocker, D. and P. Overell, "Augmented BNF for Syntax [6] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, November 1997. Specifications: ABNF", RFC 2234, November 1997.
[7] Burger, E., Candell, E., Eliot, C. and G. Klyne, "Message [7] Burger, E., Candell, E., Eliot, C., and G. Klyne, "Message
Context for Internet Mail", RFC 3458, January 2003. Context for Internet Mail", RFC 3458, January 2003.
Informational References 10.2. Informational References
[8] Vaudreuil, G. and G. Parsons, "Voice Profile for Internet Mail
- version 2", RFC 2421, September 1998.
[9] Freed, N. and N. Borenstein, "Multipurpose Internet Mail [8] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046, November Extensions (MIME) Part Two: Media Types", RFC 2046, November
1996. 1996.
[10] Resnick, P., "Internet Message Format", RFC 2822, April 2001. [9] Resnick, P., Ed., "Internet Message Format", RFC 2822, April
2001.
[11] Rosenberg, J., Roach, A. and B. Campbell, "A Session Initiation [10] Rosenberg, J., Roach, A.B., and B. Campbell, "A Session
Protocol (SIP) Event Notification Extension for Resource Initiation Protocol (SIP) Event Notification Extension for
Lists", draft-ietf-simple-event-list-04 (work in progress), Resource Lists", Work in Progress, June 2003.
June 2003.
[12] Telcordia, "GR-506: Signaling for Analog Interfaces, Issue 1, [11] Telcordia, "GR-506: Signaling for Analog Interfaces, Issue 1,
Revision 1", Nov 1996. Revision 1", Nov 1996.
Author's Address 11. Author's Address
Rohan Mahy Rohan Mahy
Cisco Systems, Inc. Cisco Systems, Inc.
101 Cooper Street 5617 Scotts Valley Drive, Suite 200
Santa Cruz, CA 95060 Scotts Valley, CA 95066
USA USA
EMail: rohan@cisco.com EMail: rohan@cisco.com
Intellectual Property Statement 12. Full Copyright Statement
Copyright (C) The Internet Society (2004). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it might or might not be available; nor does it represent that it has
has made any effort to identify any such rights. Information on the made any independent effort to identify any such rights. Information
IETF's procedures with respect to rights in standards-track and on the procedures with respect to rights in RFC documents can be
standards-related documentation can be found in BCP-11. Copies of found in BCP 78 and BCP 79.
claims of rights made available for publication and any assurances of
licenses to be made available, or the result of an attempt made to Copies of IPR disclosures made to the IETF Secretariat and any
obtain a general license or permission for the use of such assurances of licenses to be made available, or the result of an
proprietary rights by implementors or users of this specification can attempt made to obtain a general license or permission for the use of
be obtained from the IETF Secretariat. such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF Executive this standard. Please address the information to the IETF at ietf-
Director. ipr@ietf.org.
Full Copyright Statement
Copyright (C) The Internet Society (2003). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assignees.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Acknowledgement Acknowledgement
Funding for the RFC Editor function is currently provided by the Funding for the RFC Editor function is currently provided by the
Internet Society. Internet Society.
 End of changes. 

This html diff was produced by rfcdiff 1.25, available from http://www.levkowetz.com/ietf/tools/rfcdiff/