ISO/IEC 29341-3-1:2011

ISO/IEC 29341-3-1
Edition 2.0 2011-09
INTERNATIONAL
STANDARD
colour
inside
Information technology – UPnP device architecture –
Part 3-1: Audio Video Device Control Protocol – Audio Video Architecture

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ISO/IEC 29341-3-1
Edition 2.0 2011-09
INTERNATIONAL
STANDARD
colour
inside
Information technology – UPnP device architecture –
Part 3-1: Audio Video Device Control Protocol – Audio Video Architecture

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
L
ICS 35.200 ISBN 978-2-88912-677-4

29341-3-1 © ISO/IEC:2011(E)
CONTENTS
1  Overview and Scope . 3
1.1  Introduction . 3
1.2  Goals . 3
1.3  Non-Go als . 3
1.4  Notation . 3
1.5  References . 3
2  Architectural Overview . 4
3  Playback Architectu re . 6
3.1  Media Se rver . 7
3.1.1  Content Directory Service . 8
3.1.2  ConnectionManager Service . 8
3.1.3  AVTransport Service . 8
3.2  MediaRenderer . 8
3.2.1  RenderingControlService . 9
3.2.2  ConnectionManagerService . 9
3.2.3  AVTransport Service . 9
3.3  Control Point . 9
3.3.1  2-Box model: Control Point with Decoder . 12
3.3.2  2-Box model: Control Point with Content . 13
3.4  Tracking streams in the network . 13
4  Example Playback Scenario s . 14
4.1  3-Box model: Isochronous-Push (IEC61883/IEEE1 394) . 14
4.2  3-Box model: Asynchronous-Pull (e.g. HTTP GET) . 15
4.3  2-Box model: Control Point with Decoder using Isochronous-Push (e.g.
IEEE-1394) . 17
4.4  2-Box model: Control Point with Decoder using Asynchronous-Pull (e.g.
HTTP GET) . 18
4.4.1  Minimal Implementation . 18
4.5  2-Box model: Control Point with Content using Isochronous-Push (e.g. IEEE-
1394) . 20
4.6  2-Box Model: Control Point with Content using Asynchronous-Pull (e.g.
HTTP GET) . 21
4.7  No ConnectionManager::PrepareForConnection() Action . 21
5  Recording Architecture . 22

Figure 1 — Typical UPnP Device Interaction Model . 4
Figure 2 — UPnP AV Device Interaction Model . 5
Figure 3 — General Device Architecture aka the 3-Box model . 6
Figure 4 — General Interaction Diagram of the 3-Box model . 11
Figure 5 — Control Point with Decoder . 12
Figure 6 — Control Point With Content . 13
Figure 7 — 3-Box Model: Isochronous-Push transfer protocols . 15
Figure 8 — 3-Box model:Asynchronus-Pull transfer protocol . 16
Figure 9 — 2-Box model: Control Point with Decoder using Isochronous-Push . 17

— 2 — 29341-3-1 29341-3-1 © ISO/IEC:2011(E)© ISO/IEC:2011(E)
Figure 10 — 2-Box model: Control Point with Decoder using Asynchronous- Pull . 18
Figure 11 — 2-Box model: Minimal Implementation . 19
Figure 12 — 2-Box model: Control Point With Content using Isochronous-Push . 20
Figure 13 — 2-Box model: Control Point with Content using Asynchronous -Pull. 21
Figure 14 — 3-Box model: no AVTransport::PrepareForConnection() function . 22

Table 1-1 — Default Short Names for the AV Specifications . 3

29341-3-1 © ISO/IEC:2011(E)
INFORMATION TECHNOLOGY –
UPNP DEVICE ARCHITECTURE –
Part 3-1: Audio Video Device Control Protocol –
Audio Video Architecture
FOREWORD
1) ISO (International Organization for Standardization) and IEC (International Electrotechnical Commission) form the
specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in
the development of International Standards. Their preparation is entrusted to technical committees; any ISO and
IEC member body interested in the subject dealt with may participate in this preparatory work. International
governmental and non-governmental organizations liaising with ISO and IEC also participate in this preparation.
2) In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote.
3) The formal decisions or agreements of IEC and ISO on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested IEC and ISO member bodies.
4) IEC, ISO and ISO/IEC publications have the form of recommendations for international use and are accepted
by IEC and ISO member bodies in that sense. While all reasonable efforts are made to ensure that the
technical content of IEC, ISO and ISO/IEC publications is accurate, IEC or ISO cannot be held responsible for
the way in which they are used or for any misinterpretation by any end user.
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Any divergence between any ISO/IEC publication and the corresponding national or regional publication
should be clearly indicated in the latter.
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any equipment declared to be in conformity with an ISO/IEC publication.
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9) Attention is drawn to the normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
10) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
International Standard ISO/IEC 29341-3-1 was prepared by UPnP Forum Steering
committee , was adopted, under the fast track procedure, by subcommittee 25:
Interconnection of information technology equipment, of ISO/IEC joint technical committee 1:
Information technology.
This International Standard replaces ISO/IEC 29341-3-1, first edition, published in 2008, and
constitutes a technical revision.
The list of all currently available parts of the ISO/IEC 29341 series, under the general title
Information technology – UPnP device architecture, can be found on the IEC web site.
This International Standard has been approved by vote of the member bodies, and the voting
results may be obtained from the address given on the second title page.
—————————
rd
UPnP Forum Steering committee, UPnP Forum, 3855 SW 153 Drive, Beaverton, Oregon 97006 USA. See also
“Introduction”.
29341-3-1 © ISO/IEC:2011(E)
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.

29341-3-1 29341-3-1 XXXX: © IEC:2010 © ISO/IEC:2011(E)© ISO/IEC:2011(E) — 3 —
1 Overview and Scope
1.1 Introduction
This document describes the overall UPnP AV Architecture, which forms the foundation for
the UPnP AV Device and Service templates. The AV Architecture defines the general
interaction between UPnP Control Points and UPnP AV devices. It is independent of any
particular device type, content format, and transfer protocol. It supports a variety of devices
such as TVs, VCRs, CD/DVD players/jukeboxes, settop boxes, stereos systems, MP3
players, still-image cameras, camcorders, electronic picture frames (EPFs), and the PC. The
AV Architecture allows devices to support different types of formats for the entertainment
content (such as MPEG2, MPEG4, JPEG, MP3, Windows Media Architecture (WMA), bitmaps
(BMP), NTSC, PAL, ATSC, etc.) and multiple types of transfer protocols (such as IEC-
61883/IEEE-1394, HTTP GET, RTP, HTTP PUT/POST, TCP/IP, etc.). The following clauses
describe the AV Architecture and how the various UPnP AV devices and services work
together to enable various end-user scenarios.
1.2 Goals
The UPnP AV Architecture was explicitly defined to meet the following goals:
• To support arbitrary transfer protocols and content formats.
• To enable the AV content to flow directly between devices without any intervention from
the Control Point.
• To enable Control Points to remain independent of any particular transfer protocol and
content format. This allows Control Points to transparently support new protocols and
formats.
• Scalability, i.e. support of devices with very low resources, especially memory and
processing power as well as full-featured devices.
1.3 Non-Goals
The UPnP AV Architecture does not enable any of the following:
• Two-way Interactive Communication, such as audio and video conferencing, Internet
gaming, etc.
• Access Control, Content Protection, and Digital Rights Management
• Synchronized playback to multiple rendering devices
1.4 Notation
Table 1-1 — Default Short Names for the AV Specifications
AV Specification Name Short Name
AVTransport AVT
ConnectionManager CM
ContentDirectory CDS
MediaRenderer MR
MediaServer MS
RenderingControl RCS
ScheduledRecording SRS
1.5 References
This clause lists the normative references used in the UPnP AV specifications and includes
the tag inside square brackets that is used for each such reference:

XXXX: © IEC:2010 — 4 — 29341-3-1 © ISO/IEC:2011(E)
[AVT] – AVTransport:2, UPnP Forum, September 30, 2008. Available at:
http://www.upnp.org/specs/av/UPnP-av-AVTransport-v2-Service-20080930.pdf. Latest
version available at: http://www.upnp.org/specs/av/UPnP-av-AVTransport-v2-Service.pdf.
[CDS] – ContentDirectory:3, UPnP Forum, September 30, 2008.  Available at:
http://www.upnp.org/specs/av/UPnP-av-ContentDirectory-v3-Service-20080930.pdf. Latest
version available at: http://www.upnp.org/specs/av/UPnP-av-ContentDirectory-v3-Service.pdf.
[CM] – ConnectionManager:2, UPnP Forum, September 30, 2008. Available at:
http://www.upnp.org/specs/av/UPnP-av-ConnectionManager-v2-Service-20080930.pdf. Latest
version available at: http://www.upnp.org/specs/av/UPnP-av-ConnectionManager-v2-
Service.pdf.
[MR] – MediaRenderer:2, UPnP Forum, September 30, 2008. Available at:
http://www.upnp.org/specs/av/UPnP-av-MediaRenderer-v2-Device-20080930.pdf. Latest
version available at: http://www.upnp.org/specs/av /UPnP-av-MediaRenderer-v2-Device.pdf.
[MS] – MediaServer:3, UPnP Forum, September 30, 2008.  Available at:
http://www.upnp.org/specs/av/UPnP-av-MediaServer-v3-Device-20080930.pdf. Latest version
available at: http://www.upnp.org/specs/av/UPnP-av-MediaServer-v3-Device.pdf.
[RCS] – RenderingControl:2, UPnP Forum, September 30, 2008. Available at:
http://www.upnp.org/specs/av/UPnP-av-RenderingControl-v2-Service-20080930.pdf. Latest
version available at: http://www.upnp.org/specs/av/UPnP-av-RenderingControl-v2-
Service.pdf.
2 Architectural Overview
In most (non-AV) UPnP scenarios, a Control Point controls the operation of one or more
UPnP devices in order to accomplish the desired behavior. Although the Control Point is
managing multiple devices, all interactions occur in isolation between the Control Point and
each device. The Control Point coordinates the operation of each device to achieve an
overall, synchronized, end-user effect. The individual devices do not interact directly with
each another. All of the coordination between the devices is performed by the Control Point
and not the devices themselves.

Control Point
UPnP Actions
Device 1 Device 2
Figure 1 — Typical UPnP Device Interaction Model

29341-3-1 29341-3-1 XXXX: © IEC:2010 © ISO/IEC:2011(E)© ISO/IEC:2011(E) — 5 —
AV
Control Point
AV AV
UPnP Actions
Device 1 Device 2
(Source) (Sink)
Out-of-Band
Transfer Protocol
Figure 2 — UPnP AV Device Interaction Model
Most AV scenarios involve the flow of (entertainment) content (i.e. a movie, song, picture,
etc.) from one device to another. As shown in Figure 2, an AV Control Point interacts with two
or more UPnP devices acting as source and sink, respectively. Although the Control Point
coordinates and synchronizes the behavior of both devices, the devices themselves interact
with each other using a non-UPnP (“out-of-band”) communication protocol. The Control Point
uses UPnP to initialize and configure both devices so that the desired content is transferred
from one device to the other. However, since the content is transferred using an “out-of-band”
transfer protocol, the Control Point is not directly involved in the actual transfer of the
content. The Control Point configures the devices as needed, triggers the flow of content,
then gets out of the way. Thus, after the transfer has begun, the Control Point can be
disconnected without disrupting the flow of content. In other words, the core task (i.e.
transferring the content) continues to function even without the Control Point present.
As described in the above scenario, three distinct entities are involved: the Control Point, the
source of the media content (called the “MediaServer”), and the sink for the content (called
the “MediaRenderer”). Throughout the remainder of the document, all three entities are
described as if they were independent devices on the network. Although this configuration
may be common (i.e. a remote control, a VCR, and a TV), the AV Architecture supports
arbitrary combinations of these entities within a single physical device. For example, a TV
can be treated as a rendering device (e.g. a display). However, since most TVs contain a
built-in tuner, the TV can also act as a server device because it could tune to a particular
channel and send that content to a MediaRenderer [MR] (e.g. its local display or some
remote device such as a tuner-less display). Similarly, many MediaServers and/or
MediaRenderers may also include Control Point functionality. For example, an MP3 Renderer
will likely have some UI controls (e.g. a small display and some buttons) that allow the user
to control the playback of music.

XXXX: © IEC:2010 — 6 — 29341-3-1 © ISO/IEC:2011(E)
3 Playback Architecture
Figure 3 — General Device Architecture aka the 3-Box model
The most common task that end-users want to perform is to render (i.e. play) individual items
of content on a specific rendering device. As shown in Figure 3, the content playback
scenario involves three distinct UPnP components: a MediaServer [MS], a MediaRenderer,
and a UPnP Control Point. These three components (each with a well-defined role) work
together to accomplish the task. In this scenario, the MediaServer contains (entertainment)
content that the user wants to render (e.g. display or listen to) on the MediaRenderer. The
user interacts with the Control Point’s UI to locate and select the desired content on the
MediaServer and to select the target MediaRenderer.
The MediaServer contains or has access to a variety of entertainment content, either stored
locally or stored on an external device that is accessible via the MediaServer. The
MediaServer is able to access its content and transmit it to another device via the network
using some type of transfer protocol. The content exposed by the MediaServer may include
arbitrary types of content including video, audio, and/or still images. The content is
transmitted over the network using a transfer protocol and data format that is that is
understood by the MediaServer and MediaRenderer. MediaServers may support one or
multiple transfer protocols and data formats for each content item or be able to convert the
format of a given content item into another formats on the fly. Examples of a MediaServer
include a VCR, CD/DVD player/jukebox, camera, camcorder, PC, set-top box, satellite
receiver, audio tape player, etc.
The MediaRenderer obtains content from a MediaServer via network. Examples of a
MediaRenderer include TV, stereo, network-enabled speakers, MP3 players, Electronic
Picture Frame (EPF), a music-controlled water fountain, etc. The type of content that a
MediaRenderer can receive depends on the transfer protocols and data formats that it
supports. Some MediaRenderers may only support one type of content (e.g. audio or still
images), where as other MediaRenderers may support a wide variety of content including
video, audio, still images.
29341-3-1 29341-3-1 XXXX: © IEC:2010 © ISO/IEC:2011(E)© ISO/IEC:2011(E) — 7 —
The Control Point coordinates and manages the operation of the MediaServer and
MediaRenderer as directed by the user (e.g. play, stop, pause) in order to accomplish the
desired task (e.g. play “MyFavorite” music). Additionally, the Control Point provides the UI (if
any) for the user to interact with in order to control the operation of the device(s) (e.g. to
select the desired content). The layout of the Control Point’s UI and the functionality that it
exposes is implementation dependent and determined solely by the Control Point’s
manufacturer. Some examples of a Control Point might include a TV with a traditional remote
control or a wireless PDA-like device with a small display.
Note: The above descriptions talk about devices “sending/receiving content to/from the home
network.” In the context of the AV Architecture, this includes point-to-point connections such
as an RCA cable that is used to connect a VCR to a TV. The AV Architecture treats this type
of connection as a small part (e.g. segment) of the home network. Refer to the
ConnectionManager Service [CM] for more details.
As described above, the AV Architecture consists of three distinct components that perform
well-defined roles. In some cases, these components will exist as separate, individual UPnP
devices. However, this need not be the case. Device manufacturers are free to combine any
of these logical entities into a single physical device. In such cases, the individual
components of these combo devices may interact with each other using either the standard
UPnP control protocols (e.g. SOAP over HTTP) or using some private communication
mechanism. In either case, the function of each logical entity remains unchanged. However,
in the later case, since the communication between the logical entities is private, the
individual components will not be able to communicate with other UPnP AV devices that do
not implement the private protocol.
As shown in Figure 3, the Control Point is the only component that initiates UPnP actions.
The Control Point requests to configure the MediaServer and MediaRenderer so that the
desired content flows from the MediaServer to the MediaRenderer (using one of the transfer
protocols and data formats that are supported by both the MediaServer and MediaRenderer).
The MediaServer and MediaRenderer do invoke any UPnP actions to the Control Point.
However, if needed, the MediaServer and/or MediaRenderer may send event notifications to
the Control Point in order to inform the Control Point of a change in the
MediaServer’s/MediaRenderer’s internal state.
The MediaServer and MediaRenderer do not control each other via UPnP actions. However,
in order to transfer the content, the MediaServer and MediaRenderer use an “out-of-band”
(e.g. a non-UPnP) transfer protocol to directly transmit the content. The Control Point is not
involved in the actual transfer of the content. It simply configures the MediaServer and
MediaRenderer as needed and initiates the transfer of the content. Once the transfer begins,
the Control Point “gets out of the way” and is no longer needed to complete the transfer.
However, if desired by the user, the Control Point is capable of controlling the flow of the
content by invoking various AVTransport actions such as Stop, Pause, FF, REW, Skip, Scan,
etc. Additionally, the Control Point is also able to control the various rendering characteristics
on the Renderer device such as Brightness, Contrast, Volume, Balance, etc.
3.1 Media Server
The MediaServer is used to locate content that is available via the home network.
MediaServers include a wide variety of devices including VCRs, DVD players, satellite/cable
receivers, TV tuners, radio tuners, CD players, audio tape players, MP3 players, PCs, etc. A
MediaServer’s primary purpose is to allow Control Points to enumerate (i.e. browse or search
for) content items that are available for the user to render. The MediaServer contains a
ContentDirectory Service [CDS], a ConnectionManager Service [CM], and an optional
AVTransport Service [AVT] (depending on the supported transfer protocols).
Some MediaServers are capable of transferring multiple content items at the same
...