IEC 62676-2-1:2013

IEC 62676-2-1 ®
Edition 1.0 2013-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Video surveillance systems for use in security applications –
Part 2-1: Video transmission protocols – General requirements

Systèmes de vidéosurveillance destinés à être utilisés dans les applications de
sécurité –
Partie 2-1: Protocoles de transmission vidéo – Exigences générales

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IEC 62676-2-1 ®
Edition 1.0 2013-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Video surveillance systems for use in security applications –

Part 2-1: Video transmission protocols – General requirements

Systèmes de vidéosurveillance destinés à être utilisés dans les applications de

sécurité –
Partie 2-1: Protocoles de transmission vidéo – Exigences générales

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX W
ICS 13.320 ISBN 978-2-8322-1181-6

– 2 – 62676-2-1 © IEC:2013
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviations . 8
3.1 Terms and definitions . 8
3.2 Abbreviations . 15
4 Video transmission network architecture . 16
4.1 General . 16
4.2 Networking and connectivity . 17
4.2.1 General . 17
4.2.2 Network streaming performance: quality of service . 18
4.3 Device discovery and description . 18
4.4 Video media types and payload formats . 18
4.5 Video transport . 18
4.6 Eventing and health check . 18
5 The building block of existing standards . 19
6 VSS device model . 19
6.1 Overview . 19
6.2 Device model elements . 20
7 General IP interoperability requirements . 21
7.1 General . 21
7.2 General protocol requirements overview . 21
7.3 General high level IP video interface and protocol requirements . 21
7.3.1 General . 21
7.3.2 Versioning, capability exchange, and extensibility requirements . 22
7.3.3 Implementations . 22
7.4 Non-conformance video transmission systems and devices . 22
7.5 Mandatory documentation for the IP video interface of a VTD . 22
7.6 Video and data transport: mandatory streaming requirements . 24
7.7 Overview . 24
8 Live streaming . 25
8.1 General . 25
8.2 Media stream protocol . 25
8.2.1 Transport format . 25
8.2.2 Media transport . 25
8.2.3 Synchronization point . 27
8.3 Media control protocol . 28
8.3.1 Stream control . 28
8.3.2 RTSP . 28
8.3.3 Keep-alive method for RTSP session . 29
8.3.4 RTSP audio and video synchronization . 30
8.3.5 RTSP message example . 31
8.4 Error handling . 32
9 Playback . 32
9.1 General . 32

62676-2-1 © IEC:2013 – 3 –
9.2 RTP header extension . 32
10 Device discovery and description. 32
11 Eventing requirements . 32
Bibliography . 34

Figure 1 – Overview IP Video standard protocol . 17
Figure 2 – Functional protocol layers . 17
Figure 3 – Building block of existing standards . 19
Figure 4 – VTD example network . 20
Figure 5 – Layer structure . 24
Figure 6 – RTCP sequence . 26
Figure 7 – RTCP sender report . 27
Figure 8 – Media synchronization. 27
Figure 9 – Stream control . 28
Figure 10 – Keep alive . 30

Table 1 – RTSP methods . 29

– 4 – 62676-2-1 © IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
VIDEO SURVEILLANCE SYSTEMS FOR USE
IN SECURITY APPLICATIONS –
Part 2-1: Video transmission protocols –
General requirements
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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6) All users should ensure that they have the latest edition of this publication.
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8) 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.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62676-2-1 has been prepared by IEC technical committee 79:
Alarm and electronic security systems.
The text of this standard is based on the following documents:
FDIS Report on voting
79/435/FDIS 79/448/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62676 series, published under the general title Video surveillance
systems for use in security applications, can be found on the IEC website.

62676-2-1 © IEC:2013 – 5 –
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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 document using a
colour printer.
– 6 – 62676-2-1 © IEC:2013
INTRODUCTION
The IEC Technical Committee 79 in charge of alarm and electronic security systems together
with many governmental organisations, test houses and equipment manufacturers have
defined a common framework for video surveillance transmission in order to achieve
interoperability between products.
The IEC 62676 series of standards on video surveillance system is divided into 4 independent
parts:
Part 1: System requirements
Part 2: Video transmission protocols
Part 3: Analog and digital video interfaces
Part 4: Application guidelines (to be published)
Each part has its own clauses on scope, references, definitions and requirements.
This IEC 62676-2 series consists of 3 subparts, numbered parts 2-1, 2-2 and 2-3 respectively:
IEC 62676-2-1, Video transmission protocols – General requirements
IEC 62676-2-2, Video transmission protocols – IP interoperability implementation based on
HTTP and REST services
IEC 62676-2-3, Video transmission protocols – IP interoperability implementation based on
Web services
The first subpart of this IEC 62676-2 series defines protocol requirements to be fulfilled by
any high-level IP video device interface. The following two parts – Part 2-2 and Part 2-3 –
define two alternative protocols, one is based on HTTP and REST services and the second is
based on Web Services. It is based on the general requirements for video transmission of
IEC 62676-1-2, which defines minimum IP connectivity requirements, basic video streaming,
stream control, eventing, discovery and description functions.
The purpose of the transmission system in a video surveillance system installation is to
provide reliable transmission of video signals between the different types of Video
Surveillance System (VSS) so far called CCTV equipment in security, safety and monitoring
applications.
Today VSS reside in security networks using IT infrastructure, equipment and connections
within the protected site itself.

62676-2-1 © IEC:2013 – 7 –
VIDEO SURVEILLANCE SYSTEMS FOR USE
IN SECURITY APPLICATIONS –
Part 2-1: Video transmission protocols –
General requirements
1 Scope
This part of IEC 62676 introduces an IP network interface for devices in surveillance
applications. This International Standard specifies a network protocol for the full
interoperability of video devices. On top of the basic layers protocols are defined to
accomplish the full interoperability of video devices. In surveillance applications IP video
devices have to use standardized protocols to accomplish following functionality: video
streaming, stream control, event handling, discovery, capability description, device
management, PTZ control, auxiliaries and other functions.
Some areas of this transmission standard are covered by more than one approach, e.g.
ZeroConf and WS-Discovery.
The network protocols recommended and defined by this video transmission standard are
selected with a sense for future relevance and further extensions.
Video transmission equipment may be combined with additional functions, e.g. for audio or
metadata transmission.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 62676-1-2, Video surveillance systems for use in security applications – Part 1-2: System
requirements – Performance requirements for video transmission
IEC 62676-2-2, Video surveillance systems for use in security applications – Part 2-2: Video
transmission protocols – IP interoperability implementation based on HTTP and REST
services
IEC 62676-2-3, Video surveillance systems for use in security applications – Part 2-3: Video
transmission protocols – IP interoperability implementation based on web services
IETF RFC 2326:1998, Real Time Streaming Protocol (RTSP)
IETF RFC 3016, RTP Payload Format for MPEG-4 Audio-Visual Streams
IETF RFC 3550, A transport protocol for Real-Time Applications (Replaces RFC 1889)
IETF RFC 3550, Standard 64, RTP: A Transport Protocol for Real-Time Applications
IETF RFC 3551, Profile for audio and video conferences with minimal control (Replaces
RFC890)
– 8 – 62676-2-1 © IEC:2013
IETF RFC 3551, Standard 65, RTP Profile for Audio and Video Conferences with Minimal
Control
IETF RFC 3984, RTP payload format for H.264/AVC
IETF RFC 4566, SDP: Session Description Protocol
IETF RFC 4571, Framing Real-time Transport Protocol and RTP Control Protocol [RTCP]
Packets over Connection-Oriented Transport
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
analog
a form of information that is represented by a continuous and smoothly varying amplitude or
frequency changes over a certain range
3.1.2
analog video
video signal made of a continuous electrical signal
3.1.3
application program interface
a set of interfaces for developers to interact with a component or application
3.1.4
bandwidth
property of networks to describe the amount of data that can be carried from one point in the
network to another in a given time period, usually a second, affected in video surveillance by
frame rate, image resolution, compression ratio, image noise, complexity detail of a monitored
scene
3.1.5
capability
a named piece of functionality (or feature) that is declared as supported or requested by an
agent
3.1.6
capturing
process of transferring video from one source to another for use on a digital video device,
network or storage, e.g. conversion of analog to digital
3.1.7
channel
one or more streams of video, audio and/or metadata that together constitute a unique entity
for the purpose of surveillance
3.1.8
client
a software application or other entity that uses the services offered by a Video Transmission
Device (VTD)
62676-2-1 © IEC:2013 – 9 –
3.1.9
codec
abbreviation of compression/decompression algorithm, used to encode and decode, or
compress and decompress data, such as video
3.1.10
component
a software or hardware object, meant to interact with other components, encapsulating certain
functionality or a set of functionalities with clearly defined interfaces and conforming to a
prescribed behavior common to all components within a standard
3.1.11
device description
formal definition of a network device, expressed in XML syntax, specified by a vendor
3.1.12
digital
information coded in discrete, separate pulses or signal levels
3.1.13
digital video recorder
DVR
network video device recording multiple analog video channels onto a hard disk in digital
format, which allows viewing, replay and management remotely via a VT client
3.1.14
discovery
act of locating a network device or machine-processable description of a service-related
resource that may have been previously unknown and that meets certain functional criteria
3.1.15
DNS
domain name system
protocol that enables hierarchical naming system in a network for identification and resolving
symbolic names such as domain or computer names for example translate http://Videoserver1
or www.upnp.org into IP addresses
3.1.16
DTD
document type definition
document defining the format of the contents presented between the tags in an XML
document, and the way they should be interpreted by the application reading the XML
document
3.1.17
dynamic host configuration protocol
DHCP
protocol to automatically provide IP addresses and other network configuration information to
network nodes
3.1.18
event
notification of one or more changes in state variables sent by a network device
3.1.19
eventing
the exchange of specially-formatted messages describing events of a event server e.g
network device
– 10 – 62676-2-1 © IEC:2013
3.1.20
frame
full frame of video as acquired in progressive mode or as combination of two image fields
interlaced together
3.1.21
identifier
code associated with each object which uniquely identifies the object e.g. for SNMP in the
global tree of objects
3.1.22
IETF
Internet engineering task force
standards body that forms Working Groups to develop technology for the Internet community
3.1.23
I-frame
independent frame coded as intraframe of an image sequence of differential coded frames
3.1.24
Internet protocol
IP
basic connectionless network-layer protocol
3.1.25
IP camera
device capturing and transmitting live video images over an IP network allowing remote
viewing, recording, and management
3.1.26
Internet protocol video
IP video
transmission of video signals over an IP network: representation of sequential image
information in digital (discrete level) formats that are transferred using IP data packets
(datagrams) including associated protocols for discovery, description, streaming, stream
control, eventing, control and configuration of video network devices
3.1.27
IP video Interface
software point of communication for IP video between a device and the network
3.1.28
IP video Network
collection of video transmission devices connected to each other allowing to communicate
with each other, share resources and information over a variety of connection protocols
3.1.29
interoperability
ability of communication of systems and units to provide services and to accept services from
other systems and units, in order to use the services for efficient operation;
ability for information or services to be exchanged directly and smoothly between providers
and consumers
3.1.30
jitter
variation in a network delay that is perceived by the receiver of each packet

62676-2-1 © IEC:2013 – 11 –
3.1.31
latency
delay in the response of far end participants, often a result of network congestion and
geographic distance
3.1.32
link
relationship between two network nodes when one resource refers to the other resource e.g.
by the means of a URI
3.1.33
message
the basic unit of communication containing the data to be transmitted between network nodes
such as client and server
3.1.34
messaging
exchange of messages, which are specially formatted data packets, describing events,
commands, status information, requests, replies, etc of a messaging source to a subscribing
or listening client
3.1.35
moving picture experts group
MPEG
working committee that defines and develops industry standards for digital video systems,
specifying the data compression and decompression processes and how they are delivered
on digital video systems
Note 1 to entry: This note applies to the French language only.
3.1.36
network architecture
framework and technology foundation for the design, building and managing of a
communication network, typically in a layered structure dividing the communication tasks into
a number of smaller parts, each part accomplishing a particular sub-task and interacting with
the other parts in a small number of well-defined ways
3.1.37
network connectivity
physical (wired or wireless) and logical (protocol) connection of multiple devices or a single
device to a network, such as a IP video network
3.1.38
network interfaces
point of communication between a device and the network
3.1.39
network node
grouping of one or more network components which provides network related functions,
administered as a single entity
3.1.40
network protocol
defined rules and procedures for the network communications

– 12 – 62676-2-1 © IEC:2013
3.1.41
network video recorder
NVR
network video device recording multiple video streams onto a hard disk in digital format,
which allows viewing, replay and management remotely via a VT client
3.1.42
OASIS
organization for the advancement of structured Information standards
a nonprofit, international consortium whose goal is to promote the adoption of product-
independent standards for information formats such as Extensible Markup Languages (XML),
Hypertext Markup Language (HTML) etc.
3.1.43
open systems interconnection
OSI
complete suite of network routing protocols developed by ISO including routing protocols
between the different layers of the system
3.1.44
payload
true message data itself without protocol information
3.1.45
principle
fundamental rule applicable to a large number of situations and variations
3.1.46
protocol error
result and answer of an incorrectly formed protocol message, which may consist of illegal
header values or payload, received unexpectedly or after a certain timeout
EXAMPLES: HTTP and RTSP define a set certain of standard status codes to notify about protocol errors.
3.1.47
quality of service
QoS
software-based ability to guarantee the required level of network resources for real-time video
traffic;
a major performance indicator for networks especially for devices such as IP cameras, access
control, and building management or security systems
3.1.48
recording
a single container for a set of video, audio and metadata tracks with an endless timeline
holding data at certain time frames or gaps without any information from any kind of real-time
video source or input including associated non-video data stored on any kind of media
3.1.49
representation
data about the actual state of a resource or component
3.1.50
RFC
request for comment
documents maintained by the IETF standards body containing standards in various stages of
completion
62676-2-1 © IEC:2013 – 13 –
Note 1 to entry: This note applies to the French language only.
3.1.51
RTCP packet
Real-Time Transport Control Protocol (RTCP) control packet that consists of a fixed header
part similar to that of RTP data packets and structured elements that vary depending upon the
RTCP packet type, as described in RFC 3550
3.1.52
RTP payload
data transported in a packet by using Real-Time Transport Protocol (RTP), as described in
RFC 3550
3.1.53
RTP session
association among a set of participants who are communicating by using the Real-Time
Transport Protocol (RTP), maintaining a full, separate space of Synchronization Source
(SSRC) identifiers, transmitted to the same destination IP address and UDP port
Note 1 to entry: Typically, there is a one-to-one mapping between RTP streams and RTP sessions, but it is
possible for multiple RTP streams to use the same RTP session (port multiplexing). The associated RTCP traffic is
also part of that RTP session although the packets are sent to the next higher UDP port number.
3.1.54
RTP stream
video stream that is encapsulated in RTP
Note 1 to entry: All of the RTP packets have the same SSRC and are transmitted on the same RTP session.
3.1.55
RTSP session
session typically consisting of a VT client creating one or more RTP Sessions (SETUP) with a
VT server, starting the stream with PLAY or RECORD, and closing the RTSP Session
3.1.56
secure hash algorithm
SHA1
algorithm which generates out of input data like a message of less than 264 bits in length a
160-bit hash code or fingerprint designed in a way that it hardly possible to find a matching
text string
service abstract resource that represents capabilities to perform tasks
3.1.57
streaming
process of sending video over a network to allow instant operation as the video is received,
rather than requiring the entire file to be downloaded prior to operation
3.1.58
transmission control protocol
TCP
connection-oriented transport-layer protocol establishing a connection between host and
recipient, guaranteeing delivery and reliability through retransmission
3.1.59
TTL
time-to-live
specified length of time that information e.g. DNS is stored in a cache and after that the
information is deleted, e.g. entry from the DNS name server’s cache

– 14 – 62676-2-1 © IEC:2013
3.1.60
user datagram protocol
UDP
connectionless transport layer protocol used to send messages as part of the IP suite of
protocols with low overhead, not using Acknowledging (ACK) or error-checking (CRC), e.g.
SNMP messages, not guaranteeing the delivery of a data packet with the advantage of using
fewer network resources than TCP, making it more suitable for transporting streams of data or
large amount of status messages
3.1.61
universal resource identifier
URI
a compact sequence of characters that identifies an abstract or physical resource on a server
in a network
3.1.62
video frame
single image shown as part of a sequence of images in a video stream
3.1.63
video management system
VMS
system managing, accessing and controlling the video transmission devices in real time in
the video surveillance environment
3.1.64
video surveillance system network
VSS network
video surveillance system based on an IP video network used within a protected site
3.1.65
video transmission device
VTD
video device with at least one IP network interface handling video and typically coding or
decoding video
EXAMPLES: Encoders, decoders, NVR systems, video management systems.
3.1.66
video transmission client
VT client
video network device acting as client or receiver requesting video streams, status messages,
etc. from a connected VTD server for the purpose of video recording, display, etc.
EXAMPLE: A VTD client can be a video management system workstation or a video decoder.
3.1.67
video transmission server
VT server
video network device acting as server or sender, encoding and sending video to a connected
VTD Client, providing video streams, video status information, etc.
EXAMPLE: A VTD Server can be an IP network camera or a video encoder
3.1.68
web service
software entity that responds to SOAP messages capable of being defined, located via the
Internet protocol, and interacting with other software applications, identified by a Uniform
Resource Identity
62676-2-1 © IEC:2013 – 15 –
3.1.69
web service definition language
WSDL
XML-based standard for specifying message-based distributed services containing either
document- or procedure-oriented information
3.1.70
XML schema
a document that describes, in a formal way, the syntax elements and parameters of a web
language, designed by W3C to replace DTD
3.1.71
zeroconf
zero configuration networking
a set of techniques that automatically create a usable IP network without configuration or
special servers.
Note 1 to entry: In this standard only the service discovery is referred to.
3.2 Abbreviations
API Application Program Interface
DA Device Architecture
DCP Device Control Protocol
DHCP Dynamic Host Configuration Protocol
DNS Domain Name System
DTD Document Type Definition
DVR Digital Video Recorder
HTML Hyper Text Mark-up Language
HTTP Hypertext Transfer Protocol
IETF Internet Engineering Task Force
IP Internet Protocol
IPsec IP Security
ISO International Standards Organization
IT Information Technology
MPEG Moving Pictures Experts Group
NAT Network Address Translation
NPT Normal Play Time
NTP Network Time Protocol
NVR Network video recorder
OASIS Organization for the Advancement of Structured Information Standards
OSI Open Systems Interconnect
PTZ Pan / Tilt / Zoom
QoS Quality of Service
REST Representational State Transfer
RFC (Request for comment) IETF Standards Draft
RTCP Real Time Control Protocol
RTP Real-time Transport Protocol
RTSP Real Time Streaming Protocol

– 16 – 62676-2-1 © IEC:2013
SDP Session Description Protocol
SMPTE Society for Motion Picture and Television Engineers
SOAP Simple Object Access Protocol
SRTP Secure Real-time Transport Protocol
SSL Secure Sockets Layer
SSRC Synchronization source
TCP Transmission Control Protocol
TCP/IP Transmission Control Protocol / Internet Protocol
TLS Transport Layer Security
TTL Time-to-live
UDP User Datagram Protocol
UPnP Universal Plug and Play
URI Uniform Resource Identifier
URL Uniform Resource Locator
UTC Universal Time Coordinated
UTF Unicode Transformation Format
UTF-8 8-bit Unicode Transformation Format
VMS Video management system
VSS Video Security Systems
VT Video Transmission
VTD Video Transmission device
W3C World Wide Web Consortium
WS Web Service
WSDL Web Services Description Language
XML eXtensible Markup Language
Zeroconf Zero Configuration Networking
4 Video transmission network architecture
4.1 General
To achieve interoperability between connected digital video devices in the VSS network, a
common set of building blocks based on existing standards is needed as a basis to develop
the video transmission standards. The present transmission network architecture is
informative
Figure 1 illustrates these functional components within the networking architecture of the
video transmission standards. The video transmission standards define usage of these
functional components to ensure interoperability among device classes defined in Clause 6. A
brief overview of each functional component follows in the subsequent subclauses.

62676-2-1 © IEC:2013 – 17 –
IEC  2729/13
Figure 1 – Overview IP Video standard protocol
Figure 2 shows the specific functional components and technology ingredients that are
covered in the video transmission standards.
RTSP/RTP Video Transport
Device Description
HTTP 1.1
Capabilities
Configuration
Discovery Service Discovery
TCP, UDP Network protocol stack
Ethernet, Wi-Fi Physical layer connectivity

IEC  2730/13
Figure 2 – Functional protocol layers
4.2 Networking and connectivity
4.2.1 General
The IP video protocol suite is the foundation for networking and connectivity for VT devices in
the digital VSS network. IP also provides the underlying network communications for
applications in security. Based on industry-standard specifications from the IETF, IP is
implemented and supported in a wide range of devices. IP has the following advantages for
use by VT devices:
• IP has demonstrated that it allows applications to run over different network topologies
transparently;
• IP allows connecting every device to a VSS network or even to a security network;
• IP connectivity solutions are widely used and are cost-effective. The most common
ones are Ethernet (802.3i and 802.3u) and wireless technologies (802.11n, 802.11b,
and 802.11g) for devices in the VSS security networking environment.

– 18 – 62676-2-1 © IEC:2013
The following subclause specifies the detailed protocols to enable interoperability between VT
devices in the digital VSS network. In addition, the VSS network environment requires
supporting network infrastructure, such as access points, bridges, gateways, routers, and
switches.
These non-normative devices are referred to in this standard as network infrastructure
devices. IEC 62676-1-2 provides performance criteria for video network streaming and
infrastructure devices to facilitate a good user experience and interoperability for video
transmission devices.
4.2.2 Network streaming performance: quality of service
Video surveillance applications on IP networks benefit from high network performance and a
good quality of service (QoS) to optimize the way shared network resources are allocated
among different surveillance applications, functions and devices.
All applications running on different video transmission devices have according to the nature
of IP networks an equal opportunity to transmit data frames. Video surveillance is according
to IEC 62676-1-2 sensitive to delay, latency variations and bandwidth reductions. By stream
limitations or prioritized streaming IP video devices define how the video packets access
network resources. In contrast to broadcasting applications with an unknown number of
clients, IP video in security does not define any QoS protocol today. The QoS in a
surveillance network is guaranteed by the proper setup and configuration at design time for a
certain number of operators or receivers and by using the capabilities of a video management
system (VMS) taking care of all video streaming and requests of the single video transmission
devices. Requirements on the quality and performance on streaming are listed in
IEC 62676-1-2.
4.3 Device discovery and description
Device discovery and description enables a device on the VSS network to discover the
presence and capabilities of the device itself and other devices on the network and
collaborate with these devices in a uniform and consistent manner. ZeroConf and WS-
Discovery address all of these needs and simplify device networking in the VSS network. For
this reason device discovery and description is part of the IP solution for VT devices. Clause
10 specifies the detailed protocols to enable interoperability between VT devices in the digital
VSS network. IEC 62676-1-2 specifies that under secure conditions devices cannot be
automatically discovered; network security is then assured and addressed in IEC 62676-1-2.
4.4 Video media types and payload formats
Video formats describe how content is encoded and formatted for transport and final
rendering on the VSS network. The video formats listed in IEC 62676-1-2 are intended to
achieve a baseline for network interoperability while encouraging continued innovation in
video codec technology.
4.5 Video transport
Video transport defines how content travels across the VSS network. VT devices that offer or
receive video streams across the VSS network shall support the streaming protocols. Clause
8 specifies the detailed protocols to enable interoperability between VT devices in the digital
VSS network.
4.6 Eventing and health check
In security providing video streams only is not sufficient. In Clause 11 the need to monitor the
health status of video transm
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