ETSI TR 102 633 V1.1.1 (2008-10)

Corporate Networks (NGCN); Next Generation Corporate Networks (NGCN) - General

DTR/ECMA-00352

General Information

• Status: Published
• Publication Date: 30-Oct-2008
• Technical Committee: Ecma - Standardizing information and communications systems
• Current Stage: 12 - Completion
• Due Date: 12-Nov-2008
• Completion Date: 31-Oct-2008

Standards Content (Sample)

ETSI TR 102 633 V1.1.1 (2008-10)
Technical Report


Corporate Networks (NGCN);
Next Generation Corporate Networks (NGCN) - General

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2 ETSI TR 102 633 V1.1.1 (2008-10)




Reference
DTR/ECMA-00352
Keywords
IP, SIP
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Contents
Intellectual Property Rights . 5
Foreword . 5
Introduction . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 7
3 Definitions . . 7
3.1 Corporate telecommunication Network (CN) (EG 201 017) . 7
3.2 Domain . 7
3.3 Enterprise network . 7
3.4 Home server . 8
3.5 Transport service provider (TSP) . 8
3.6 Medium . 8
3.7 Next Generation CN (NGCN) . 8
3.8 Next Generation Network (NGN) . 8
3.9 Private network traffic . 8
3.10 Public network traffic . 8
3.11 Roaming . 9
3.12 Roaming hub . 9
3.13 Session service provider (SSP) . 9
3.14 SIP intermediary . 9
4 Abbreviations . 9
5 Background . 10
6 General concepts . 11
6.1 Basic communication architecture . 11
6.2 Session level architecture . 13
6.2.1 Signalling using SIP. 13
6.2.2 Media path . 14
6.2.3 Example . 15
6.3 Domains . 15
6.4 Mobility . 16
6.4.1 Roaming of enterprise users outside their home domain . 16
6.4.2 Accommodating guest users on an NGCN . 17
6.5 The hosting concept. 17
6.5.1 Dedicated NGCN . 19
6.5.2 Enterprise hosted by a single public network infrastructure . 19
6.5.3 Enterprise hosted by multiple public network infrastructures . 20
6.5.4 Enterprise hosted by a combination of enterprise infrastructure and a public network infrastructure . 20
6.6 Private network traffic and public network traffic . 21
6.7 Other technical considerations . 22
7 Scenarios for session-based communications . 22
7.1 Session-based intra-domain communications. 22
7.2 Session-based inter-domain communications within a single enterprise network. 24
7.2.1 Communication between domains supported by the same infrastructure . 24
7.2.2 Communications between domains of an NGCN via a TSP . 25
7.2.3 Communications between domains of an NGCN using private network traffic through a hosting
NGN. 25
7.2.4 Communications between domains of an NGCN using public network traffic through a public SSP
such as an NGN . 26
7.2.5 Communications between a dedicated NGCN domain and a domain hosted by an NGN . 26
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7.2.6 Communications between a dedicated NGCN domain and a domain hosted by an NGN as private
network traffic via an intermediate NGN domain . 27
7.3 Session-based communication between two enterprises . 27
7.3.1 Extension of enterprise network to include partner networks . 27
7.3.2 Direct peering . 27
7.3.3 Indirect peering . 28
7.3.4 Third party assistance . 29
7.3.5 Direct peering between two enterprises hosted by the same hosting enterprise infrastructure . 30
7.4 Session-based communication with users of public networks . 30
7.4.1 Communication between an NGCN user and an NGN public network user . 31
7.4.2 Communication between an NGCN user and an NGN public network user with break-in or break-
out function in the NGN . 31
7.4.3 Communication between an NGCN user and a public network user of a remote NGN . 32
7.4.4 Communication between an NGCN user and a public network user of a remote NGN with break-in
or break-out function in the local NGN . 32
7.4.5 Communication between an NGCN user and a public network user of a remote NGN with break-in
or break-out function in the remote NGN . 32
7.4.6 Communication between an NGCN user and a PSTN/ISDN user via an NGN . 33
7.4.7 Communication between an enterprise user hosted by a public network infrastructure and a public
network user of that same infrastructure . 33
7.5 Session-based roaming . 34
7.5.1 An NGCN user at a visited sub-domain of the NGCN . 34
7.5.2 An NGCN user at a visited sub-domain of the NGCN using private network traffic through an NGN . 34
7.5.3 An NGCN user at a visited NGN . 35
7.5.4 An NGCN user at a visited NGN using indirect roaming . 35
7.5.5 An NGN-hosted enterprise user at a visited NGN . 35
7.5.6 An NGN-hosted enterprise user at a visited NGCN . 36
8 NGN considerations . 36
8.1 Summary of scenarios involving NGN . 36
8.1.1 Scenarios involving NGN as a TSP . 36
8.1.2 Scenarios involving NGN as a SSP . 37
8.1.3 Roaming scenarios involving NGN as a SSP . 37
8.2 Interfacing NGCN to NGN . 37
8.2.1 Subscription-based business trunking . 37
8.2.2 Peering-based business trunking . 38
8.2.3 Roaming . 38
9 Application considerations . 38
10 Current standards and standardization efforts . 39
10.1 IETF Real-time Applications and Infrastructure (RAI) area . 39
10.2 SIP Forum . 40
10.3 ETSI TISPAN . 40
10.4 3GPP . 40
10.5 ITU-T Study Group 13 . 40
History . 41

ETSI

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Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ECMA on behalf of its members and those of the European
Telecommunications Standards Institute (ETSI).
Introduction
The present document is the first of a series of Ecma publications that explore IP-based enterprise communication
involving Corporate telecommunication Networks (CNs) (also known as enterprise networks) and in particular Next
Generation Corporate Networks (NGCN). The series particularly focuses on inter-domain communication, including
communication between parts of the same enterprise, between enterprises and between enterprises and carriers. The
present provides general information on the subject, defines some architectural concepts, identifies various
communication scenarios, and provides a framework in support of other publications that provide greater detail on
particular topics.
The present document is based upon the practical experience of Ecma member companies and the results of their active
and continuous participation in the work of ISO/IEC JTC1, ITU-T, ETSI, IETF and other international and national
standardization bodies. It represents a pragmatic and widely based consensus. In particular, Ecma acknowledges
valuable input from experts in ETSI TISPAN.
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1 Scope
The present document is part of a series of publications that provides an overview of IP-based enterprise
communication involving Corporate telecommunication Networks (CNs) (also known as enterprise networks) and in
particular Next Generation Corporate Networks (NGCN). The series particularly focuses on session level
communication based on the Session Initiation Protocol (SIP) [i.6], with an emphasis on inter-domain communication.
This includes communication between parts of the same enterprise (on dedicated infrastructures and/or hosted), between
enterprises and between enterprises and public networks. Key technical issues are investigated, current standardization
work and gaps in this area are identified and a number of requirements are stated.
The present document provides general information on the subject, defines some architectural concepts, identifies
various communication scenarios, and provides a framework in support of other publications that provide greater detail
on particular topics. At the time of publication of the present document, one further document in the series has been
published, on the subject of identification and routing [i.3].
The scope of the present document is limited to communications with a real-time element, including voice, video,
real-time text and instant messaging.
Further details on mobility in an NGCN environment are to be found in ECMA TR/92 [i.2].
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably,
the primary source of the referenced document should be cited, in order to ensure traceability. Furthermore, the
reference should, as far as possible, remain valid for the expected life of the document. The reference shall include the
method of access to the referenced document and the full network address, with the same punctuation and use of upper
case and lower case letters.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
Not applicable.
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2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
[i.1] ECMA-269: "Services for Computer Supported Telecommunications Applications (CSTA) Phase
III".
[i.2] ECMA TR/92: "Corporate Telecommunication Networks - Mobility for Enterprise
Communication".
[i.3] ECMA TR/96: "Next Generation Corporate Networks (NGCN) - Identification and Routing".
[i.4] ITU-T Recommendation H.248: "Gateway control protocol".
[i.5] ITU-T Recommendation H.323: "Packet-based multimedia communications systems".
[i.6] IETF RFC 3261: "SIP: Session Initiation Protocol".
[i.7] IETF RFC 3550: "RTP: A Transport Protocol for Real-Time Applications".
[i.8] IETF RFC 4566: "SDP: Session Description Protocol".
[i.9] SIP Forum sf-adopted-twg-IP-PBX-SP-Interop-sibley-sipconnect: "IP-PBX / Service Provider
Interoperability - SIPConnect 1.0 Technical Recommendation".
[i.10] ETSI EG 201 017: "Corporate Telecommunication Networks (CN); Standardization plan".
[i.11] ETSI TR 180 000: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); NGN Terminology".
[i.12] IEEE 802.1x: "Port Based Network Access Control".
3 Definitions
For the purposes of the present document the following definitions apply:
3.1 Corporate telecommunication Network (CN) (EG 201 017)
Telecommunication network serving a corporation, i.e. a single organization, an extended enterprise, or an industry
application group as defined by the International Chamber of Commerce (ICC).
NOTE: Sets of equipment [Customer Premises Equipment (CPE) and/or Customer Premises Networks (CPN)]
are typically located at geographically dispersed locations and are interconnected to provide networking
services to a defined group of users. A CN can employ connection-oriented and connectionless
technology.
3.2 Domain
Session level capabilities within a single administrative area.
NOTE: A domain may or may not correspond to a DNS domain.
3.3 Enterprise network
A CN comprising session level capabilities and optionally application layer capabilities hosted on one or more
infrastructures.
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NOTE: Infrastructures can include the enterprise's own infrastructure (dedicated NGCN), the infrastructure of one
or more hosting NGNs, the infrastructure of one or more hosting NGCNs or any combination of these.
3.4 Home server
For a given user, as identified by a SIP address of record, the SIP intermediary that contains registrar and proxy
functionality in support of that user.
NOTE: It is therefore the SIP intermediary with which the user's UAs register.
3.5 Transport service provider (TSP)
A business or organization separate from an enterprise that provides services for transporting data based on the use of IP
at the network layer, thereby allowing the enterprise to communicate with entities outside the enterprise or with
geographically dispersed parts of the enterprise.
NOTE 1: Communication can but need not be via the public Internet.
NOTE 2: A TSP should not intervene above the transport layer. This does not preclude a business or organization
that acts as a TSP also acting as the provider of higher level services, e.g. as an SSP.
3.6 Medium
A given type of payload transported between session users (e.g. audio, video, text), separate from any signalling used
for session establishment.
3.7 Next Generation CN (NGCN)
That part of an enterprise network that is not based on public network infrastructure, that is designed to take advantage
of emerging IP-based communications solutions and that can have its own applications and service provisioning.
NOTE: An NGCN can be an entire enterprise network if none of that network is based on public network
infrastructure.
3.8 Next Generation Network (NGN)
The definition in [i.11] applies.
NOTE: This defines an NGN as follows: "A Next Generation Network is a packet-based network able to provide
services including Telecommunication Services and able to make use of multiple broadband,
QoS-enabled transport technologies and in which service-related functions are independent from
underlying transport-related technologies. It offers unrestricted access by users to different service
providers. It supports generalized mobility which will allow consistent and ubiquitous provision of
services to users." It also goes on to list some fundamental aspects that characterize NGN.
3.9 Private network traffic
Signalling for session level communications that is handled according to rules specific to an enterprise network.
3.10 Public network traffic
Signalling for session level communications that is handled according to rules for public networks.
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3.11 Roaming
The use of session capabilities of a visited domain to allow a user to access session level services at his home domain.
NOTE 1: This usually requires a roaming agreement between the operators of the domains concerned.
NOTE 2: This definition of roaming reflects the concept of roaming as found in mobile telephone networks, for
example. It does not encompass certain other common uses of the term, e.g. concerning transport service
provision.
3.12 Roaming hub
A network or other entity with which an enterprise domain has a roaming agreement, allowing enterprise users to visit
other domains that have a roaming agreement with the roaming hub but not directly with the enterprise domain.
3.13 Session service provider (SSP)
A business or organization separate from an enterprise that provides communication capabilities at the session layer
using SIP and thereby allows the enterprise to communicate using SIP with entities outside the enterprise or with
geographically dispersed parts of the enterprise.
3.14 SIP intermediary
Any intermediate entity involved either actively or passively in SIP signalling between two UAs, including but not
limited to proxies, Back-to-Back User Agents (B2BUAs), Application Layer Gateways (ALGs) and Session Border
Controllers (SBCs).
4 Abbreviations
ALG Application Layer Gateway
B2BUA Back-to-Back User Agent
CN Corporate telecommunication Network
DNS Domain Name System
IP Internet Protocol
IPPBX IP Private Branch eXchange
IPSEC Internet Protocol Security
ISDN Integrated Services Digital Network
LAN Local Area Network
NAT Network Address Translator
NGCN Next Generation Corporate Network
NGN Next Generation Network
PNP Private Numbering Plan
PSTN Public Switched Telephone Network
QoS Quality of Service
RTP Real Time Protocol
SBC Session Border Controller
SDP Session Description Protocol
SIP Session Initiation Protocol
SRTP Secure Real Time Protocol
SSP Session Service Provider
TLS Transport Layer Security
TSP Transport Service Provider
UA User Agent
UAC User Agent Client
UAS User Agent Server
URI Universal Resource Identifier
VPN Virtual Private Network
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WAN Wide Area Network
5 Background
Many enterprises and other organizations require their own telecommunications capabilities to support their own
internal communications as well as supporting communications with the outside world. This avoids incurring
unnecessary charges and provides added value in terms of services and features available, integration with other
enterprise applications, etc. These capabilities are provided through enterprise telecommunication networks (or
corporate telecommunication networks, CN, or simply enterprise networks). Many administrations do not apply the
same licensing conditions or regulation to enterprise networks and their internal traffic as they do to public networks
and their public network traffic. Many public networks also offer optional services
...