ETSI TR 101 287 V1.2.1 (2001-09)

Services and Protocols for Advanced Networks (SPAN); Terms and Definitions

RTR/SPAN-140003

Storitve in protokoli za napredna omrežja (SPAN) – Pojmi in definicije

General Information

• Status: Published
• Publication Date: 26-Sep-2001
• Technical Committee: SPAN 14 - SPAN Overall Network and System Architecture (ONSA)
• Current Stage: 12 - Completion
• Due Date: 30-Oct-2001
• Completion Date: 27-Sep-2001
• Ref Project: SIST-TP ETSI/TR 101 287 V1.2.1:2005 - Services and Protocols for Advanced Networks (SPAN); Terms and Definitions

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TP ETSI/TR 101 287 V1.2.1:2005
01-januar-2005
Storitve in protokoli za napredna omrežja (SPAN) – Pojmi in definicije
Services and Protocols for Advanced Networks (SPAN); Terms and Definitions
Ta slovenski standard je istoveten z: TR 101 287 Version 1.2.1
ICS:
01.040.33 Telekomunikacije. Avdio in Telecommunications. Audio
video tehnika (Slovarji) and video engineering
(Vocabularies)
33.040.35 Telefonska omrežja Telephone networks
SIST-TP ETSI/TR 101 287 V1.2.1:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005

---------------------- Page: 2 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005

ETSI TR 101 287 V1.2.1 (2001-09)
Technical Report


Services and Protocols for Advanced Networks (SPAN);
Terms and definitions

---------------------- Page: 3 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 2 ETSI TR 101 287 V1.2.1 (2001-09)



Reference
RTR/SPAN-140003
Keywords
vocabulary
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
Individual copies of the present document can be downloaded from:
http://www.etsi.org
The present document may be made available in more than one electronic version or in print. In any case of existing or
perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF).
In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive
within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
http://portal.etsi.org/tb/status/status.asp
If you find errors in the present document, send your comment to:
[e-mail]
Copyright Notification
No part may be reproduced except as authorized by written permission.
The copyright and the foregoing restriction extend to reproduction in all media.

© European Telecommunications Standards Institute 2001.
All rights reserved.

ETSI

---------------------- Page: 4 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 3 ETSI TR 101 287 V1.2.1 (2001-09)
Contents
Intellectual Property Rights.4
Foreword.4
1 Scope.5
2 References.5
3 Information about the present document.9
3.1 The distinction between old and new technologies .9
3.2 Generic vs. Specific.10
4 Vocabulary of terms.11
5 Abbreviations and acronyms.54
History .66

ETSI

---------------------- Page: 5 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 4 ETSI TR 101 287 V1.2.1 (2001-09)
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://www.etsi.org/legal/home.htm).
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 ETSI Technical Committee Services and Protocols for Advanced
Networks (SPAN).
ETSI

---------------------- Page: 6 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 5 ETSI TR 101 287 V1.2.1 (2001-09)
1 Scope
The present document lists the terms used in the ETSI Standards and Technical Reports covering network aspects in
general. Included are terms already defined in other technical areas if they have a special meaning in a network aspects
context or if an unambiguous definition is essential.
The terms are listed in alphabetical order only and are not sorted according to the technical area (services, powering,
transfer mode, signalling, interfaces etc.) to which they belong.
The list of abbreviations and acronyms include acronyms defined in other contexts and used in network aspect
documents.
2 References
For the purposes of this Technical Report (TR) the following references apply:
[1] ITU-T Recommendation B.13 (1988): "Terms and definitions".
[2] ITU-T Recommendation D.000 (2000): "Terms and definitions for the Series-D
Recommendations".
[3] ITU-T Recommendation E.164 (1997): "The international public telecommunication numbering
plan".
[4] ITU-T Recommendation E.600 (1993): "Terms and definitions of traffic engineering".
[5] ITU-T Recommendation F.500 (1992): " International public directory services".
[6] ITU-T Recommendation G.601 (1980): "Terminology for cables".
[7] ITU-T Recommendation G.701 (1993): "Vocabulary of digital transmission and multiplexing, and
pulse code modulation (PCM) terms".
[8] ITU-T Recommendation G.707 (2000): "Network node interface for the synchronous digital
hierarchy (SDH)".
[9] ITU-T Recommendation G.803 (2000): "Architecture of transport networks based on the
synchronous digital hierarchy (SDH)".
[10] ITU-T Recommendation G.805 (2000): "Generic functional architecture of transport networks".
[11] ITU-T Recommendation G.810 (1996): "Definitions and terminology for synchronization
networks".
[12] ITU-T Recommendation G.823 (2000): "The control of jitter and wander within digital networks
which are based on the 2048 kbit/s hierarchy".
[13] ITU-T Recommendation G.902 (1995): "Framework Recommendation on functional access
networks (AN) Architecture and functions, access types, management and service node aspects".
[14] ITU-T Recommendation H.223 (1996): "Multiplexing protocol for low bit rate multimedia
communication".
[15] ITU-T Recommendation H.323 (2000): "Packet-based multimedia communications systems".
[16] ITU-T Recommendation I.112 (1993): "Vocabulary of terms for ISDNs".
[17] ITU-T Recommendation I.113 (1997): "Vocabulary of terms for broadband aspects of ISDN".
[18] ITU-T Recommendation I.140 (1993): "Attribute technique for the characterisation of
telecommunication services supported by an ISDN and network capabilities of an ISDN".
ETSI

---------------------- Page: 7 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 6 ETSI TR 101 287 V1.2.1 (2001-09)
[19] ITU-T Recommendation I.150 (1999): "B-ISDN asynchronous transfer mode functional
characteristics".
[20] ITU-T Recommendation I.233.1 (1991): "ISDN frame relaying bearer service".
[21] ITU-T Recommendation I.322 (1999): "Generic protocol reference model for telecommunication
networks".
[22] ITU-T Recommendation I.363 series: "B-ISDN ATM Adaptation Layer (AAL) specification.
Type x AAL".
[23] ITU-T Recommendation I.371 (1996): "Traffic control and congestion control in B-ISDN".
[24] ITU-T Recommendation I.374 (1993): "Framework Recommendation on "network capabilities to
support multimedia services".
[25] ITU-T Recommendation I.501 (1993): "Service interworking".
[26] ITU-T Recommendation I.510 (1993): "Definitions and general principles for ISDN
interworking".
[27] ITU-T Recommendation I.570 (1993): "Public/private ISDN interworking".
[28] ITU-T Recommendation J.1 (1999): "Terms, definitions and acronyms applicable to the
transmission of television and sound-programme signals and of related data signals".
[29] ITU-T Recommendation M.60 (1993): "Maintenance terminology and definitions".
[30] ITU-T Recommendation M.3010 (2000): "Principles for a Telecommunications management
network".
[31] ITU-T Recommendation Q.9 (1988): "Vocabulary of switching and signalling terms".
[32] ITU-T Recommendation Q.65 (1997): "The unified functional methodology for the
characterisation of services and network capabilities".
[33] ITU-T Recommendation Q.825 (1998): "Specification of TMN applications at the Q3 interface:
Call detail recording".
[34] ITU-T Recommendation Q.921 (1997): "ISDN user-network interface - Data link layer
specification".
[35] ITU-T Recommendation Q.1290 (1998): "Glossary of terms used in the definition of intelligent
networks".
[36] ITU-T Recommendation Q.2931 (1995): "Digital Subscriber Signalling System No. 2
- User-Network Interface (UNI) layer 3 specification for basic call/connection control".
[37] ITU-T Recommendation V.56bis (1995): "Network transmission model for evaluating modem
performance over 2-wire voice grade connections".
[38] ITU-T Recommendation X.200 (1994): "Information technology - Open Systems Interconnection -
Basic Reference Model: The basic model".
[39] ITU-T Recommendation X.213 (1995): "Information technology - Open Systems Interconnection -
Network service definition (Common text with ISO/IEC)".
[40] ITU-T Recommendation X.700 (1992): "Management framework for Open Systems
Interconnection (OSI) for CCITT applications".
[41] ITU-T Recommendation X.903 (1995): "Information technology - Open distributed processing -
Reference Model: Architecture (Common text with ISO/IEC)".
[42] ITU-T Recommendation Y.101 (1999): "GII Terminology".
[43] ITU-T Recommendation Y.110 (1998): "Global Information Infrastructure principles and
framework architecture".
ETSI

---------------------- Page: 8 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 7 ETSI TR 101 287 V1.2.1 (2001-09)
[44] ITU Radio Regulations.
[45] ETSI ETR 044: "Network Aspects (NA); Reference events for network performance parameters in
an ISDN".
[46] ETSI ETR 149: "Network Aspects (NA); Interworking between Metropolitan Area Networks
(MANs) and Asynchronous Transfer Mode (ATM) networks for the Connectionless Broadband
Data Service (CBDS)".
[47] ETSI ETR 155: "Asynchronous Transfer Mode (ATM); Operation Administration and
Maintenance (OAM) functions and parameters for assessing performance parameters".
[48] ETSI ETR 161: "Broadband Integrated Services Digital Network (B-ISDN); Functional
description of Virtual Path (VP) cross-connect".
[49] ETSI TR 101 287 (V1.1.1): "Network Aspects (NA); Terms and definitions".
[50] ETSI TR 101 615: "Network Aspects (NA); Services and networks architecture evolution for
telecommunications".
[51] ETSI TR 101 686: "Hybrid Fibre Coax (HFC) access networks; Interworking with B-ISDN
networks".
[52] ETSI TR 101 694: "Asynchronous Transfer Mode (ATM); Provision of internet applications via
ATM based networks and interworking with IP networks".
[53] ETSI TR 101 734: "Internet Protocol (IP) based networks; Parameters and mechanisms for
charging".
[54] ETSI TR 101 619: "Network Aspects (NA); Considerations on networks mechanism for charging
and revenue accounting".
[55] ETSI TR 102 100: "Network Aspects (NA); Interworking framework".
[56] ETSI EG 201 400: "Hybrid Fiber Coax (HFC) access networks; Part 1: Interworking with PSTN,
N-ISDN, Internet and digital mobile networks".
[57] ETSI ETS 300 349: "Broadband Integrated Services Digital Network (B-ISDN); Asynchronous
Transfer Mode (ATM); Adaptation Layer (AAL) specification - type 3/4".
[58] I- ETSI ETS 300 353: "Broadband Integrated Services Digital Network (B-ISDN); Asynchronous
Transfer Mode (ATM); Adaptation Layer (AAL) specification - type 1".
[59] ETSI ETS 300 354: "Broadband Integrated Services Digital Network (B-ISDN); B-ISDN Protocol
Reference Model (PRM)".
[60] ETSI ETS 300 404: "Broadband Integrated Services Digital Network (B-ISDN); B-ISDN
Operation And Maintenance (OAM) principles and functions".
[61] ETSI ETS 300 469: "Broadband Integrated Services Digital Network (B-ISDN); Asynchronous
Transfer Mode (ATM); Management of the network element view [ITU-T Recommendation I.751
(1996)]".
[62] ETSI ETS 300 478: "Network Aspects (NA); Connectionless Broadband Data Service (CBDS)
over Asynchronous Transfer Mode (ATM); Framework and protocol specification at the User-
Network Interface (UNI)".
[63] ETSI ETS 300 479: "Network Aspects (NA); Connectionless Broadband Data Service (CBDS)
over Asynchronous Transfer Mode (ATM); Protocol specification at the Network Node
Interface (NNI)".
[64] ETSI ETS 300 780: "Broadband Integrated Services Digital Network (B-ISDN); Broadband
Connection-Oriented Bearer Service (BCOBCS) [ITU-T Recommendation F.811 (1996)]".
[65] ETSI EG 201 898: "Services and Protocols for Advanced Networks (SPAN); Relationship
between IP and telecommunication networks".
ETSI

---------------------- Page: 9 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 8 ETSI TR 101 287 V1.2.1 (2001-09)
[66] ETSI ES 201 803-1: "Dynamic synchronous Transfer Mode (DTM); Part 1: System Description".
[67] ANSI T1.105.06 (1996): "Synchronous Optical Network (SONET) - Physical Layer Specification
(Revision of ANSI T1.106-1988)".
[68] IEEE 802.3, 2000 Edition (ISO/IEC 8802-3, 2000): "IEEE Standard for Information technology -
Local and metropolitan area networks - Part 3: Carrier sense multiple access with collision
detection (CSMA/CD) access method and physical layer specifications".
[69] ATM-Forum (af-ra-0106.000): "ATM Forum Addressing: Reference Guide".
[70] IETF FYI 4 (RFC 2664): "FYI on Questions and Answers - Answers to Commonly Asked New
Internet User Questions".
[71] IETF RFC 768 (1980): "User Datagram Protocol".
[72] IETF RFC 1208 (1991): "Glossary of networking terms".
[73] IETF RFC 1953 (1996): "Ipsilon Flow Management Protocol Specification for IPv4 Version 1.0";
P. Newman, W. Edwards, R. Hinden, E. Hoffman, F. Ching Liaw, T.Lyon & G. Minshall".
[74] IETF RFC 1983 (August 1996): "Internet Users' Glossary", G. Malkin, Editor".
[75] IETF RFC 2663 (1999): "IP Network Address Translator (NAT) Terminology and
Considerations"; P. Srisuresh, M. Holdrege".
[76] IETF RFC 2828 (2000): "Internet Security Glossary".
[77] IETF RFC 2881 (July 2000): "Network Access Server Requirements Next Generation
(NASREQNG) NAS Model".
[78] Federal Standard FED-STD-1037C (1996): "Telecommunications: Glossary of
Telecommunication Terms"; The U.S. Department of Commerce, National Telecommunications
and Information Administration, Institute for Telecommunication Sciences (NTIA/ITS)".
[79] "Telephony's Dictionary", second Edition; Graham Langley; Telephony Publishing Corporation,
1986, USA; ISBN 0-917845-04-8.
[80] ITU-T Recommendation X.680: "Information technology - Abstract Syntax Notation One
(ASN.1): Specification of basic notation".
[81] ITU-T Recommendation X.690: "Information technology - ASN.1 encoding rules: Specification of
Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding
Rules (DER)".
[82] ISO 8859-1: "Information technology - 8-bit single-byte coded graphic character sets -
Part 1: Latin alphabet No. 1".
[83] ISO 10646: "Information technology - Universal Multiple-Octet Coded Character Set (UCS) -
Part 1: Architecture and Basic Multilingual Plane".
[84] IETF RFC 1519: "Classless Inter-Domain Routing (CIDR): an Address Assignment and
Aggregation Strategy".
[85] ETSI ETS 300 415: "Private Integrated Services Network (PISN); Terms and definitions".
[86] IETF RFC 791: "Internet Protocol".
[87] ITU-T Recommendation I.510: "Definitions and general principles for ISDN interworking".
[88] ITU-T Recommendation I.114: "Vocabulary of terms for universal personal telecommunication".
[89] ITU-T Recommendations G.825: "The control of jitter and wander within digital networks which
are based on the synchronous digital hierarchy (SDH)".
[90] ITU-T Recommendation I.361: "B-ISDN ATM layer specification".
ETSI

---------------------- Page: 10 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 9 ETSI TR 101 287 V1.2.1 (2001-09)
[91] ISO/IEC 11579-1: "Information technology - Telecommunications and information exchange
between systems - Private integrated services network - Part 1: Reference configuration for PISN
Exchanges (PINX)".
[92] ITU-T Recommendation I.430: "Basic user-network interface - Layer 1 specification".
[93] ITU-T Recommendation I.431: "Basic user-network interface - Layer 1 specification".
[94] ITU-T Recommendation F.850: "Principles of universal personal telecommunication (UPT)".
[95] ETSI ETS 300 455: "Broadband Integrated Services Digital Network (B-ISDN); Broadband
Virtual Path Service (BVPS); Part 1: BVPS for Permanent communications (BVPS-P)".
[96] IETF RFC 1577: "Classical IP and ARP over ATM".
3 Information about the present document
Terms and definitions taken from ITU Recommendations are identified by appropriate reference in parentheses at the
end of the definition. The numbers after the Q.9, G.601, G.701, I.112, I.113 and I.114 references are the word numbers
in these documents.
Where the definition has been based upon, but differs from, a definition in another document, the reference is given
followed by "modified".
Terms defining general used acronyms such as Asynchronous Transfer Mode (ATM) are written with leading
capitals.
Some definitions include terms in italics to indicate that these terms are defined elsewhere in the present document.
The list of abbreviations and acronyms includes acronyms such as PAL and SECAM normally not used in network
aspect contexts but generally used in the relevant standards and technical reports. Also included are acronyms with
more than one meaning such as CC for Call Control, Country Code or Cross Connect. For some acronyms it is indicated
in brackets in which context they are created, e.g. (Internet), (ATM Forum). Some out-of-date acronyms are marked
(deprecated).
Many terms are overloaded with several meanings. For instance "virtual circuit" has a generic meaning and also a very
specific non-generic meaning in ATM. For these multiple-meaning cases the generic form is presented first and the
specific forms follow the generic form as new definitions but marked with area/scope within square brackets after the
term in question. In cases where a term is valid within more than one field (and is not valued as a generic definition) the
areas for which it applies are given within square brackets as a comma separated alphabetically ordered list
During the revision of the document specific concerns were raised regarding the usage of terminology which were
found to be worth addressing them in particular. It is considered that these will be enlightening to the reader of the
present document and provide a guideline outside the scope of the contained definitions while also conveying the
specific generic revision decisions being made.
3.1 The distinction between old and new technologies
In older telecommunication definitions many terms were defined with an embedded distinction to some other
technology. A classical example would be "analogue link" versus "digital link" which was required to distinguish old
analogue FDM systems with then new TDM systems. Thus, the need to create definitions for digital switching only
becomes of interest if you know and assume that switching normally used to be done with analogue channels.
Furthermore, the use of qualifiers like "emerging" is also part of a definition which will not survive the time. What was
emerging and new at the time of the definition will be old in 10 to 20 years time and possibly be amusing to the
engineers at that time.
A more subtle error of the same kind is to be found when a technology is being associated with a certain bit rate. For
most technologies the bit rates they can support is changing over time. So, stating that Ethernet has the bit rate of 10
Mbit/s (which used to be true) would only date the definition to be historic at best. The usage of bit rates other than for
examples or when a certain name has been given to denote a speed (i.e. E1, T1 etc.) shall thus be avoided.
ETSI

---------------------- Page: 11 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 10 ETSI TR 101 287 V1.2.1 (2001-09)
3.2 Generic vs. Specific
Many terms have been found to apply only for specific technology areas even though the term bears no reference to that
area. In such cases a more generic definition has been included. Also, some definitions have carried a subtle binding to
a specific technology or means of implementation while this may be questioned. For those cases the definition was
modified or replaced in order to provide a generic definition that only grasps the property while not implicating certain
types of implementations.
ETSI

---------------------- Page: 12 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 11 ETSI TR 101 287 V1.2.1 (2001-09)
4 Vocabulary of terms
address mask: bit mask used to identify the bits in an address which correspond to certain specific portions of the
address
address resolution: Conversion of a network-layer address (e.g. IP address) into the corresponding physical address
(e.g., MAC address) (see IETF RFC 1983).
addressable entity: entity which is recognizable by the network, to which the network is able to route a call
addressing domain: context within which an identifier (name, number, etc.) is unique
Abstract Syntax Notation One (ASN.1): language used by the OSI protocols for describing abstract syntax
NOTE 1: ASN.1 is defined in ISO documents 8824.2 and 8825.2, and ITU Recommendations X.680-X690,
ISO standards 8824.2 and 8825.2, ITU-T Recommendations series X.680 to X.690.
access capability [ISDN]: Number and type of the access channels at an ISDN access interface that are actually
available for telecommunication purposes (see ITU-T Recommendation I.112-416).
access channel (channel) [ISDN]: Channel provided at the User Network Interface (see: channel).
NOTE 2: The term "access channel" may be qualified, for example by H, B or D in which case it is appropriate to
abbreviate the term to "H-channel", to "B-channel" or to "D-channel".
access connection element (subscriber access) [ISDN]: equipment providing the concatenation of functional groups
between and including the exchange termination and the NT1
NOTE 3: The term should be qualified by the type of access supported. That is either basic access connection
elements or primary rate access connection elements (see ITU-T Recommendation I.112-429).
access contention [ISDN]: Conflict between the demands made on a network termination in multipoint access (see
ITU-T Recommendation I.112-423).
access contention resolution [ISDN]: Arbitration of conflicting demands on a network termination in multipoint
access (see ITU-T Recommendation I.112-424).
access function: Set of processes in a network that provide for interaction between the user and a network (see ITU-T
Recommendation Q.1290).
access network: Implementation comprising those entities (such as cable plant, transmission facilities, etc.) which
provide the required transport bearer capabilities for the provision of telecommunication services between one or more
Service Node Interfaces (SNI) and each of the associated User Network Interfaces (UNI). An access network according
to ITU-T Recommendation G.902 does not interpret user signalling. ITU-T Recommendation G.902 (modified), see
also ITU-T Recommendation Y.101.
Access Network Interface (ANI): Interface between a local switch and an access network within a local network (see
ITU-T Recommendation Y.101).
access network operator: Network operator to which the customer is physically connected (see TR 101 619).
access node: edge node of a network providing access to a network and its services
access protocol: Defined set of procedures that is adopted at an Access Network Interface enable the user to employ the
service and/or facilities of that network (see ITU-T Recommendation I.112-406 modified).
accounting: procedure whereby revenue is shared between operators (see ITU-T Recommendation D.000 modified).
acknowledgement (ACK): Type of message sent to indicate that a previously sent message arrived at its destination.
(See also: Negative Acknowledgement IETF RFC 1983 modified).
activation [ISDN]: Function which places a system, or part of a system, which may have been in low power
consumption mode during deactivation, into its fully operating mode (see ITU-T Recommendation I.112-602).
ETSI

---------------------- Page: 13 ----------------------

SIST-TP ETSI/TR 101 287 V1.2.1:2005
 12 ETSI TR 101 287 V1.2.1 (2001-09)
actor: person or an entity who plays a visible role in the IN environment
address: String or combination of decimal digits, symbols, and additional information which identifies the specific
termination point(s) in a network(s) (see ITU-T Recommendation E.164, modified).
address mask [IP]: Bit mask used to identify which bits in an IP address correspond to the network and subnet portions
of the address. This mask is often referred to as the subnet mask because the network portion of the address (i.e., the
network mask) can be determined by the encoding inherent in an IP address. See also: Classless Inter- domain Routing
(see IETF RFC 1983).
address resolution: conversion of an address into some other address, possibly of another address format
addressable entity: entity which is recognizable by the network, to which the network is able to route a call or message

addressing domain: context within which an identifier (name, number, etc.) is unique
Adjunct (AD): Entity in the Intelligent Network that is functionally equivalent to a service control point but is directly
connected to a service switching point (see ITU-T Recommendation Q.1290).
Administrative Domain (AD): Collection of hosts and routers, and the interconnecting network(s), managed by a
single administrative organization (see IETF RFC 1983 modified).
Administrative Interface [Number Portability]: Interface/information base in which information on ported numbers
is available for Network Operators (see TR 101 619).
Advice Of Charge (AOC): supplementary service related to the presentation of charging information to the user
NOTE 4: AOC appears in three versions AOC-S provides the served user with information about the charging rates
at call establishment. In addition, the served user shall be informed if a change in charging rates takes
place during the call. AOC-D provides the served user with cumulative charging information during the
call. AOC-E provides the served user with charging information for a call when the call is terminated (see
TR 101 619).
agent: Agent is an element that performs some task on behalf of some party (i.e., a user, machine, application, or
another agent) rather than having the party itself perform the task (see ITU-T Recommendation Y.101).
aggregate stream: Stream composed of an aggregation of many individual streams (see EG 201 898).
alias: name/address that is translated into another name/address
NOTE 5: The translation may be done in order to provide shorter and/or easier names to a user.
NOTE 6: The translation may be done in order to make a virtual name/address to be widely spread while the real
name/address is being kept in some database (see IETF RFC 1983 modified).
American Standard Code for Information Interchange (ASCII): standard character-to-number encoding widely
used in the computer industry
NOTE 7: In more recent times it is being replaced by ISO 8859-1 and ISO 10646. However, ASCII is still widely
used to denote binary encoding of alphanumeric text (see IETF RFC 1983).
analogue signal: Signal one of whose characteristic quantities follows continuously the variation of another quantity
representing information (see ITU-T Recommendation I.112-103).
anisochronous: essential characteristic of a time-scale or a signal such that the time intervals between consecutive
significant instants do not necessarily have the same duration or durations that are integral multiples of the Unit Interval
NOTE 8: Isochronous and anisochronous are characteristics of a signal, while synchronous and asynchronous are
relationships (see ITU-T Recommendation G.701 modified and US Fed. Std.1037C.
appliance: Generic term used to describe the termina
...