Download 6. Next Generation Networks A. Transition to NGN B. Key

6. Next Generation Networks
6.1. Transition to NGN
6.2. Key drivers of NGN development
6.3. Evolution of networks’ architecture to NGN
6.4. NGN architecture
6.5. Main NGN protocols and building blocks
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6.1. Transition to NGN: First wave
• Growth of Internet and other IP-based networks with their
requirements for bandwidth and capacity has driven rapid
innovation in telecommunication access and transport networks
Examples:
– leveraging copper wire “last-mile” networks through digital
subscriber line (“DSL”) technologies
– re-architecturing of cable networks to support IP services
– advances in optical networking technologies (e.g. PON)
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Convergence of Telephony World and Internet World
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Transition to NGN: Second wave
• Ongoing trend towards integration & interoperability of IPbased and PSTN network services and applications
• Emergence of differentiated Quality of Service IP-based services
• Managed end-to-end performance needed for new applications
requiring real-time traffic (e.g., video, voice)
• New network management, QoS, traffic engineering, pricing &
accounting models
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Transition to NGN: Third wave
• Evolution of current PSTN, mobile, wireless and
IP-based networks to unified Next Generation Networks
providing both Internet and carrier-grade telecommunications
networks and services offerings with QoS
• Transition to Third wave:
Ubiquitous & Pervasive Networks
– anybody, anytime, anywhere
• Global Information Infrastructure (GII) – ITU, 1995
• EII ETSI Project (1995)
• ETSI – 3GPP (1998)
• 3GPP activity (FMC and IMS development)
• TISPAN Project (ETSI, 2003)
TISPAN - Telecoms & Internet converged Services & Protocols for Advanced
Networks
• ITU NGN 2004 Project
• Y.1xx ITU-T – SG 13 “NGN – Architecture, Evolution and Convergence”
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Transition to NGN: Third wave
Today
Tomorrow
Internet
Telephone
network
Mobile radio
network
IP-Network
Multimedia Access - Advantages
• easy to handle
• reliable
• mobile
One unified network for everything
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The Unified Network
The Vision
Situation Today
Target Solution
Voice
Fix and Mobile
The Unified
Multi Service
Network
FR
...
IP
ATM
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The Unified Network
The Data Migration
Voice
The Unified
Multi Service
Network
FR
...
ATM
IP
Pure technology/standardization matter:
How different data services
can transport over a unique data backbone
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The Unified Network
The Voice Migration
Somewhat more complex
- From circuit switched to packet switched
- Voice switches need to disappear in the long term
Voice
The Unified
Multi Service
Network
FR
...
ATM
IP
A new network concept supporting voice in
a packetized environment is required
The Next Generation Network
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ITU-T definition of NGN (Y.2001, Feb 2004)
“A Next Generation Network (NGN) is a packet-based network
able to provide services including Telecommunications 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.”
One of the primary goals of NGN is to provide a common, unified,
and flexible service architecture that can support multiple types of
services over multiple types of transport networks.
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NGN is the public packet-based network with the
following main features:
– Layered architecture
– Open interfaces between the layers and all other networks
– Seamless control of multiple transport technologies
– Centralized intelligence
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NGN Characteristics
The NGN is characterized by the following fundamental aspects:
• Packet-based transfer in the core NGN network
• Support for a wide range of services, applications and mechanisms
(including real time/ streaming/ non-real time services and multi-media)
• Independence of service-related functions from underlying transport
technologies
• Separation of control functions among bearer capabilities, call/session, and
applications/services
• Broadband capabilities with required end-to-end QoS
• Interworking with legacy networks via open interfaces
• Generalized mobility
• Unrestricted access by users to different service providers
• Services convergence between Fixed/Mobile
• Compliance with all Regulatory requirements, for example concerning
emergency communications, security/privacy, etc.
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6.2. Key drivers of NGN development
• Short Term objective:
Create new revenue possibilities
– Removal of boundaries between voice and data opens
the way to new kind of services
– Can be realized relatively quickly with limited
investments
• Long Term objective:
Realize cost savings
– Simpler network
– More efficient network
– Cheaper network components
– Full benefit only realized when all separate networks
have fully migrated towards to the target solution
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Key drivers: technologies and services
Driven by
Cost Reduction
Possibilities
Driven by
Revenue Increase
Possibilities
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NGN key drivers:
From IP Technology to User and Application
Centric
• User demands
–
–
–
–
easiness to use and personalization of services
seamless service regardless of the access technology
a “beautiful garden” offering valuable services with security
openness to the entire Community
• Operator challenges need to be addressed
–
–
–
–
need to manage complexity to deliver simplicity
platform for convergence of services and technologies
support of different device and access technologies
revenue opportunities by mobility and nomadicity, worldwide
use
– support migration from existing technologies
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NGN services
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NGN Services
• Voice Telephony – NGN will likely need to support various existing voice telephony
services (e.g., Call Waiting, Call Forwarding, 3-Way Calling, various IN features,
various Centrex features and etc.).
• Data Services – Allows for the real-time establishment of connectivity between
endpoints, along with various value-added features
• Multimedia Services – Allows multiple parties to interact using voice, video, and/or
data.
• Virtual Private Networks (VPNs) – Voice VPNs improve the interlocation networking
capabilities of businesses by allowing large, geographically dispersed organizations to
combine their existing private networks with portions of the PSTN, thus providing
subscribers with uniform dialing capabilities.
.
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NGN Services
• Public Network Computing (PNC) – Provides public
network-based computing services for businesses and
consumers.
• Unified Messaging – Supports the delivery of voice mail, email,
fax mail, and pages through common interfaces.
• Information Brokering – Involves advertising, finding, and
providing information to match consumers with providers.
• E-Commerce – Allows consumers to purchase goods and
services electronically over the network. Home banking and
home shopping fall into this category of services. This also
includes business-to-business applications
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NGN Services
• Call Center/Web Contact Services – A subscriber could place
a call to a call/Web contact center agent by clicking on a Web
page.
• Interactive gaming – Offers consumers a way to meet online
and establish interactive gaming sessions (e.g., video games).
• Distributed Virtual Reality – Refers to technologically
generated representations of real world events, people,
places, experiences, etc.,
• Home Manager – With the advent of in-home networking and
intelligent appliances, these services could monitor and
control home security systems, energy systems, home
entertainment systems, and other home appliances.
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Applications
•
•
•
•
•
•
•
•
•
•
•
•
•
VoIP
Web Browsing
Chat
Instant Messaging
WAP Browsing
Multimedia Messaging
VoD – Movies/Gaming/News/Sports/Training
Video Telephony
Video Broadcasting
Video Conferencing
Video Collaboration
IP PBX/Centrex
Email
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NGN Today:
Facing the Multi-Application/Multi-Access Challenge
Web, email,
chat, etc.
Video on Demand
(VoD)
High Definition TV
(HDTV)
Gaming
Conversational realtime communication
Smart Home
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6.3. Evolution of networks’ architecture to NGN
• The unified network will use packet-based technology as
the common transport mechanism
– Data is the fastest growing segment due to
• Success of Internet
• Growing use of E-mail
• Growing data traffic between business users
– Data should be handled in the most efficient way
– Packet technology is the best way to transport data
– Packet technology is only technology that allows
simultaneous delivery of different information streams
towards one and the same end-point on one single
connection
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Evolution of network architecture
•Traditional telephony - Circuit switch based PSTN
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Evolution of network architecture
• Circuit Switched PSTN + Packet Switched IP network (VoIP
Gateway)
SG – Signaling gateway
MGC – Media gateway controller
MG – Media gateway
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Evolution of network architecture
•Completely IP-oriented network
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Convergence of network technologies and
media
Nx64 kbps
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6.4. NGN architecture
Management
System Management Servers
Application
Servers
Applications
Softswitches
Signaling
gateways
Control
Core
Edge
Access
Mobile
UTRAN
Enterprise Customers
Packet Network
Media
Gateway
Media
Gateway
Broadband
DSL
Cable
Remote Office/SOHO
PSTN
CO
WLL
Residential
Users
Mobile
Users
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NGN architecture - NGN functional model
Application Servers
Management Servers
Application/Managemen
t Part
Open Services
Interfaces/API
…
Softswitches
Session Part
(Call control)
Media Gateway
Control
…
Media Gateways
Transport Layer
API - Application Programming Interface
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NGN architecture
Softswitch
Application Server
Network Management
Server
Services
PSTN, GSM, ATM, ...
Multiservice Access
IP network
Media Gateway
Transport
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ITU-T NGN architecture (Y.1001) and
corresponding protocols
IP Network IW Functions PSTN/ISDN
•Softswitch includes MGC, SG
•Media Gateway is protocol converter
•Media Gateway Controller is master
controller of a media gateway
•Intelligent Database - Network directory,
ID/MGC
Billing, Call records
H.323/SIP/SIP-T/
SIGTRAN
Intelligent
Database (ID)
.
.
ID/SG
.
API
Signaling
Gateway (SG)
SG/MGC
MGC/MGC
.
.
.
CC7/SS7
ISUP
MG Controller
(MGC)
.
MGC/MG MGCP/Megaco(H.248)
.
RTP Packet Flow
(Voice/Data/MM)
Media Gateway
(MG)
.
TDM Flow (Voice)
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6.5. Main NGN protocols and building blocks
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A.
Main control protocols
Call Control (Session Control)
The ability of a network element to establish new calls.
A “call” in the next generation network can be viewed as
a session in which the session establishes either a voice
conversation or, ultimately, a multimedia (audio plus video)
stream.
There are two primary call control protocols unique to
packet-based networks:
H.323
SIP
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H.323, ITU-T
• H.323 - first call control standard for multimedia networks.
Was adopted for VoIP by the ITU in 1996
• H.323 is actually a set of recommendations that define how
voice, data and video are transmitted over IP-based networks
• The H.323 recommendation is made up of multiple call control
protocols. The audio streams are transacted using the
RTP/RTCP
• In general, H.323 was too broad standard without sufficient
efficiency. It also does not guarantee business voice quality
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SIP - Session Initiation Protocol, IETF (Internet
Engineering Task Force)
• SIP - standard protocol for initiating an interactive user session
that involves multimedia elements such as video, voice, chat,
gaming, and virtual reality. Protocol claims to deliver faster callestablishment times.
• SIP works in the Session layer of IETF/OSI model. SIP can
establish multimedia sessions or Internet telephony calls. SIP
can also invite participants to unicast or multicast sessions.
• SIP supports name mapping and redirection services. It makes
it possible for users to initiate and receive communications and
services from any location, and for networks to identify the
users wherever they are.
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SIP - Session Initiation Protocol, IETF
•SIP – client-server protocol, Rq from clients, Rs from servers.
Participants are identified by SIP URLs. Requests can be sent
through any transport protocol, such as UDP, or TCP.
•SIP defines the end system to be used for the session, the
communication media and media parameters, and the called
party's desire to participate in the communication.
•Once these are assured, SIP establishes call parameters at
either end of the communication, and handles call transfer and
termination.
•The Session Initiation Protocol is specified in IETF Request
for Comments (RFC) 2543.
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IN Control
Feature servers provide IN control with legacy central
offices and Softswitches.
INAP (Intelligent Network Application Part) - a member
of the family of SS7 application protocols.
Additional IN protocols have also been developed
for mobile networks (e.g. GSM-CAMEL).
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Gateway control
The target of the Gateway control - to enable a simple
media gateway implementation with intelligence
centralized on a media gateway controller (which is also
called a call agent or a Softswitch)
Two gateway control protocols:
Media Gateway Control Protocol (MGCP) as the de
facto standard
H.248/Megaco as the ITU and IETF approved standard.
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MGCP/Megaco/H.248
• MGCP - Media Gateway Control Protocol, IETF
[Telcordia (formerly Bellcore)/Level 3/Cisco]
• MGCP – control protocol that specifically addresses the
control of media gateways
• Megaco/H.248 (IETF, ITU) - standard that combines
elements of the MGCP and the H.323, ITU (H.248)
• The main features of Megaco - scaling (H.323) and
multimedia conferencing (MGCP)
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Media Control
Media control is a form of device control used for network
elements that are specialized for advanced media processing.
Media control includes instructions to play and record voice
files, collect and generate tones (including DTMF touch-tones),
establish N-way conferences, perform fax conversions, generate
text-to-speech, and perform speech recognition.
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Application Program Interface
API - routing, billing, call control, and media control on
the feature server and application server.
The goal of the APIs is to enable:
1. Service logic that is independent of network protocols,
network deployment architecture, and reference element
architecture to meet the service provider requirement for
service ubiquity
2. Services that scale from an entry level integrated
solution to a distributed network deployment without
modifications, meeting the service provider requirement
for low cost infrastructure
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Main transport protocols
Real-Time Transport Protocol (RTP) and Real-Time Control Protocol (RTCP)
RTP - for end-to-end network transport of communications services requiring
real-time data (i.e., audio and/or video).
Real-Time Control Protocol (RTCP) – for data transport monitoring
RTP and RTCP are designed to be independent of the underlying network layers (e.g.,
UDP/IP, MPLS, or ATM).
RTP does not address resource reservation nor does it guarantee quality-of-service
(QoS).
Resource Reservation Setup Protocol (RSVP)
Multi-Protocol Label Switching (MPLS)
RTP routing over MPLS sessions
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NGN architecture – possible NGN configuration
Network
Manager
Application Server
ID AAA
API
(Parlay, LDAP)
SNMP
RADIUS
Softswitch
SIP/SIP-T
H.323/BICC
SG
SIGTRAN
SIGTRAN
ISUP
Switch
SS7
STP
PSTN/ISDN
SIP
SG
SS7
ISUP
Switch
Softswitch
SS7
STP
PSTN/ISDN
MGC
MGCP/Megaco/H.248
Gatekeeper/
Proxy Server
Media
Gateway
Media
Gateway
Core IP Network (QoS)
Н.323/ IP Network
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•
•
•
•
•
B. NGN building blocks
Media Gateway - protocol converter
Media Gateway Controller - master controller of a
media gateway
Softswitch = MGC + SG
Signaling Gateway
Application Server – Information Database (ID) Network directory, Billing, Call records, Authentication,
authorization, and accounting (AAA)
• Network Manager – Operation, Administration,
Management (OAM); provides network elements’
management from a centralized web interface
43
Media Gateway (IETF RFC 3015)
Media gateway (MG) – protocol converter between different types
of networks (Example – MG between circuit-switched voice
network - TDM flows, and the IP network - RTP packet flows.)
MG processes incoming calls via requests to the Application
Server using HTTP.
The media gateway (MG) terminates IP and circuit-switched
traffic. MGs relay voice, fax, modem and ISDN data traffic over the
IP network using Quality of Service enabled IP technology.
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Media Gateway (IETF RFC 3015)
• All types of traffic (voice, data, video)
• Control (from Media Gateway Controller): MGCP, Megaco/H.248
• Interfaces: STM-1to transport network, E1 to PSTN; Eth-Fast/Gb to
IP network
• Voice Packetization/Compression (Codecs: ITU-T G.711, G.723.1, G.726,
G.729A
• Echo cancellation: ITU-T G.165, G.168
• QoS via DiffServ and ToS bits marking
• Mapping addresses: E.164
IP address
45
Softswitch
Signaling Gateway
Signaling Gateway (SG) offers a consolidated signaling
interface - SS7 signaling point for the NGN platform.
Also, SG supports a SIGTRAN interface (IETF SS7 telephony
signaling over IP) as well as IP Proxy functions (SIP).
Media Gateway Controller
•
•
•
•
MGC acts as the master controller of a media gateway
Supervises terminals attached to a network
Provides a registration of new terminals
Manages E.164 addresses among terminals
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Signaling Gateway Function
•Several millions BHCA
•Several hundreds controlled trunk ports
•Control: MGCP, MEGACO, SIP
•Signaling: ISUP, H.323, SIP, SIP-T, INAP, SIGTRAN
•Mgmt: SNMP
Транспортная
сеть
IP Signaling
сигнализации IP
IP Network
SCTP/IP
SIGTRAN
SGW
MTP
ISUP
Signaling Gateway
Транспортная
сеть
SS7
Signaling
сигнализации
SS7
PSTN
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Application Server
Application server – provides the applications (i.e., service logic) for new and
innovative services such as unified messaging, conferencing, speech dial tone,
and multimedia messaging services. Application servers are typically based on
advanced Java tool environments that provide multi-modal integration of voice
and data.
Application Server generates application documents (VoiceXML pages) in
response to requests from the Media Gateway via the internal Ethernet
network.
The application server leverages a web application infrastructure to interface
with data stores (messages stores, user profile databases, content servers)
to generate documents (e.g., VoiceXML pages).
AS provide interoperability between applications like WAP, HTML, and voice
allowing the end user to simultaneously input voice command and receive
presentation via WAP or HTML.
48
Appendix A: Parlay
Parlay is an evolving set of specifications for industry-standard application
programming interfaces (APIs) for managing network "edge" services:
• call control
• messaging
• content-based charging.
Parlay specifications are being developed by the Parlay Group, a
consortium of member companies that include AT&T, BT, Cisco, IBM,
Lucent, Microsoft, Nortel Networks, and others.
Use of the Parlay specifications is expected to make it easier to add new
cross-platform network applications so that users need not depend solely
on the proprietary offerings of carriers.
The Parlay Group is not a standards group itself, but sees itself as a
facilitator of needed interfaces. Application program interfaces are or will
be defined for:
49
Parlay
•
•
•
•
•
•
•
•
•
•
•
•
•
Authentication
Integrity management
Operations, administration, and maintenance (OA&M)
Discovery (of the closest provider of a service)
Network control
Mobility
Performance management
Audit capabilities
Generic charging and billing
Policy management
Mobile M-commerce/E-commerce
Subscriber data/user profile/virtual home environment (VHE)
The Parlay APIs are said to complement and encourage use of the
Advanced Intelligent Network (AIN) protocols.
50
Appendix B: Application level protocols
A. LDAP (Lightweight Directory Access Protocol)
• LDAP (Lightweight Directory Access Protocol) is a software protocol for
enabling anyone to locate organizations, individuals, and other resources
such as files and devices in a network, whether on the public Internet or on a
corporate Intranet.
• LDAP is a "lightweight" (smaller amount of code) version of Directory Access
Protocol (DAP), which is part of X.500, a standard for directory services in a
network. LDAP is lighter because in its initial version it did not include
security features.
• LDAP originated at the University of Michigan and has been endorsed by at
least 40 companies. Netscape includes it in its latest Communicator suite of
products. Microsoft includes it as part of what it calls Active Directory in a
number of products including Outlook Express. Novell's NetWare Directory
Services interoperates with LDAP. Cisco also supports it in its networking
products.
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B. LDAP
•
In a network, a directory tells you where in the network something is located. On
TCP/IP networks (including the Internet), the domain name system (DNS) is the
directory system used to relate the domain name to a specific network address (a
unique location on the network). However, you may not know the domain name.
LDAP allows you to search for an individual without knowing where they're located
(although additional information will help with the search).
• An LDAP directory is organized in a simple "tree" hierarchy consisting
of the following levels:
# The root directory (the starting place or the source of the tree), which branches out to
# Countries, each of which branches out to
# Organizations, which branch out to
# Organizational units (divisions, departments, and so forth), which branches out to (includes an
entry for) Individuals (which includes people, files, and shared resources such as printers)
•
An LDAP directory can be distributed among many servers. Each server can have a replicated
version of the total directory that is synchronized periodically. An LDAP server is called a
Directory System Agent (DSA). An LDAP server that receives a request from a user takes
responsibility for the request, passing it to other DSAs as necessary, but ensuring a single
coordinated response for the user.
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•
•
•
B. Authentication, Authorization, Accounting (AAA)
Authentication, Authorization, Accounting (AAA) is a term for a framework for
intelligently controlling access to computer resources, enforcing policies, auditing
usage, and providing the information necessary to bill for services. These combined
processes are considered important for effective network management and security.
As the first process, authentication provides a way of identifying a user, typically by
having the user enter a valid user name and valid password before access is
granted. The process of authentication is based on each user having a unique set of
criteria for gaining access. The AAA server compares a user's authentication
credentials with other user credentials stored in a database. If the credentials match,
the user is granted access to the network. If the credentials are at variance,
authentication fails and network access is denied.
Following authentication, a user must gain authorization for doing certain tasks. After
logging into a system, for instance, the user may try to issue commands. The
authorization process determines whether the user has the authority to issue such
commands. Simply put, authorization is the process of enforcing policies:
determining what types or qualities of activities, resources, or services a user is
permitted. Usually, authorization occurs within the context of authentication. Once
you have authenticated a user, they may be authorized for different types of access
or activity.
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B. Authentication, Authorization, Accounting (AAA)
•
•
The final term in the AAA framework is accounting, which measures the resources a
user consumes during access. This can include the amount of system time or the
amount of data a user has sent and/or received during a session. Accounting is
carried out by logging of session statistics and usage information and is used for
authorization control, billing, trend analysis, resource utilization, and capacity
planning activities.
Authentication, authorization, and accounting services are often provided by a
dedicated AAA server, a program that performs these functions. A current standard
by which network access servers interface with the AAA server is the Remote
Authentication Dial-In User Service (RADIUS).
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C. RADIUS
Remote Authentication Dial-In User Service (RADIUS) is a
client/server protocol and software that enables remote access
servers to communicate with a central server to authenticate
dial-in users and authorize their access to the requested
system or service. RADIUS allows a company to maintain user
profiles in a central database that all remote servers can share.
It provides better security, allowing a company to set up a policy
that can be applied at a single administered network point.
Having a central service also means that it's easier to track
usage for billing and for keeping network statistics. Created by
Livingston (now owned by Lucent), RADIUS is a de facto
industry standard used by a number of network product
companies and is a proposed IETF standard.
55
Appendix C. Additional NGN signaling protocols
• SIP-T
• SIGTRAN
• BICC
56
A. SIP-T
• SIP-T (SIP for telephones) is a mechanism that uses SIP to
facilitate the interconnection of the PSTN with IP. SIP-T defines
SIP functions that map to ISUP interconnection requirements.
• This is intended to allow traditional IN-type services to be
seamlessly handled in the Internet environment. It is essential
that SS7 information be available at the points of PSTN
interconnection to ensure transparency of features not
otherwise supported in SIP. SS7 information should be
available in its entirety and without any loss to the SIP network
across the PSTN-IP interface.
57
B. SIGTRAN
• SIGTRAN (for Signaling Transport) is the standard
Telephony Protocol used to transport Signaling System 7
signals over the Internet. SS7 signals consist of special
commands for handling a telephone call.
• The IETF Signaling Transport working group has
developed SIGTRAN to address the transport of packetbased PSTN signaling over IP Networks, taking into
account functional and performance requirements of the
PSTN signaling. For interworking with PSTN, IP
networks will need to transport signaling such as Q.931
or SS7 ISUP messages between IP nodes such as a
Signaling Gateway and Media Gateway Controller or
Media Gateway. Applications of SIGTRAN include
Internet dial-up remote access and IP telephony
interworking with PSTN.
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B. SIGTRAN
A telephone company switch transmits SS7 signals to a SG. The gateway,
in turn, converts the signals into SIGTRAN packets for transmission over IP
to either the next signaling gateway.
The SIGTRAN protocol is actually made up of several components (this is
what is sometimes referred to as a protocol stack):
• standard IP
• common signaling transport protocol (used to ensure that the data
required for signaling is delivered properly), such as the Streaming
Control Transport Protocol (SCTP)
• adaptation protocol that supports "primitives" that are required by
another protocols.
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C. Bearer Independent Call Control (BICC)
• Bearer Independent Call Control (BICC) is a signaling protocol
based on N-ISUP that is used to support NB-ISDN service over
a BB backbone network without interfering with interfaces to the
existing network and end-to-end services. Specified by the ITUT in recommendation Q.1901, BICC was designed to be fully
compatible with existing networks and any system capable of
carrying voice messages. BICC supports narrowband ISDN
services independently of bearer and signaling message
transport technology.
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C. Bearer Independent Call Control (Cntd.)
ISUP messages carry both call control and bearer control
information, identifying the physical bearer circuit by a Circuit
Identification Code (CIC). However, CIC is specific to timedivision multiplexed TDM networks. BICC was developed to be
interoperable with any type of bearer, such as those based on
asynchronous transfer mode ATM and IP technologies, as well
as TDM.
BICC separates call control and bearer connection control,
transporting BICC signaling independently of bearer control
signaling. The actual bearer transport used is transparent to the
BICC signaling protocol - BICC has no knowledge of the
specific bearer technology.
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C. Bearer Independent Call Control (Cntd.)
• The ITU announced the completion of the second set of BICC protocols
(BICC Capability Set 2, or CS 2) in July 2001; these are expected to help
move networks from the current model - which is based on public-switching
systems - to a server-based model. The BICC deployment architecture
comprises a proxy server and a media gateway to support the current
services over networks based on circuit-switched, ATM, and IP technologies,
including third-generation wireless.
•
The completion of the BICC protocols is an real and important ITU step
toward broadband multimedia networks, because it will enable the seamless
of circuit-switched TDM networks to high-capacity broadband multimedia
networks. The 3GPP has included BICC CS 2 in the UMTS release 4.
Among the future ITU-T plans for BICC are the inclusion of more advanced
service support and more utilization of proxies, such as the SIP proxy.
62