Active Directory

Active Directory is Microsoft’s new directory service included with Windows 2000.

Active Networks

Active Networks are networks that have the ability to identify users and content in order to optimise delivery according to business priorities.

ADSL

ADSL (asymmetric DSL) is one of the major types of digital subscriber lines, a new technology allowing more data to be sent over existing copper lines by transforming them into high-speed digital lines. ADSL enables ultra-fast Internet access and enables teleworkers to access corporate networks. ADSL is also being used for new multimedia applications such as multiplayer gaming, video on demand and video catalogs.

ADSL provides a number of key benefits including the ability to enable simultaneous Internet and voice/fax capabilities over a single telephone line, the provision of uninterrupted Internet access that is continually on-line and the provision of data security that exceeds other technologies.

With analog modems possibly reaching a practical limit at 56 kbps, ADSL speeds of between 1.5 Mbps and 8.0 Mbps mean that high speed Internet access is seen by many as its ‘killer application.’  ADSL promises to allow the downloading of video applications over the Internet.  Though ADSL is being developed primarily in North America,  ADSL services are now beginning to be deployed around the world thereby giving millions access to the advantages of this broadband service.  (see DSL, xDSL & SDSL).

Application Protocols

examples of Application protocols are Telnet, FTP, HTTP, SNMP & SMTP.

ARCnet

ARCnet (Attached Resource Computer Network) is one of the main types of Token Ring networks. Inexpensive and easy to install, ARCnet was originally limited by its signaling speed of 2.5 Mbits per second but a newer version, ARCnet Plus is capable of a throughput of 20 Mbits per second. (see Token Ring).

Atlantech

Atlantech Technologies, whose acquisition by Cisco System was announced in March 2000, is recognised, with its AccessVision product family, as a world leader in the development of network element management software for managing large-scale broadband telecommunications networks. Cisco’s acquisition of Atlantech will allow it to provide service providers and ecosystem partners with a single integrated platform for enabling network management functionality across multiple diverse networks and thereby enable the delivery of integrated data, voice and video networks.

ATM

ATM (Asynchronous Transfer Mode) is a network technology based on transmitting data in small, fixed size packets (or ‘cells’) of 53 bytes. With its ability to transmit video, audio and computer data over the same network, ATM is of considerable interest as a multimedia transport technology.

ATM technology, which offers a bandwidth of up to 155 Mbps, is viable for both LAN’s & WAN’s and has the ability to guarantee a QoS for a transmission. It has been designated by the ITU as the basis for broadband ISDN, the next generation of its narrow-band counterpart.   (see QoS).

ATM Vendors & Products

The major ATM vendors (& their products) include: Cisco Systems (LightStream 1010), 3Com (CELLPlex 7000), Bay Networks (Centillon), Cabletron Systems (MMAC Plus), FORE Systems (ASX1000), IBM (IBM 8260) & Newbridge Networks (VIVID).

BECN

BECN is an acronym for Backward Error Congestion Notification. In congested Frame Relay networks, BECN informs the transmitting device that the network is congested and that it should ‘back off’ to enable improved throughput.  (see Frame Relay and FECN)

BISDN

BISDN or B-ISDN is an acronym for Broadband ISDN

Broadband Services

Broadband Services is a generic term to describe high-speed wireline and fibre-optic data services are able to transmit multiple information formats simultaneously at high speeds and deliver reliable digital networking such as xDSL.

CHAP

CHAP (Challenge Handshake Authentication Protocol) is an access protocol that enables a user’s ID and password to be transmitted in an encrypted form. It forms the basis of a popular authentication method for PPP that uses a randomly generated challenge. This challenge requires a matching response which is dependent upon the cryptographic hash of the challenge and a secret key. 

Circuit Switched Digital Services

Circuit Switched Digital Services is a type of Token Ring network that provides an alternative to high cost, dedicated LAN-to-LAN , dial-up circuit vendors offering signaling rates from 56 kbs to 1.544 Mbps. (see Token Ring)

CLEC

In the USA, a CLEC (competitive local exchange carrier) is a company that has been allowed by the state utility commission to offer local telephone service in competition with the former local carrier monopolies (or ILEC’s.). CLECs are sometimes referred to as ‘ new entrants’ or ‘ emerging carriers.’  (see ILEC’s)

CLLI

CLLI is a system devised by Telcordia Technologies (formerly Bellcore) for identifying locations and equipment in a telephone network.

CMIP

CMIP (Common Management Information Protocol) is the functional equivalent to SNMP in OSI infrastructures. Designed to succeed SNMP in the late 1980’s by removing its shortcomings, CMIP has failed, due to a number of implementation related problems,  to make any headway in TCP/IP networks and its use is  restricted to OSI networks. (see SNMP).

CSMA/CD

CSMAJCD (Carrier-Sense Multiple Access with Collision Detection) is a technique used by Ethernet networks (see Ethernet).

CSP

acronym for Communications Service Provider

CTI

acronym for Computer Telephony Integration

DHCP

DHCP (Dynamic Host Configuration Protocol) is a protocol that enables dynamic addressing in which a device can have a different IP address every time it connects to the network.

Dial-Up Access

Dial -up access HCP

Directory Service

Directory Service is a network service that identifies all resources on a network, including e-mail addresses and peripherals, and makes them accessible to users and applications. The development of a comprehensive, directory service, by enabling  the centralisation of network administration across the enterprise, promises to be as important as technological know-how in the implementation of new network infrastructures.

The two most widely used directory services are LDAP (used primarily for e-mail addresses) & NDS (used on Novell Netware networks). Although virtually all directory services are based on the X.500 standard, the complexity of the standard makes it difficult for vendors to fully comply. (see LDAP, NDS & X.500)

DSL

DSL is an acronym for Digital Subscriber Line (see ADSL & xDSL)

DSLAM

DSLAM (digital subscriber line access multiplexer) is a multiplexing system that is used to aggregate DSL traffic before transmission across a network.

DSML

DSML (Directory Service Markup Language) is a markup language for representing directory services in XML. By combining LDAP technolgy and XML syntax, it helps XML-based applications make better use of directories. It was developed in the late 90’s in an initiative by Bowstreet to provide an open standard which would allow the easy use and sharing of personalised data across both technology and company boundaries. The initiative had the support of major companies including IBM, Novell, Microsoft, Oracle and Sun Microsystems. (see Directory Services, LDAP and XML). 

DWDM

DWDM, an acronym for dense WDM, is one of the major enabling technologies for optical networks and is used, for example, in Lucent Technologies’ WaveStar optical networks. Lucent is the global leader in deploying DWDM technology. Its Wavestar systems enable transmission at speeds of up to 400 gigagbits per second across individual hair-thin fibres (ie equivalent to transmitting the data in 75 CD ROMs per sec.)

E1

E1 is the European format for digital transmission supporting data rates of 2.048 Mbps. It is the European counterpart to the North American T1 format.

E-Business Network Architecture

The emergence of Internet technologies has created the need for most  companies, dot-com and brick-and-mortar enterprises alike, to implement an e-business strategy (and underlying network architecture / infrastructure) simply to remain competitive. An e-business network architecture consists of LAN’s and WANs that support e-business activities along with the tools and services required to manage these networks. The e-business network architecture encompasses both the network infrastructure (layers 1-4) and application services (layers 5-7) of the OSI architectural model (Lucent 2000).

EOS

EOS is an acronym for Enterprise Operating System. The leading EOS is currently Windows NT. Other EOSs, including NetWare, Unix variants (mainly Sun  Solaris and HP-UX) and Linux, are also common throughout IT organisations. Linux, is particular, is making increasing headway, reflecting the growing acceptance of the open source movement. The major trend is towards the deployment of a single EOS across the entire IT organisation that is capable of handling all the functionality required across the full range of networks. The success of an EOS will very much depend on its ability to fulfill the important characteristics of security, reliability, compatibility and scalability.

Ethernet

Ethernet, one of the most common types of network architectures, transmits only when the channel is quiet using a technique called CSMA/CD. Different types of Ethernet networking architectures are distinguished by the physical characteristics and the speed of of cabling.

There are 3 main types of Etthernet cabling: Thinnet (inexpensive, thin coaxial cables used to connect the network), Twisted Pair (the twisting cancels electrical noise from adjacent pairs) and Fast Ethernet & Gigabit Ethernet (the latest and next generation of Ethernet which provides a great advantage in scalability).

FDDI

FDDI (Fibre Distributed Data Interface) is an emerging, high speed, 100 Mbps LAN standard and is one of the main types of Token Ring network. Developed by ANSI, FDDI is designed to work on fibre-optic cables. The topology is a dual attached, counter-rotating token ring. (see Token Ring).

FECN

FECN is an acronym for Forward Error Congestion Notification. In congested Frame Relay networks, FECN tells the receiving device that the network is congested to enable the upper layer protocols to expect a delay.   (see Frame Relay and BECN)

FRAD

FRAD is an acronym for Frame Relay Access Device. FRADs are simple devices that convert streams of data (including IP, SNA, IPX etc) ) into frames to allow transmission over a Frame Relay network. As such, FRADs enable the extension of Frame Relay networks to branch offices. As the market for Frame Relay continues to grow, so does the market for FRADs. FRADs are sometimes referred to as Frame Relay Assemblers/Disassemblers.  (see Frame Relay). 

Frame Relay

Frame Relay is a high speed packet-switching protocol for connecting devices on a WAN and is much faster than X25 networks. It has become the dominant method for wide area interconnection of corporate enterprise networks.  Unlike X25, Frame Relay has become a major wide area technology in the USA partly due to it being relatively inexpensive; it is losing ground in some areas to faster technologies such as ATM.

FRF

FRF is an acronym for the Frame Relay Forum which is an association of  vendors, carriers, users, and consultants committed to the education, promotion and implementation of Frame Relay in accordance with  international standards. The FRF has over 300 members worldwide. (see Frame Relay, FRF.5 and FRF.8)

FRF.5

FRF.5 (Frame Relay-to-ATM Network Interworking) is a feature that provides networking functionality that allows Frame Relay and ATM networks to exchange data despite using different transmission protocols. FRF.5 is a useful feature for Internet Services Providers that need to link Frame Relay and ATM networks.  (see FRF, ATM and Frame Relay).

FRF.8

FRF.8 (Frame Relay-to-ATM Service Interworking) is a feature that allows Frame Relay and ATM networks to exchange data despite differing network protocols. It does this by providing service interworking functionality that allows a Frame Relay end user to communicate with an ATM end user. jFRF.8 atm aprovides networking functionality that all

FUNI

FUNI (Frame-based User-to-Network Interface), like ATM-DXI,  is an access protocol for ATM networks.

H323

H.323 is an ITU (International Telecommunication Union) approved standard for video conferencing over packet-switched networks. It allows for any combination of voice, video or data to be transmitted. H.123 is also used in Internet telephony.

HDSL

HDSL is an acronym for High-data-rate DSL (see ADSL & xDSL)

IETF

IETF (Internet Engineering Task Force) is the organisation that provides the coordination of standards and specification development for TCP/IP networking. It comprises of  a large, open community of network professionals whose aim is to coordinate the operation, management and evolution of the Internet and also to resolve short- and mid-range protocol and  architectural issues.

ILEC

ILECs (incumbent local exchange carriers) are traditional telecommunications services providers. (see CLECs)

ILMI

ILMI (Interim Local Management Interface) is an ATM forum defined interim specification for network management functions between an end user and public or private network and between a public network and a private network.

IN

IN is an acronym for Intelligent Networks, which allow operators to develop and speedily deliver highly focused services designed to meet the needs of specific groups or individuals. (see WIN & CAMEL).

Internet Protocols

Examples of Internet protocols are TCP/IP, RIP, OSPF, BGP, NAT, L2TP & PPTP

IPoA

IPoA (IP over ATM) is a specification that enables the encapsulation and transmission of IP packets across an ATM connection.

IP Pipes

IP Pipes is the name given to high speed IP backbones capable of providing high bandwidth and reliable communications.  A number of major global companies, including MCI and Level 3, are building very large worldwide IP backbones that will allow seamless communications on a global scale.

IPSec

IPSec, short for IP Security, is a set of protocols developed to enable the secure exchange of IP packets over unprotected networks such as the Internet. It is anticipated that IPsec will be widely used in the implementation of VPN’s which are categorised by intranets, extranets and remote dial access.

ISDN

ISDN (integrated services digital network) is a DSL system that was introduced in the 1970’s and is still used to enable digital, high-capacity, simultaneous voice and data transmission over existing copper lines.

IPVPN

Internet Protocol Virtual Private Networks (see VPN’s).

ITU

The ITU (International Telecommunication Union) is an international  organisation within which governments and the private sector coordinate global telecom networks & services. It is responsible for adopting international treaties, regulations and standards governing telecommunications.

IXC

IXC (interexchange carrier) is a term used for a long-distance carrier.

JAIN

JAIN is a technology initiative organised by Sun Microsystems in June 1998  to  to address the needs of next-generation telecommunications networks via the development of a set of industry-defined API’s for Integrated Networks.

Network services were traditionally developed using proprietary interfaces that required service providers to design a new interface in order to run an application on different nodes or networks.  By bringing the benefits of the JAVA platforms to the public telecommunications network, JAIN aims to enable greater openness and facilitate the development and rollout of telecoms applications and services.

The initiative has achieved a global reach with a diverse membership that includes Andersen Consulting, CMG, Lucent Technologies, Motorola, Nokia, Oracle and Sun Microsystems.

In October 1999, Sun Microsystems announced a joint effort between the JAIN technology initiative and the Parlay Group to ensure a JAVA platform/JAIN implementation of the Parlay specifications through the creation of the JAIN Parlay API 2.0 specification. (see Parlay) 

L2TP

L2TP (Layer 2 Tunneling Protocol) is an IETF protocol used for creating VPN’s over the Internet.

LDAP

LDAP (Lightweight Directory Access Protocol) is a protocol used to access a directory listing in directory services architectures. It is based on the standards  contained within the X.500 standard but unlike X.500, LDAP supports TCP/IP. It is expected to provide a common method of obtaining directory information including email addresses and public keys on the Internet, eventually leading to global white pages.

LDIF

LDIF (LDAP Data Interchange Format) is a standard format used to store directory entries in text form. It allows users to import & export entries from and to a  local directory.

MCS

Mobile Service Switching Centres

MDS

ATM (Asynchronous

MGCP

Developed by Nortel Networks, MGCP (Media Gateway Control Protocol) is a protocol for IP telephony. It is one of a number of new standards being developed to compete with H323 due to the growing popularity of VoIP.

MIB

The MIB (Management Information Base) is a specification containing the definitions of management information required by an NMS. The size of MIB’s can range anywhere from tens of megabytes to gigabytes.

MLPPP

MLPPP is a WAN protocol.

MONs

 MONs is an acronym for Metropolitan Optical Networks which are rapidly emerging as viable, cost-effective solutions for many cosmopolitan service providers facing rapidly growing demand and expensive fibre-expansion costs.

MPLS

Multi Protocol Label Switching is a new technology which facilitates the high-performance transport of IP traffic across WAN’s by combining connectionless IP technology to connection-oriented technologies such as ATM. As such, it promises to open up the Internet by providing many additional services to applications using IP and is set to be a major component in VoIP networks.

MPOA

MPOA (Multi- Protocol over ATM) is a specification from the ATM Forum that allows LAN’s to transmit packets to each other over ATM networks.

NDS

NDS (Novell Directory Services) is Novell’s flagship directory service for Netware networks.  It complies with the X.500 directory standard.

NE’s

Network Elements: the equipment component(s) of NMS’s.

network element management software

Network element management software performs provisioning and performance management functions across multiple elements of a service provider’s network.

NIS

NIS is an acronym for Network Information Service. Known also by its earlier name Yellow pages or NIS/YP, it is an RPC-based service designed to provide distributed access to centralised administrative information, such as password files and email aliases), shared by machines at a site. (see RPC and NIS+)

NIS+

NIS+ is a revised version of NIS/YP available from some vendors that attempts to improve secrity (see NIS/YP). 

NIS/YP

see NIS

NMS

Network Management System

NNI

NNI is an acronym for Network to Network Interface.

OC

OC (Optical Carrier) is the transmission speeds as defined in the SONET specification. For example, OC-1, OC-3 & OC-48 represent the SONET transmission rates of 51.84 Mbps, 155.52 Mbps & 2488.32 Mbps respectively.

Optical Internets

The recent wide scale deployment of DWDM systems and introduction of new traffic engineering protocols such as MPLS is enabling many carriers and ISP’s to deploy optical Internets. An optical Internet is an Internet network in which the network link layer connections are dedicated wavelengths on WDM optical fibres directly connected to a high performance network router (which replaces traditional ATM & SONET/SDH switching and multiplexing equipment). Nortel Networks was ranked as the global leader in optical Internet solutions according to market data for 1999. (See Optical Networks, WDM, DWDM, ATM & SONET.) 

Optical Networks

Optical Networks are high-capacity telecommunications networks based on optical technologies and components that provide higher capacity and reduced costs for new applications such as the Internet, video/multimedia interaction and advanced digital services. Described as next generation networks, they’re  poised to become the dominant networking infrastructure over the next decade, providing services which have hitherto been supported by telecommunication  voice and data network providers.This is being made possible by the rapid developments in optical transmission technologies, switching, high-speed protocols and high-bandwidth applications.

Optical networks began with WDM which arose to provide additional capacity on existing fibres. Like SONET, defined network elements & architectures provide the basis of the optical network. However unlike SONET, which is based on a defined bit-rate and frame structure, the optical network is based on wavelengths. (see WDM & SONET)

OSI

OSI (Open Systems Interconnection) is the 7 layer hierarchical reference model developed by the ISO for defining, specifying and relating communications protocols. The model itself is not a standard or a protocol.

OSPF

OSPF (Open Shortest Path First) is an IP routing protocol initially developed by the IETF in 1987. Since then, extensions have been added to the protocol as is has been continually expanded to meet the changing scope of IP networks.

Parlay

The Parlay Group is a broad-based telecom industry group, formed by 11 companies (including AT & T, BT, Cegetel, Cisco, Ericsson, IBM, Lucent Technologies, Microsoft, Nortel Networks, Siemens & Ulticom), which developed an open standard specification for enabling secure, public access to telecom and data networks.  The Parlay 1.2 specification enables a new generation of applications that can be created and maintained by the customers of telecom networks using their own data.

In October 1999, the Parlay Group announced a joint effort with the Sun Microsystems-led JAIN technology initiative to ensure a JAVA platform/JAIN implementation of the Parlay specifications through the creation of the JAIN Parlay API 2.0 specification. (see JAIN) 

PNNI

PNNI (Private Network-to-Network Interface) is a routing protocol used on an ATM network between ATM switches to enable them to dynamically reroute packets dependent upon current line traffic.

PPP

PPP (Point-to-Point Protocol) is a data link  protocol that provides dial-up access for connecting to the Internet.

PVC’s

PVC’s (Permanent Virtual Circuits) are virtual circuit connections between two permanently set up locations. They contract to SVC’s which are virtual circuit connections between two locations which get set up and switched dependent upon whether data is being transmitted.  With regards to both ATM and Frame Relay technology, there is a debate over which whether they should be based upon PVC’s or SVC’s.  (see SVC’s).

QoS

QOS (Quality of Service) is the ability to specify a level of throughput (ie quality of service) in a data communications system. With voice and video being increasingly transmitted over IP-based data networks, QoS has become an major issue on the Internet as well as in enterprise networks. ATM has the ability to support QoS levels, giving it a big advantage over competing technologies such as Frame Relay and Fast Ethernet, by enabling ATM providers  to guarantee performance levels. 

Real-Time Operating Systems

Examples of real-time operating systems are pSOS, VxWorks, RTXC, QNX & VRTX).

SDH

SDH (Synchronous Digital Hierarchy) is an international standard for the transmission of synchronous data over fibre-optic cables. SONET is the European equivalent of SONET used in North America (see SONET).

SDSL

SDSL (symmetric DSL) is one of the major types of digital subscriber lines, a new technology allowing more data to be sent over existing copper lines. SDSL is being developed primarily in Europe (see xDSL & ADSL).

SIP

SIP (Session Initialisation Protocol) is a protocol that provides telephony services similar to H.323 but is less complex (from techweb).

SNMP

SNMP (Simple Network Management Protocol) is one of the two main standards for controlling telecommunications equipment, the other being TMN. Its very simple design ( a client-server model where requests and responses are used to query and manipulate NE’s) makes it easy to implement even in quite extensive networks. Support for SNMP is almost universal in the private network environment (see TMN, CMIP & NE’s).

SOA

SOA (semiconductor optical amplifier) is one of the most promising technologies for optical networks that will lead to large cost reductions and improved performance in future optical network equipment.

SONET

SONET (Synchronous Optical NETwork) is a fibre-optic transmission system for high speed digital traffic. It is a format that uses TDM to enable different types of formats to be transmitted on one line. Used in North America, its counterpart in Europe is SDH. (see SDH).

SS7

SS7 (Signaling System 7) is a telecommunications protocol defined by the ITU that is characterised by high-speed packet switching. It is used in the US telephone system to set up calls and enable new transaction services such as caller ID.

SVC’s

SVC’s (Switched Virtual Circuits) which are virtual circuit connections between two locations which get set up and switched (ie  torn down) dependent upon whether data is being transmitted. They are useful in  situations where data transmission is sporadic. By providing dynamic, on-demand connectivity, their use enables businesses to reduce costs and manage bandwidth. 

They contrast to PVC’s which are virtual circuit connections between two permanently set up locations. With regards to both ATM and Frame Relay technology, there is a debate over which whether they should be based upon SVC’s or PVC’s.  The on-demand bandwidth benefits of SVC’s lends for greater scalability and lower costs compared with PVC’s and with the rapid growth in communications traffic allow carriers to provide a greater range of QoS. (see PVC’s, QoS, ATM & Frame Relay).

TDM

Time Division Multiplexing

T1

T1 is  dedicated, point-to-point dedicated, digital phone connection supporting data rates of 1.544 Mbps. T1 lines are used widely for private networks and by ISP’s connecting to the Internet backbone. They are also used as a leased line option for businesses connecting to the Internet.

TLS

TLS (Transport Layer Security) is a security protocol from the IETF that is expected to supersede SSL to become a major security standard for the Internet. TLS uses Triple DES encryption.

TMN

TMN (Telecommunication Management Network) is one of the two main standards for controlling telecommunications equipment, the other being SNMP. The TMN standards are complex and difficult to implement. Despite the integration requirements being more complex than SNMP, TMN is gaining popularity for large complex networks.  (see SNMP).

Token Ring

Token Ring is one of the most common types of network architectures. Unlike Ethernet, Token Ring is distinguished by its token passing communication method rather than by the physical characteristics of its cabling. The main types of token ring networks are ARCnet, FDDI and Circuit Switched Digital Services.

UNI

UNI is an acronym for User Network Interface.

Unified Messaging

Unified Messaging (UM), the outcome of the general convergence in the world of communications, is the creation of a single infrastructure allowing the integration of voice telephony, wireless data, and Internet networking. This gives users the ability to retrieve and send voice, fax, and e-mail messages from a single interface, whether it be a wireline phone, mobile phone or PC.  By bringing together all types of messages into a single data store, Unified Messaging replaces the multiple separate infrastructures that were required before its introduction.

According to IDC (International Data Corporation), the deployment of UM will grow from 35000 mailboxes in 1998 to over 25 million by 2003 turning if from a $7.6 million market to one worth $1.9 billion. One of its key applications will be in providing knowledge workers with access to any message and all types of corporate information at any time, anywhere and from any device. (see Unified Messaging Platform)

Unified Messaging Platform

A variety of plaftforms have emerged to provide Unified Messaging. Vendors include Alcatel, Calltech Communications, Callware Technologies, ITC, Lucent Technologies, Microsoft and Telcordia. (see Unified Messaging).

VDSL

VDSL (Very High Speed DSL) is a type of digital subscriber line, a new technology allowing more data to be sent over existing copper lines. It’s not yet widely deployed as it is currently going through a standards issue. (see xDSL).

VoAT

VoAT is an acronym for voice over alternative technologies which include IP, frame relay and ATM. There are many objectives and benefits to delivering voice services over alternative technologies. Delivering voice over an alternative technology enables enterprises to bypass the traditional public switched telephone network (PSTN) and its time- and distance-based fee structure. According to a survey of companies undertaken by Lucent, the percentage of voice traffic transported using alternative technologies is expected to jump from just 9% in 1999 to 35% in 2001.  The major drivers of VoAT solutions at present are basic voice services and computer telephony integration.

VoATM

VoATM (Voice over ATM) enables voice traffic (e.g. faxes & phone calls) to be transmitted over an ATM network.

VoIP

VoIP (Voice over IP) is the ability & process of carrying voice over an IP network.  One of the main drivers of VoIP is that data traffic is overtaking voice traffic. Rather than having separate, discrete network for voice, the trend is likely to pull voice into the packet-based network.

VoMPLS

VoMPLS (Voice over MPLS) is the term applied to the transfer of voice traffic over an MPLS network.

VPN’s

VPN’s (Virtual Private Networks) physically enable private networks to be extended to encompass remote sites by connecting them through the Internet; they manage this by enabling IP traffic to travel securely over a public TCP/IP network by encrypting all traffic from one network to another. In this way, VPN’s enable customers, business partners &  remote users to securely access enterprise computing resources.

They are called ‘virtual’ as it appears that there exists a separate, private network whereas the reality is that the company’s VPN is part of a big mesh and is physically sharing lines with many other companies. The trend is expected to move away from companies having their own private enterprise network based on leased lines towards outsourcing the running of them  to Telcos and Service Providers.

WAN Protocols

Examples of WAN protocols are PPP, MLPPP, Frame Relay, ISDN, HDLC & T1/E1.

WDM

WDM is an acronym for Wave division multiplexing

X.500

X.500 is an ITU standard that defines how global directories should be structured ; the goal is to have a directory that can be used globally.  An X.500 directory, called a DIB (Directory Information Base) or white pages, is hierarchical in structure, conforming with the world’s classification system (ie countries, states, cities, streets etc.). 

xDSL

xDSL is a term which refers collectively to all types of DSL’s (digital subscriber lines) which include ADSL, SDSL &  HDSL and. Similar to ISDN, DSL technologies operate over existing copper telephone lines but at much higher speeds. They are sometimes referred to as last mile technologies as they are only used for the final connection from a telephone switching station to the home or office.  

Yellow Pages

Yellow Pages is an old term for what is now known as NIS or NIS/YP (see NIS)