]> There are no glossary terms that begin with this letter. See definition for: See also: A Active Directory The directory service for Windows 2000 Server. It stores information about objects on the network and makes this information available for authorized administrators and users. Active Directory gives network users access to permitted resources anywhere on the network using a single logon process. It provides administrators with an intuitive hierarchical view of the network and a single point of administration for all network objects. Active Directory Sites and Services A Microsoft Management Console (MMC) snap-in that allows administrators to manage the replication of data, including information about domain controllers, sites, replication between sites, and replication of network service configuration. Active Directory Users and Computers A Microsoft Management Console (MMC) snap-in that allows administrators to manage objects in the domain. ActiveX A set of technologies that allows software components to interact with one another in a network environment, regardless of the language in which the components were created. address mask A number that, when compared by the computer with a network address number, blocks out all but the necessary information. For example, in a network that uses XXX.XXX.XXX.YYY and where all computers within the network use the same first address numbers, the mask will block out XXX.XXX.XXX and use only the significant numbers in the address, YYY. administrative group A collection of Active Directory objects that are grouped together for the purpose of permissions management. An administrative group can contain policies, routing groups, public folder hierarchies, servers, and chat networks. The content of an administrative group depends on choices you make during installation. authentication In a multiuser or network operating system, the process by which the system validates the user's logon information. A user's name and address are compared against an authorized list, and if the system detects a match, access is granted to the network. authentication certificate A certificate provided by a remote host, to establish trustworthiness when a connection is attempted by an application, to ensure a secure data connection. B backbone The network connection between LAN segments. Basic Rate Interface (BRI) An ISDN subscriber service that uses two B (64 Kbps) channels and one D (16 Kbps) channel to transmit voice, video, and data signals. bits per second (bps) The measure of transmission speed used in relations to networks and communication lines. Although bps represents the basic unit of measure, networks and communications devices, such as modems, are so fast that speeds are usually given in multiples of bps Kbps (kilobits, or thousands of bits, per second), Mbps (megabits, or millions of bits, per second), and Gbps (gigabits, or billions of bits, per second). bps BRI C certificate An electronic credential that authenticates a user on the Internet and intranets. Certificates ensure the legitimate online transfer of confidential information or other sensitive material by means of public encryption technology. In Exchange, certificates contain information used for digital signatures and encryption that binds the user's public key to the mailbox. certificate authority (CA) An issuer of digital certificates. A certificate authority may be an external issuing company (such as VeriSign) or an internal company authority (such as Microsoft Certificate Services) for issuing and verifying certificates. A certificate authority is responsible for providing and assigning the unique strings of numbers that make up the keys used in digital certificates for authentication and to encrypt and decrypt sensitive or confidential incoming and outgoing online information. Certificate Services Software services that provide authentication support including secure email, Web-based authentication, and smart card authentication. The services contrast with Internet Authentication Services (IAS) which provide authentication for dial-in users. certificate template A Windows 2000 construct that pre-specifies the format and content of certificates based on their intended usage. In Exchange, Key Management Service (KMS) requests certificates from Windows 2000 Certificate Services to enroll Exchange users. There are two certificate types it can issue, depending on what the certificate will be used for: Exchange User and Exchange Signature Only. A third certificate type, Enrollment Agent (Computer), is also required on the Certificate Services server. This certificate type enables KMS to request certificates on behalf of KMS users. certification authority (CA) An entity with a server that issues certificates to clients and servers. A certification authority attests to the identification of a user of a public key and can also revoke certificates when the private key associated with the certificate is compromised or when the subject of the certificate leaves an organization. chat Real-time conversation with other chat participants through your computer. When a participant types a line of text and then presses the Enter key, the text appears on the screens of the other participants, who can then respond. Class D IP addresses A range of Internet protocol (IP) addresses that range from 224.0.0.0 to 239.255.255.255 for exclusive use in IP multicasting. These addresses are not used for regular Dynamic Host Configuration Protocol (DHCP) scopes. codec coder/decoder (codec) Hardware or software that can convert audio or video signals between analog and digital forms. conference access pages Web pages that are used to join conferences. Each conferencing sites instance of Conference Management Service has a Web site that hosts the conference access pages through which users access other conferences. conference calendar mailbox The central storage area for all scheduled online conferences in a conferencing site. Conference Management Service The component of Exchange 2000 Conferencing Server responsible for the reservation and scheduling of online meetings. conference resource An Exchange 2000 mailbox that users invite when scheduling an online meeting. conference resource mailbox One of the two types of mailboxes used by Exchange Conferencing Server. The conference resource mailbox is invited to a conference to reserve the virtual conference room of the conference technology providers hosting the conference. conference technology provider A provider of online conferencing services. conference URL The Web address where a conference is conducted. conference window The window displayed by the browser when a partipant joins a conference. The appearance of the conference window varies according to the conference technology providers used and whether participants access the conference before, during, or after the scheduled time of the conference. The left frame of the conference window, the conference panel, displays general information about the conference. The conference window can include additional frames, each of which is associated with a specific conference technology provider. Conferencing Manager A Microsoft Management Console tool for managing and configuring conferencing services. conferencing site Defined by a Windows 2000 site, a conferencing site contains a collection of conference resources and conference technology providers associated with Conference Management Service. console A collection of administrative tools in Microsoft Management Console (MMC) that contains items such as snap-ins, extension snap-ins, monitor controls, tasks, wizards, and documentation for managing the hardware, software, and networking components of your Windows 2000 system. D data conference Online conferences in which members share date in real time. Data Conferencing Provider A conference technology provider, supplied with Exchange 2000 Conferencing Server, that permits the hosting of data online meetings. datagram One packet or unit of information along with relevant delivery information, such as the destination address, that is sent through a packet-switching network. DHCP digital certificate An electronic credential that authenticates a user on the Internet and intranet. Certificate authorities issue digital certificates. Digital certificates ensure the legitimate online transfer of confidential information, by means of public encryption technology. A digital certificate holder has two keys (strings of numbers): a private key held only by the user, for signing outgoing messages and decrypting incoming messages; and a public key, for use by anyone, for encrypting data to send to a specific user. digital signature A personal authentication method based on encryption and secret authorization codes that is used for signing electronic documents. Digital signatures not only validate the sender's identity, they ensure the message contents have not been altered. No one can tamper with a digitally signed message without detection. When the sender encrypts a message, only the recipient is able to decrypt it and read its contents. DNS domain A group of computers that are part of a network and share a common directory database. In Windows 2000 a domain is a security boundary and permissions that are granted in one domain are not carried over to other domains. Domain Name System (DNS) A TCP/IP standard name service that allows clients and servers to resolve names into IP addresses and vice versa. The Dynamic Domain Name Services in Windows 2000 enables clients and servers to automatically register themselves without the need for administrators to manually define records. domain tree A collection of domains that have a contiguous namespace, such as microsoft.com, sample.microsoft.com, and example.microsoft.com. Domains within the forest that do not have the same hierarchical domain name will be in a different domain. dual key pair system A security architecture that uses two separate key pairs, each with separate usage restrictions. One key pair is used for message encryption, while the other is used for generating and validating digital signatures. Exchange Key Management Service (KMS) uses a dual key pair design so it can archive, and provide recovery of, the user's private encryption key. The private signature key is kept solely in the possession of the user, to prevent the possibility of signature forgery by an administrator. Dynamic Host Configuration Protocol (DHCP) A protocol for assigning Internet Protocol (IP) addresses to computers and other devices on a TCP/IP network. Dynamic addressing permits a computer to have a different address each time it logs on to a network. E encryption An advanced security feature that provides confidentiality by allowing users to conceal data. Data is encrypted as it resides on disk and travels over a network. Exchange 2000 Conferencing Server An application that provides scalable, reliable online data and video conferences. F firewall A combination of hardware and software that function as a security system intended to protect an organization's network against external threats coming from another network, such as the Internet. A firewall prevents direct communication between a network and external computers by routing communication through a proxy server that exists outside the network. forest One or more domain trees that do not form a contiguous namespace. Forests allow organizations to group divisions that operate independently but still need to communicate with one another. full-duplex Capable of carrying information in both directions over a communications channel. A system is full-duplex if it can carry information in both directions at once. G GAT GCC generic application template (GAT) A generic application template specifies a common set of guidelines for building application protocols. The GAT defines the management facility that controls the resources used by application functions. generic conference control (GCC) The generic conference control initiates and administers multipoint data conferences. The GCC performs the following functions: Serves as the information center, directing users and data in and out of conferences and monitoring progress so that the latest conference information is always available. Maintains lists of conference participants and their applications; the GCC identifies compatible applications and features so that products can interoperate. Tracks resources so that conflicts do not occur when conference participants use multiple application protocols. Group Special Mobile 6.10 codec (GSM 6.10 codec) A type of audio codec optimized for voice to allow efficient compression of voice data. H H.323 An International Telecommunications Union (ITU) interoperability protocol enabling cross-communication of multimedia products and applications over packet-based networks. Under H.323, multimedia products offered by one vendor can work with those of another, regardless of hardware compatibility. For example, a PC can share audio and video streams over either an intranet or Internet. Applications are thus network-, platform-, and application-independent. host server For Exchange 2000 Conferencing Server, the conferencing server running the active instance of Conference Management Service. HTTP Hypertext Transfer Protocol (HTTP) A client/server protocol used on the Internet for sending and receiving HTML documents. HTTP is based on the TCP/IP protocol. I IANA IETF IGMP IIS Integrated Services Digital Network (ISDN) A high-speed digital communications network evolving from existing telephone services. The goal in developing ISDN was to replace the current telephone network, which requires digital-to-analog conversions, with facilities totally devoted to digital switching and transmission, yet advanced enough to replace traditionally analog forms of data, ranging form voice to computer transmissions, music and video. ISDN is available in two forms, called BRI (Basic Rate Interface) and PRI (Primary Rate Interface). BRI consists of two B (bearer) channels that carry data at 64 Kbps and one D (data) channel that carries control and signal information at 16 Kbps. In North America and Japan, PRI consists of 30 B channels and 1 D channel. Computers and other devices connect to ISDN through simple, standardized interfaces. inter-subnet network traffic Network traffic that travels over more than one sub-network. International Telecommunication Union - Telecommunications (ITU-T) The sector of the International Telecommunication Union (ITU) responsible for telecommunication standards. ITU-T replaces the Comit Consultatif Internationale de T l graphie et T l phonie (CCITT). Its responsibilities include standardizing modem design and operations, and standardizing protocols for networks and facsimile transmission. ITU is an international organization within which governments and the private sector coordinate global telecom networks and services. International Telecommunications Union (ITU) The International Telecommunications Union coordinates, develops, regulates, and standardizes global telecommunications and organizes regional and world events. For more information about ITU, see the ITU Web site: http://www.itu.int/ Internet Assigned Numbers Authority (IANA) The organization historically responsible for assigning Internet protocol (IP) addresses and overseeing technical parameters, such as protocol numbers and port numbers related to the Internet protocol suite. Under the direction of the late Dr. Jon Postel, IANA operated as an arm of the Internet Architecture Board (IAB) of the Internet Society (ISOC) under contract with the United States government. However, given the international nature of the Internet, IANA s functions, along with the domain name administration handled by U.S.-based Network Solutions, Inc. (NSI), were privatized in 1998 and turned over to a new nonprofit organization know as ICANN (Internet Corporation for Assigned Names and Numbers). Internet Engineering Task Force (IETF) A worldwide organization of individuals interested in networking and the Internet. Managed by the IESG (Internet Engineering Steering Group), the IETF is charged with studying technical problems facing the internet and proposing solutions to the IAB (Internet Architecture Board). The work of the IETF is carried out by various Working Groups that concentrate on specific topics, such as routing and security. The IETF is the publisher of the specifications that led to the TCP/IP protocol standard. Internet Group Membership Protocol (IGMP) A protocol used by IP hosts to report their host group memberships to any immediately neighboring multicast routers. Internet Information Services (IIS) Microsoft's Web service for publishing information on an intranet or the Internet, and for building server-based Web applications. Upon installation, Exchange 2000 extends the messaging capabilities of IIS and incorporates it into the Exchange message routing architecture. Internet Protocol multicasting (IP multicasting) The extension of local area network multicasting technology to a TCP/IP network. Hosts send and receive multicast datagrams, the destination fields that specify IP host group addresses rather than individual IP addresses. A host indicates that it is a member of a group by means of Internet Group Management Protocol. Internet Relay Chat (IRC) A client-server chat protocol that enables an Internet user to participate in an online conversation, in real time, with other users. IP Multicast Initiative (IPMI)IP Multicast Initiative is an international, multi-vendor forum accelerating the adoption of IP multicast as an IETF standard. For more information about IPMI, see the IPMI Web site: http://www.ipmulticast.com/ IPMI ISDN See definition for: Integrated Service Digital Network ITU J K key pair Used in message security, a cryptographic key pair consists of a public key and a private key. A public key is associated with a user through a certificate that is published to a location available to anyone. The corresponding private key is stored in a secure location on the user's client computer. Key Management servers generate key pairs for encryption in Exchange 2000, while Microsoft Outlook generates key pairs for digital signatures. Kilobit (Kb) A data unit of 1,024 bytes. L M MAC MADCAP See definition for: Multicast Address Dynamic Client Allocation Protocol MBone An MBone is a virtual network consisting of those portions of the Internet, sometimes called multicast islands, on which multicasting has been enabled. MCU MDB Media Access Control (MAC) In the IEEE 802.x specifications, the lower of the sublayers that make up the ISO/OSI data-link layer. MAC manages access to the physical network, delimits frames, and handles error control. meeting access pages A set of Web application pages, hosted by Internet Information Services (IIS), to facilitate client access to online meetings. message database (MDB) An instance of a database implemented in Exchange. A single MDB is identified as a mailbox store or public folder store, depending on the type of data that it stores. Microsoft Management Console (MMC) A management display framework that hosts administration tools and applications. Using MMC you can create, save, and open collections of tools and applications. MMC Multicast Address Dynamic Client Allocation Protocol (MADCAP) A protocol that automates distribution of multicast address configurations for network clients. MADCAP replaces MDHCP in the DHCP protocols. It is built on a client-server model that allows hosts to request multicast address allocation services from multicast address allocation servers. In general, the client unicasts or multicasts a message to one or more servers, which may also respond with messages that are unicast to the client. For clients to support MADCAP configuration, their programs must use the new MADCAP application programming interface (API) calls that are available for Windows 2000. multicasting The process of sending a message simultaneously to more than one destination on a network. multipoint control unit (MCU) The entry point through which a participant's computer connects to other conference participants. The MCU is a t.120 data communication service that synchronizes and distributes conference data between participants. N network address/subnet mask A network IP address us four numbers, separated by periods, that represent the Internet name and location of a network device. The host portion of a network IP address is all zeros. A subnet mask is a 32-bit address used to block or "mask" a portion of the IP address to distinguish the network ID from the host ID. non-repudiation A security measure provided by digital signatures. Because a digital signature cannot be forged, senders of digitally signed documents cannot claim their identity was impersonated. Therefore they are bound to any promises or commitments contained in the signed documents. This is why Key Management Service (KMS) does not archive private signing keys, so that administrators (or anyone else) won't have unauthorized access to them. O P private key One of two keys in public key encryption. The user keeps the private key secret and uses it to encrypt digital signatures and to decrypt received messages. public key One of two keys in public key encryption. The user releases this key to the public, who can use it for encrypting messages to be sent to the user and for decrypting the user s digital signature. public key infrastructure (PKI) The laws, policies, standards, and software that regulate or manipulate certificates and public and private keys. In practice, it is a system of digital certificates, certification authorities, and other registration authorities that verify the validity of each party involved in an electronic transaction. Exchange Key Management Service (KMS) works in conjunction with Windows 2000 Certificate Services to provide a PKI for Exchange organizations. Through a third-party certificate authority, a Windows 2000 Certificate Server may be part of a larger PKI that extends beyond an organization. Certificate Server issues X.509 version 3 certificates that bind a user's identity, such as e-mail address and distinguished name, to their public keys. KMS maintains an encrypted database of the corresponding private encryption keys. Q quality of service (QoS) On networks, quality of service is a way to describe error rates, data transmissions rates, and other characteristics that can be measured and possibly improved. R RAS Real Time Control Protocol (RTCP) Real Time Control Protocol is a companion protocol for transmitting real-time data over packet-switched networks. RTCP is now an Internet standard described in RFC 1890. Applications built on top of RTP must also support RTCP. As the name suggests, this protocol only carries control messaging information, not the actual data. Real Time Protocol (RTP) Real Time Protocol is another Internet standard for transmitting real-time data over packet-switched networks. RTP is designed and optimized for real-time media delivery over private and public IP networks. These IP networks change their behavior every millisecond, going from a heavily congested state to normal loads in a matter of seconds. But real-time data such as stock quotes requires fast, speedy delivery to all the sites. real-time Real-time operations are those in which the machine s activities match the human perception of time or those in which computer operations proceed at the same rate as a physical or external process. Real- time operations are characteristic of aircraft guidance systems, transaction-processing systems, scientific applications, and other areas in which a computer must respond to situations as they occur (for example, animating a graphic in a flight simulator or making corrections based on measurement). remote Not on the same computer, or in the immediate vicinity, as a computer or other device located in another place (room, building, or city) and accessible through some type of cable or communications link. Remote Access Services (RAS) A Windows software that allows a user to gain remote access to the network server through a modem. remote procedure call (RPC) A routine that transfers functions and data among computers on a network. Request for Comments (RFC) The official document of the Internet Engineering Task Force (IETF) that specifies the details for protocols included in the TCP/IP family. resource An Active Directory object that can be scheduled and is commonly used for conference rooms and shared equipment. Resource Reservation Protocol (RSVP) A communications protocol designed to allow for bandwidth on demand. A remote receiver requests that a certain amount of bandwidth be reserved by the server for a data stream; the server sends back a message (similar to the RSVP sent in reply to an invitation) indicating whether or not the request was granted. RFC round robin A sequential, cyclical allocation of resources to more than one process or device. RPC RSVP RTCP RTP S scalable Relating to the characteristic of a piece of hardware or software that makes it possible for it to expand to meet future needs. scope mask A scope mask is a network address or subnet mask pair that defines a range of IP addresses. Secure Sockets Layer (SSL) A protocol designed to establish a secure communications channel to prevent the interception of critical information, such as credit card numbers. site A Windows 2000 site consists of one or more reliable and fast TCP/IP subnets. Setting up Windows 2000 sites allows you to configure Active Directory access and a replication topology to take advantage of the physical network. snap-in Software that makes up the smallest unit of a Microsoft Management Console (MMC) extension. One snap-in represents one unit of management behavior. System Manager is an Exchange snap-in in MMC. SSL System Manager An MMC snap-in that provides a framework for containing all Exchange snap-in so that administrators can manage an entire Exchange organization from a single console. Within System Manager, administrators can manage servers, public folders, routing, and policies. System Monitor A Windows 2000 tool that allows you to measure the performance of your own computer or other computers on the network in real time or for historical trending. With System Monitor, you can collect and view extensive data about the usage of hardware resources and the activity of system services on computers you administer. T T.120 data conferencing T.120 data conferencing enables two or more users to communicate and collaborate as a group in real time. Participants in a T.120 data conference share applications, exchange information through a shared clipboard, transfer files, collaborate on a shared whiteboard, and use a text-based chat feature. Also, support for the T.120 data conferencing standard enables interoperability with other T.120-based products and services. T.120 MCU server A multipoint control unit (MCU) server supporting the T.120 standard for real-time multipoint data connections and conferencing. T.120 multipoint control unit server A T.120 multipoint control unit(MCU)server allows three or more terminals to participate in a data conference. An MCU manages the terminal functions and capabilities in a data conference and processes the audio, video, and data streams between terminals. T.120 standard The International Telecommunications Union (ITU) T.120 standard is made up of a suite of communication and application protocols developed and approved by the international computer and telecommunications industries. Using these protocols, developers can create compatible products and services for real-time, multipoint data connections and conferencing. With T.120-based programs, multiple users can participate in conferencing sessions over different types of networks and connections. TAPI Telephony Application Programming Interface (3.0) (TAPI) TAPI 3.0 is an API that combines traditional PSTN telephony and IP telephony. TAPI 3.0 enables IP telephony on Microsoft Windows operating systems by providing simple and generic methods for making connections between two or more computers and accessing any media streams involved in the connection. Time to Live (TTL) A header field for a packet sent over the Internet that indicates how long the packet should be held. topology The configuration or layout of a network formed by the connections between devices on a local area network (LAN) or between two or more LANs. trust relationship The relationship between two domains that makes it possible for a user in one domain to access resources in another domain. TTL U unicast To transmit between a single sender and single receiver over a network. A two-way, point-to-point transmission, unicast is typical of network communications. user An Active Directory object that has a Windows security account and a password. A user is the only Active Directory object that can have a mailbox associated with it. A user in Windows 2000 is the equivalent of a mailbox in earlier versions of Exchange. V video conferencing Teleconferencing in which video images are transmitted among the various geographically separated participants in a meeting. Originally done using analog video and satellite links, today video conferencing uses compressed digital images transmitted over wide area networks or the Internet. Video Conferencing Provider A conference technology provider, supplied with Exchange 2000 Conferencing Server, that permits the hosting of video online meetings. virtual root A mapping between a specific path or name and a physical storage location, be it a local file directory network share or redirection to another URL. For HTTP a virtual root defines a mapping between a URL path and a physical storage location. For NNTP a virtual root defines a mapping between a news group name and a physical storage location. W whiteboard Software that allows multiple users across a network to work together on a drawing that is simultaneously displayed to all the users screens as though they are all gathered around a physical whiteboard. Windows CryptoAPI (CAPI) An application programming interface (API) that is provided as part of Microsoft Windows. CryptoAPI provides a set of functions that allow applications to encrypt or digitally sign data in a flexible manner while providing protection for the user's sensitive private key data. Actual cryptographic operations are performed by independent modules known as cryptographic service providers (CSPs). Windows Internet Naming Service (WINS) A Windows 2000 server method for associating a computer s host name with its address. Windows QoS Admissions Control A Windows 2000 component that administrators can use to manage the use of network resources (bandwidth) at the subnet level. It is based on the Internet Engineering Task Force standard for subnet bandwidth management (SBM). With QoS Admission Controls, administrators can centrally designate how, when, and by whom subnet resources are used. QoS promotes efficient allocation of bandwidth by preventing programs from consuming more bandwidth than a particular subnet can handle. Windows Terminal Services A Windows service that provides remote access to a server desktop through thin client software, serving as a terminal emulator. Terminal services transmits only the user interface of the program to the client. The client then returns keyboard and mouse clicks back to the server for processing. WINS X Y Z