glossary of terms

 sjg provides you here with a basic guide to some of the terminology & abbreviations used in the field of GSM, data, ip & telecomms

A

A security mechanism that determines which operations a user, group, service, or computer is authorized to perform on a computer or on a particular object [eg a file]

Predefined groupings of Internet addresses with each class defining networks of a certain size. The range of numbers that can be assigned for the first octet in the IP address is based on the address class

• Class A networks (values 1 to 126) are the largest, with more than 16 million hosts per network

• Class B networks (128 to 191) have up to 65,534 hosts per network

• Class C networks (192 to 223) can have up to 254 hosts per network

A resource record used to map a DNS domain name to a host IP address on the network

• Windows XP Professional: a person responsible for setting up & managing domain controllers or local PCs and their user and group accounts, assigning passwords and permissions, and helping users with networking problems. Administrators are members of the Administrators group and have full control over the domain or computer.

• Windows XP Home Edition: a person who can make system-wide changes to the computer, install software, and who has access to all files on the computer. A person with a computer administrator account has full access to other user accounts on the PC

A partition from which an x86-based computer starts up. The active partition must be a primary partition on a basic disk. If you use Windows exclusively, the active partition can be the same as the system volume

The volume from which the computer starts up. The active volume must be a simple volume on a dynamic disk. You cannot mark an existing dynamic volume as the active volume, but you can upgrade a basic disk containing the active partition to a dynamic disk. Once the disk is upgraded to dynamic, the partition becomes a simple volume that is active

A set of technologies that allows software components to interact with one another in a networked environment, regardless of the language in which the components were created

Automatic Private IP Addressing - A feature of Windows XP: TCP/IP that automatically configures a unique IP address from the range 169.254.0.1 through 169.254.255.254 and a subnet mask of 255.255.0.0 when the TCP/IP protocol is configured for dynamic addressing and a Dynamic Host Configuration Protocol (DHCP) is not available

• ASCII uses designated 7-bit or 8-bit number combinations to represent either 128 or 256 possible characters. Standard ASCII uses 7 bits to represent all uppercase and lowercase letters, the numbers 0 through 9, punctuation marks, and special control characters used in U.S. English. Most current x86-based systems support the use of extended (or "high") ASCII. Extended ASCII allows the eighth bit of each character to identify an additional 128 special symbol characters, foreign-language letters, and graphic symbols

• In TCP/IP, ARP is a protocol that uses broadcast traffic on the local network to resolve a logically assigned IP address to its physical hardware or media access control layer address
• In ATM, ARP is used two different ways. For classical IP over ATM, ARP is used to resolve addresses to ATM hardware addresses. For ATM LAN emulation, ARP is used to resolve Ethernet/802.3 or Token Ring addresses to ATM hardware addresses

Assistive Technology Program

A service that provides recommendations for technology that can help people with disabilities

B

broadband integrated services digital network - An ITU-T communication standard for high-speed networking that provides new services, including voice, video, and data on the same network

communications systems in which the medium of transmission (such as a wire or fiber-optic cable) carries multiple messages at a time, each message modulated on its own carrier frequency by a modem 

broadband connection

A high-speed connection. Broadband connections are typically 256 kilobytes per second (KBps) or faster. Broadband includes DSL and cable modem service

C

computer networking: a group of independent computers that work together to provide a common set of services and present a single-system image to clients. The use of a cluster enhances the availability of the services and the scalability and manageability of the operating system that provides the services

D

• A TCP/IP service protocol that offers dynamic leased configuration of host IP addresses and distributes other configuration parameters to eligible network clients. DHCP provides safe, reliable, and simple TCP/IP network configuration, prevents address conflicts, and helps conserve the use of client IP addresses on the network.
• DHCP uses a client/server model where the DHCP server maintains centralized management of IP addresses that are used on the network. DHCP-supporting clients can then request and obtain lease of an IP address from a DHCP server as part of their network boot process

• A hierarchical, distributed database that contains mappings of DNS domain names to various types of data, such as IP addresses. DNS enables the location of computers and services by user-friendly names, and it also enables the discovery of other information stored in the database

• An Active Directory domain is a collection of computers defined by the administrator of a Windows network. These computers share a common directory database, security policies, and security relationships with other domains. An Active Directory domain provides access to the centralized user accounts and group accounts maintained by the domain administrator. An Active Directory forest is made up of one or more domains, each of which can span more than one physical location.
• A DNS domain is any tree or subtree within the DNS namespace. Although the names for DNS domains often correspond to Active Directory domains, DNS domains should not be confused with Active Directory domains

• A communications device that is the source or destination of channels on a network. Terminals and computers are examples of DTE
• In the RS-232-C hardware standard, any device, such as a remote access server or client, that has the ability to transmit information in digital form over a cable or a communications line

E

• An IEEE 802.3 standard for contention networks. Ethernet uses a bus or star topology and relies on the form of access known as Carrier Sense Multiple Access with Collision Detection (CSMA/DC) to regulate communication line traffic. Network nodes are linked by coaxial cable, fiber-optic cable, or by twisted-pair wiring. Data is transmitted in variable-length frames containing delivery and control information and up to 1,500 bytes of data. The Ethernet standard provides for baseband transmission at 10 megabits (10 million bits) per second.

F

G

The Active Directory replication system builds the global catalog automatically. The attributes replicated into the global catalog include a base set defined by Microsoft. Administrators can specify additional properties to meet the needs of their installation

H

By default, most hive files (Default, SAM, Security, and System) are stored in the systemroot\System32\Config folder. The systemroot\Profiles folder contains the user profile for each user of the computer. Because a hive is a file, it can be moved from one system to another. However, you must use the Registry Editor to edit the file

For Network Load Balancing, a host's precedence for handling default network traffic for TCP and UDP ports. It is used if a host within the cluster goes offline, and it determines which host within the cluster will assume responsibility for the traffic previously handled by the offline host

Hosts file

• A common connection point for devices in a network. Typically used to connect segments of a local area network (LAN), a hub contains multiple ports. When data arrives at one port, it is copied to the other ports so that all segments of the LAN can see the data.

I

If a device is IEEE 1394 compatible, you can connect the device to the IEEE 1394 connector while the computer is running and Windows will detect the device and inform you when it is ready for use. Similarly, you can unplug the device while the computer is running, but you should use the Add Hardware Wizard to inform Windows that you are unplugging the device. Windows will then inform you when the device can be unplugged from the computer.

The IEEE 1394 bus is used primarily to connect high-end digital video and digital audio devices to your computer; however, some hard disks, printers, scanners, and DVD drives can also be connected to your computer using the IEEE 1394 connector

http: Web server uses the Hypertext Transfer Protocol.

www: site is on the World Wide Web.

.co.uk: This is a UK based company

When a router port detects a packet, the router checks the routing table. The port attempts to match the network number of the destination IP address with its routing table entry. If the port finds a match, it forwards the packet to the destination network. With no match, the port forwards the packet to a router defined as the default gateway [ie the www]

• A 32-bit address used to identify a node on an IP internetwork. Each node on the IP internetwork must be assigned a unique IP address, which is made up of the network ID, plus a unique host ID. This address is typically represented with the decimal value of each octet separated by a period (eg, 192.168.7.27). In this version of Windows, you can configure the IP address statically or dynamically through DHCP

J

A physical location on a hard disk that points to data located at another location on the hard disk or another storage device. Junction points are created when you create a mounted drive. You can also create a junction point using the linkd command

K

L

ech part of a full DNS domain name that represents a node in the domain namespace tree. Domain names are made up of a sequence of labels, such as the three labels (example, microsoft, and com) that make up the DNS domain name example.microsoft.com. Each label used in a DNS name must be 63 bytes or less in character length

aka propagation delay: In Active Directory replication, the delay between the time an update is applied to a given replica and the time it is applied to some other replica

LDAP Data Interchange Format - Files that contain LDAP instructions that manipulate directory information. Before the LDAP commands in an LDIF file are carried out, they can be read or modified

For RFC compliance, DNS domain names will use name labels made up only of valid uppercase and lowercase letters, number characters, and hyphens (A through Z, a through z, 0 through 9, and -) separated by periods

M

developed by RSA Data Security, an industry-standard one-way, 128-bit hashing scheme,  used by various Point-to-Point Protocol vendors for encrypted authentication. A hashing scheme is a method for transforming data (eg, a password) in such a way that the result is unique and cannot be changed back to its original form. The CHAP authentication protocol uses challenge-response with one-way MD5 hashing on the response. In this way, you can prove to the server that you know your password without actually sending the password over the network

• Provide message routing and session concentration for independent clients.
• Provide message routing between sites over routing links.
• Create queues and store messages for dependent clients.
• Access information in Active Directory (if installed on a Windows domain controller)

Musical Instrument Digital Interface - A serial interface standard that allows for the connection of music synthesizers, musical instruments, and computers. The MIDI standard is based partly on hardware and partly on a description of the way in which music and sound are encoded and communicated between MIDI devices. The information transmitted between MIDI devices is in a form called a MIDI message, which encodes aspects of sound, such as pitch and volume, as 8-bit bytes of digital information.

MIDI devices can be used for creating, recording, and playing back music. Using MIDI, computers, synthesizers, and sequencers can communicate with each other, either keeping time or actually controlling the music created by other connected equipment

The main MMC window provides commands and tools for authoring consoles. The authoring features of MMC and the console tree itself may be hidden when a console is in User Mode

Microsoft Disk Operating System - An operating system used on PCs and compatibles. Translates user keyboard input into operations the computer can perform. MS-DOS can be easily accessed by using the command prompt, while MS-DOS-based programs can be accessed through the use of shortcuts on the desktop

N

An advanced file system that provides performance, security, reliability &advanced features that are not found in any version of FAT. eg, NTFS guarantees volume consistency by using standard transaction logging and recovery techniques. If a system fails, NTFS uses its log file and checkpoint information to restore the consistency of the file system. In Windows 2000 and Windows XP, NTFS also provides advanced features such as file and folder permissions, encryption, disk quotas, and compression

Network News Transfer Protocol - A member of the TCP/IP suite of protocols used to distribute network news messages to NNTP servers and clients (newsreaders) on the Internet. NNTP is designed so that news articles are stored on a server in a central database enabling a user to select specific items

An object that represents the configuration of the Active Directory service running on a specific domain controller. eg, the NTDS-DSA object holds the setting that determines whether or not the Active Directory service provides global catalog services. NTDS-DSA objects are created and deleted in the course of running the Active Directory Installation Wizard (dcpromo.exe).

An NTDS-DSA object is stored in the Configuration directory partition and is always a child of the Server object representing the domain controller where this particular Active Directory service is running.

eg, if the distinguished name of an NTDS-DSA object is:

• CN=NTDS Settings, CN=RESKIT1,CN=Servers, CN=Washington, CN=Sites, CN=Configuration, DC=reskit,DC=com

then the distinguished name of the corresponding Server object is:

• CN=RESKIT1, CN=Servers, CN=Washington, CN=Sites,
  CN=Configuration, DC=reskit, DC=com

A security package that provides authentication between clients & servers

The NTLM challenge/response protocol was the default for network authentication in Windows NT version 4.0 and earlier

Special cable / lead that eliminates the modem's need for asynchronous communications between two computers over short distances. A null modem cable emulates modem communication

An implementation of the Internetwork Packet Exchange (IPX), Sequenced Packet Exchange (SPX), and NetBIOS protocols used in Novell networks. NWLink is a standard network protocol that supports routing and can support NetWare client-server applications, where NetWare-aware Sockets-based applications communicate with IPX/SPX Sockets-based applications

O

An entity, such as a file, folder, shared folder, printer, or Active Directory object, described by a distinct, named set of attributes. eg, the attributes of a File object include its name, location, and size; the attributes of an Active Directory User object might include the user's first name, last name, and e-mail address.

For OLE and ActiveX, an object can also be any piece of information that can be linked to, or embedded into, another object

1. the physical layer,
2. the data link layer,
3. the network layer,
4. the transport layer,
5. the session layer,
6. the presentation layer,
7. the application layer.

P

packet assembler/disassembler - A device that connects a non-X.25 device such as a modem to an X.25 packet switching network

On basic disks, partitions are known as basic volumes, which include primary partitions and logical drives. On dynamic disks, partitions are known as dynamic volumes, which include simple, striped, spanned, mirrored, and RAID-5 volumes

 removable, credit card sized, device that can be plugged into a Personal Computer Memory Card International Association (PCMCIA) slot in a portable computer. PCMCIA devices can include modems, network cards, and hard disk drives

peripheral component interconnect - A specification introduced by Intel that defines a local bus system that allows up to 10 PCI-compliant expansion cards to be installed in the computer - a high performance 32-bit or 64-bit bus designed to be used with devices that have high bandwidth requirements, such as a display subsystem

PCI expansion slot

A connection socket for a peripheral designed for the PCI local bus on a PC motherboard

The domain controller assigned to act as a Windows NT 4.0 primary domain controller (PDC) to service network clients that do not have Active Directory client software installed, and to replicate directory changes to any Windows NT backup domain controllers (BDCs) in the domain. The PDC emulator master receives preferential replication of password changes performed by other domain controllers in the domain and handles any password authentication requests that fail at the local domain controller. At any time, there can be only one PDC emulator master in a particular domain

process identifier - A numerical identifier that uniquely distinguishes a process while it runs. Use Task Manager to view PIDs

public key infrastructure - The term generally used to describe 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 and authenticate the validity of each party involved in an electronic transaction. Standards for PKI are still evolving, even though they are being widely implemented as a necessary element of electronic commerce

A set of Intel specifications by that allows a PC to automatically detect & configure a device with the required drivers

The mechanism by which desktop settings are configured automatically, as defined by the administrator. Depending on context, this can refer to Group Policy, Windows NT 4.0 System Policy, or a specific setting in a Group Policy object

Post Office Protocol 3 - protocol used for receiving e-mails. Favoured by ISPs, POP3 servers allow access to a single Inbox in contrast to IMAP servers, which provide access to multiple server-side folders

·  offers service providers similar billing and access control with a presence in dial-up services.

·  provides session authentication using Password Authentication Protocol (PAP).

·  provides session authentication using Challenge Handshake Authentication Protocol (CHAP).

·  achieves session accounting and conservation of bandwidth by closing down unused sessions.

·  allows the IAD/Router and ISP link to easily negotiate network parameters

PPPoE is the main method for running PPP protocol over Ethernet. PPPoE:

·  offers service providers similar billing and access control with a presence in dial-up services.

·  provides a low-cost solution to multiple host maintenance at the customer premises.

·  provides session authentication using Password Authentication Protocol (PAP).

·  provides session authentication using Challenge Handshake Authentication Protocol (CHAP).

·  achieves session accounting & conservation of bandwidth by closing down unused sessions.

·  allows the IAD/Router and ISP link to easily negotiate network parameters

Point-to-Point Tunneling Protocol - Networking technology that supports multiprotocol virtual private networks (VPNs), enabling remote users to access corporate networks securely across the Internet or other networks by dialing into an Internet service provider (ISP) or by connecting directly to the Internet. The Point-to-Point Tunneling Protocol (PPTP) tunnels, or encapsulates, IP, IPX, or NetBEUI traffic inside of IP packets. This means that users can remotely run applications that are dependent upon particular network protocols

The node on which you prefer each group to run. eg, the static load balancing model performs best when groups are appropriately balanced between two nodes. When a node fails, the remaining node takes over the groups from the failed node, but performance is diminished. By setting those groups to fail back to their preferred server (the failed node), you automatically restore maximum performance when failback occurs. A group does not fail back if a preferred owner is not selected.

You will not always choose a preferred owner because it may not matter where the group resides; all that matters is that the group is still running on one of the two nodes. Or, the nodes may be equally capable of handling the load required to use some or all of the resources

Primary disk

The hard disk drive that contains the system and boot partitions used to start Windows

primary master

An authoritative DNS server for a zone that can be used as a point of update for the zone. Only primary masters have the ability to be updated directly to process zone updates, which include adding, removing, or modifying resource records that are stored as zone data. Primary masters are also used as the first sources for replicating the zone to other DNS servers

primary partition

aka volumes - A type of partition that you can create on basic disks. A primary partition is a portion of a physical disk that functions as though it were a physically separate disk. On basic master boot record (MBR) disks, you can create up to four primary partitions on a basic disk, or three primary partitions and an extended partition with multiple logical drives. On basic GPT disks, you can create up to 128 primary partitions

Q

R

Remote Authentication Dial-In User Service - A security authentication protocol based on clients and servers and widely used by Internet service providers (ISPs) on remote servers in non-Windows-brand operating systems. RADIUS is the most popular way of authenticating and authorizing dial-up & tunnelled network users

A type of public key Group Policy object used by Encrypting File System (EFS) that provides for one or more user accounts to be designated as recovery agents

• Profiles for each user
•  The programs installed on the computer and the types of documents each can create.
• Property settings for folders and program icons.
• What hardware exists on the system.
• Which ports are being used.

The registry is organized hierarchically as a tree and is made up of keys and their subkeys, hives, and value entries

• For the distinguished name CN=MyName,CN=Users,DC=Microsoft,DC=Com the relative distinguished name of the MyName user object is CN=MyName. The relative distinguished name of the parent object is CN=Users

relative ID master

The domain controller assigned to allocate sequences of relative IDs to each domain controller in its domain. Whenever a domain controller creates a security principal (user, group, or computer object), the domain controller assigns the object a unique security ID. The security ID consists of a domain security ID that is the same for all security IDs created in a particular domain, and a relative ID that is unique for each security ID created in the domain. At any time, there can be only one relative ID master in a particular domain

relative name

The partial DNS domain name configured in individual resource records to locate & qualify the record within a zone. The relative name is joined to the front of the parent domain (domain of origin) for each resource record to form a fully qualified domain name (FQDN) within the zone. In DNS Manager, the relative name will correspond to fields that use record-specific name properties, such as the Host computer name field used in an address (A) resource record

remote access

Part of the integrated Routing and Remote Access service that provides remote networking for telecommuters, mobile workers, and system administrators who monitor and manage servers at multiple branch offices. Users with a computer running Windows and Network Connections can dial in to remotely access their networks for services such as file and printer sharing, electronic mail, scheduling, and SQL database access

remote access server

A Windows-based PC running the Routing and Remote Access service and configured to provide remote access

Request for Comments - An official document of the Internet Engineering Task Force (IETF) that specifies the details for protocols included in the TCP/IP family

relative ID - The part of a security ID (SID) that uniquely identifies an account or group within a domain

Routing Information Protocol over IPX - A protocol used by routers to exchange information between routers on an IPX network and by hosts to determine the best router to use when forwarding IPX traffic to a remote IPX network

read-only memory - A semiconductor circuit that contains information that cannot be modified

The highest or uppermost level in a hierarchically organized set of information. The root is the point from which further subsets are branched in a logical sequence that moves from a broad or general focus to narrower perspectives

root authority

The certification authority (CA) at the top of a certification hierarchy. The root CA has a self-signed certificate. aka the root certification authority

root certificate

A self-signed certification authority certificate. It is called a root certificate because it is the certificate for the root authority. The root authority must sign its own certificate because by definition there is no higher certifying authority in the certification hierarchy

root domain

The beginning of the Domain Name System (DNS) namespace. In Active Directory, the initial domain in an Active Directory tree. Also the initial domain of a forest

root hints

aka Cache hints - Local information stored on a DNS server that provides helping resource records to direct the server to its root servers. For DNS, the root hints are stored in the file Cache.dns, located in the Systemroot\System32\Dns folder

root servers

DNS servers that are authoritative for the root of the namespace

round robin

A simple mechanism used by DNS servers to share and distribute loads for network resources. Round robin is used to rotate the order of resource records (RRs) returned in a response to a query when multiple RRs of the same type exist for a queried DNS domain name

round robin

• In a Windows environment, hardware that helps LANs and WANs achieve interoperability and connectivity, and can link LANs that have different network topologies (such as Ethernet and Token Ring). Routers match packet headers to a LAN segment and choose the best path for the packet, optimizing network performance.

• In the Macintosh environment, routers are necessary for computers on different physical networks to communicate with each other. Routers maintain a map of the physical networks on a Macintosh internet (network) and forward data received from one physical network to other physical networks. Computers running the Server version of Windows with AppleTalk network integration can act as routers, and you can also use other routing hardware on a network with AppleTalk network integration

Message Queuing: a communications link established between Windows sites for routing messages. Specially configured Message Queuing servers with routing services enabled are used to create a routing link between sites

a service on a Message Queuing server that provides message routing services. If so configured, this feature can be used on a Message Queuing server to:

• Enable computers that use different network protocols to communicate
• Reduce the number of sessions by acting as a gateway for all incoming or outgoing messages for independent clients

S

subnet bandwidth management - An IETF standard that enables administrative control at the subnet level

A description of the object classes and attributes stored in Active Directory. For each object class, the schema defines the attributes an object class must have, the additional attributes it may have, and the object class that can be its parent.

The Active Directory schema can be updated dynamically. eg, an application can extend the schema with new attributes and classes and use the extensions immediately. Schema updates are accomplished by creating or modifying the schema objects stored in Active Directory. Like every object in Active Directory, schema objects have an access control list, so only authorized users may alter the schema

schema master

The domain controller assigned to control all updates to the schema within a forest. At any time, there can be only one schema master in the forest

Session Description Protocol - A protocol that TAPI uses to advertise IP multicast conferences. This protocol describes multimedia sessions for the purposes of session announcement, session invitation, and other forms of session initiation. SDP descriptors are stored in Active Directory. SDP is described in RFC 2327 of the IETF

second-level domains

Domain names that are rooted hierarchically at the second tier of the domain namespace directly beneath the top-level domain names such as .com and .org. When DNS is used on the Internet, second-level domains are names such as microsoft.com that are registered and delegated to individual organizations and businesses according to their top-level classification. The organization then assumes further responsibility for parenting management and growth of its name into additional subdomains

server cluster

A group of independent computer systems, known as nodes, working together as a single system to ensure that mission-critical applications and resources remain available to clients. A server cluster is the type of cluster that Cluster service implements

server zone

The AppleTalk zone on which a server appears. On a Phase 2 network, a server appears in the default zone of the server's default network

A program, routine, or process that performs a specific system function to support other programs, particularly at a low (close to the hardware) level. When services are provided over a network, they can be published in Active Directory, facilitating service-centric administration and usage. Some examples of services are the Security Accounts Manager service, File Replication service, and Routing and Remote Access service

A resource record used in a zone to register and locate well-known TCP/IP services. The SRV resource record is specified in RFC 2782, and it is used to locate domain controllers for Active Directory

Service Provider Interface

Calling conventions that back-end services use to make themselves accessible to front-end applications

service ticket

A ticket issued by the Kerberos V5 ticket-granting service (TGS) that allows a user to authenticate to a specific service in the domain

A logical connection created between two hosts to exchange data. Typically, sessions use sequencing and acknowledgments to send data reliably.

• In load balancing TCP/IP traffic, a set of client requests directed to a server. These requests can be invoked with multiple, possibly concurrent, TCP connections. The server program sometimes maintains state information between requests. To preserve access to the server state, Network Load Balancing needs to direct all requests within a session to the same cluster host when load balancing

session concentration

For Message Queuing, a feature that typically reduces network bandwidth within a site and the number of sessions between sites. Specially configured Message Queuing servers with routing services provide session concentration

simple volume

A dynamic volume made up of disk space from a single dynamic disk. A simple volume can consist of a single region on a disk or multiple regions of the same disk that are linked together. You can extend a simple volume within the same disk or onto additional disks. If you extend a simple volume across multiple disks, it becomes a spanned volume. You can create simple volumes only on dynamic disks. Simple volumes are not fault tolerant, but you can mirror them to create mirrored volumes

Server Message Block - A file-sharing protocol designed to allow networked computers to transparently access files that reside on remote systems over a variety of networks. The SMB protocol defines a series of commands that pass information between computers. SMB uses four message types: session control, file, printer, and message

Service Profile Identifier - An 8-digit to 14-digit number that identifies the services that you ordered for each B-channel. eg, when you order Primary Rate ISDN, you obtain two phone numbers and two SPIDs from your ISDN provider. Typical ISDN adapters cannot operate without configuring SPIDs

Permanent routes in the routing table that the router stores. An entry manually configured by a network administrator defined in a routing table that never changes or expires. A static route entry will contain the target address, the next hop router address on the way to that target, and a value assigned to the entry indicating how it rates compared to other router to the same target If the routing protocol is configured to support auto-static routes (automatically added static routes), then the router can issue a request to a protocol to get an update of routing information on a specific interface. The results of such an update are then converted and kept as static routes

A subdivision of an IP network. Each subnet has its own unique subnetted network ID

 Subnet masks split one network into a set of mini networks or subnets. Subnetting helps to reduce traffic on each subnet. Subnetting also makes the network more manageable. Each subnet functions as if it were an independent network

Any node within a tree, along with any selection of connected descendant nodes. In the registry structure, subtrees are the primary nodes that contain keys, subkeys, and value entries

system files

Files used by Windows to load, configure, and run the operating system. Generally, system files must never be deleted or moved

system partition

The partition that contains the hardware-specific files needed to load Windows (ie, Ntldr, Osloader, Boot.ini, Ntdetect.com). The system partition can be, but does not have to be, the same as the boot partition

System Policy

A Windows NT 4.0-style policy based on registry settings made using Poledit.exe, the System Policy Editor

system queue

For Message Queuing, a queue that stores various types of administrative messages. Message Queuing uses up to five system queues, all of which are private queues. System queues cannot be deleted

System Restore

A tool that tracks changes to your computer and creates a restore point when it detects the beginning of a change. You can use the System Restore Wizard to select a restore point to restore your computer to an earlier state when your computer was functioning the way you like

system volume

The volume that contains the hardware-specific files that are needed to load Windows on x86-based computers with a BIOS. The system volume can be, but does not have to be, the same volume as the boot volume

The path and folder name where the Windows system files are located. eg, C:\Windows

A shared directory that stores the server copy of the domain's public files, which are replicated among all domain controllers in the domain

T

Telephony application programming interface - used by communications programs to work with telephony and network services. Communications programs like HyperTerminal and Phone Dialer use TAPI to dial, answer, and route telephone calls on conventional telephony devices, including PBXs, modems, and fax machines. TAPI 3.0 also provides Internet Protocol (IP) telephony support, which Phone Dialer and other programs use to transmit, route, and control real-time audio and video signals over IP-based networks such as the www

Transport Driver Interface - A common set of routines for network layer components that communicate with the session layer of the Open Systems Interconnection (OSI) model. These routines allow software components above & below the transport layer to be mixed and matched without reprogramming

time stamp

A certification by a trusted 3rd party specifying that a particular message existed at a specific time & date. 3rd parties generate a trusted time stamp for a given message by having a time stamping service add a time value to a message and then digitally sign

Transport Layer Security - A standard protocol that is used to provide secure Web communications on the Internet or intranets. It enables clients to authenticate servers or, optionally, servers to authenticate clients. It also provides a secure channel by encrypting communications. TLS is the latest and a more secure version of the SSL protocol

transport provider

The driver and support files that provide transport services in a networking environment

In Simple Network Management Protocol (SNMP), a message sent by an agent to a management system indicating that an event has occurred on the host running the agent

A logical connection over which data is encapsulated. Typically, both encapsulation and encryption are performed and the tunnel is a private, secure link between a remote user or host and a private network

tunnel server

A server or router that terminates tunnels and forwards traffic to the hosts on the target network

two-way trust

A type of trust relationship in which both of the domains in the relationship trust each other. In a two-way trust relationship, each domain has established a one-way trust with the other domain. eg, domain A trusts domain B and domain B trusts domain A. Two-way trusts can be transitive or nontransitive. All two-way trusts between Windows domains in the same domain tree or forest are transitive

U

A socket that transmits datagrams over the User Datagram Protocol

Unicode Transmission Format 8 - A character set for protocols evolving beyond the use of ASCII. The UTF-8 protocol provides for support of extended ASCII characters and translation of UCS-2, an international 16-bit Unicode character set. UTF-8 enables a far greater range of names than can be achieved using ASCII or extended ASCII encoding for character data

Universal Naming Convention - A convention for naming files and other resources beginning with two backslashes (\), indicating that the resource exists on a network computer. UNC names conform to the \\SERVERNAME\SHARENAME syntax, where SERVERNAME is the server's name and SHARENAME is the name of the shared resource. The UNC name of a directory or file can also include the directory path after the share name, with the following syntax: \\SERVERNAME\SHARENAME\DIRECTORY\FILENAME

universal group

A security or distribution group that can be used anywhere in the domain tree or forest. A universal group can have members from any Windows domain in the domain tree or forest. It can also include other universal groups, global groups, and accounts from any domain in the domain tree or forest. Rights and permissions must be assigned on a per-domain basis, but can be assigned at any domain in the domain tree or forest.

Universal groups can be members of domain local groups and other universal groups, but they cannot be members of global groups. Universal groups appear in the global catalog and should contain primarily global groups

A powerful, multiuser, multitasking operating system initially developed at AT&T Bell Laboratories in 1969 for use on minicomputers. UNIX is considered more portable, that is, less computer-specific, than other operating systems because it is written in C language. Newer versions of UNIX have been developed at the University of California at Berkeley and by AT&T

Uniform Resource Locator - An address that uniquely identifies a location on the www. aka Internet address: An address for a resource on the Internet that is used by Web browsers to locate Internet resources. An Internet address typically starts with a protocol name, followed by the name of the organization that maintains the site; the suffix identifies the kind of organization it is. eg, the address http://www.sjgl.co.uk/ provides the following information:

http: Web server uses the Hypertext Transfer Protocol.

www: site is on the World Wide Web.

.co.uk: This is a UK based company

user profile

A file that contains configuration information for a specific user, such as desktop settings, persistent network connections, and application settings. Each user's preferences are saved to a user profile that Windows uses to configure the desktop each time a user logs on

Tasks that a user is permitted to perform on a computer system or domain. There are two types of user rights: privileges and logon. An example of a privilege is the right to shut down the system. An example of a logon right is the right to log on to a computer locally. Both types are assigned by administrators to individual users or groups as part of the security settings for the PC

A special group that contains all users who have user permissions on the server

V

Video Graphics Array

an ordered series of words or numbers used in an index query

virtual address