- PC - Buzz - 1 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z *

P&T = Post & Telegrafvæsenet

www.postdanmark.dk/postdanmark/om_post_danmark/historie/historie_start.htm : PostDanmarks historie

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packet switching

Packets (frames) are routed between hosts with no previously established communication path (Connectionless.). Packets may follow different routes. Destination host reassemble packets in appropriatte sequence. Bandwidth is optimized - latency is minimized.
> X.25

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PAD = Peripheral Access Device, Packet Assembly/Disassembly

Skaber kompatibilitet mellem forskellige typer terminaler og det pakkekoblede X.25 netværk - PAD sender et standardiseret format ud på X.25 nettet
> X.25

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PAIH = Public Access Internet Host

 

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PAIS = Public Access Internet Site

 

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pakke

= (Eng.) 'packet' - kaldes også 'frame'.
pakkekoblet = packet switching.

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pakkeprogram

Program, som kan pakke (komprimere) filer - og udpakke.
DOS : >ARCE, ARJ, LHA, PKZIP
WIN : >WinZip, WinRAR

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PAL = Phase Alternation Line

analog TV-standard, som benyttes i Europa. 625 vandrette linier.
>NTSC, SECAM

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PAP = Password Authentication Protocol

A simple PPP authentication mechanism where a cleartext username and password are transmitted to prove identity. PAP is not as secure as CHAP because the password is passed in cleartext.
A procedure used by PPP servers to validate a connection request. PAP works as follows:

1. After the link is established, the requestor sends a password and an id to the server.
2. The server either validates the request and sends back an acknowledgement, terminates the connection, or offers the requestor another chance.

Passwords are sent without security and the originator can make repeated attempts to gain access. For these reasons, a server that supports CHAP will offer to use that protocol before using PAP. PAP protocol details can be found in RFC 1334.

> CLID

PAP = Packet-Level Procedure

is a full-duplex protocol for transferring packets between parties in an X.25 network. PAP supports data sequencing, flow control, accountability, and error detection and recovery.

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PARC = Palo Alto Research Center

owned by Xerox

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Pascal

pascal.miningco.com/mlibrary.htm : Pascal programming

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password

caching

support.microsoft.com/support/kb/articles/Q90/2/71.asp : Password Caching in Windows for Workgroups

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PBX = Private Branch eXchange

- elektronisk RS232C omskifterbox. Når en tilsluttet enhed (bruger) sender et 'request signal' svarer PBXen med en menu - brugeren vælger modtager - PBX etablerer forbindelse. Til simple 'netværk' - der benyttes standard kommunikationsprogrammer.
> DISA

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PC = Personal Computer

- a micro computer (workstation) - an IBM_PC
> mini, Mac

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PC-99

Hardware specifikation udviklet af Microsoft
Hvis følgende minimums-krav er opfyldt, kan PC'en forsynes med et Windows-logo:
- 300 MHz processor (233 MHz for bærbare)
- 64 MB RAM
- 2 USB porte
- Ingen ISA sokler
- understøttelse af OnNow/ACPI

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PC-brugeruddannelsen

PC-brugeruddannelsen er en erhvervsrettet, åben voksenuddannelse.
Formålet med uddannelsen er at give deltagerne de nødvendige IT-færdigheder i forbindelse med en pc-arbejdsplads.
Reglerne for uddannelsen er fastlagt af Undervisningsministeriet, som godkender, hvilke skoler der kan udbyde uddannelsen.

www.retsinfo.dk/_GETDOCM_/ACCN/B19970096105-REGL : Bekendtgørelse om uddannelse til pc-bruger
www.retsinfo.dk/_GETDOCM_/ACCN/B19980045905-REGL : Bekendtgørelse om ændring af bekendtgørelse om uddannelse til pc-bruger

 
En samlet uddannelse består af 7 fag, heraf de to obligatoriske fag:

1. Grundlæggende informationsteknologi
2. Pc'en og dens styresystem

De øvrige 5 fag vælges blandt følgende fag:

3. Tekstbehandling
4. Regneark
5. Databaser
6. Præsentationsprogrammer
7. Informationsnetværk
8. Desktop Publishing
9. Økonomistyring med edb
10. Integreret informationsbehandling og -formidling
11. Udvidet tekstbehandling
12. Udvidet regneark
13. Udvidet databaser

 

>PC-kørekort

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PC-Card

= PCMCIA. Små udvidelseskort til især bærbare PCer

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PCI = Peripheral Component Interconnect, Peripheral Computer Interface

Bus developed by Intel for the Pentium CPU
supports plug-and-play
64-bit data bus
33MHz
66MHz, max data rate: 264MBps
100MHz
> AGP, ISA, EISA, MCA, VESA-bus
2.1 : better handling of hardware interrupt conflicts

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PC-kørekort

En europæisk standard for IT-kompetence ( > ECDL), som i Danmark varetages af DDF.
Består af 7 moduler, som der i vilkårlig rækkefølge kan aflægges prøve i:

1. Grundlæggende IT-kendskab
2. PC'en og dens styresystem
3. Tekstbehandling
4. Regneark
5. Databaser
6. Præsentations- og tegneværktøjer
7. Informationsnetværk (med Internet)

 

dansk-it.dk/sw536.asp : PC-kørekort
www.dansk-it.dk/sw564.asp?view_syllabus=ja   : Kompetancemål (Syllabus)

 

>PC-brugeruddannelsen

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PCM = Pulse Code Modulation

- used by modems

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PCMCIA = Personal Computer Memory Card International Association

> PC-Card

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PCT = Private Communication Technology

Protocol - proposed by Microsoft - for securing privacy in Internet communications - uses authentication and encryption

[ www.generation.net/~hleboeuf/lettrep.htm]: PCT : Internet Explorer 3.0 supports both SSL and PCT. Like SSL, PCT uses public-key cryptography to encrypt a private key, which is used for the rest of the session between the browser and server. The major difference between SSL and PCT is in the handshake protocol phase. According to the Internet draft proposal written by Microsoft and presented to the IETF, PTC requires fewer messages to negotiate a compatible set of protocols, support more encryption algorithms, and provides additional security by using different keys for authentication and encryption.
In addition to supporting these security protocols, Internet Explorer 4.0 uses its security zones to let user configure their browser's security levels different sites. Each zone is assigned a security level that allows only certain activities to take place. For example, you could assign your company's intranet site to the trusted zone, in which case you could surf the site without encrypting transmissions. On the other hand, you could assign Internet sites you are visiting for the first time to the un-trusted zone, which would require the server to provide SSL authentication before the browser uploaded any information.
Internet Explorer 4.0 ships with four defined zones: local intranet, trusted sites, Internet, and restricted sites.

> SSL

www.math.tau.ac.il/~sadov/net-html/index.html : SSL vs PCT

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PDA = Personal Digital Assistant

 

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PDC = Primary Domain Controller

- domæneserver i Windows NT
The standard logon processes, Winlogon and Netlogon, require users to sign on with a user ID and, usually, a password controlled by a Primary Domain Controller.
> BDC

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PDF = Portable Document Format

Filformat (.pdf) som benyttes af Adobe Acrobat.

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PDU = Protocol Data Unit

> SAP

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PEM = Privacy Enhanced Mail

En 'officiel' erstatning for PGP

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PEP = Packet Exchange Protocol

- in network layer of XNS

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peer-to-peer

forbindelse mellem 'ligemænd' - LAN hvor alle computere (workstations) er lige: de kan alle fungere som servere og klienter
- ex: Windows 3.11 for Workgroups, 95, 98, NT Workstation, Personal NetWare
> NOS

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Perl = Practical Extraction and Report Language

- bruges fx på UNIX-computere til fremstilling af CGI-applikationer. Til Win32 findes 'Perl 5'.
- gratis > GNU

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PGP = Pretty Good Privacy

- gratis kryptering udviklet 1991 af amerikaneren Philip Zimmermann - til især e-mail - benytter RSA algoritmen

 

Pretty Good Privacy (PGP) is an encryption method for E-Mail and files. PGP was created by Phil Zimmerman in 1991 and distributed as "freeware". PGP now serves as the worldwide standard for E-Mail encryption. PGP consists of four main modules:

1. a symmetric cipher such as IDEA
2. a public key cipher like RSA
3. a one-way hash
4. a random number generator

PGP is available for most operating systems and is the closest a user is likely to get to "military-grade" encryption.

A freeware, public-key authentication and encryption method based on the IDEA single-key and RSA public-key encryption algorithms.
Well suited to electronic-mail communications (email), Electronic Data Interchange (EDI), and Electronic Funds Transfer (EFT). It does not require the secure exchange of encryption keys (even initially), yet messages that are exchanged will be authenticated (so both the sender and receiver can be assured that the message was not changed) and encrypted (so only the intended receiver can read the message), and the receiver can be assured that the sender really did send the message.

> PEM, WinPGP

web.mit.edu/network/pgp.html : MIT distribution site for PGP
www.pgpi.org : The International PGP Home Page
www.aod.dk/aod/net-kurs/ss_pgp.htm : PC\Magazines\AOD\Datasikkerhed\ss_pgp.htm : Steven Snedker: PGP for noble fritænkere
www.ora.com/reference/dictionary/terms/P/Pretty_Good_Privacy.htm

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Phoenix

BIOS

www.phoenix.com/pcuser/bios.html

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PHP = Personal Home Page / PHP Hypertext Preprocessor

PHP is an HTML-embedded scripting language. Much of its syntax is borrowed from C, Java and Perl with a couple of unique PHP-specific features thrown in. The goal of the language is to allow web developers to write dynamically generated pages quickly.

www.php.net/
www.netcoders.dk/docs/php/manual.html

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pica

typografisk mål = 12 punkter (points) = 1/6 tomme = 4,27 mm

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PIF = Program Information File

used by windows for running DOS applications

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PIM = Personal Information Manager

 

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PIN = Personal Identification Number

"pin-kode"

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PING = Packet Internet Gopher

- a TCP/IP utility - lets you know whether a remote host is accessible - transmits 4 packets (32 bytes) to a specified IP address (numeric or name) - uses ICMP
Windows: PING.EXE (DOS program, PING or PING -H lists options)

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PIO = Programmed Input/Output

- method used to transfer data from harddisk
mode 2 - max 3,33 Mbps
mode 4 - max 16,66 Mbps

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pipe

A pipe is a section of shared memory that processes use for communication. The process that creates a pipe is the pipe server. A process that connects to a pipe is a pipe client. One process writes information to the pipe, then the other process reads the information from the pipe.
 

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ipc/base/pipes.asp

 
>mailslot

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PIPEX

backbone network in UK

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PKUNZIP

Program, som kan udpakke filer (*.zip) pakket med PKZIP
PKUNZIP
> PKWARE

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PKWARE

Producent af pakkeprogrammer
>PKZIP, PKUNZIP, WinZip

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PKZIP

DOS Pakkeprogram. Pakkede filer har endelsen .zip - kan udpakkes med PKUNZIP
PKZIP
>PKWARE, WinZip

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Plug-and-play

> PCI

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PM = Presentation Manager

- OS/2 shell

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PMD = Physical layer Medium Dependant

- part of FDDI

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PNA = Phoneline Networking Alliance

> Home PNA

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PNG = Portable Network Graphics

32-bit Billedformat med fire farveværdier pr pixel: Rød, grøn, blå og alfa (transparens).
PNG-billeder er komprimerede (uden tab), så de egner sig til Internettet.
> RGB, alfa-kanal
> GIF, JPG

www.w3.org/TR/REC-png-multi.html : PNG (Portable Network Graphics) Specification

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PNNI = Private Network-to-Network Interface

> BICI

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point

= 'punktstørrelse' - måleenhed for skrift-størrelse fra top til bund:
1 point = 1/72 tomme = 0,356 mm.
12 point = 4,27 mm (>pica )
> twip

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PnP = Plug and Play

 

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port

> I/O, IP-porte

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portal

= 'indgang' - et system af sider på Internettet med emne-inddelte links til udvalgte sider på Internettet.
Kaldes også 'emne-katalog' eller 'indeks'
>søgemaskine
 

Jubii, Yahoo, NyhedsIndeks
Portaler og Søgemaskiner

 

Portal Server
>Sharepoint Portal Server

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POP = Point Of Presence

A site with telecoms equipment and routers
The access point to a service provider's network. The device that the user dials in to.

 

POP = Post Office Protocol

Anvendes på internettet til at hente e-mail fra en mail-server til en mail-klient.
Indgående post (POP): IP-port 110
Udgående post (SMTP): IP-port 25
> IMAP > RFC 1725
 
A protocol for servers on the Internet that receive, store and transmit e-mail - and for clients on computers that connect to the servers to download and upload e-mail
TCP/IP protocol allowing client to copy mail from server and then delete the mail on the server.
 
POP2
 

POP3
POP3 is the most recent version of a standard protocol for receiving e-mail. POP3 is a client-server protocol in which e-mail is received and held for you by your Internet server. Periodically, you (or your client e-mail receiver) check your mail-box on the server and download any mail. POP3 is built into the Netmanage suite of Internet products and one of the most popular e-mail products, Eudora. It's also built into the Netscape browser.
An alternative protocol is IMAP (Interactive Mail Access Protocol). With IMAP, you view your e-mail at the server as though it was on your client computer. An e-mail message deleted locally is still on the server. E-mail can be kept on and searched at the server.
POP can be thought of as a "store-and-forward" service. IMAP can be thought of as a remote file server.
POP and IMAP deal with the receiving of e-mail and are not to be confused with SMTP, a protocol for transferring e-mail across the Internet. You send e-mail with SMTP and a mail handler receives it on your recipient's behalf. Then the mail is read using POP or IMAP.

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POSIX = Portable Operating System Interface for UniX

An IEEE (1003.1-1988) standard that defines a set of operating-system services. Programs that adhere to the POSIX standard can be easily ported from one system to another. POSIX was based on UNIX system services, but it was created in a way that allows it to be implemented by other operating systems.
Using POSIX programmers can write applications for many (UNIX) platforms
32-bit POSIX applications are supported by Windows NT through a command sub-system
Software developed for the US Government must be POSIX compliant.

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POST = Power On Self Test

Test af computerens hardware - udføres af BIOS når maskinen startes.
> Boot

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PostScript

> Adobe Type 1, EPS
> OpenType, TrueType

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POTS = Plain Old Telephone Service

En ganske almindelig, analog telefon-forbindelse.
Sammenlign ISDN.

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PowerPC

A microprocessor architecture developed in 1992 by Motorola and IBM, with some participation by Apple. A PowerPC microprocessor is RISC-based and superscalar, with a 64-bit data bus and a 32-bit address bus. It also has separate data and instruction caches, although the size of each varies by implementation. All PowerPC microprocessors have multiple integer and floating-point units, and all have an operating voltage of 3.3 volts, except for the 601, which operates at 3.6 volts. The operating speed and number of instructions executed per clock cycle varies with the implementation. The 601 is available in a 80-MHz or 100-MHz version and executes three instructions per clock cycle. The 603, available in 80-MHz, 100-MHz, and 200-MHz versions, executes three instructions per clock cycle. The 604, available in 100-MHz, 120-MHz, and 133-MHz versions, executes four instructions per clock cycle. The 620, available in a 133-MHz version, also executes four instructions per clock cycle. PowerPC is a registered trademark of IBM.
> microprocessor

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PP = Protection Profile

A protection profile defines an implementation-independent set of security requirements and objectives for a category of products or systems which meet similar consumers needs for IT security. A PP is intended to be reusable and to define requirements which are known to be useful and effective in meeting the identified objectives. The PP concept has been developed to support the definition of functional standards, and as an aid to formulating procurement specifications. PPs are already under development for firewalls, relational databases, etc, and to enable backwards compatibility with TCSEC B1 and C2 ratings.
> CC

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PPP = Point-to-Point Protocol

TCP/IP protokol til transmission af data over en telefonlinje - fx via modem.

 

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PPTP = Point-To-Point Tunneling Protocol

A Microsoft proprietary tunneling protocol that was combined with L2F to create L2TP.
Developed by Microsoft, 3Com, Ascend and others - for secure, multiprotocol VPN across the Internet
PPTP embed data into the standard IP packet. This data, which is usually encrypted, is disassembled from the packet, decrypted, and passed securely between the remote user and the central network.

PPTP is a tunneling protocol defined by the PPTP Forum that allows PPP packets to be encapsulated within Internet Protocol (IP) packets and forwarded over any IP network, including the Internet itself. In order to run the Windows95 PPTP client, you must be able to establish an IP connection with a tunnel server such as the WindowsNT Server 4.0 Remote Access Server (RAS).
Windows Dial-Up Networking uses the Internet standard Point-to-Point Protocol (PPP) to provide a secure, optimized multiple-protocol network connection over dialed telephone lines. PPTP adds the ability to treat the Internet as point-to-point Dial-Up Networking connection. All data sent over this connection can be encrypted and compressed, and multiple network level protocols (TCP/IP, NetBEUI, IPX) can be run concurrently.

WindowsNT Domain Login level security is preserved even across the Internet. PPTP can be used to connect to an Intranet that is otherwise isolated from the Internet, and may even have Internet address space conflicts. PPTP appears as new modem type (Virtual Private Networking Adapter) that can be selected when setting up a connection in the Dial-Up Networking folder. The VPN Adapter type does not appear elsewhere in the system. Since PPTP encapsulates its data stream in the PPP protocol, the VPN requires a second dial-up adapter. This second dial-up adapter for VPN is added during the installation phase of the Upgrade in addition to the first dial-up adapter that provides PPP support for the analog or ISDN modem

> L2TP, tunneling, VPN

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PRAM = Parameter RAM

- in Macintosh, special RAM, maintained by a battery, for storage of system settings.
> CMOS

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PRI = Primary Rate Interface, Primary Rate ISDN

24 channels (23B+D) : 23 64kbps B channels (data transmission) - one 64kbps D channel (control). The B channels may be combined for 1.4Mbps

The Primary Rate standard is a higher-level network interface defined at the rate of 1.544 Megabits per second (for North America). This particular rate was selected for compatibility with T1 digital lines commonly used today. The Primary Rate is comprised of 23 B channels, each at 64 Kbps, and one 64 Kbps D channel for signaling. These B channels can interconnect with the Basic Rate Interface, or when carrying voice services to any POTS line

> BRI

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PRML = Partial Response Maximum Likelyhood

- hard disk technology for fast internal data transfer and low seek time.

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profile

En specifikation af rettigheder og personlige indstillinger for en bruger - især i netværk.
> DAC

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programmeringssprog

Assembler, Basic, C, C++, COBOL, Comal, Delphi, Java, Pascal, Prolog

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protokol

Et regelsæt for kommunikation - især mellem computere i et netværk.

>OSI-modellen

>TCP/IP, HTTP, FTP, PPP

www.protocols.com/

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proxy

= 'stedfortræder'
> SOCKS PROXY

proxy server

En computer som formidler trafikken til og fra Internettet. Computerne i lokalnettet sender forespørgsler til proxy-serveren, som sender dem videre til Internettet. Herfra returneres svarene til proxy-serveren, som sender dem videre til de rette computere i lokalnettet.
Proxy-serveren kan dels fungere som sikkerheds-filter ('firewall') for denne trafik - dels som cache for de senest benyttete Internet-sider, så responstiden forkortes og trafikken over Internettet formindskes (Alle de største Internet udbydere såsom Teledanmark, Cybercity, Telia benytter denne teknik.)

Intercepts requests for information and hides the address of the actual location of information from the external Internet.

 

[whatis]: In an enterprise that uses the Internet, a proxy server is a server that acts as an intermediary between a workstation user and the Internet so that the enterprise can ensure security, administrative control, and caching service. A proxy server is associated with or part of a gateway server that separates the enterprise network from the outside network and a firewall server that protects the enterprise network from outside intrusion.
A proxy server receives a request for an Internet service (such as a Web page request) from a user. If it passes filtering requirements, the proxy server, assuming it is also a cache server, looks in its local cache of previously downloaded Web pages. If it finds the page, it returns it to the user without needing to forward the request to the Internet. If the page is not in the cache, the proxy server, acting as a client on behalf of the user, uses one of its own IP addresses to request the page from the server out on the Internet. When the page is returned, the proxy server relates it to the original request and forwards it on to the user.
To the user, the proxy server is invisible; all Internet requests and returned responses appear to be directly with the addressed Internet server. (The proxy is not quite invisible; its IP address has to be specified as a configuration option to the browser or other protocol program.)
An advantage of a proxy server is that its cache can serve all users. If one or more Internet sites are frequently requested, these are likely to be in the proxy's cache, which will improve user response time. In fact, there are special servers called cache servers. A proxy can also do logging.
The functions of proxy, firewall, and caching can be in separate server programs or combined in a single package. Different server programs can be in different computers. For example, a proxy server may in the same machine with a firewall server or it may be on a separate server and forward requests through the firewall.

Microsoft's Proxy Server for Windows NT also serves as a firewall and cache server.
 

Tips from the Proxy Gurus - Configuring & Trouble-Shooting Services and Applications to work with MS Proxy 2.0 FAQ

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PS/2

IBM personal computer
> MCA

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PSDN = Public Switched Data Network

- Supports X.25 and X.28 - A PSDN is an interconnecting set of switching nodes that enables subscribers to exchange data using a standard protocol and packet-switching technology. Such a network carries messages divided into packets over circuits that are shared by many network users. A single physical line into an office can handle many concurrent connections.

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PSN = Packet Switch Node

- computer that routes and forwards packets

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PSTN = Public Switched Telephone Network

- the common worldwide analog telephone network
> ISDN

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PWS = Peer Web Services

A simple web server in Windows NT Workstation - limited to 10 connections - useful for internal webpages in a small workgroup (intranet)

PWS = Personal Web Server

A scaled down web server in Windows 95-98 (based on IIS) - limited to 10 simultaneous connections - useful for internal webpages in a small workgroup (intranet).

Indeholdt i NT Option Pack 4.
PWS ligger også på Windows 98 CD'en i mappen "\Add-ons\PWS".
Når PWS er installeret, kan man bruge sin egen PC både som klient og som ASP-server.

>MDAC

http://members.ozemail.com.au/~geoffch/appnotes/pws/index.html

 

Personal Web Manager - interface to PWS

 

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