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all choreographed to perfection by the intricate routers, switches, and bridges.

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Infoarch Multimedia Terms

Disclaimer: This section is intended as a quick reference for those with technical background only. Advice posted in this area may be simplified; certain key steps may be neglected with the assumption that you know what you are doing. If you don't, please consult your Infoarch representative.

Multimedia Term Description
Aspect Ratio The width/height ratio of a television set or movie screen. Most television sets have a 4:3 aspect ratio. Wide screen television sets have a 16:9 aspect ratio.
Bidirectional (B) Frame One of the three picture types in MPEG compression. B frames are coded in relation to previous or subsequent I or P frames. B frames do not serve as a reference for other frames
Data Rate The speed of the data stored on a type of media, usually expressed in bits per second or bytes per second.
Data Transfer Rate The transfer rate of the storage media itself. VCD transfer rate is 1.2MB.
Downmix The process of converting a multi-channel audio track to two- or one-channel track.
Dolby Digital Also known as AC-3. A high-quality, bandwidth-efficient perceptual audio coding system originally developed by Dolby Laboratories for multi-channel digital sound in the cinema. It can be used in broadcast, cable, film, and recorded media in both professional and consumer applications. Dolby Digital is one of the main audio formats used in DVD.
Dolby Surround The consumer version of the original analog Dolby multi-channel film sound format.
Drop Frame Time Code A mode of operation when playing back NTSC video. In NTSC, the actual frame rate is roughly 29.97 fps. When the time code indicates 1 hour of film, 1 hour, 3 seconds, and 18 frames worth of actual time has elapsed, or a discrepancy of 108 frames. Some encoders resolve the time code discrepancy by dropping two frame numbers every minute, on the minute, except the tenth minutes.
DTS (Digital Theater Sound) An audio encoding technology developed for theaters. DTS was developed to compete with Dolby Digital and is an additional audio format for DVD.
GOP (Group of Pictures) A GOP is a single MPEG video random access unit.
Intra (I) Frame A key reference frame in the MPEG compression algorithm. I Frames are one of the three types of frames used in MPEG compression. They contain all the data needed to represent an entire frame, hence are referred to as key reference frames.
Linear PCM A non-compressed digital audio format. The DVD specification allows for 16 to 24 bit Linear PCM audio sampled at 48 or 96 kHz.
MP3 MP3 is the MPEG audio layer 3 standard. Layer 3 is one of three coding schemes (layer 1, 2, and 3) for the compression of audio signals defined by the MPEG committee. Layer 3 uses perceptual audio coding and psychoacoustic compression to remove the redundant parts of a sound signal. It also adds an MDCT (Modified Discrete Cosine Transform) that implements a filter bank, increasing the frequency resolution 18 times higher than that of MPEG audio layer 2.
MPEG-1 ISO/IEC standard designed for low bandwidth of compressed digital video and audio. VCD uses this format with resolution of 352x288@25fps (PAL) or 352x240@29.97fps (NTSC).
MPEG-2 ISO/IEC standard designed for transmission of high bandwidth compressed digital video and audio such as that used by broadcast television. DVD uses this format with resolution of 720x576@25fps (PAL) or 720x480@29.97fps (NTSC).
MPEG-4 ISO 14496 is an ISO/IEC standard developed by MPEG (Moving Picture Experts Group). Although defined as one standard, MPEG-4 is actually a set of compression/decompression formats and streaming technologies that address the need for distributing rich interactive media over narrow and broadband networks.
MPEG Audio Multi-channel digital audio defined by the MPEG specification. MPEG-1 Layer 2 is compressed using perceptual coding. It has a sample rate of 32, 44.1, and 48 kHz at 16 bits and can contain mono or stereo streams. MPEG-1 Layer 3 supports variable sample rate. MPEG-2 audio is an extension of MPEG-1 audio. It supports low bit rates and up to 7.1 audio channels.
Multiplexing Combining two or more data streams together into a single stream.
Predicted (P) Frame Frames used in MPEG compression which are coded in relation to the nearest previous I or P frame. P frames serve as a prediction reference for B frames and future P frames.
SDDS (Sony Dynamic Digital Sound) An audio encoding technology developed by Sony for multi-channel audio in cinemas and theaters. SDDS was developed to compete with Dolby Digital and is an optional audio format for DVD.
S-Video A video signal that carries separate luminance and chrominance signals.
SMPTE EBU Time Code A standard for a signal recorded on videotape to uniquely identify each frame of the video signal. It is used to control editing operations. (SMPTE stands for Society of Motion Picture and Television Engineering).

Infoarch Networking Terms

This section is intended as a quick reference for those with technical background only. Advice posted in this area may be simplified; certain key steps may be neglected with the assumption that you know what you are doing. If you don't, please consult your Infoarch representative.

Networking Term Description
Amplifier A network component, also known as a repeater. Amplifiers increase the power of a signal when it is lost due to attenuation. They allow signals to cover greater distances in a LAN environment.
Application Layer The seventh layer in the OSI model. The Application layer defines program-to-program communication, or how applications access network services. Services defined by the Application layer include file transfer, job transfer, and terminal emulation.
ATM Broad bandwidth (155 Mb). ATM can be implemented either as a backbone solution or as an entire network solution. In the backbone scenario, ATM is used to connect departments, floors, or any part of the organization that is distant from the main server center. In the network scenario, ATM is used as the entire LAN, WAN, or MAN. LAN Emulation (LANE) is used in these types of networks to give an Ethernet feel to the network. This emulation is easier to implement than IP emulation over ATM and is much more popular.
Bandwidth The amount of data that can be transmitted in a fixed amount of time. For digital devices, the bandwidth is usually expressed in bits per second or bytes per second. For analog devices, the bandwidth is expressed in cycles per second, or Hertz (Hz).
Bridge A network component that connects two LANs, thus extending the range of the network. Bridges check data and forward them across LANs.
Broadband A single wire or network pipe that has sufficient bandwidth to carry large amounts of data simultaneously.
Broadcast When data is sent simultaneously to all stations on a network.
Brouter A network component that serves as both a Bridge and a Router.
Buffer Space allocated on a system's Random Access Memory (RAM) where data is stored temporarily until it is transferred to another part of the system.
Bus Topology A LAN network structure in which all stations (nodes) are connected to the same cable. Data is transmitted up and down this single cable.
Cable Modem A modem that connects home networking systems (computer + TV) to cable TV networks, bypassing traditional phone networks. Cable TV networks use a coaxial cable or HFC infrastructure.
Circuit Switching A communication technology in which a dedicated channel (circuit) is established for the duration of a transmission.
Collisions In an Ethernet network, every host connected to the network can transmit at any time. This may result in two hosts transmitting at the same time. If a collision between packets is sensed by both hosts, their NICs (Network Interface Cards) perform a Back Off - a transmission time-out. Since the length of the back-off is randomly determined, in most cases when the time-out has elapsed both NICs will be able to re-transmit without interfering with each other. There is always a chance that another host will try to send a packet, causing the back-off procedure to start again.
Coaxial Cable Copper cable that consists of a central wire surrounded by insulation and then a grounded shield of braided wire. Coaxial wire is widely used by the cable television industries. It is less prone to interference than regular wire cables. Most older Ethernet networks also use coaxial cable.
Connectionless vs Connection-oriented Protocols When using a connectionless protocol, hosts send data without establishing a connection with the recipient. The host does not know if the data arrives at its destination or not. In contrast, connection-oriented protocols require a designated path to be established between the sender and receiver before any messages are transmitted.
Dial-Up Access When computer devices hook up to a network via modem and public phone system on a pay-per-time basis. Usually, dial-up connections offer limited bandwidths. The alternative is a leased line that offers continuous access at a constant bandwidth to a network.
DSL (Digital Subscriber Lines) A general acronym relating to Digital Subscriber Lines. The two main types are ADSL (Asynchronous) and SDSL (Synchronous). DSL modulate data over copper wires. Also known as 'last mile' technologies because they are used to connect only between telephone switching stations to a home or office, not between switching stations.
E1/T1 In the United States, a T1 service is a framed communication protocol that delivers a two-way connection at 1.544 Mbits/s each way. In many other countries, the equivalent of T1 is a service called E1 - a two-way connection at 2.048 Mbit/s.
FDDI (Fiber Distributed Data Interface) A set of ANSI protocols for sending digital data over fiber optic cable. FDDI networks are token-passing networks. They support data rates of up to 100 Mbps. FDDI networks usually serve as backbones for wide-area networks. FDDI-2 is an extension of FDDI that supports the transmission of voice and video too.
FTP (File Transfer Protocol) A protocol that defines the transfer of files over the Internet.
Hub A networking component that enables the common connection of devices to a network. Hubs are usually used to connect nodes in local area networks. Active hubs can regenerate data over the network, whereas passive hubs only transfer information.
Jitter Data packets, in general, are not sensitive to how long it takes for them to arrive or when they arrive in relation to the preceding or subsequent packets. The delay added by the network is called latency. The difference over time between the latencies of different packets is called jitter.
IP (Internet Protocol) The protocol that defines how packets are formatted and addressed when sending data over the Internet. The IP frame header contains routing information and control information associated with datagram delivery. IP is part of the TCP/IP group of protocols.
IP Multicast To send information over the Internet to a group of computers that share the same IP address.
Local Area Networks (LAN) A network that covers a small geographical area.
Latency The amount of time it takes a packet to travel from source to destination. Together, latency and bandwidth define the speed and capacity of a network.
Leased Line A permanent connection to a network that guarantees constant bandwidth and network access. Leased lines cost a fixed monthly fee.
Modem A network interface device that allows computers to send and receive data over telephone lines.
Quality of Service (QoS) Quality of Service refers to the way data is transmitted between two hosts on a network. Networking protocols that offer QoS make sure that when information needs to be communicated, the sender requests a designated path with the network for a connection to the destination. The sender specifies the type, speed, and other attributes of the call, which determine and guarantee the end-to-end quality of service.
Packet Switching A networking technology in which messages are divided into packets before they are sent. Each packet is transmitted individually and can even follow different routes to its destination. Once all the packets forming a message arrive at the destination, they are recompiled into the original message. Packet switching is more efficient and robust for data that can withstand some delays in transmission, such as e-mail messages and Web pages.
Router A networking device that connects different types of networks. Routers know how to direct data between networks that use different architectures and protocols.
RTP (Real-Time Transport Protocol) An Internet protocol that defines the transmission of real-time data, for example, audio and video. RTP provides mechanisms for the sending (server) and receiving applications to support streaming data. RTP usually runs on top of the UDP protocol.
Star Topology A local-area network (LAN) in which all nodes (stations) are connected to a central device.
Streaming A technique for transferring data so that it is received as a continuous real-time stream.
TCP (Transmission Control Protocol) TCP is one of the main protocols in TCP/IP networks. TCP defines the way two hosts establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent.
TCP/IP A set of protocols designed by the US Department of Defense for transferring data between networks.
UDP (Universal Data Protocol) A transfer protocol that allows any station on a network that possesses a standard network card to transmit or receive information, without the need for a special interface card. UDP is mainly used to broadcast messages over a network.
Virtual Private Network (VPN) A network dedicated to a specific user or group of users that is part of a public network. For example, there are a number of systems that enable users to create dedicated networks using the Internet as the backbone for transporting data.
VLANS Virtual Local Area Networks are networks that allow any user, no matter where they are, to log on to their home network.
WAP (Wireless Application Protocol) A protocol that defines delivery and access of information to wireless devices.
Wide Area Network (WAN) A network that covers large geographical areas by connecting many local area networks together.

Infoarch TCP/UDP Ports

We have included a generalized list for your perusal, you should possess sufficient knowledge of TCP, IP and UDP to effectively make use of this table. For example, port 53 is used by DNS, but TCP and UDP 53 are used differently, which we will not go into details here.
This is not a comprehensive list, showing only the ports used by Internet well known services.

Firewall Tips: To maximize protection against intruder, configure your gateway to block all incoming and outgoing traffics except from and to certain sites specifically chosen.
For ease of administration, you may choose to allow all traffic to get through except certain specific ports. For example, you may want to block port 4000 to prevent your users from using ICQ, which can be a resource hog


Port List

Port Number Service
1tcpmux
5rje
7echo
9discard
11systat
13daytime
15netstat
17qotd
18send/rwp
19chargen
20ftp-data
21ftp
22ssh, pcAnywhere
23Telnet
25SMTP
27ETRN
29msg-icp
31msg-auth
33dsp
37time
38RAP
39rlp
42nameserv, WINS
43whois, nickname
49TACACS, Login Host Protocol
50RMCP, re-mail-ck
53DNS
57MTP
59NFILE
63whois++
66sql*net
67bootps
68bootpd/dhcp
69Trivial File Transfer Protocol (tftp)
70Gopher
79finger
80www-http
88Kerberos, WWW
95supdup
96DIXIE
98linuxconf
101HOSTNAME
102ISO, X.400, ITOT
105cso
106poppassd
109POP2
110POP3
111Sun RPC Portmapper
113identd/auth
115sftp
117uucp
119NNTP
120CFDP
123NTP
124SecureID
129PWDGEN
133statsrv
135loc-srv/epmap
137netbios-ns
138netbios-dgm (UDP)
139NetBIOS
143IMAP
144NewS
152BFTP
153SGMP
161SNMP
175vmnet
177XDMCP
178NextStep Window Server
179BGP
180SLmail admin
199smux
210Z39.50
218MPP
220IMAP3
259ESRO
264FW1_topo
311Apple WebAdmin
350MATIP type A
351MATIP type B
363RSVP tunnel
366ODMR (On-Demand Mail Relay)
387AURP (AppleTalk Update-Based Routing Protocol)
389LDAP
407Timbuktu
434Mobile IP
443ssl/https
444snpp, Simple Network Paging Protocol
445SMB
458QuickTime TV/Conferencing
468Photuris
500ISAKMP, pluto
512biff, rexec
513who, rlogin
514syslog, rsh
515lp, lpr, line printer
517talk
520RIP (Routing Information Protocol)
521RIPng
522ULS
531IRC
543KLogin, AppleShare over IP
545QuickTime
548AFP
554Real Time Streaming Protocol
555phAse Zero
563NNTP over SSL
575VEMMI
581Bundle Discovery Protocol
593MS-RPC
608SIFT/UFT
626Apple ASIA
631IPP (Internet Printing Protocol)
635mountd
636sldap
642EMSD
648RRP (NSI Registry Registrar Protocol)
655tinc
660Apple MacOS Server Admin
666Doom
674ACAP
687AppleShare IP Registry
700buddyphone
705AgentX for SNMP
901swat, realsecure
993s-imap
995s-pop
1062Veracity
1080SOCKS
1085WebObjects
1227DNS2Go
1243SubSeven
1338Millennium Worm
1352Lotus Notes
1381Apple Network License Manager
1417Timbuktu
1418Timbuktu
1419Timbuktu
1433Microsoft SQL Server
1434Microsoft SQL Monitor
1494Citrix ICA Protocol
1503T.120
1521Oracle SQL
1525prospero
1526prospero
1527tlisrv
1604Citrix ICA, MS Terminal Server
1645RADIUS Authentication
1646RADIUS Accounting
1680Carbon Copy
1701L2TP/LSF
1717Convoy
1720H.323/Q.931
1723PPTP control port
1755Windows Media .asf
1758TFTP multicast
1812RADIUS server
1813RADIUS accounting
1818ETFTP
1973DLSw DCAP/DRAP
1985HSRP
1999Cisco AUTH
2001glimpse
2049NFS
2064distributed.net
2065DLSw
2066DLSw
2106MZAP
2140DeepThroat
2301Compaq Insight Management Web Agents
2327Netscape Conference
2336Apple UG Control
2427MGCP gateway
2504WLBS
2535MADCAP
2543sip
2592netrek
2628DICT
2727MGCP call agent
2998ISS Real Secure Console Service Port
3000Firstclass
3031Apple AgentVU
3128squid
3130ICP
3150DeepThroat
3264ccmail
3283Apple NetAssitant
3288COPS
3305ODETTE
3306mySQL
3389RDP Protocol (Terminal Server)
3521netrek
4000icq, command-n-conquer
4321rwhois
4333mSQL
4827HTCP
5004RTP
5005RTP
5010Yahoo! Messenger
5060SIP
5190AIM
5423Apple VirtualUser
5500securid
5501securidprop
5631PCAnywhere data
5632PCAnywhere
5800VNC
5801VNC
5900VNC
5901VNC
6000X Windows
6112BattleNet
6502Netscape Conference
6667IRC
6670VocalTec Internet Phone, DeepThroat
6699napster
6776Sub7
6970RTP
7007MSBD, Windows Media encoder
7070RealServer/QuickTime
7648CU-SeeMe
7649CU-SeeMe
7778Unreal
8010WinGate 2.1
8080HTTP
8181HTTP
8383IMail WWW
8530WSUS
8875napster
8888napster
10008cheese worm
11371PGP 5 Keyserver
13223PowWow
13224PowWow
14237Palm
14238Palm
18888LiquidAudio
21157Activision
23213PowWow
23214PowWow
23456EvilFTP
26000Quake
27001QuakeWorld
27010Half-Life
27015Half-Life
27960QuakeIII
30029AOL Admin
31337Back Orifice
32773rpc.ttdbserverd
32776rpc.spray
32777rpc.walld
32779rpc.cmsd
38036timestep
40193Novell
41524arcserve discovery
45000Cisco NetRanger postofficed