Acronym Dictionary


In order to help you understand some of the telecom industry terms, T1 Town has created the acronyms section, below. We have selected some of the most commonly used acronyms and descriptions for your information.

ALI (Automatic Location Identification)
A 9-1-1 Feature by which the name, address and responding agencies associated with the number of the telephone used to dial 9-1-1 is displayed at the PSAP at the time the call is answered.

ANI (Automatic Number Identification)
The number transmitted through the network identifying the calling party.

ARIN (American Registry for Internet Numbers)
A non-profit organization established for the purpose of administration and registration of Internet Protocol (IP) numbers.

ATM (Asynchronous Transfer Mode)
A high-speed switching technique that uses fixed size cells to transmit voice, data and video.

BAN (Billing Account Number)

An organization owned jointly by the Bell regional holding companies that may in the future be owned partially or totally by other persons. The organization conducts research and development projects for its owners, including development of new telecommunications services. Bellcore also provides certain centralized technical and management services for the regional holding companies and also provides generic requirements for the telecommunications industry for products, services and technologies

CAC (Carrier Access Code)
A dialing sequence used by the general public to access a preferred provider of service.

Calling Records
The CPUC considers calling records to be the records of calls made from a subscriber’s telephone no matter how recorded and regardless of whether such information appears in the subscriber’s monthly telephone service bill.

CARE (Customer Account Record Exchange)
The process of exchanging customer account information between local and long distance carriers. Every time a local carrier signs up a new customer, or every time an existing customer changes their PIC code, thereby changing their long distance carrier, the local carrier is responsible for notifying the long distance carrier. This applies even when the customer is keeping their current LD carrier while changing local carrier: the local carrier is still supposed to notify the LD carrier.

Casual PICing
This is when the customer has chosen one primary long distance carrier (the long distance carrier they are “pic’d” to), but occasionally wants to make a call using another long distance carrier. In order to route the call through the alternative long distance carrier, the customer dials the carrier’s PIC code before entering the telephone number. This is exactly the process for all those “Dial 10221” commercials. Because the customer does not sign up with this alternative carrier, they are only “casually” picing them. Some long distance carriers will not accept casual picing, and will only let you use them if you have pre-registered with them (like Cable & Wireless).

CCB (Common Carrier Bureau)
A branch of the FCC that monitors the telephone industry.

Central Office Switch
A switch used to provide telecommunications services including (1) End Office Switches which are Class 5 switches from which end-user Exchange Services are directly connected and offered, and (2) Tandem Office Switches which are Class 4 switches which are used to connect and switch trunk circuits between and among central office switches. Central office switches may be employed as combination end office/tandem office switches (combination Class 5/Class 4).

CIC (Carrier Identification Codes)
CICs provide routing and billing information for calls from end users via trunk-side connections to inter-exchange carriers and other entities.

CFA (Connecting Facility Assignment)
Long Distance Carriers must give Local Access Carriers (TelePacific) “CFA”, which are directions about where specifically on our interconnecting equipment to physically put the circuit.

CLASS (Custom Local Area Signaling Services)
Consists of number-translation services, such as call-forwarding and caller identification, available within a LATA.

CLC (Competitive Local Carrier)
The same thing as a CLEC.

CLEC (Competitive Local Exchange Carrier)
Any company or person authorized to provide local exchange services in competition with an ILEC. The CPUC’s (California Public Utility Commission’s) official definition is ” Competitive Local Carrier (CLC) means a common carrier that is issued a Certificate of Public Convenience and necessity (CPCN) after the effective date of July 24, 1995, to provide local exchange telecommunications service for a geographical area specified by such carrier. There are two CLEC types: Facilities-based and Non-facilities-based, see definitions.

CLLICODE (Common Language Location Identifier)
A code, which identifies a customer at a physical address. (All codes are of an abbreviation for the city, state, an identifier for that particular building, and an identifier for the customer on a particular floor.)

CO (Central Office)
A LEC (Local Exchange Carrier) office that has a switch.

Pipe or tubing used to pass telephone cables through to a demarc.

CPCN (Certificate of Public Convenience and Necessity)
A certificate that must be filed by every CLEC with the CPUC.

CPE (Customer Provided Equipment)

CSR (Customer Service Representative)

CSU or CSU/DSU (Channel Service Unit/Data Service Unit)
A device to terminate a digital channel on a customer’s premise. It performs certain line coding, line-conditioning and equalization functions, and responds to loop-back commands sent from the central office. A CSU sits between the digital line coming in from the central office and devices such as channel banks or data communications devices and is found in every digital link and allows the transfer of data at a range greater than 56 Kbps.

Demarc (also Dmark or de-mark)
Demarcation point between the wiring that comes in from the local telephone company and the wiring you install to hook up your equipment or system to the CPE.

DID (Direct Inward Dialing)
A service offered by telephone companies which allows the last 3 or 4 digits of a phone number to be transmitted to the destination exchange.
For example, a company could have 10 incoming lines, all with the number 234 000. If a caller dials 234 697, the call is sent to 234 000 (the company’s exchange), and the digits 697 are transmitted. The company’s exchange then routes the call to extension 697. This gives the impression of 1000 direct dial lines, whereas in fact there are only 10. Obviously, only 10 at a time can be used.

A digital transmission link with a capacity of 1.544 Mbps (1,544,00 bits per second). This link can handle 28 point-to-point DS-0s, or 24 “DS-0s” for 24 voice conversations.

A digital transmission link with a capacity of 44.736 Mbps. This link can handle 28 DS-1s.

DNCF (Directory Number Call Forwarding)
From Pacbell. Provides TelePacific the option for the end user to retain an existing PB assigned telephone number when the end user changes local service provider from PB to TelePacific. (Service provider number portability)

E-911 (Enhanced 9-1-1)
A method of routing 911 calls to a Public Service Answering Point that uses a customer location database to determine the location to which a call should be routed. E-9 .1 .1 service includes the forwarding of the caller’s Automatic Number Identification (ANI) to the PSAP where the ANI is used to retrieve and display the Automatic Location Identification (ALI) on a terminal screen at the answering Attendant’s position displaying name, address, and telephone number. It usually includes selective routing.

End Carrier
The local carrier who terminates the call to the end user.

EUCL (End User Common Line Charge)
A FCC tariff term defined in FCC Rules 69.104 as follows: “A charge that is expressed in dollars and cents per line per month shall be assessed upon end users that subscribe to local exchange telephone service, Centrex or semi-public coin telephone service to the extent they do not pay carrier common line charges. Such charge EUCL shall be assessed for each line between the premises of an end user and a Class 5 office that is or may be used for local exchange service transmissions. Each Single Line Service is charged one CALC or EUCL. The amount varies by state.”

Exchange Area
Geographically bounded areas that a LATA is divided into.

Extended Demarc
A demarcation point that is extended beyond the MPOE (Minimum Point of Entry).

Facilities-based CLEC
When a CLEC utilizes unbundled network elements from the LEC and/or provides facilities such as its own switch or transmission media. The CPUC’s definition is: those CLECs who directly own, control, operate, or manage conduits, ducts, poles, wires, cables, instruments, switches, appurtenances, or appliances in connection with or to facilitate communications within the local exchange portion of the public switched network.

FCC (Federal Communications Commission)
The government agency that regulations telecommunications and other broadcast medium.

FOC (Firm Order Commitment)

ICB (Individual Case Basis)
Unusual products often require an ICB to determine the pricing. Marketing supports this.

IEC (InterExchange Carrier)
Refers to a Long Distance Carrier. IXC is another term.

ILEC (Incumbent Local Exchange Company)
Companies such as Pacbell and GTE.

INC (Industry Numbering Committee)
An industry forum sponsored by the Alliance of Telecommunications Industry Solutions (ATIS). It provides an open forum to address and resolve industry-wide issues associated with the planning, administration, allocation, assignment and use of numbering resources and related dialing considerations for public telecommunications within the North American Numbering Plan (NANP) area. INC documents are available from: (npagdln.doc, INC Documents,

Independent LEC (Independent Local Exchange Carrier)
Refers to non- “Ma” Bell Companies, such as GTE.

Communications inside one state.

Communications between states.

ISDN (Integrated Services Digital Network)
A standard digital network that lets users send voice, data and video over one telephone line from a common network interface.

IXC (InterExchange Carrier)
Abbreviation for any long distance carrier. IEC is another abbreviation favored by LECs.

LAN (Local Area Network)
A data communications network that is geographically limited (typically to a 1 km radius) allowing easy interconnection of terminals, microprocessors and computers within adjacent buildings. Ethernet and FDDI are examples of standard LANs.
Because the network is known to cover only a small area, optimizations can be made in the network signal protocols that permit data rates up to 100Mb/s.

LEC (Local Exchange Company)
Refers to companies such as Pacbell or GTE.

LERG (Local Exchange Routing Guide)
The LERG contains information about the current network configuration and scheduled changes within the local exchange providers’ networks. The LERG is primarily designed to be used for routing of interLATA calls by inter-exchange carriers. The LERG informs telecom companies which end office or tandem office the NNX resides in and how calls should be routed and rated so that they can properly terminate to the appropriate telephone number at the proper rate.

LNP (Local Number Portability)
LNP is the ability of end users to retain their existing telephone numbers when remaining at a location, or changing their location but staying within the same geographical exchange area served by the initial carrier’s serving central office, regardless of the LEC or CLC selected. LNP is also referred to as Service Provider Portability.

LOA (Letter of Agency)
This is exchanged between telecomm companies, or between a customer and a telecomm company granting permission for the receiver to install telecomm service to the sender.

Within each rate center there may be more than one “locality” – locality usually denotes a sub-city name such as the “called-from” place appearing on a customer’s bill, to a rate center, to the exchange area that the NXX is identified with in a local tariff. Localities that are associated with specific rate centers can be looked up in section 6 of the LERG.

Local Loop
The local loop is the telephone line that runs from the local Telephone Company to the end user’s premise. The local loop can be made up of fiber, copper or wireless media. Same as local exchange loop facility whose formal definition is “known as a basic level network access channel, local exchange loop facility means a transmission path capable of delivering analog voice grade signals or digital signals at less than 1.544 Mbps between the network interface at a customer’s premises and the main distribution frame or any other point of interconnection to the LEC network.”

LRN (Local Routing Number)
A 10-digit code that represents a specific carrier. This code is “attached” to each phone number to indicate which “carrier” the phone number currently is subscribed with for routing purposes. Created for the LNP process, when a customer switches carriers, the new carrier’s LRN replaces the old.

LSO (Local Serving Office)

LSP (Local Service Provider)
A term intended to encompass all companies providing dial tone to end users, including but not limited to Incumbent Local Exchange Carriers (ILEC), Alternative Local Exchange Carriers (ALEC) and Private Branch Exchange (PBX) providers.

MPOE (Minimum Point of Entry)

MSAG (Master Street Address Guide)
A listing of all streets and number ranges within a 9-1-1 service area. The streets and address ranges are assigned routing codes, or emergency service numbers (ESNs), to enable proper routing of 9-1-1 calls.

Multiplexing or Mux
Multiplexing is a technique whereby multiple devices can share a telephone line. With multiplexing, users do not have to lese individual telephones for each computer that wishes to communicate. T-1 multiplexers enable 24 devices to share one telephone line.

NANPA (North American Numbering Plan Administration)

NANP (North American Numbering Plan)
A numbering architecture in which every station in the area served by the plan is identified by a unique ten-digit address consisting of a three-digit NPA code, a three digit central office code of the form NNX/NXX, and a four-digit line number of the form XXXX.

NAT (Network Address Translation)
A hardware device currently being developed and used to extend the Internet addresses already in use. NAT has been suggested as an alternative to adopting IPv6 (IPng). It allows duplicate IP addresses to be used within a corporation and unique addresses outside.

NID (Network Interface Device)
The point of demarcation between the end user’s inside wiring and LEC’s facilities. Same as a NIU (Network Interface Unit).

NIU (Network Interface Unit)
Same as a NID (Network Interface Device), it serves as the point of demarcation between the local exchange carrier network and the customer’s premise. It is required to be placed at the MPOE (minimum point of entry) which is typically in the basement, first floor telco room, garage, or even outside the building. NIUs are multi-functional devices, which include a protector block to prevent high-voltage surges from affecting premise equipment and inside wiring. It also usually allows the carrier to initiate a loop-test back from the central office to test the integrity of the local loop. A local exchange carrier will never install an NIU at an extended demarc – this is in their tariffs.

Non-Facilities Based CLECs
Those CLECs which do not directly own, control, operate, or manage conduits, ducts, poles, wires, cables, instruments, switches, appurtenances or appliances in connection with or to facilitate communications within the local exchange portion of the public switched network.

Non-published Service
The CPUC considers non-published service to be when a subscriber requests that their name, address, and telephone number not be listed in any telephone directory, street address directory, or in the directory assistance records available to the general public (411).

NPA (Numbering Plan Area also called area code)
An NPA is the 3-digit code that occupies the A, B, and C positions in the 10-digit NANP format that applies throughout the area served by the NANP. NPAs are of the form NXX, where N represents the digits 2-9 and X represents any digit 0-9. In the NANP, NPAs are classified as either geographic or non-geographic.

NPAC (Number Portability Administration Center)
A center, which supports the implementation of Local Number Portability (LNP).

NPAC SMS (Number Portability Administration Center Service Management System)
NPAC’s system that manages the porting of telephone numbers from one service provider to another.

N is any digit 2 through 9, X is any digit 0 through 9 (800 possible combinations). Also known as CO codes, or DRD (destination code) once entered into the RDBS records.

NXX Service Area
The geographically-bounded area designated as the area within which a LEC or CLC may provide local exchange telecommunication services bearing a particular NPA-NXX designation.

OCN (Operating Company Number)
Assignments must uniquely identify the applicant. Must have a CO number to get this, but prior to a CO number you can use a NECA assigned number called a Company Code by calling NECA at 201-884-8355. To get an OCN call NECA at 973-884-8355.

PBX (Private Branch Exchange)
PBXs are computerized on site telephone systems located at commercial premises. They route calls both within an organization, and from the outside world to people within the organization.

When used as a noun, a port (also known as a basic level network access channel connection) is the interface between the local loop and the appropriate LEC Central Office switching equipment.

PSAP (Public Safety Answering Point)
The central point where the 911 call is received and responded to.

PSTN (Public Switched Telecommunications Network)
The PSTN is composed of all transmission and switching facilities and signal processors supplied and operated by all telecommunications common carriers for use by the public. Every station on the PSTN is capable of being accessed from every other station on the PSTN.

Rate Center (referred to as RRD in RDBS)
A geographically specified area used for determining mileage and/or usage dependent rates in the Public Switched Telephone Network. The geographic point is identified by a specific Vertical and Horizontal (V&H) coordinate that is used to calculate distance-sensitive end user traffic to/from the particular NPA-NXXs associated with the specific Rate Center. A rate center is not always the exact equivalent of an Exchange Area, but can be.

RBOC (Regional Bell Operating Company)
Refers to any of the “Ma Bell” local exchange carriers, such as Pacific Bell, Southwestern Bell, etc.

Resp Org
Responsible Organizations are entities designated to manage and administer a customer’s Toll Free number using the SMS/800 system.

ROE (Right of Entry)

A device, with routing intelligence, that connects parts of local and remote networks together. Because they use routing tables to look up addresses for each message, routers introduce delays into networks.

Service Provider
Any entity that is authorized, as appropriate, by local, state, federal, or other governmental authorities within the area served by the NANP to provide communications services to the public. Same as “Telecommunications Service Provider”. (npagdln.doc, INC Documents,

Service Territory
The area in which a CLC is authorized to provide service.

SONET (Synchronous Optical Network)
A standard for transmitting high-speed digital bits over fiber optic cabling. Telephone companies use SONET to transmit data from multiple customers.

SS7 (Signaling System 7)
The signaling protocol, Version 7, of the CCS network, based upon American National Standards Institute (ANSI) standards, which allows all carriers’ networks to work together. Protocols are: CCS is common channel signaling, which allows signals to be sent in both directions, which results in faster speeds.

Slang, and now most common identification for a DS-1. See DS-1 for definition.

Slang, and now most common identification for a DS-3. See DS-3 for definition.

TC (Technical Consultant)
A technical consultant from the marketing department.

Toll Free
When calling a Toll Free number (area code/NPA 800, 888, 877), the dialing party incurs no toll charges.

Wire Center
A building or space within a building that serves as an aggregation point on a LEC’s network, where transmission facilities and circuits are connected or switched.
Wire Center can also denote a building in which one or more Central Offices, used for the provision of exchange services and access services, are located.

1.544 Mbps Circuit
See DS-1.

The three-digit telephone number that has been designated as the “Universal Emergency Number,” for public use throughout the United States to request emergency assistance. It is intended as a nationwide telephone number giving the public direct access to a Public Safety Answering Point (PSAP) which will be responsible for taking the appropriate action.


Below is an alphabetized listing of some common acronyms that you’ll hear in the VoIP industry.


Third Generation Partnership Project: A collaboration under the International Telecommunication Union aimed at creating a third generation mobile phone specification system that is globally applicable.


Application Programming Interface: An interface provided by a software application to allow communication by other programs. This interface allows for requests for service to be made by other computer programs, and/or to allow data to be exchanged between computer systems.


Business Support Systems: Business support services include services like billing, order entry, provisioning, order fulfillment and order activation. These are the systems that support service level agreements.


Competitive Local Exchange Carrier: A telecommunications provider company (sometimes called a “carrier”) that competes with other, already established carriers (generally the incumbent local exchange carrier).


COmpressor-DECompressor, COder-DECoder, or ‘Compression/DECompression: A device or program capable of performing Encoding and Decoding on a data stream or signal. CODECs can also be used to compress and decompress data to allow for smaller data file transmission.


Customer Premise Equipment: Any equipment located on the customer’s side of a demarcation point (the point that distinguishes where the service provider’s equipment ends and where the customer’s begins.)


Customer Relationship Management: The group of systems and practices (methodologies, strategies, software and web-based capabilities) that encompass a business’s management of its customers.


Computer Telephony Integration: Technology that allows interactions on a telephone and a computer to be integrated or coordinated. CTI encompasses all contact channels (voice, email, video, fax etc.)


Direct Inward Dialing: The number assigned to a VoIP user that allows that user to connect to the old PSTN Networks around the world.


Demarcation Point: The point that distinguishes where the service provider’s equipment ends and where the customer’s begins. For practical purposes, this is the point where a telco hands control or responsibility of a line to the customer.


Enhanced 911: E911 services connect VoIP services to the existing 911 infrastructure. This allows for a VoIP emergency call to provide the same emergency-relevant location information that traditional telephony provides.


Enterprise JavaBeans: A Java-based API.


Element Management System: An element management system manages one or more of a specific type of network elements (NEs). In relation to hosted VoIP, the term is often used in describing delegated administration functions.


Independent Software Vendor: Refers to companies that specialize in making or selling customized software, usually for niche markets. Examples include applications like time scheduling for service employees, stock maintenance, and bar code scanning.


Interactive Voice Response: A computerized system that allows a person to select an option from a voice menu or otherwise interface with a computer system by speaking.


Network Address Translation: A process in which the source or destination of an IP packet is re-written as it passes through a firewall or router. This is usually done to allow multiple hosts behind a firewall or router to access the Internet via a single public IP-address


Operational Support Systems: Applications that report on usage trends for performance evaluation and capacity planning purposes.


Plain Old Telephone System: Refers to the services available to analog phones prior to the introduction of digital technology.


Public Switched Telephone Network: The world’s public circuit-switched telephone networks. The PSTN is largely governed by technical standards created by the International Telecommunication Union.


Session Border Control: A device used in VoIP networks. SBCs are put into the signaling and media path between calling and called party. The SBC acts as if it were the called VoIP phone and places a second call to the called party. This means that both signaling traffic and media traffic (voice, video etc) cross the SBC. With that capability, SBCs can function as firewalls, protocol transcoders, bandwidth managers, etc.


Session Initiation Protocol: A protocol and standard for initiating, modifying, and terminating a multimedia (voice, video, etc) interactive session. SIP was accepted in 2000 as the 3GPP signaling element and a permanent element of IMS architecture.


SIP Back-to-Back User Agent: A device in which user calls are established between the caller’s phone and the server, and then between the server and the called party (similar to a SBC). This architecture allows for advanced PBX features both before a call is connected and during the actual call. However, because all calls flow through the B2BUA, if it goes down, all call traffic is affected.


Originally, Simple Object Access Protocol, now simply SOAP: A protocol for exchanging XML-based messages over a computer network, normally using HTTP.


Unified Messaging: The integration of email, fax, voice, video, etc. into a single in-box, accessible from a variety of different devices. Unified Messaging generally integrates telephone-based voice mail and is accessible via conventional or cellular phones.


Virtual Private Network: A private communications network usually used within a company or group of companies to communicate over a public network. VPNs are typically encrypted with various grades of cryptography.


VoiceXML: The W3C’s standard XML format for specifying interactive voice dialogues between a human and a computer. For example: the speech that prompts users to input their voice-mail password was most likely scripted in VXML.


World Wide Web Consortium: A consortium of member organizations, staff, and the public that aims at developing standards for the World Wide Web.


Web Services Description Language: An XML format published for describing web services. Phrased differently, WSDL is an XML format used to allow machine-to-machine interactions over a network.


eXtensible Markup Language: A W3C-recommended general-purpose markup language for creating special-purpose markup languages, capable of describing different types of data. In other words, XML is a method of describing data that is primarily used to facilitate data sharing across different systems. Programs can modify and validate documents based in XML without prior knowledge of their form.

Common Satellite Internet Acronyms

1.2 Meter Satellite Dish – Satellite dishes are measured in Square Meters. They may be elliptical or round. Satellite dishes reflect the satellite signal to the feed horn where the signal is captured and decoded by the LNB. Other common sizes for satellite dishes are .74 Meter, .98 Meter, 1.8 Meter and 2.4 Meter.

AZIMUTH – The rotational Axis of a mobile satellite system.  Most mobile systems have a greater than 360 degree rotation so that scanning for a signal is not impeded by a physical limit on the mobile dish.

BANDWIDTH – The amount of data that can be transmitted in a fixed amount of time. Most commonly expressed in bits-per-second (bps with a small b) but occasionally in Bytes-per-second (Bps with an upper case B).  Kbps is Kilobits per second, or 1000 bits per second. Mbps is a million bits per second. A dial-up modem normally uses 56Kbps. A typical iDirect connection us 3Mbps download, or about 60 times faster.

BROADBAND – is simply “High-Speed” Internet access that is much faster than “Dial-up” Internet access. Normally broadband is anything faster than 300 Kbps.

BUC– The “Block Up Converter” is simply the transmitter for a satellite dish. BUC’s are rated by wattage, the higher the wattage, the better the upload performance, especially during bad weather.

C-Band – The C band is primarily used for voice and data communications as well as backhauling. Because of its weaker power it requires a larger antenna, usually above 1.8m (6ft). However, due to the lower frequency range, it performs better under adverse weather conditions on the ground. It operates in the frequency range for VSAT satellite communication from 3.7 to 4.2 GHz for downlink and 5.925 to 6.425 GHz for uplink communication. C-Band systems are lightheartedly referred to as a “BUD” or Big Ugly Dish.

CIR – Committed Information Rate. CIR is the guaranteed speed you can rely on with your satellite connection. Your speeds will not drop below this amount. CIR is normally associated with an unshared channel where there are no other subscribers are using that channel. This means that full speed is available at all times. Since a 1:1 CIR channel is not shared, it is typically much more expensive. Some companies use the term CIR loosely in describing their shared plans, however, these plans are not 100% guaranteed to committed speeds.

Contention Ratio – Contention Ratio refers to the number of subscribers that are sharing the connection at the same time. Many “consumer” organizations like Hughesnet have contention ratios that approach 400 to 1, which makes the speeds crawl. Ground Control posts its contention ratios so you can predict your connection speed at any time. Most of our Standard iDirect plans are between 10:1 to 20:1 contention ratios.

dBW – Decibel Watts is a measurement of energy beamed from a satellite to a point on the earth. The higher the dBW, the stronger the signal strength, and the small satellite dish that is required.

DHCP – Dynamic Host Configuration Protocol, pronounced as four letters. A protocol for assigning dynamic IP addresses to devices on a network.  With dynamic addressing, a device may have a different IP address each time it connects to the network. DHCP also supports a mix of static and dynamic IP addresses.  Windows ICS uses the address range of through when it assigns addresses. It also works fine when computers on the ICS network are assigned addresses in that range statically, but it is a good idea to use high numbers to avoid conflicts.

DNS – Domain Name System (or Service or Server), pronounced as three letters. An Internet service that translates domain names into IP addresses. 

Because domain names are alphabetic, they’re easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name translates to 

The DNS system is, in fact, its own network. If one DNS server doesn’t know how to translate a particular domain name, it asks another one, and so on, until the correct IP address is returned.

DOWNLOAD – Information that comes to your computer from the Internet.  The typical Download speeds of an iDirect connection is between 2500 Kbps (Kilobits per second)

Dynamic IP Refers to the addresses assigned by the router your computer is connected to each time you log into the network. The IP address is how all information flows to and from your computer. Like a street address, it is this address that is required for communication. The reason it is Dynamic (And not static) is it changes each time that you log on to a network (or the Internet). Alternatively, a static IP address never changes for your computer.

ELEVATION – The vertical axis (up & down) motion of pointing the satellite dish.

FAP – Fair Access Policy, pronounced as a word that rhymes with gap. Satellite connections, while always on, are not unlimited. Bandwidth is a finite resource, so the method used to provide high download bandwidth for all while preventing any one user from hogging that bandwidth is FAP.

FOOTPRINT – The satellite signal strength as it falls on the Earth. It can also be called a coverage map.

IP ADDRESS – Internet Protocol, pronounced as two separate letters. IP specifies the format of packets, and the addressing scheme used on the Internet. 

The Internet combines IP with a higher-level protocol called Transmission Control Protocol (TCP), which establishes the connection between a destination and a source.

IP by itself is something like the postal system. It allows you to address a package and drop it in the system, but there’s no direct link between you and the recipient. TCP/IP (pronounced as 5 letters), on the other hand, establishes a connection between two hosts so that they can send messages back and forth for a period of time. 

IP addresses are in the form of a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, could be an IP address. 

Within a LAN, you can assign IP addresses at random as long as each one is unique; addresses which are public to the Internet must be within assigned ranges in order to avoid duplication. The authorities that assign public Internet addresses have designated certain ranges as never to be used on the Internet; by convention, those are normally used as private addresses on a LAN. The ranges for private addresses are all addresses starting with 10 (e.g., addresses between and, and addresses between and

IDU – Indoor Unit.  It use to refer to equipment the satellite dish connects to inside of a building, such as a satellite modem.

Kbps – Kilobits Per Second.  Thousands of bits that are transferred in one second. KBps represents (Upper case B) represents thousands of bytes (a byte is made up of 8 bits) in one second.

Ka-Band – The Ka band is primarily used for two-way consumer broadband and military networks. Ka band dishes can be much smaller and typically range from 60cm-1.2m (2′ to 4′) in diameter. Transmission power is much greater compared to the C, X or Ku band beams. Due to the higher frequencies of this band, it can be more vulnerable to signal quality problems caused by rain fade.

Ku-Band – (pronounced “kay-yoo”) Ku band is used typically for consumer direct-to-home access, distance learning applications, retail and enterprise connectivity. The antenna sizes, ranging from 0.7m to 2.4m, are much smaller than C band because the higher frequency means that higher gain can be achieved with small antenna sizes than C-band. Networks in this band are more susceptible to rain fade, especially in tropical areas. Ku communication is the microwave range of the electromagnetic frequency from 11.7 to 12.7 GHz (downlink frequencies) and 14 to 14.5 GHz (uplink frequencies). An interesting note is that older and gray market radar detector/jammers operate on the Ku-Band frequency and have caused interference to disable a VSAT satellite systems.

LATENCY (also known as ping time) – Internet traffic travels at the speed of light. That means that a New York to California fiber optic connection will take 0.03 seconds (30 milliseconds) round trip. In reality, the overhead processes of a dozen or more routers and switches adds a bit of time, so an average connection would be about 50 to 90 milliseconds.

With satellite connections the distances are so vast that even light speed isn’t fast enough. Why? Because all stationary satellites are located 22,300 miles above the equator, so the round trip is 90,000 miles or more. The speed of light is 186,000 MPH, so the time it takes for a round trip is just under 500 milliseconds (1/2 second). (If you were standing directly under a satellite on the equator, the speed-of-light round trip would be 476 milliseconds).

Ground Control’s iDirect services have very low overhead processes that take place on so you can expect just over over 500 milliseconds latency period. This half a second latency is outstanding for VOIP voice communication over satellite, as the pause between speakers is not nearly noticed. Many other satellite providers, (such as Hughesnet) have a latency of over 1 second.

Latency is not good for real-time gaming because the time it takes for the game to notice you’ve pulled the trigger is half a second or longer.

LNB – Line Noise Block, which is simply the receiver on a satellite dish.

MESH SATELLITE NETWORK – The orbiting satellite acts as a “router in space” and can direct traffic to other VSAT dishes on the ground. This topology cuts satellite latency (ping times) in half because data doesn’t need to make two round trips to the orbiting satellite as with the more common Star topology satellite network. Mesh networks can also be a combination of Star and Mesh where some traffic may be routed through an Earth based NOC.

ODU – Out Door Unit.  Refers to the radio BUC and LNB on the satellite dish.

PING TIME – the term round-trip delay time or round-trip time (RTT) is the time required to send a signal in both directions over a particular communication link. This is the soonest that it is possible to receive an acknowledgement of a message.

QoS – Quality of Service is a term used to show the requirements of some applications and users are more critical than others, which means that some traffic needs preferential treatment. By using QoS mechanisms, network administrators can use existing resources efficiently and ensure the required level of service without reactively expanding or over-provisioning their networks. Traditionally, the concept of quality in networks meant that all network traffic was treated equally. The result was that all network traffic received the network’s best effort, with no guarantees for reliability, delay, variation in delay, or other performance characteristics. With best-effort delivery service, however, a single bandwidth-intensive application can result in poor or unacceptable performance for all applications.

ROUTER – A device that forwards data packets along networks. Typically, a router will have a single WAN connection (like the Internet) and one or more LAN connections (such as the computers in an office). As computers on the LAN make requests from Internet servers, the router forwards those requests to the Internet, and then routes the response to the computer that made the request. 

Routers can be distinct devices that do nothing but routing, or they can be combined in a single box with other devices including Modems, Hubs or Switches, and wireless Access Points.

SKEW – The rotation of a dish around its center point. Seen as a clockwise or counter-clockwise rotation when facing the front of the dish.

Skew is needed to align the antenna with the polarization of the satellite signal when the dish is not located on the same longitude as the satellite. When a dish is west of the satellite, the skew is a negative number, and from the front of the dish the left edge will be higher than the right. When the dish is east of the satellite it will have a positive skew, with the left edge lower than the right edge.

STAR TOPOLOGY NETWORKS – use an Earth based NOC (Network Operations Center) to route all traffic to and from the orbiting satellite to the smaller VSAT dish clients which requires. Star Network differ from Mesh Networks, because Mesh networks avoid an Earth Based NOC, and route traffic from the orbiting satellite. The obvious advantage is Mesh Networks latency (ping time) is half as much as a star networks because Mesh doesn’t need to take two round trips to the satellite in order for bit of information to be requested and received from a client Star Network VSAT site. Mesh networks are also inherently more secure because data is transmitted from VSAT dish to VSAT dish.

STATIC IP – Refers to an IP that is permanently assigned, and does change each time that you log on to a network (or the Internet). It is possible for a static IP to be a private one, meaning that a computer with that IP is invisible to other computers on the Internet. That sort of static IP occurs when a computer owner chooses to set the network properties directly for a computer that would otherwise have a Dynamic IP assigned by DHCP.

In the satellite world, most references to static IPs mean public IPs, visible from the Internet. Such IPs are desired for a number of applications such as VPNs or to run a server such as a web cam.

When a satellite modem has a static IP, that IP can only be assigned to a single computer (an exception is the DW4020 modem, which can be ordered with up to 5 static IPs). Other computers on the network will normally be assigned private dynamic IPs by a router with DHCP server. That router/server can be an ICS compute on a DW4000 system, or a broadband router on a DW4020 or DW6000 system.

A computer with a public static IP should always have good Firewall software running to avoid malicious intruders. Computers that are behind a router and have private IPs, dynamic or static, are nearly immune from such intrusion.

UPLOAD SPEED – Transmitting information from your computer to a location on the Internet.  The typical upload speeds of an iDirect system are 500 to 900 Kbps (Kilobits per second).

VPN – Virtual Private Network, pronounced as 3 letters. Computers connected by dedicated wires form a “private network”. A Virtual Private Network uses the Internet or Public channels and create an encrypted secure date tunnel from point to point.

VSAT – “Very Small Aperture Terminal”. VSAT is two-way (transmit and receive) satellite dish that is normally under 3 square meters in size. VSAT dishes only communicate with geosynchronous orbiting satellites, and they are on client-side of the satellite network (where the Network Operations Center or NOC is on the other side). Frequency bands used by VSAT dishes are C-Band, Ku-Band, Ka-Band and X-Band. A VSAT system is comprised of the reflector (dish or antenna) the Transmitter (BUC) the receiver (LNB), The waveguide, and the indoor unit (IDU) that is the equipment the dish is connected to.

X-Band – The X band is used mainly for military communications and Wideband Global SATCOM (WGS) systems. With relatively few satellites in orbit in this band, there is a wider separation between adjacent satellites, making it ideal for Comms-on-the Move (COTM) applications. This band is less susceptible to rain fade than the Ku Band due to the lower frequency range, resulting in a higher performance level under adverse weather conditions. The X-Band uses 7.9 to 8.4 GHz for the uplink and 7.25 to 7.75 GHz for the downlink. The X-Band is heavily used by military organizations.