Glossary of Terms

Aggregation Site
A term that refers to a technique used in networks to collect N cables or service points into a site or piece of electronics and then transport the accumulated services in one (1) or at least N-1 cables. Aggregation allows a network provider to scale a network since an aggregated network does not have to have a 1:1 ratio between customer end-sites and backbone network facilities.

Backbone
KKFL owned and operated fiber optic cable and network electronics that provides managed wavelengths, IP peering services, and transit network services. KKFL customers do not connect directly to the backbone. They connect to their local loop.

Broadband
Generally used for fiber optic communication, broadband is greater than 45 MBPS. This is the speed at which a T3 or DS3 operates (see T3 or DS3).

Byte
The smallest unit of information that a computer system can locate within its data storage or memory. A byte consists of eight bits and represents an amount of information roughly equivalent to a single printed or typewritten character.

Class 3 Site
A network aggregation site that provides backbone and local loop cable cross-connect services. A Class 3 site does not contain active electronics.

Class 4 Site
A network aggregation site that provides backbone and local loop cable cross-connect facilities as well as DWDM electronics. End sites can connect to backbone managed wavelengths (_) at Class 4 sites. A Class 4 site does not contain IP switching or routing electronics.

Class 5 Site
A network aggregation site that provides backbone and local loop cable cross-connect facilities, DWDM facilities and IP aggregation and peering facilities.

CPE
Customer Premise Equipment – Typically CPE equipment is customer owned and managed equipment and facilities. A service provider who places equipment on a client site may also call that set of equipment CPE equipment.

Demarc
Shorthand for demarcation point. A physical point where ownership and management transitions from one enterprise/owner to another.

DS-3 Pipe
The total spectrum for a DS-3 is 44.736 Mb/s. The 44.736 spectrum can be channelized into 28 T-1s or 672 DS-0 channelized circuits. Telecommunications customers use the full spectrum of the DS-3 circuit as private line to connect telecommunications and data devices from one geographical location to another or transport large amounts of dial tone to the premises. DS-3 circuits are also used to connect directly to another carrier to provide video or other broadband services. When the DS-3 signal is not channelized, report as one circuit if the full spectrum is used.

DWDM
Dense Wavelength Division Multiplexing – Equipment that allows multiple wavelengths of light to injected into Singlemode fiber optic cable. Each wavelength can carry a separate network service such as 10 Mbps Ethernet, Gigabit Ethernet, SONET OC-3, OC-12, OC-48 etc.

Data Compression
Techniques to reduce the amount of computer memory space or transmission resources required to handle a given quantity of data usually achieved through the application of mathematic algorithms to the data transformation process.

Digital
The use of binary code to represent information. There are two major benefits to digital signals. First, the signal can be reproduced precisely. This is especially helpful in long transmissions where the signal loses strength along the way, picking up static and other interference. Instead of just amplifying the signal (as is done in analog), the code is put through a filter of sorts to delete the noise and then transmitted. The other benefit is that digital technology is becoming cheaper and more powerful, whereas analog is becoming a thing of the past.

EMI/RFI
Electromagnetic Interference/Radio Frequency Interference – High voltage or high-frequency radio (microwave) services can induce electric current in metal devices such as cables or electronics circuit boards. The induced currents, if high enough, can negatively impact and even impair the ability of the cable or electronics to function. EMI/RFI effects are directly related to distances between the source and the receiver.

IRU
Indefeasible Right of Use - The effective long-term lease “as is and where is,” of a portion of optical capacity. IRUs are specified in terms of a certain number of channels of a given bandwidth. An IRU is granted by the company or consortium of companies that built the (usually optical fiber) cable. Some IRU legal agreements forbid resale of the capacity ownership. An IRU gives a carrier or large-scale Internet service provider (ISP) the ability to assure its own customers of service on a long-term basis.

Local Loop
The fiber optic cable and network electronics that directly connects to the customer's CPE equipment. The local loop provides customer access to the backbone network.

Microwave
Electromagnetic waves in radio frequencies above 890 MHz and below 20 GHz. They only travel in straight lines, and are used for communication between satellites or radio towers.

NOC
Network Operations Center – The NOC is a physical local dedicated to electronically monitoring and managing the network. A NOC is typically managed on a 24 x7 schedule. The NOC responds to alarms by contacting and dispatching support staff.

Optical Fiber
Made of very pure glass, it is used in fiber optic communications. It carries a digital signal made of modulated light. It can carry much more much faster than the traditional copper lines.

Pipe
Refers to a measure of transmission bandwidth.
POP
Point of Presence - means the terminal facility where the capacity is delivered to Customer.

Redundancy
Having back-up systems available to provide continuous service in the case of a failure in the main system.

Remote Access
Sending and receiving data to and from a computer through communications links such as phone lines.

SONET
Synchronous Optical Network – A network technology that runs over fiber optic cable. SONET networks are very high speed, provide significant levels of multiplexing services, and provide automatic protection switching (APS) services. SONET networks are used extensively by telephone carriers to interconnect their central offices.

Synchronous
Transmissions of data at a fixed rate, eliminating the need for start and stop bits, because the receiver and transmitter work at the same time.

T-1
Trunk Level 1. A digital transmission with a speed of 1.544 MBPS. This is the standard for digital transmission in North America. It is capable of handling 24 voice conversations at one time. (See Trunk).

T-2
Trunk Level 2. North American standard for DS-2. Operates at 6.312 MBPS, or 4 times the capacity of a T-1. Generally used only in carrier networks, it is capable of handling 96 voice conversations at one time.

T-3
Trunk Level 3. North American standard for DS-3. Operates at 44.736 MBPS, or the equivalent of 28 T-1's. It can carry 672 voice conversations, each of 64 KBPS. This is used with microwave or fiber optics only.

Telemedicine
The provision of health care services from a distance using audio, video and computer technology. Traditionally uses videoconferencing to diagnose an illness and provide medical treatment. Also used to view or teach surgical procedures.

VoIP
Voice-over-IP – Simply the transport of voice traffic by using the Internet Protocol (IP). It is a method of connecting voice conversations over controlled IP environments, such as private data networks comprised of frame relay and ATM.

SDH
Short for Synchronous Digital Hierarchy, an international standard for synchronous data transmission over fiber optic cables. The North American equivalent of SDH is SONET. SDH defines a standard rate of transmission at 155.52 Mbps, which is referred to as STS-3 at the electrical level and STM-1 for SDH. STM-1 is equivalent to SONET's Optical Carrier Level 3 (OC-3).

NADH
The North American version of PDH is called NADH (North American Digital Hierarchy). The telephone system has evolved from an analog system to a digital system, at least in the core. Early core transmission facilities used frequency division multiplexing, but in the 1960s this system was largely replaced with the PDH (Plesiochronous Digital Hierarchy), which is a system of multiplexing numerous individual channels into higher-level channels. The system is not synchronous like SONET, but integrates with it.

OC-X
Short for Optical Carrier, used to specify the speed of fiber optic networks conforming to the SONET standard. The number following the term refers to the speed for common OC levels (i.e. OC-1 = 51.85 Mbps, OC-3 = 155.52 Mbps, OC-12 = 622.08 Mbps, OC-24 = 1.244 Gbps, OC-48 = 2.488 Gbps, OC-192 = 9.952 Gbps, and OC-255 = 13.21 Gbps).