Glossary of Telecom Terms : M

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Main Distribution Frame (MDF)
The primary point at which outside plant facilities terminate within a wire center for interconnection to other telecommunications facilities within the wire center. Also known as Central Office Distribution Frame.


Maintenance Limit
The maximum margin, value, or deviation associated with normal in-service performance.


Maintenance of Service Charge (MSC)
A charge to the CLEC or Reseller when the field technician is dispatched to remedy a problem found in the customer premise equipment (at the end user's premises).


Major Trading Area (MTA)
Boundaries that segment the country for telecommunication licensing purposes. MTAs are based on Rand McNally's Commercial Atlas & Marketing Guide. Each MTA is named after one or more cities which are designated as Major Trading Centers. The FCC uses MTA boundaries for licensing services such as Personal Communications Services (PCS). NOTE: MTAs are larger than Basic Trading Areas (BTA).


In network operations, the logical association of one set of values, such as addresses on one network, with quantities or values of another set, such as devices on a second network; for example, name-address mapping, internetwork-route mapping.


Master Account
A Verizon Wholesale bill that consolidates the billed charges from the Reseller's component (end user) accounts.


Master Customer Number (MCN)
A unique number that identifies a customer. Also known as Customer Identification Number (CIN).


Maximum Burst Size (MBS)
ATM network performance parameter that defines the duration of transmission at a peak rate that would be accepted on a given ATM virtual circuit.


See Maximum Burst Size.


See Minimum Cell Rate.


See Message Customer Record Information System.


Mechanized Loop Test (MLT)
A test system that tests the end user's loop, which is comprised of the wires and equipment used to provide dial tone/calling service to that end user.


See Multiple Exchange Carrier Access Billing.

See Multiple Exchange Carrier Ordering and Design Guidelines for Access Services-Industry Support Interface.


Mediated Access
Allows CLECs to use Verizon network facilities, switches, and operating systems while prohibiting access to proprietary Verizon databases.


Meet Point
See Interconnection Point.


Meet-Point Billing (MPB)
The process whereby two or more local exchange carriers jointly provide to a third party the transport element of a Switched Exchange Access Service to a local exchange carrier end office switch. Under this process, each local exchange carrier receives an appropriate share of the transport element revenues, as defined by their effective Exchange Access tariffs.


Meet-Point Billing Traffic
Refers to traffic that is subject to an effective Meet Point arrangement. Also see Meet-Point Billing.


Megabits (Mb)
A measure, representing 1,000,000 bits, generally used to express the speed per second of telecommunications services and equipment. See Kilobit A bit is the smallest unit used to express digital information.


Megabits per second (Mbps)
A measurement of data transmission. One megabit per second equals one million bits per second.


A measure, representing 1,000,000 bytes generally used to express the storage capacity of digital A components. A byte represents a single character, or group of eight bits.


Merger Conditions
Federally mandated conditions imposed on Verizon at the time of the merger of GTE and Bell Atlantic.


Message Customer Record Information System (MCRIS)
A system used by Verizon to receive and interpret central office switch usage records.


Message Ready Service
A Verizon Wholesale Billing Service whereby Verizon prepares and distributes billing statements for end user customers. Verizon prepares and distributes billing statements and collects payments and deposits.


Metropolitan Statistical Area (MSA)
As defined by the U.S. Census Bureau, areas based on counties that have cities and surrounding regions with populations of 50,000 or more. Sometimes known as SMSA.


See Modified Final Judgment.


Microwave Band
The band of frequencies, 1,000 megahertz or greater, that uses very short waves. These bands are used primarily for point-to-point communications.


Mid-Span Fiber Meet Interconnection
An interconnection architecture whereby two carriers' transmission facilities meet at a mutually agreed upon Point of Interconnection (POI), using a fiber hand-off. At the delivering carrier's option, may interface with the carrier's collocated equipment to gain access to unbundled network elements.


Mileage Range Indicator
A code that denotes the mileage range being billed.


Milliwatt (102 Type) Test Line
An arrangement in an end office that provides a 2004 Hz tone at 0 dBm0 for one-way transmission measurements towards the customer's premises from the local exchange carrier's end office.


Minimum Cell Rate (MCR)
ATM performance parameter that specifies the minimum rate for cell transmission that a network must guarantee to a user on a given virtual circuit. Also, a field in an RM cell specifying the smallest value to which the ER field can be set.


Minutes of Use Charges
Usage data added to monthly bill for UNE services.


See Mobil-to-Land Traffic.


Mobile Switching Center or Mobile Telecommunications Switching Office (MSC or MTSO)
Used by a CMRS provider for originating and terminating functions for calls to or from end user customers of the CMRS carrier. Also known as MTSO (Mobile Telecommunications Switching Office).


Mobile-to-Land Traffic (M/L)
Traffic that originates on a CMRS provider's system and is terminated to a landline user.


Contradiction of modulator-demodulator. A device that converts signals transmitted over communication facilities; for example, converts analog voice signals to digital signals.


Modified Final Judgment (MFJ)
The federal court judgment that set up the rules and regulations concerning deregulation and divestiture of AT&T and the Bell system.


See Meet-Point Billing.


See Mobile Switching Center or Mobile Telecommunications Switching Office.


See Major Trading Area.


See Mobile Telecommunications Switching Office or Mobile Switching Center.


Multicast Address
A single address that refers to multiple network devices. Also known as Group Address.


Multiple Exchange Carrier Access Billing (MECAB)
The document prepared by the Billing Committee of the Ordering and Billing Forum (OBF). The MECAB document, published by Telcordia as Special Report SR-BDS-000983, contains the recommended guidelines for the billing of an access service provided by two or more Local Exchange Carriers, or by one LEC in two or more states within a single LATA.


Multiple Exchange Carrier Ordering and Design Guidelines for Access Services-Industry Support Interface (MECOD)
A document developed by the Ordering/Provisioning Committee of the Ordering and Billing Forum (OBF). The MECOD document, published by Telcordia as Special Report SR-STS-002643, establishes methods for processing orders for access service which is to be provided by two or more Local Exchange Carriers.


The process of combining a number of individual channels into a common frequency band or into a common bit stream for transmission.



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