DPNSS was developed in the early 1980s by BT, or its forerunner, Post Office Telecommunications in recognition that the emerging Digital Private Circuit Primary Rate product ' Megastream ' had to address the market for both data and voice, the latter being significantly greater because of the market for PBXs.

There are several kinds of access interfaces to ISDN defined as Basic Rate Interface ( BRI ), Primary Rate Interface ( PRI ) and Broadband ISDN ( B-ISDN ).

The other ISDN access available is the Primary Rate Interface ( PRI ), which is carried over an E1 ( 2048 kbit / s ) in most parts of the world.

Primary Rate Interface ( PRI ), also called primary rate access ( PRA ) in Europe — contains a greater number of B channels and a D channel with a bandwidth of 64 kbit / s.

The following is an example of a Primary Rate ( PRI ) ISDN call showing the Q. 921 / LAPD and the Q. 931 / Network message intermixed ( i. e. exactly what was exchanged on the D-channel ).

The Primary Rate Interface ( PRI ) is a standardized telecommunications service level within the Integrated Services Digital Network ( ISDN ) specification for carrying multiple DS0 voice and data transmissions between a network and a user.

The Integrated Services Digital Network ( ISDN ) prescribes two levels of service, the Basic Rate Interface ( BRI ), intended for the homes and small enterprises, and the Primary Rate Interface ( PRI ), for larger applications.

A T1 Primary Rate Interface user would have access to a 1. 472-Mbit / s data service.

An E1 Primary Rate Interface user would have access to a 1. 920 Mbit / s data service

The Primary Rate Interface channels are typically used by medium to large enterprises with digital PBXs to provide them digital access to the Public Switched Telephone Network ( PSTN ).

The Primary Rate user is hooked up directly to the telephone company central office.

fr: Primary Rate Interface

it: Primary Rate Interface

pl: Primary Rate Interface

In contrast to the BRI, the Primary Rate Interface ( PRI ) configuration provides more B channels and operates at a higher bit rate.

In the typical telephony environment, a PBX connects to the local service provider through Primary Rate Interface ( PRI ) trunks.

* Primary Rate Interface, telecommunication standard

Additionally, for voice T1s there are two main types: so-called " plain " or Inband T1s and PRI ( Primary Rate Interface ).

Non-Facility Associated Signalling or NFAS is a Primary Rate Interface configuration whereby multiple T1 carriers share a signalling channel ( or D channel ).

When a T1 circuit is used to carry Primary Rate ISDN one of the timeslots is used to carry the D channel.

A single Primary Rate ISDN circuit is thus sometimes described as 23B + D. There are 23 bearer channels carrying voice or data, and one D channel carrying the Common Channel Signaling.

Customers ordering a Primary Rate ISDN service will be charged for each signalling channel.

* Non-Facility Associated Signalling, a Primary Rate Interface configuration whereby multiple T1 carriers share a signaling channel ( or D channel ).

Primary research articles are published in the sister journals Proceedings of the Royal Society, Biology Letters, Journal of the Royal Society Interface, and Interface Focus.

E & M is considered an obsolete technology for new installations, which generally use Basic Rate ( BRI ) or Primary Rate ( PRI ) digital interfaces.

Primary ( or elementary ) education consists of the first 5 – 7 years of formal, structured education.

The Batesville Community School Corporation consists of a Primary School, Intermediate School, Middle School, and High School.

The school district consists of seven schools and two ALP academies The seven schools are St. Michael-Albertville High School ( Grades 9-12 ), St. Michael-Albertville Middle School East ( Grades 5-8 ), St. Michael-Albertville Middle School West ( Grades 5-8 ), St. Michael Elementary School ( Grades 1-4 ), Fieldstone Elementary School ( Grades 1-4 ), Big Woods Elementary School ( Grades 1-4 ), and Albertville Primary School ( Kindergarten ).

The Steilacoom School District # 1 consists of Cherrydale Primary School, Saltar's Point Elementary School, Harriet Taylor Elementary School, Anderson Island School, Chloe Clark Elementary School, Pioneer Middle School, and Steilacoom High School.

The Thomasville City Schools system consists of four schools: Thomasville Primary ( K-2 ), Liberty Drive Elementary ( 3-5 ), Thomasville Middle School ( 6-8 ), Thomasville High School ( 9-12 ).

Piedmont's school district consists of 7 school facilities: Primary School, 3 Elementary Schools, Intermediate School, Middle School, and High School.

The local education consists of three schools ; St. Luke's Church of England Primary School, Endon Hall Primary School and Endon High School.

* Primary or natural subject matter: The most basic level of understanding, this stratum consists of perception of the work ’ s pure form.

Located in Nassau, Queen's College operates under the auspices of The Bahamas Conference of the Methodist Church and consists of three sections-The Early Learning Centre, The Primary School and The High school.

Ilchester Community Primary School consists of a Junior school and a Infant school, which cover key stage 1 and key stage 2 of the national curriculum.

The School of Letters consists of the Departments of History, Archaeology, Philosophy, Social Studies, and Philology ; the School of Social Sciences consists of the Departments of Economics, Psychology, Sociology and Political Sciences ; the School of Education consists of the Departments of Primary Education and Pre-Primary Education.

Ireland's national road network consists of of National Primary Routes and of National Secondary Routes.

It consists of a Hard Upper Torso ( HUT ) assembly, a Primary Life Support System ( PLSS ) which incorporates the life support and electrical systems, arm sections, gloves, an Apollo-style " bubble " helmet, the Extravehicular Visor Assembly ( EVVA ), and a soft Lower Torso Assembly ( LTA ), incorporating the Body Seal Closure ( BSC ), waist bearing, brief, legs, and boots.

The regiment consists of four battalions, three in the Regular Force and one in the Primary Reserve ( militia ).

The RCAF consists of 14, 500 Regular Force and 2, 600 Primary Reserve airmen and airwomen, supported by 2, 500 civilians.

The town of Waddicar, of which most of the population of Melling consists, is usually regarded as part of Melling itself and is served by the parish council which is based in the local Melling Primary School.

The facility is supervised by Dr. Eisenberg and consists of a Primary Operations Complex and a network of five Forward Observation Pods suspended over a canyon.

The Primary School, built in Neo-Classical style during the British Colonial era, consists of two primary schools, Żejtun Primary ' A ' Dun Alwiġ Camilleri and Żejtun Primary ' B '.

The National Network consists of ( 1 ) the Interstate Highway System and ( 2 ) highways, formerly classified as Primary System routes, capable of safely handling larger commercial motor vehicles, as certified by states to FHWA.