
The serving area interface or service area interface (SAI) is an outdoor
enclosure
Enclosure or inclosure is a term, used in English landownership, that refers to the appropriation of "waste" or "common land", enclosing it, and by doing so depriving commoners of their traditional rights of access and usage. Agreements to enc ...
or metal box that allows access to telecommunications wiring.
Alternate names
*Access point (AP)
*Cabinet (cab)
*B-box (breakout box)
*Cross box
*Cross-connect box
*Jumper wire interface (JWI)
*Outside plant interface (OPI)
*Pedestal (ped)
*Primary cross-connection point (PCP) (UK)
["Multimedia Telecommunications" (BT Telecommunications Series), B. Whyte (Ed.), Springer 1997]
*Secondary cross-connection point (SCP) (UK)
*Telecom cabinet
Function
The SAI provides the
termination of individual
twisted pairs of a telephony
local loop
In telephony, the local loop (also referred to as the local tail, subscriber line, or in the aggregate as the last mile) is the physical link or circuit that connects from the demarcation point of the customer premises to the edge of the co ...
for onward connection back to the nearest
telephone exchange
A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the establishment of communication circuits ...
(US: "
central office" (CO)) or remote switch, or first to transmission equipment such as a
subscriber loop carrier multiplexer and then to the exchange
main distribution frame (MDF).
In the United Kingdom, the components from the PCP onwards to the customer are known as "
D-side" (distribution side), and from the PCP back to the MDF as the "E-side" (exchange side). In the United States, the connection back to the MDF is known as the F2 (secondary distribution cable) and/or the F1 (main feeder cable) pairs.
SAIs are used in suburban and low-density urban areas, serving some of the same purposes that
manholes do in high-density urban areas. Besides a cross connect point, they sometimes contain a
DSLAM
A digital subscriber line access multiplexer (DSLAM, often pronounced ''DEE-slam'') is a network device, often located in telephone exchanges, that connects multiple customer digital subscriber line (DSL) interfaces to a high-speed digital co ...
or more rarely a
remote concentrator or both.
See also
*
Demarcation point
*
Enclosure (electrical)
An electrical enclosure is a cabinet for electrical or electronic equipment to mount switches, knobs and displays and to prevent electrical shock to equipment users and protect the contents from the environment. The enclosure is the only ...
*
Fiber to the telecom enclosure
*
Sub-loop unbundling
References
Local loop
Street furniture
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