RCDD/TDMM Chapter 4) Backbone
Distribution Systems Exam 2025
Questions and Answers 100% Pass
Backbone Distribution System - ✔✔The part of the premises distribution system that
provides connection between telecom spaces.
CO - ✔✔Central Office. A common carrier switching center office (also called public
exchange) that is conveniently located in areas to serve subscriber homes and
businesses. It provides telephone services (lines0 that are connected on a local loop.
The CO contains switching equipment that can switch calls locally or to long-
distance carrier telephone offices.
EF - ✔✔Entrance Facility; an entrance to a building for both public and private
network service cables (including wireless) including the entrance point of the
building and continuing to the entrance room or space. (TIA)
EFM - ✔✔Ethernet in the First mile; Term used to describe the access network from
the access point to the subscribers premises. Also referred to as Ethernet in the Last
Mile.
ER - ✔✔Equipment Room; An environmentally controlled centralized space for
telecom equipment that usually houses a main or immediate cross connect (TIA)
HC (FD) - ✔✔Horizontal Cross Connect (Floor Distribution); A group of connectors
that allow equipment and backbone cabling to be cross-connected or interconnected
with patch cords or jumpers to horizontal cabling
COPYRIGHT © 2025 BY EMILLY CHARLOTTE, ALL RIGHTS RESERVED 1
, IC (BD) - ✔✔The connection point between a backbone cable that extends from the
MC (CD) [first level backbone] to the HC (FD) [second level backbone].
MC (CD) - ✔✔Main Cross connect; campus distribution; The cross connect normaly
located in the main equipment room for cross connection and interconnection of
entrance cables, first level backbone cables, and equipment cables.
RMC - ✔✔Rigid Metallic Conduit; A threaded metal raceway of circular cross
section with a coupling
TE - ✔✔Telecom Enclosure; a case or housing that may contain telecommunications
equipment, cable terminations, or horizontal cross connect cabling. (TIA)
TR - ✔✔Telecom Room; an enclosed architectural space for housing telecom
equipment, cable terminations, and cross connect cabling. (TIA)
Name the 2 function a backbone system provides in a campus. - ✔✔1) Building
connections between floors in multi-story buildings. 2) Campus connections in
multi-building environments
Name 7 components of a backbone distribution system - ✔✔1) Cable pathways. 2)
ERs that may contain HCs (FDs), ICs (BDs), or MCs (CDs). 3) TRs that typically
contain HCs (FDs). 4) TEs that typically contain HCs (FDs). 5) Entrance Facility (EF).
6) Transmission Media. 7) Misc Support Facilities.
Which componenct of the backbone distribution system provides routing space for
cables? - ✔✔Cable Pathways
Which componenct of the backbone distribution system usually houses the main
cross connect? (MC) - ✔✔Equipment Room
Which component of a backbone distribution system is described as an encosed
architectural space for housing telecommunications equipment, cable terminations,
or horizontal cross connect cabling? - ✔✔Telecommunications Room (TR)
COPYRIGHT © 2025 BY EMILLY CHARLOTTE, ALL RIGHTS RESERVED 2
Distribution Systems Exam 2025
Questions and Answers 100% Pass
Backbone Distribution System - ✔✔The part of the premises distribution system that
provides connection between telecom spaces.
CO - ✔✔Central Office. A common carrier switching center office (also called public
exchange) that is conveniently located in areas to serve subscriber homes and
businesses. It provides telephone services (lines0 that are connected on a local loop.
The CO contains switching equipment that can switch calls locally or to long-
distance carrier telephone offices.
EF - ✔✔Entrance Facility; an entrance to a building for both public and private
network service cables (including wireless) including the entrance point of the
building and continuing to the entrance room or space. (TIA)
EFM - ✔✔Ethernet in the First mile; Term used to describe the access network from
the access point to the subscribers premises. Also referred to as Ethernet in the Last
Mile.
ER - ✔✔Equipment Room; An environmentally controlled centralized space for
telecom equipment that usually houses a main or immediate cross connect (TIA)
HC (FD) - ✔✔Horizontal Cross Connect (Floor Distribution); A group of connectors
that allow equipment and backbone cabling to be cross-connected or interconnected
with patch cords or jumpers to horizontal cabling
COPYRIGHT © 2025 BY EMILLY CHARLOTTE, ALL RIGHTS RESERVED 1
, IC (BD) - ✔✔The connection point between a backbone cable that extends from the
MC (CD) [first level backbone] to the HC (FD) [second level backbone].
MC (CD) - ✔✔Main Cross connect; campus distribution; The cross connect normaly
located in the main equipment room for cross connection and interconnection of
entrance cables, first level backbone cables, and equipment cables.
RMC - ✔✔Rigid Metallic Conduit; A threaded metal raceway of circular cross
section with a coupling
TE - ✔✔Telecom Enclosure; a case or housing that may contain telecommunications
equipment, cable terminations, or horizontal cross connect cabling. (TIA)
TR - ✔✔Telecom Room; an enclosed architectural space for housing telecom
equipment, cable terminations, and cross connect cabling. (TIA)
Name the 2 function a backbone system provides in a campus. - ✔✔1) Building
connections between floors in multi-story buildings. 2) Campus connections in
multi-building environments
Name 7 components of a backbone distribution system - ✔✔1) Cable pathways. 2)
ERs that may contain HCs (FDs), ICs (BDs), or MCs (CDs). 3) TRs that typically
contain HCs (FDs). 4) TEs that typically contain HCs (FDs). 5) Entrance Facility (EF).
6) Transmission Media. 7) Misc Support Facilities.
Which componenct of the backbone distribution system provides routing space for
cables? - ✔✔Cable Pathways
Which componenct of the backbone distribution system usually houses the main
cross connect? (MC) - ✔✔Equipment Room
Which component of a backbone distribution system is described as an encosed
architectural space for housing telecommunications equipment, cable terminations,
or horizontal cross connect cabling? - ✔✔Telecommunications Room (TR)
COPYRIGHT © 2025 BY EMILLY CHARLOTTE, ALL RIGHTS RESERVED 2
