Test Access Terminology - Cisco ONS 15454 Reference Manual

2.2.1 Test Access Terminology

unit (RTU) also provide the capability of splitting a circuit under test. A split consists of breaking the
transmission path of the circuit under test. This is done out of service. The two sides of the access point
are called the Equipment (E) and Facility (F) directions. For a 4-wire or 6-wire circuit, the transmission
pairs within the access point are defined as the A and B pairs. The circuit under test should be wired into
the access point so the direction of transmission on the A pair is from E to F, and the transmission
direction for the B pair is from F to E
Figure 2-1
(2 times the bandwidth
of the circuit accessed)
A dual FAD (facility access digroup) TAP uses twice the bandwidth of the circuit under test. This can
be specified by the TAPTYPE parameter as shown in ED-<MOD2> command syntax in the
Creation and Deletion" section on page
A single FAD TAP uses half the bandwidth as that of the dual FAD, for example, it will use the same
bandwidth as the circuit accessed for the TAP creation. This can be specified by the TAPTYPE parameter
as shown in the
The MONEF, SPLTAB and SPLTEF modes are not supported by single FAD TAPs
Figure 2-2
Single FAD TAP
(same bandwidth
as circuit accessed)
2.2.1 Test Access Terminology
BRTU—Broadband remote test unit
DFAD—Dual facility access digroup
FAD—Facility access digroup
FAP—Facility access path
LOOPE—Split/loop access on A and B paths equipment side
LOOPF—Split/loop access on A and B paths facility side
MONE—Monitor access with signal detector on A path
Cisco ONS SONET TL1 Command Guide, R6.0
2-6
Circuit With No Access Dual FAD TAP
E
A
AID
B
Dual-FAD TAP
"2.2.2 TAP Creation and Deletion" section on page
Circuit With No Access Single FAD TAP
E
A
AID
B
(Figure 2-1).
F
"Mapped"
AID
2-7. The values are SINGLE/DUAL. It defaults to DUAL.
F
"Mapped"
AID
Chapter 2 Procedures and Provisioning
"2.2.2 TAP
2-7. The values are SINGLE/DUAL.
(Figure 2-2).