Comtest Networks MTAS-192 METALLIC TEST ACCESS SYSTEM - Manual (Page 15)

CT-IG-MTAS192-2008-v1_8.doc Comtest Networks
MTAS-192
June 2006 Installation Guide 9
1.3.3 The Line Cards (Splitter Cards and Test Access Only Cards)
There are 6 unique types of line cards divided into 2 categories: Splitter Cards (4
varieties) and Test Access Only Cards (2 varieties) (refer to Table 2).
Each splitter card has a DSL (Digital Subscriber Loop) interface using a standard 50-pin
(25 pair) RJ-21 female connector. In addition, each splitter card has two TAPs (Test
Access Paths) and each TAP consists of 2 pairs of wires (making a 4-wire TAP):
• One for the upstream (Equipment) side called AE
• One for downstream (Facility) side called AF.
The AF (facility) pair is intended for testing on the line (facility) side and it is always used
in any test mode. The AE (equipment) pair is intended for testing on the equipment side.
Figure 9: Test Access Paths (TAPs)
Facility Side (F)
(Downstream)
AF
Equipment Side (E)
(Upstream)
AE
PSTN
Class 5
DSLAM
Splitter PC DSL
Modem
1 2 3 4 5 6 7 8 9 * 8 #
CPE
Splitter
RTU (Test Head)
MTAU (MTAS -192)