FCD-IPM Installation and Operation Manual Chapter 1 Introduction
Functional Description 1-7
The main and sublinks have two line interfaces:
• 120Ω balanced line interface, terminated in an RJ-48C eight-pin (ISO 10173)
connector
• 75Ω unbalanced interface, terminated in two BNC coaxial connectors
• T1 versions have a 100Ω balanced interface.
You can select the E1 interface to activate the LTU option. With the T1 version,
you can choose to activate CSU or DSU.
When a power failure occurs, the failsafe bypass of the sub E1/T1 link ensures the
continuity of voice services between the main and the fix sublink.
The fail-safe bypass of the E1/T1 sub-link is not available for the FCD-IPM units
equipped with SHDSL interface.
E1 over SHDSL
E1 traffic can also be transmitted using 2-wire SHDSL physical interface. The
SHDSL link uses TC-PAM technology and complies with the requirements of the
ITU-T G.991.2 standard. Table 1-1 lists typical FCD-IPM ranges over 2-wire
24 AWG line.
Table 1-1. Typical FCD-IPM Ranges over SHDSL Link
Data Rate 2-wire, 24 AWG (0.5 mm)
kbps km miles
192 6.5 4.0
384 5.8 3.6
512 5.1 3.1
768 4.8 2.9
1024 4.1 2.5
1152 3.5 2.1
2048 3.2 1.9
IO Data Channel Interfaces Each of the two IO data channels can be operated as n x 64k or n x 56k data port
(DCE only).
System Timing Considerations Internally, FCD-IPM uses one system timing source (clock). This system clock
determines the transit timing of all the E1 links and data ports. The clock source
options are as follows:
• Main link 1
• Sublink (each of them)
• Internal.
Note