Specifications

Appendix A
107
A.10.1 Functional Details
Fiber
The FXO/FXS fiber modem uses a proprietary scrambled NRZ optical line coding to provide extremely low BER
for Voice over fiber.
Electrical
The electrical interface is software selectable between FXO (Foreign eXchange Office) and FXS (Foreign
eXchange Subscriber) interface.
An RJ-11 provides the interface port connections.
Management
The FRM220-FXO/FXS has a small processor that is used to read the on-board DIP switches. When used
stand-alone, the configuration can be done via the DIP switches.
When placed in a managed chassis, such as our FRM220-CH20 with NMC (Network Management Controller),
the FXO/FXS card and remote are configured and monitored through the chassis NMC via console, Telnet, Web
HTTP or SNMP.
1. Stand-alone – DIP settings when placed in CH01.
2. Rack management - When placed in NMC managed rack, all other settings can be overridden by the NMC management.
3. FXO/FXS supports in-band management.
A.10.2 Panel
Figure A.10.1 Panel designations of FRM220-FXO/FXS
There are two variations of this media converter; the FXO/FXS converter with fixed optical transceiver or in an
SFP version.