DS3/E3 over Fibre Modem



Fibre modems that work in pairs to transparently extend DS3, E3 or STS-1 transmissions over optical fibre.

  • In-band Management via Terminal, web or SNMP in FRM220 chassis
  • DS3/E3 Coax (BNC) to Fibre SFP fibre modem
  • Supports AIS (Alarm Indication Signal)
  • Selectable E3 or DS3 setting
  • Electrical and optical Loop back tests
  • Standalone RS232 console management via CH01M


The FRM220-DS3/E3 is a fibre modem used in pairs to transparently extend DS3, E3 or STS-1 transmissions over optical fibre. By utilizing pluggable SFP transceivers (155Mbps), these converters may be easily deployed on multimode or single mode fibre, at a distance up to 120km, or over a single core fibre using BiDi (WDM) SFP modules.

The DS3/E3 connections utilize industry standard BNC connections for transmit and receive via coaxial cables. When the FRM220-DS3/E3 card is used standalone in a single slot chassis(see mounting options below), DIP switches may be used for configuration and loopback control. When placed in a single slot chassis with console port, an easy to maneuver user menu is available via terminal to configure, monitor, and run diagnostic loop back functions. The EOC (embedded operations channel) allows in-band management to control the remotely connected modem over a working fibre link. When the FRM220-DS3/E3 card is placed in the FRM220 rack with NMC management, the administrator can configure and view the local and remote converter cards' status, type, version, fibre link status and alarms.

E3 example application




Item Description
Optical Interface

Connector SFP : LC (Uses standard 100Base-X/OC-3 SFP)
Data Rate DS3/T3 = 44.7 Mbps; E3 = 34.4 Mbps

Line Coding

Distance MM 2km, SM 15/30/50/80/120km, WDM 20/40/60/80km
Wavelength 1310nm, 1550nm, CWDM 1471nm ~1611nm


Card: 155 x 20.8 x 88mm (D x W x H)




0 ~ 50°C (Operating), -10 ~ 70°C (Storage)



Electrical Interface

Connector 75 ohm Coax, TX output min: +2.5dBm max : +9.1dBm
RX input min: -9.7dBm, max +10.5dBm
Standards ANSI, ITU-TS, ETSI, AT&T, G.703, G.921 & G.955
Indications Power, Coax link, coax loop-back, AIS on coax link; FX link, fibre loop-back ,AIS on FX link

Power Input


Power Consumption

< 6W

Ordering Information

Order Code Description
CT-FRM220-DS3/E3 DS3/E3 coax (BNC) to fibre SFP fibre media converter card

More Information

Chassis and mounting options for the FRM220 family.

AC and DC power options available.  See individual products for further details.

1 Slot standalone chassis for ISDN, voice or data modules, AC or DC
1 Slot chassis with DB9 console port for Ethernet, voice or serial cards
2 Slot Ethernet, ISDN and serial chassis with console port
2 Slot chassis manageable via NMC card
4 slot Ethernet, ISDN and serial chassis, 1U
8 Slot multi service rack, 1U
20 Slot multi function chassis with Ethernet, serial and ISDN, 2u
20 Slot Ethernet aggregation rack, 2u