Ethernet over Bonded E1 NTU



Connect 2 Ethernet networks across  E1/G703  circuits. E1 Inverse multiplexor supports up to 8 E1 channels bonded to provide a single data pipe.

  • Use up to 16 E1 Circuits to connect two Ethernet networks
  • Built-in GFP bridge operates at WAN rate
  • Features diagnostic capabilities for performing remote loopback
  • Maximum 220ms delay variance between E1 link
  • Unbalanced E1/BNC or balanced E1/RJ45
  • LED Alarm indication & Auto-Negotiation
  • SNMP, Web or Standalone RS232 console management
  • Support MTU 1916 bytes


The FRM220A-iMux is an E1 inverse multiplexer capable of bundling 4, 8 or 16 E1 lines for the cost-effective connection of 10/100Base-TX LANs over multiple E1 transports. The FRM220A-iMux bridges the gap between E1 and E3, allowing bridges to operate at faster rates. It also provides high speed access to SDH/SONET backbones where the only access services available are E1 lines. The FRM220A-iMux supports E1 attenuation of up to 43 dB on twisted pair or coax cable. This provides an approximate operating range up to 2km (using 22AWG).The FRM220A-iMux features diagnostic capabilities for performing remote loopback. The operator at either end of the line may test both FRM220A-iMux NTU and the line in the digital loopback mode.The Ethernet copper interface supports auto-negotiation and auto MDI/MDIX, allowing plug-and-play Ethernet connection without any additional configuration.

Bonded E1 circuits


Management functions are accessed via RS232 when the iMux is used in a CH01M or CH02M (see "Mounting Options" below).  Alternatively, web or SNMP may be used when the iMux is used in a larger chassis with an FRM220-NMC card.

Lifetime support

Lanode offers a Free Lifetime Telephone Support Service with these products, to all customers, giving you access to our specialist technical team.  Simply phone and ask to speak to an engineer.



Item Description
E1 Interface

Framing CCS+CRC (Framed)
Standard ITU-T G.703/G.704/G.706 & G.732,G.823
Encapsulation ProtocolVCAT & LCAS (ITU-T G.7042) GFP-F (ITU-T G.7041)
Bit rate 2.048Mbps± 50ppm (up to 5E1)
Line code HDB3
Clock setting Internal OSC or recovery clock
Receive level -43dB
Line impedance 75 ohm (BNC) / 120 ohm (RJ45)
Jitter Performance Complies with ITU-T G.823
Pulse Mask Complies with ITU-T G.703
Pulse amplitude Nominal 2.37V ± 10%
Delay Variance 220ms
Connector RJ45, BNC
Diagnostics Digital remote loopback

Ethernet Interface

Standards IEEE 802.3, 802.3u, 802.1q VLAN, 802.1d bridging
Mac Address 1K
Data rate 10/100Base-TX, Half/Full duplex
Connector RJ45 10/100Base-TX
Power, ALM, E1 signal loss


Power, ALM, E1 signal loss, E1 Alarm(AIS, LOF, RAI, LOMF), LAN link /ACT, 10/100M, SD (100Base-FX)

Power Input


Power Consumption

< 12W


Card: 155 x 42.1 x 88mm (D x W x H)




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


10 ~ 90% RH (non-condensing)




65,000 hrs

Ordering Information

Order Code Description
CT-FRM220A-IMUX16T-R 10/100Base-TX to 16 E1 mux card with 16E1 RJ45 cable
CT-FRM220A-IMUX16T-B 10/100Base-TX to 16 E1 mux card with 16E1 BNC cable
CT-FRM220A-IMUX8T-R 10/100Base-TX to 8 E1 mux card with 8 E1 RJ45 cable
CT-FRM220A-IMUX8T-B 10/100Base-TX to 8 E1 mux card with 8 E1 BNC cable
CT-FRM220A-IMUX4T-R 10/100Base-TX to 4 E1 mux card with 4E1 RJ45 cable
CT-FRM220A-IMUX4T-B 10/100Base-TX to 4 E1 mux card with 4E1 BNC cable

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
Product Category