UTD-EM-M4 device is an Ethernet inverse multiplexer with 4 x E1 (G.703 2048kbit/s) interfaces. It allows connection of Ethernet network using one to four E1 channels aggregating their band. Ethernet packages stream is divided into 4 E1 channels and then, in the second device, different E1 channels are multiplexed into one channel by using 4 E1 channels, it is possible to obtain the maximum throughput of 8.192 Mbit/s for Ethernet packages. The malfunction of a single E1 channel, regardless of a direction, causes its automatic switch off and no loss of packages. In case the line is back in operation, such a condition is automatically detected by the device.

Inverse Multiplexer / Concentrator
​10/100Mbit/s Ethernet / 4x E1 2.048Mbit/s
UTD-EM-M4 10/100 Mbit/s
4x E1


Special features:
  • Connects two 10/100 Mbit/s Ethernet LANs over up to 4E1 line (8192 kbit/s)
  • Structured (Comply with ITU-T G.704) and ustructured E1 (selectable)
  • Can be used in point-to-point or hub-and-spoke topologies
  • Built-in Ethernet switch with an array of 1000 MAC addresses IEEE 802.1q support
  • Automatic E1 channel failure detection
  • IEEE 802.1q support. Possibility of defining up to 15 VLAN networks (full range VID)
  • QoS support (depending on default port priority, VLAN priority, IP DSCP field)
  • Maintenance and Management: WWW, TELNET, SNMP, RS232 serial port
  • Optional power supply redundancy
  • Local and remote E1 loopbacks
Technical specification:


Ethernet Ports

  • Baud rate 100/10 Mbit/s
  • Flow control function
  • ​Connection state signalling
  • 4 x RJ45 connector

Power supply

  • Supply voltage range 12 to 60V DC
  • External power supply included, 230VAC/48VDC
  • Up to 6W power consumption
  • ​Optional power supply redundancy


  • ​4x E1 channels
  • Maximum delay difference between E1 channels of up to 50 ms
  • Minimum loss of band in E1 channels for Ethernet frames of 1500 bytes < 1%

Line interface 2048kbit/s

  • Framed and unframed, G.703 and G.704 compliance
  • ​2048 kbit/s ± 50 ppm binary throughput
  • 120 Ohm E1 impedance
  • Line code HDB-3
  • ​RJ45 connectors


  • Housing: 483x170x44mm,19'