BSTU4 – Ethernet First Mile Termination Unit

Product Overview

The BSTU4 is an Ethernet Network Termination Unit of the ULAF+ SHDSL product family designed to transmit broadband traffic over multiple copper wire-pairs.
The BSTU4 is the leading choice for delivering business class service levels over Ethernet Networks with its high reliability. The built in Layer 2 switch with comprehensive VLAN support and flexible QoS prioritisation allows for carrier class multiservice applications.
In Metro and Campus applications the BSTU4 transmits Ethernet services up to 22,8 Mbit/s.
The BSTU4 helps network operators bridging the existing bandwith gap between E1 and E3/STM-1 services by bundling up to 4 E1 channels, over legacy SDH/TDM networks.


  • 4-port self-learning layer2 switch with VLAN and Provider VLAN-Support (including Q-in-Q)
  • Support fo QoS
  • Enabling Ethernet Private Line (EPL), Ethernet Virtual Private Line (EVPL) and Ethernet LAN (E-LAN) service delivery
  • MEF9 and 14 certified
  • Integrated Remote Power Supply (RPS) for remote feeding of repeaters or other termination units
  • 96% payload utilization (compared to 79% with ATM IMA)
  • Low power consumption


  • SHDSL.bis over 1, 2 or 4 wire pairs
  • 4 port Fast Ethernt switch (Full/Half duplex, flow control, auto neg., auto MDI-X)
  • self learning bridge with up 1024 MAC addresses
  • frame size up to 2048 bytes
  • VLAN support (IEEE 802.1Q)
  • Provider VLAN support
  • 4 priority queues (PQ or WFQ)
  • traffic classification according 802.1p, DSCP, port based, VLAN based
  • 4 stage repeater support (BSRU/BSRU+)
  • optional integrated remote power supply
  • units are configurable as LT or NT

Supported Standards

  • ITU-T G.991.2 SHDSL
  • ITU-T G.994.1 Handshake
  • ETSI TS 101 524 SDSL
  • IEEE 802.1D MAC Bridging
  • IEEE 802.1Q VLAN Bridging
  • IEEE 802.1ad Provider Bridges
  • IEEE 802.3i 10BASE-T
  • IEEE 802.3u 100BASE-TX
  • IEEE 802.3x Flow Control
  • ITU-T G.703 Physical signal characteristics
  • ITU-T G.823 Jitter and Wander
  • ITU-T G.826 Error Performance Parameters

Data Sheets


4 wire-pair termination unit for Ethernet First Mile Applications

[ File type: PDF | File size: ca. 600KB ]