The BX21, AimValley’s next-generation SDH Access Device, enables true multi-service carrier-grade access network solutions for tomorrow’s converged networks. The cost-effective terminal multiplexer integrates voice, leased line and packet transport on a compact platform. The system is designed for customer premises access as well as metro aggregation networks, furthermore it is very well suited as a transport device in the wireless infrastructure. The BX21 is optimized to provide unparalleled density and small size at low cost.



  • SDH interfaces: STM-1 interface enabling SDH carrier class transport
  • Access interfaces: E1 and Fast Ethernet
  • Hot-pluggable SFP module for flexible reach selection
  • Standards compliant Ethernet mapping via GFP and Virtual Concatenation and LCAS for Ethernet private line applications
  • Intuitive web-browser based user interface
  • Compact design measuring only 1RU high, 19″ wide
  • Low power and low cost start configuration

Capex & Opex reduction

Capex and Opex reductions are the main benefits of the BX21:

  • Highly integrated architecture with all functions combined on a single low-cost box
  • The system is preconfigured to ease installation and simplify service turn up without the need for costly and trained staff
  • Convergence of data and voice combined with high integration density significantly reduces the amount of equipment; this results in considerable lower investment, installation, operational and maintenance costs
  • Optimal bandwidth utilization and flexibility is guaranteed by data mapping using GFP, Virtual Concatenation and LCAS. The operator can allocate a specific amount of bandwidth per end user, in steps of 2 Mbit/s up to 100 Mbits/s
  • Hot-pluggable small form factor pluggable (SFP) modules for the STM-1 optical interface allows flexibility to select the required optical power budget and link distance

Integration in existing networks

The BX21 protects the investments made in the installed SDH network and improves the operator’s TDM services and revenue through its higher integration and lower cost solution. In addition, the system supports effective Ethernet transport over the existing network without the need for costly deployment of an overlay network.

Management of the BX21 is easily integrated in an existing network management solution. The system provides an Ethernet management port for on-site craft maintenance. Remote management is via a dedicated VC12 and does not conflict with DCC channels already in use for existing network management. The TCP/IP stack and OSPF routing simplify management of remote BX21 systems from a single operations system.

The BX21 provides SNMP alarm traps as well as web-browser based provisioning.

Technical Specifications

Traffic Interfaces 1x STM-1 via SFP
4x E1, 75 or 120 Ohm (RJ45)
2x Fast Ethernet: 10 or 100 Mb/s (RJ45)
Pluggable Modules STM-1 (S1.1) 15km
STM-1 (L1.1) 40km
STM-1 (L1.2) 80km
STM-1 single fiber
STM-1 electrical
Cross connect and Protection Pre-defined configurations for cross connect and VCAT bandwidth allocation
LCAS based protection
Loopbacks on E1 and Fast Ethernet interfaces
Synchronization Internal 4.6 ppm SEC G.813 clock
Clock reference mode selection:
– Locked to STM-1 line timing
– Hold-over mode
– Free running on local clock
Ethernet applications Point-to-point Ethernet Private Line
Up to 100 Mb/s end-to-end on Ethernet port 1
Up to 20 Mb/s end-to-end on Ethernet port 2
Ethernet mapping GFP-F encapsulation
Virtual Concatenation VC3-xv (1..2) or VC12-xv (1..46)
OAM&P Ethernet Port Performance counters
STM-1 MS Performance Monitoring
Fault management and reporting
Local and remote software and database download
Alarm contact and discrete inputs
Management Ethernet 10/100BASE-T for local management access
Console port (RS232)
SNMP traps for alarming
Web-browser based provisioning
TCP/IP and PPP over dedicated VC12 for remote management access
OSPF routing for remote management access

19″ wide, 1 RU high, 180 mm deep


Power input configurations (factory option):
– 230V AC power input
– Redundant 48V/60V DC power
Power dissipation less than 15 Watt


Operating condition: ETS 300 019, class 3.1E
Storage condition: ETS 300 019, class 1.2
Transport condition: ETS 300 019, class 2.3
Free convection cooling without the need for fans

Standards compliance

In compliance with the latest ITU, ETSI, IEC and IEEE standards for SDH and Ethernet equipment

For more information about the specifications, please contact us.