Liberator E - ISDN Converter, ISDN Splitter, Switch, and Concentrator

Liberator E

The Liberator E high reliability ISDN Converter, ISDN Splitter, Switch, and Concentrator supports 8, 16, 24 or 32 PRI/E1/T1 interfaces and Dual load-sharing PSUs. Ability to inter-link Liberator ‘E’ units to support additional PRI ports in a virtual non-blocking single switch. The Liberator models can support up to 32 E1/T1/PRI interfaces via two card types, either 8-port or 16-port cards. The PRI ports on the 8-port card can be user-switched between NT and TE and have Telecoms Approvals for direct connection to the ISDN network. The PRI ports on the 16-port cards are NT only. When mixing an 8-port and a 16-port card the 8-port is always in the lower position. Purchasing the optional E1 T1 conversion pack means both E1 and T1 can be supported on the same unit and this can be selected on a per-port basis. The unit will connect any port to any port and any ‘B’ channel to any ‘B’ channel without constraint, giving full cross-connectivity between all ports, both local and network channels.


  • Modular, resilient PRI ISDN switch, ISDN splitter, sharer or concentrator
  • Non-blocking
  • Full cross-connection between any/all ‘B’ channels
  • Connects to ISDN networks and/or local ISDN devices
  • Load-share hot-swappable AC/DC PSUs
  • Advanced routing capabilities
  • Number manipulation
  • Shares ISDN access between multiple local devices
  • High call rate
  • Switch between devices for load-sharing or resiliency
  • Least Cost Routing
  • Dynamic re-directing of calls if destinations unavailable
  • Local connectivity between any ports
  • Ports NT/TE user switchable
  • Optional PRI E1 to T1 conversion
  • Supports A-Law to μ-Law for voice conversion
  • Tones generated from network and/or by Liberator “E”
  • Clocking hierarchy
  • Inter-link Liberator “E”s for a larger crossconnect switch
  • Remotely manageable and software upgradeable

ISDN Services
- Signalling is carried/converted between ports and ISDN types including when converting between ETSI and ANSI standards. Supplementary Services from the network are passed transparently to local devices. Enbloc and Overlap dialling are supported and Liberator can convert between the two.

Routing - Liberator supports many routing options including the ability to configure Primary, Secondary and Tertiary destinations. Call routing can be based on the incoming port and /or channel, DDI (DID) number, CLI, sub-address and/or Call Type (Bearer Capability). CLIs can be locally generated. Number Translation is standard on the Liberator “E” which means leading, trailing or digits in the middle of dialled number or CLIs can be modified, giving a great deal of flexibility. It is extremely rare that Liberator cannot be configured to meet a customer requirement.

Configuration/Management - Liberator is configured and managed by DbManager which is an intuitive GUI which supports multiple real-time workstations and is the common platform for all Liberator & PacketBand products (see below). Versions are available which can be configured for the smallest installation, or up to many thousands of devices. Configuration/management sessions can be established remotely via an ISDN call or locally through the unit’s LAN/Ethernet port or the RJ serial port. SNMP Traps & Alarms are supported as is a call analysis tool.

Liberator E DbManagerr

Ports, inter-connectivity and routing:
Ports, Channels and Groups
- Liberator employs a simple system where PRIs or individual ‘B’ channels within one or more PRIs can be allocated to one or more customer named “Groups”. These Groups form the basis of all configurations, making it fast, simple and intuitive to your applications.

Cross-Connection - Any ‘B’ channel can be connected to any other within Liberator without constraints (unless some are programmed). Any port can be barred from calling any other port or number. Any call can be routed to a Group of ports or 'hunt-group’. Multiple devices can be configured to accept calls dialling to a range of numbers and the calls can be routed to a Group in a variety of ways (sequential, always the lowest available port etc). Incoming calls can be automatically rerouted to alternate preprogrammed destinations if the main number is busy or unavailable, or after a set time of not being answered (1-20 seconds)

Call Rate - Liberator can maintain a constant call rate (in-coming or out-going) of 10 calls/sec with peaks of up to 20 calls/sec 3.4 Redirection on ‘Busy’ or ‘Unavailable’.

Redirection on ‘Busy’ or ‘Unavailable’ - Incoming calls can be automatically rerouted to alternate preprogrammed numbers, groups or ports if the main number or port is unavailable. This gives the ability to automatically switch to backup or standby device for resilience purposes. Liberator supports a Secondary and Tertiary destination Routing Profiles. If an out-going call to the ISDN network cannot be established (user or network busy, for example), Liberator can automatically redial via other network ports without the end user having to take any action. The same can be done for incoming calls switching between local devices.

E1 to T1 Conversion - Liberator can optionally convert between E1 and T1 PRIs. Liberator supports the necessary A-Lau to μ-Law encoding conversion necessary for voice traffic.

Number Translation or Conversion - Any incoming dialled number can be converted by Liberator and presented on any ISDN interface. For example an incoming call to 12345 may be converted to 98765, perhaps because the original extension at 12345 has moved onto a VoIP gateway on a different ISDN PRI and now the user has a different DDI number. Liberator can convert/add/delete leading digits, digits in the middle of numbers and/or trailing digits. It can also manipulate sub-addresses and CLIs. All of this flexibility is not required by all, but if you should need it, it is easy to use and configure.

Tone Generation - Liberator normally passes the tones transparently between ISDN points but this is not always possible in all instances, such as some least-cost routing applications, if there is no network at all, or in certain other circumstances such as when Liberator cannot make a final routing decision until the number is dialled. In these instances, Liberator can be configured to generate dial, ring, busy, N/U tones itself.

CLI Generation - Liberator is able to generate a CLI field. The number of the CLI can be programmed for individual ports or calling numbers.


PRI/E1/T1 - 1, 2, 3 or 4 PRI ports.
16-port NT-only card and 8-port selectable NT/TE. 16-port cards marked as Ports 1 to 16 and Ports 17 to 32. 8-port cards marked as ports 1 to 8 and 17 to 24. When mixing 8 and 16 port cards ports 9-16 will not exist. By default all ports are NT – a crossed cable is required to connect TE ports on the 8-port card.

  • RJ45 120Ohm balanced (E1)
  • Auto-detect CRC4 or non- CRC4 framing (Multiframe or Doubleframe)
  • Support of non-switched E1 and Fractional E1 services
  • ISDN PRI ETSI Q.931/921, ETSI-DSS1, ETSI 300-011, ETSI300-125, ETSI 300-102, approved to TBR4
  • A-Law and μ-Law tones


  • RJ45 100Ohm balanced T1
  • ESF or D4 Framing selectable
  • B8ZS or AMI Line code selectable
  • NI-2, DMS-100, AT&T 5ESS Switch selectable
  • AT&T TR-62411 and ANSI T1.403 Compliant
  • A-Law and μ-Law tones

Control Ports

  • RJ11 Marked ‘Cmd’ - Asynchronous 8 data, 1 stop bit no parity 19.2kbps to 115kbps
  • Password protected
  • Optional Ethernet RJ45 Marked 10baseT/100baseT/1GE
  • Dry contact alarm relay


  • Each PRI has 1 associated LEDs
  • Fl slowly=synchronising to Layer 1; fl quickly = synchronising
  • Layer 2; solid= synchronised

PWR x 1: Unlit=no power; Green=power on unit
Run x 1: Slow flash=microprocessor OK and configured; fast; flash=internal error or lost base configuration
LAN ACT x 1: Activity on the LAN
LAN 100 x 1: Off=LAN running at 10baseT; on=LAN running at 100baseT



  • Support for 1 or 2 supplies
  • Hot swapable to ATCA.
  • One supply can power a fully populated chassis.


  • Auto-sensing 96VAC – 240VAC
  • Max consumption 0.5A RMS @230VAC


  • 4mm terminal Block
  • 36VDC tp 57VDC
  • 1.2A max


  • Operating 0 – 55 °C
  • Humidity 10-90% non-condensing
  • Natural convection cooling


  • Metal chassis and front/rear panels
  • W – 225; D – 320 (300 from mounting); H-88mm
  • Weight – 10.5Kg max

There are no serviceable parts or maintenance required. The battery used for the real-time clock and some NV RAM elements has a 7 year (typical) life-time.

All approvals completed in UK

  • TBR12/TBR13
  • TBR4:1995, 1997 Amendment
  • TIA/E1A-IS/968
  • TNA117
  • AS-ACIF-S006/S016
  • CS-03 Canada
  • TIA-968-A USA


  • EN55022:1998
  • EN55024:1998
  • A12001
  • EN61000-3-2/3:1995
  • AS/NZS CISPR22:2000


  • IEC60950-1:2007
  • ACS/NZS60950:2000
  • AS/NZS3260:1993
  • ACA TS001:1997