Central Site I-Mux

Central Site I-Mux

The DataBand CSI and ISU range connect high speed serial data devices together using multiple ISDN calls, in effect dialling a high-speed “leased line” between non-ISDN devices. It is ideal for use with videoconference units, MCUs, encryptors (such as KIVs) or any high-speed serial device that needs bandwidth on demand. It aggregates or inverse multiplexes multiple ISDN channels from multiple ISDN PRI interfaces into N*64kbps V.35, RS530, X.21/V.11 and E1 ports. A single CSI (Central Site I-Mux) supports from 1 to 8 ISDN PRIs for network access, and from 8 to 16 serial data ports with data rates of up to 1.024Mbps per port. CSIs can be linked together to form larger systems. Easy to manage and configure, the CSI is an ideal central-site solution for:

  • New Inverse multiplexing and Terminal Adaptor applications
  • Replacement of existing unsupportable legacy platforms
  • Migrate and free-up multiple single port I-Muxes/aggregators at central sites and redeploy them at remote sites


  • ISDN inverse multiplexer or I-Mux
  • Central site system high port density
  • Multiple PRI (E1/T1) ISDN
  • Multiple V.35, RS530, X.21/V.11 interfaces
  • Speeds to 1.024Mbps
  • Supports BONDing standard and 64K ‘clear’
  • Option to clock or not clock idle ports
  • RS366 dialling*
  • Calls on any PRI can be aggregated
  • Ability to isolate PRIs from data ports via fibre link
  • Dual load-sharing hot-swappable AC/DC PSUs
  • Inter-works with other I-Muxes, including Adtran® ISU and KLAS® adaptors
  • Interworks with DataBand ISU
  • Intuitive GUI
  • Local serial port and optional Ethernet port for management
  • Optional fibre port for management
  • Password protected
  • Encrypted Management protocol
  • NV RAM stores configuration
  • Dual FLASH banks for updates
  • New design using latest supportable components
  • Extensive Approvals incl Telecoms
  • Low power usage
  • RoHS compliant

Other Configurations:

  • 2-wire “U”BRI interfaces see DataBand ISU 512U
  • 4-wire “S”BRI interfaces see DataBand ISU 512S
  • Stand-alone PRI inverse mux with optional BRI ports
  • DataBand ISU 1024
  • ISDN satellite splitter see DataBand Splitter
  • For other ISDN switch, conversion and sharing capabilities see our Liberator range

Typical Applications:

  • Video conferencing and MCUs
  • Inter-connectivity of encryptors
  • Fibre isolation
  • High speed file transfer
  • Central site Terminal Adaptor
  • Reduce ISDN costs and space
  • Replace obsolete Access Switch and Oasis equipment

Configuration Examples:

1. Standalone Use - The I-Mux capability, using industry standard BONDing algorithms, aggregates the individually dialled and routed ISDN channels, reordering them and handling the differential delays between all of the ISDN calls.

Central Site I-Mux diagram 1

2. Typical Current Central Site Installations - By way of an example, Diagram 2 below shows inverse multiplexers with encryptors (such as KIVs and Thamers) and video conference units. Currently many users populate multiple BRIs and stand-alone inverse multiplexers at the central site. This has several issues:

  • Not easy to manage
  • Large space and power requirements for muxes
  • Space and cable problems with multiple BRI ISDN
  • Reliability issues of multiple BRIs
  • Costs of muxes and BRI ISDN connections

Central Site I-Mux diagram 2

3. Transition Networks (Patapsco) CSI - Replace the multiple central site muxes with the compact DataBand which simplifies the installation and delivers:

  • An easy to manage and configure solution with specific GUI designed for ease of arranging and reserving calls.
  • Huge space savings
  • Cost benefits
  • Easily expandable
  • PRI is a fully managed/monitored service and more reliable than BRIs
  • Any installed central site stand-alone muxes can be redeployed at remote locations

Central Site I-Mux diagram 3

4. Other Legacy Central Site Equipment - There are several very old central-site platforms in the field (for example Oasis and AccessSwitch). However, they have been obsolete and unavailable for many years and are naturally becoming increasing unreliable, difficult to support and maintain. The DataBand CSI is a new design, using the latest modern components. It will be available for many years to come with an ongoing commitment to excellent support. Furthermore, the management and control of the CSI is more up-to-date via an intuitive GUI. The GUI is designed specifically for the application, making the job of operators simple and intuitive with excellent visibility of status of all the ports and calls. Some secure installations also need an inverse multiplexer to reconvert the serial output from the encryptor back to ISDN for use by the VC or MCU. In which case the DataBand is an equally effective unit on the “Red” side of the encryptor, as shown below:

Central Site I-Mux diagram 4

5. Network Resilience - Unlike BRIs, PRIs can often be sourced from more than one carrier, so it is easy to add resilience by dual-sourcing the PRI network access or by diversely routing circuits.

Central Site I-Mux diagram 5

6. Isolation and Boundary Issues - Some applications, particularly those involving the military, government or security organisations, have to be careful about radiated emissions and will often either only allow fibre-based circuits across the boundary or will add fibre links into the system for isolation. DataBand CSI can be configured with two chassis, one for the PRI ISDN and one for the data services. The two separate devices are then completely isolated and linked via fibre.

Central Site I-Mux diagram 6


Other Example Configurations:

7. Single chassis with dual AC PSUs, 8 x 256kbps RS530 aggregations and a single PRI

Central Site I-Mux diagram 7

8. Single chassis with single AC and single DC PSU, 16 x 384kbps V.35 aggregations and 4 x PRIs

Central Site I-Mux diagram 8

9. Dual inter-linked chassis each with dual DC PSU, a total of 48 data ports (16 x 512k X.21, 16 x 384K V.35 and 16 x 256k RS530) and 8 x PRIs.

Central Site I-Mux diagram 9


A single chassis supports two Interface cards. Two chassis can be inter-linked via the fibre Cascade capability to isolate data ports from ISDN ports.

A. Network Interfaces

  • RI RJ45 ISDN interface
  • User switchable E1/T1 per port
  • 1, 2, 4, 8 ports

B. DTE Interfaces

  • 8 or 16 HDMI with supporting:
  • V.35 “MRAC”
  • RS530 25-way “D” – Adtran compatible
  • X.21/V.11 15-way “D”
  • Speeds to 1.024Mbps each interface

C. Out-going Dialling Options

  • GUI (operator controlled)
  • Control lead – pre-stored
  • RS366 - under development

D. In-coming Call Options

  • GUI (operator controlled)
  • Accept all
  • Accept authorised (CLI)
  • Reject all

E. Data rates: 64kbps to 1.024Mbps per data port
F. Inter-operability: BONDing compatible devices, including inverse multiplexers
G. ISDN switch compatibility: National 1 (USA), 5ESS, DMS100, Euro-ISDN
H. Management: RJ12 serial port; RJ45 Ethernet port 10/100/1GE
(Optional Security pack encrypts Management traffic using AES 256byte)
I. Configuration: Held in NV Memory
J. Firmware: Held in dual FLASH banks
K. Power: Support for one or two PSUs in any combination complying to ATCA. One supply will power a fully populated CSI. Dual hot-swappable supplies for load-sharing and resilience.


  • Internal switch mode supply
  • Standard IEC connector
  • 96-240VAC auto-sensing
  • Max current consumption 0.2A RMS @230VAC


  • Internal supply
  • Standard 4mm Terminal Block
  • -36 to -57 VDC
  • 1.2A max consumption

L. Cascade/Fibre Card

  • Single or dual-port card with SFP cage
  • Customer or optionally Patapsco supplied SFP modules
  • Customer or optionally Patapsco supplied SFP fibre

M. Physical

  • 225w x 320d (300 from mounting) x 88h
  • Metal chassis, front & rear panels
  • 10.5Kg max

N. Environment

  • Operating -20º to 55ºC radiated cooling
  • Natural convection cooling
  • Optional fans are available for higher temp environments
  • Humidity 10-90% non-condensing

O. Maintenance: There are no serviceable parts or maintenance required. The battery used for the real-time clock and some NV RAM elements have a 10 year (typical) life-time.

P. Approvals

  • CE marked
  • IEC60950-1:2nd Edition
  • ACS/NZS60950:1:2003


  • FCC Part 15 Class A
  • EN55022:1998
  • EN55024:1998-A12001
  • EN61000-3-2/3:1995
  • AS/NZS CISPR22:2000


  • TBR12/TBR13
  • TIA/E1A-IS/968
  • TNA117
  • AS-ACIF-S006/S016
  • CS-03 Canada
  • TIA-968-A USA


  • Compliant

Live Demo of FRM220 Chassis

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