Dialogic DSI SS7LDH4 Network Interface Board

DSI SS7LDH4 Signalling Board


The Dialogic® DSI SS7LDH4 Network Interface Board offers SS7 network connectivity to service nodes handling low volumes of signaling traffic (for example, 200 calls per second or less), and its half-sized PCI Express form factor helps reduce deployment costs. These characteristics, in addition to the ability to choose a bundle of circuit protocols in capacities suitable for small configurations, can help businesses meet the price points needed for success in a highly competitive segment of the market.

The DSI SS7LDH4 can deliver cost-effective signaling functionality for value-added services, such as call completion, prepaid calling, and call routing applications.

The DSI SS7LDH4 supports the Dialogic® DSI SS7 Stack, allowing API-level compatibility with applications developed for other Dialogic® DSI SS7 Boards, including the Dialogic® DSI SPCI Network Interface Boards. Application development for the SS7LDH4 is accelerated by a comprehensive suite of test utilities, sample code, and user-part programming guides.

Key Features

From 2 to 16 low-speed MTP links

Provides a choice of densities

Board and protocol license packages

Allows the purchase of a capacity that helps make a solution more price-competitive in low traffic markets

Half-length, PCI Express form factor

Permits the use of lower-cost rack-mount servers design for small footprint peripherals

Development package of programming aids, configuration tools, and run-time management and monitoring facilities

Enables rapid development  of robust, scalable applications


Digital interfaces
  • 4 T1, E1 (software selectable on a per trunk basis)
  • High impedance selectable for monitoring
  • Selectable synchronization source from any line interface
Telecom clock management
  • Configurable LT (clock slave) or NT (clock master) mode
  • Internal and external loop back capability
Pulse mask
  • T-1 ANSI T1.403
  • E-1 ITU-T G.703
Data rate
  • T-1 1544 Kb/s ± 50 ppm
  • E-1 2048 Kb/s ± 50 ppm
Frame format
  • T-1 D3/D4 and ESF
  • E-1 E1 and E1-CRC4
Line codes
  • HDB3, B8ZS
Connector type
  • RJ-48C
Maximum boards/system
  • 16
Host interface
  • PCI Express compatible as a 1-lane that can be installed in 1, 4, 8, or 16 lane PCI Express slots
  • Bus speed 1 x PCI-Express lane (2.5 Gb/s, full-duplex)
Channelized links 
  • From 2 to 16 channelized 64 kbps MTP Low Speed Links (LSL)
  • High impedance monitoring from 4 to 32 uni-directional links
Protocol execution
  • MTP2 onboard, higher levels on host
Network protocol execution
  • SS7 (MTP1 & MTP2)
 HDLC monitoring
  • Passive monitoring of HDLC format data links including, SS7, LAPB, LAPD, ISDN, and DPNSS
 Form factor
  • x1 standard height, half-length board
Power Requirements  
+12 VDC power  max
  • 0.25 A max
+3.3 VDC power
  •  1.8 A
Power dissipation
  •  8.94 W max
Environmental Requirements  
Operating temperature
  •  0° C to +55° C
Air flow
  •  1.5 Mbps (300 LFM)
Storage temperature
  •  –20° C to +70° C
Relative humidity
  •  8% to 80% non-condensing
System Software Requirements The Dialogic® DSI SS7LDH4 Network Interface Board is supported by the SS7 Development Package (DevPak) for Linux, Windows and Solaris.  See the application note at http://www.dialogic.com/systemreleases for details about the operating systems currently supported. DevPaks contain device drivers and the tools for developing complex multichannel applications, including a native SS7 API that allows full access to the SS7 messages.


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Ordering Information

Use the Purchase page linked below to find partners to purchase Dialogic products. The order codes below are for your reference when making a purchase.

Where to Buy
ProductOrder CodeDescription
SS7LDH4 Signaling Board:



PCI Express, 4 T1/E1, 4 LSL

SS7LDH4 Board Software Licenses:



License, 2 LSL (MTP2, MTP3), 1,024 CICs (ISUP)



License, 4 LSL (MTP2, MTP3), 2,048 CICs (ISUP)



License, 4 LSL (MTP2, MTP3), 4,096 CICs (ISUP)



License, 8 LSL (MTP2, MTP3), 4,096 CICs (ISUP)



License, 16 LSL (MTP2, MTP3), 4,096 CICs (ISUP)

SS7LDH4 Board & Software License Bundles:



SS7LDH4Q Board & SS7SBLDISUP1K License



SS7LDH4Q Board & SS7SBLDISUP2K License



SS7LDH4Q Board & SS7SBLDISUP4K License



SS7LDH4Q Board & SS7SBLDISUP4K8L License



SS7LDH4Q Board & SS7SBLDISUP4K16L License