ISDN PRI to SS7 Signaling Converter

Device for integrating the SS7 signaling system and PBXs with support for the DSS1, QSIG, Q.931 protocols


  • from 2 to 16 E1 interfaces
  • PRI (DSS1, QSIG protocols, recommendation Q.931)
  • SS7, V5.2, R2 MFC, R1.5
  • SIP, hardware echo cancellation (option)
  • full accessible commutation 16 E1
  • SNMP v2 alarm trap


PRI to SS7 Signaling Converter is the powerful tool used to interface the telecommunications equipment and provide its interaction using various signaling systems.

Primary Rate Interface (PRI) – standard interface ISDN network  using the following signaling protocols: DSS1, QSIG, Q.931.

ISDN PRI to SS7 Signaling Converter, support DSS1, QSIG, Q.931 protocols, connection network diagram

Pic 1. PRI to SS7 Signalling Converter Connection Diagram

Using signaling converters helps to optimize capital expenditures when upgrading the PSTN network and extend the lifetime of the existing systems.

Key Features, Signalings, Protocols and Interfaces

The signaling and PCM protocol converter provides:

  • converting signaling protocols of PCM digital links
  • creating semipermanent connections
  • dividing E1 links into channels
  • converting the subscriber number when the connection is being established over the assigned masks
  • visual monitoring of how system information flows in signal channels
  • full-service switching of 16 PCM links

PRI to SS7 Signaling Converter supports the following signaling protocols:

  • SS7 (or Signaling System #7, CCS7 Common Channel Signaling System 7, C7, CCITT7, N7 Signalisierungssystem Nummer 7)
  • ISDN PRI (or Euro-ISDN, EDSS1, DSS1, QSIG protocols, recommendation Q.931)
  • V5.2
  • R2 MFC
  • R1.5

Implementation of the SS7 and the number of links supported

Signaling System No. 7 (or SS7) is a globally accepted protocol for out-of-band signaling systems and is regulated by the International Telecommunication Union (ITU-T).

SS7 Signaling Converter from Terratel covers the full functionality of the MTP2, MTP3 and ISUP subsystems in accordance with ITU standards and guidelines.

SS7 Signaling Converter allows you to organize from 1 to 16 links on 16 E1 ports.
Accordingly, for a device with physically installed 8E1 ports, support from 1 to 8 SS7 links is possible. Those, оn 1E1 port – 1 link SS7.

What is a PRI E1?

PRI or Primary Rate Interface – is a standard telecommunication interface of the ISDN digital network which is used to connect office PBX, central telephone exchanges or digital switches.

PRI E1 operates at a speed of 2.048 Mbps and consists of 32 channels (time intervals).

Management of PRI channels, combining telecommunication equipment into one PSTN network, occurs by using the following signaling protocols: DSS-1, QSIG, Q.931.

Design and Management

Technically, the product is designed as a dedicated industrial controller based on the state-of-the-art telecommunications processor. The PRI to SS7 Signaling Converter is designed to be installed in a server closet 19″ rack with 1U height of the housing.

Monitoring and control (changing configuration, monitoring operation etc.) are performed locally (RS-232 interface, COM1 port) or over Ethernet (TCP/IP).

Monitoring the operation of the device and reporting of accidents is carried out using the SNMP protocol.

Electrical power supply

The power is supplied from the DC source operating within from -36V to 72V range or from the AC source operating within from -90V to 265V range.

AC/DC redundancy power supply support. Power redundancy can be provided by installing two power sources that are operated concurrently with various configurations: AC 220V+AC 220V, AC 220V+ DC 48V/ DC 60V or DC 48V/60V+DC48V/60V.