Software for Signaling Interworking

TeleSoft International provides signaling interworking, which includes TeleSoft's Embedded SIP source code software, ISDN protocol stack, QSIG protocol stack and  T1 RBS  E1 R2 CAS protocol stack in order to accelerate development and interoperability testing of your gateway or similar product. TeleSoft's SIP, ISDN, QSIG, CAS R2 and RBS protocol stacks provides the fastest path to market-ready telephone, PBX, gateway and similar products for manufacturers worldwide.

TsGATE is an integrated software SIP to PSTN Gateway software design kit that translates the packetized signaling messages on IP networks to the  messages used on the digital PSTN networks. TsGATE can also be used with analog telephones (POTS, or plain old telephone service).   TsGATE takes advantage of existing proven TeleSoft stacks by combining the CompactSIP SIP stack with the TsLink3 PSTN signaling stacks and integrating these with the TeleSoft SIP-PSTN Interworking Module. TsGATE is an ideal solution for OEMs developing embedded gateways and adapters since the TsGATE Soft Gateway is hardware and RTOS independent and can be ported to a wide variety of platforms to create IP to TDM conversion products.   SIP-SIP "gateways", such as a session border controller or SIP enabled firewall, are best served by the CompactSIP or IMS CompactSIP stack.

SIP-PSTN Signaling Interworking Features

  • CompactSIP User Agent software SIP Stack
  • World-wide PRI, QSIG, BRI software Signaling Stacks
  • CAS R2 support for many countries
  • Robbed Bit Signaling stack
  • Analog Telephone ("Black Phone" or "POTS Phone") interface
  • IETF & ITU Standards-based software
  • Processor and RTOS independent software
  • Based on field-proven software stacks
  • Written in ANSI C source code for ease of portation
  • Developed for embedded applications

SIP-PSTN Signaling Interworking applications


TsGATE Soft Gateway is ideal for for cost and memory sensitive applications, from a desktop terminal adapter to the largest system.  There are several configurations of TsGate available.  In addition to the configurations listed, protocols may be added to create a gateway with any combination, or all combinations.

SIP-QSIG Gateway software library

This version of TsGATE uses the  CompactSIP protocol stack or IMS CompactSIP protocol stack and the QSIG protocol stack.   QSIG has the most supplementary services defined in the specification, and may be the best choice when it is available.  However, manufacturers choose which QSIG features to implement, and whether to implement QSIG at all in their PBXes and other devices, so "YMMV".  Generally, the Public Switched Telephone System does not support QSIG.

Compliant with RFC 4497 -- Interworking between the Session Initiation Protocol (SIP) and QSIG

Some uses of the QSIG-SIP Gateway SDK:

  • Legacy PBX-VoIP service interworking device
  • Legacy PBX-SIP based adjunct device adapter such as a PBX or Key Telephone System to
    • Voicemail
    • Interactive Voice Response system
      • Corporate Information (e.g. stock price, directions to facility)
      • Product information  (e.g. nearest store, railroad schedule)
      • User Commands (e.g. online auction)
    • Auto-Attendant
    • Auto-Dialer and announcement (e.g. school announcements, tornado warnings)
  • SIP PBX - Legacy PBX or Key Telephone System interworking device
  • Add SIP phone to legacy PBX
  • Add legacy adjunct device to SIP PBX

SIP-ISDN Gateway software library

This version of TsGATE uses the  CompactSIP protocol stack or IMS CompactSIP protocol stack and the ISDN protocol stack.  ISDN allows connection to the Public Switched Telephone System, and has more features than Channel Associated Signaling (CAS).  However, it does not have as many features defined as QSIG does.

Based on RFC 4497, which defines Interworking between the Session Initiation Protocol (SIP) and QSIG, modified for ISDN.

Some uses of the ISDN-SIP Gateway SDK::

  • All of the uses as the SIP-QSIG gateway, plus
  • Interworking device to enable Primary Rate ISDN or Basic Rate ISDN on SIP PBX
  • Device to enable SIP Key Telephone Systems to use PRI or BRI
  • Allow legacy PBXes, Key Telephone Systems and even Telephones to connect to a VoIP service.
    • Add remote office telephones and telephone systems to corporate PBX - centralized system may be more efficient:
    • Reduce cost of telecommunications (toll bypass)
    • Better service by operator because all operators can service all calls, not just the ones for their location.
    • Better use of adjunct devices because one larger system is shared by all branches
    • IT or Telecom department can configure, backup, and service on-site devices more easily

SIP-CAS R2 RBS Gateway software library

This version of TsGATE uses the  CompactSIP protocol stack or IMS CompactSIP protocol stack and the T1 RBS  E1 R2 CAS protocol stack. 

The uses of the CAS R2 RBS - SIP Gateway SDK are similar to the uses of the SIP-ISDN Gateway library above.  However, MF-R2 and Robbed Bit Signaling do not have all the features that ISDN and QSIG have.  R2 features vary by country, but in general, R2 has more available features than RBS.

SIP-POTS Gateway software library

This version of TsGATE uses the  CompactSIP protocol stack or IMS CompactSIP protocol stack and TsGATE.  TsGATE has an interface to support analog phones, which are sometimes called "Black Phones" or "POTS phones" (POTS stands for Plain Old Telephone Service"). 

Some uses of the  POTS-SIP Gateway are:

  • Adding VoIP capability to SOHO routers
  • VoIP Terminal Adapters (TAs)
  • POTS-VoIP multi-phone TA that allows remoting a larger number of phones to connect to a SIP PBX over an ethernet connection
    • similar to a Media Gateway, but uses SIP instead of MGCP or Megaco
  • Adding VoIP capability to existing PBXes and Key Telephone Systems

QSIG - ISDN - CAS R2 RBS Gateway software library

This version of TsGATE uses one or more of the ISDN protocol stack protocol stack, T1 RBS  E1 R2 CAS protocol stack and the QSIG protocol stack. 

Tthe QSIG-ISDN-CAS-R2-RBS Gateway SDK is a great addition to the existing TsGare ISDN, CAS and QSIG stacks, but is perhaps misnamed.  This gateway can be used for QSIG-ISDN calls, QSIG-CAS calls, ISDN-CAS calls and also for ISDN, QSIG and CAS calls. It adds a very simple user interface to the powerfull and flexible TsLink3 API.   TsGATE offers a library of code that you would otherwise have to write yourself if you are building a transit (class 4) switch, CO (class 5) switch, PBX, or similar device.

TeleSoft International is a premier supplier of circuit switched telephony and VoIP Protocol signaling stacks & solutions to leading OEMs worldwide. TeleSoft has been selected by more than 250 OEM customers and we continue to provide robust, mature, conformance and interoperability tested solutions to customers who require the best performing software stack solutions.

 

The TeleSoft protocol software development toolkits (SDKs) offer highly optimized protocol stack solutions that combines very small memory footprints with high performance and no compromises on functionality and scalability. All TeleSoft SDKs are supplied in source code written in ‘C’ for ease of portation.

Telecom and VoIP have needs that are different than data communications, and the industry is just realizing how different VoIP is from datacom.   Telecom protocols are required to be robust, and if VoIP is to be widely accepted, it must be as robust as the existing PSTN.  Doesn't it make sense to license your Voice over IP (VoIP) signaling protocol from the voice experts?