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svi tas headerTelephony Application Server

The Telephony Application Server (SVI_TAS) enables the rapid delivery of converged services across IMS, NGN and Legacy SS7 networks. The SVI_TAS enables operators to leverage existing infrastructure, extend return-on-investment and rapidly deploy new services.

SVI_TAS Telephony Application Server 

tas interfaces image 

Rapidly devise, test and deploy services. Whether you are looking to interwork DIAMETER or SIP with legacy SS7 CAMEL/INAP/MAP, or you are looking to interface a new subscriber database over SQL/SOAP/HTTP into your incumbent networks the SVI_TAS will:

  • LEVERAGE existing IMS, NGN and legacy infrastructure
  • MITIGATE against vendor lock-in and product end-of-life
  • RAPIDLY deliver custom services across disparate networks


tas api network


tas apiThe SVI_TAS operates over clearly defined API's that present an abstracted version of the underlying DIAMETER, SIP, CAMEL, MAP etc signalling. It can be driven by either Squire Technologies python based client (SVI_TAC) or by operators 3rd party applications, and provides an extremly flexible, service driven platform with huge benefits:


tas cost saving iconCost Savings
Deliver only those services that you require instead of paying for a full application suite that you will never use


tas powerful iconPowerful
Services built using industry standard Python scripting language


tas scalability iconExtendable
Extend services using in-house resources or let our experts develop at a fixed cost


tas speed iconSpeed
Script based delivery removes compilation and upgrade cycle


tas flexibility iconFlexible 
Allows monitoring, termination and transmission over API’s for service creation


tas nfv iconNFV
NFV ready technology


USSD Gateway

ussd iconUnstructured Supplementary Services Data (USSD) is a session based protocol used in 2G/3G networks to send text between a mobile phone and an application program in the network. Unlike SMS there is no store and forward as USSD transactions only exist for the length of a session. USSD applications are generally menu driven as able to push text in menu format to subscriber handsets.


  • Pre-Paid Roaming  - USSD used in the network to check in real-time
    subscriber has enough credit for call
  • Pre-paid subscribers use USSD to manage and top-up their accounts  
  • Mobile Money – subscribers able to make payments and purchases
    via their phones menu driven USSD interface

Example Case Study

Working with a 4G mobile operator rolling out roaming services they needed to insure that pre-paid subscribers credit checks operate correctly in 3G networks

Some 3G networks perform credit checks via USSD. The SVI-TAS integrated with a DIAMETER SVI_IWF product is deployed in the clients 4G network to deliver the required USSD to DIAMETER messaging inter-operability. In a subsequent phase of the project the client decided to provide their subscribers with a full USSD driven menu application. This was interfaced and configured using the SVI_TAS to provide the HTTP interface to their OCS platform. This flexibility and ease of deployment allows our clients to rapidly evolve and extend functionality according to their requirements.



The SVI-TAS supports the 3GPP IMS component the IM-Service Switch Function (IM-SSF) 3GPP 23.278 providing a seamless bridge between an IMS network (SIP) and a CAMEL based SS7 Intelligent Network.

When an operator initially deploys an IMS network they are unlikely to be able to enable all the revenue services available to their existing legacy subscribers. To insure continuity of service the IMS network can leverage the existing Intelligent Network through the IM-SSF component.

im ssf


Reverse IM-SSF

In “reverse” the IM-SSF allows legacy subscribers to access the new services available in an IMS network. It is the glue that allows legacy subscribers to access new services run from SIP application servers – i.e Mobile PBX, OTT etc.

rim ssf


Example Services

Subscriber Authentication
Mobile Number Portability
Billing and Charging
Fraud Detection
Lookups & Dips 800
Call Barring
Call Forwarding
Equipment Identity Register (EIR)
Location Based Services

Interface Support