Guaranteed Caller TDM-SHAKEN

The Challenge

American consumers receive over 200K unwanted and/or fraudulent calls every minute, many using spoofed caller IDs to increase the likelihood that the called party will answer the call. Both the FCC in the USA, through the TRACED Act and the CRTC in Canada, have mandated service provider implementation of the STIR/SHAKEN set of standards as a solution to the widespread use of CLI spoofing in fraudulent calls.

SS7 network elements cannot sign calls per STIR/SHAKEN as they lack the SIP infrastructure to transport the result. Also, SS7 anywhere on the signaling path of signed calls strips the signed Identity Header. Hence, originating from an SS7 service area or transiting an SS7 interconnect leaves calls “unverified”.

Many smaller service providers operate native SS7 cores and connect “upstream” via SS7/TDM. Moving to SIP isn’t always an option because even if STIR/SHAKEN is implemented within the service area, the result is islands of verification in a sea of unverified, since signed identity headers can’t pass across the upstream interconnect points. Also, migrating to end-to-end SIP connectivity may not be a viable short-term option for some carriers because the network core must be upgraded to SIP and the nearest SIP interconnect point may be more distant than the current SS7 interconnect points, imposing significant new transit fees.

Remaining unverified isn’t really an option either. Traffic offered upstream from SS7 service areas will quickly become less and less attractive economically, as subscribers everywhere become used to familiar verification symbols. An unverified call will soon become an unanswered call. Businesses presently in these service areas will face economic pressure to move to areas where IP connectivity is end to end.

The NetNumber Solution

Guaranteed Caller™ is NetNumber’s family of STIR/SHAKEN solutions, providing proactive and IETF/ATIS compliant CLI validation solutions for all common calling scenarios.

Guaranteed Caller™ TDM-SHAKEN extends the STIR/SHAKEN trust network into the TDM/SS7 domain by providing the TDM-enabling Call Placement Service (CPS) element. Also included is full support for SS7 physical interfaces, leveraging NetNumber’s 20+ years of experience in the SS7 domain. TDM-SHAKEN is included with Guaranteed Caller™ Service Provider. It includes CPS and the optional, in-network Cloud Connect element.

On SS7 origination, Guaranteed Caller™ TDM-SHAKEN creates a signed identity header for the call and store it in an out-of-band real-time Call Placement Service (CPS). On SS7 termination, it retrieves the signed identity header for the call from the CPS and verifies the signed identity header.

Key Features
  • All key features of Guaranteed Caller Service Provider in addition to the below. 
  • Provides ATIS STIR/SHAKEN compliant call signing and call signature validation for both TDM and SIGTRAN SS7/ISUP calls. 
  • Fully compliant with ATIS 1000096 out-of-band SHAKEN, including STI-CPS support. 
  • In combination with Guaranteed Caller Service Provider, implements full STIR/SHAKEN coverage across the entire network, eliminating the need for additional and costly robocall mitigation solutions. 
  • Supports optional incremental usage of STI-CPS for SIP STIR/SHAKEN, protecting call signatures from intermediate SS7 transport that would otherwise delete call signatures. 
  • Guaranteed Caller TDM-SHAKEN STI-CPS usage is pre-integrated with NetNumber’s Guaranteed Caller STI-AS and STI-VS, saving one cloud dip each for call signing and signature validation.