What is SIP trunking? Communication service providers offer Session Initiation Protocol (SIP) trunking, a communication type that uses protocols to provide Voice Over IP (VoIP) connectivity between telephone systems and Public Switched Telephone Networks (PSTN). The technology contains SIP trunking architecture to enable it making call formation, management and teardown. SIP trunking is usually sold as a digital replacement for Primary Rate Interfaces (PRI), which is based on Time-Division Multiplexing (TDM). 

Most communication providers around the world utilize the SIP trunking to replace TDM-based services. The SIP trunking usage through existing Ethernet or Multiprotocol Label Switching (MPLS) network infrastructure brings many benefits. The SIP trunking enables the providers reducing cost and management complexities associated with older digital platforms and providing additional features.

Benefits of SIP trunking

Then you need to know about the benefits of technology. A customer can enjoy greater purchase flexibility when choosing the SIP trunking over the TDM. While the TDM trunks usually support a minimum of 23 voice channels, the customer can purchase the SIP trunks in any addition without the need for a Wide Area Network (WAN) circuit. They can apply the SIP trunking to existing WAN services, dedicated WAN connections or even public internet.

SIP trunking architecture

SIP trunking architecture comes next after the benefits of the technology. The SIP trunking architecture has a Session Border Controller (SBC) to mediate the connection between the SIP trunking and the telephone system in place. SBC provides a central point for security management, call routing policy, plan numbering, and voice codec transcode.

Other SIP trunking services include:

  • voice call encryption to meet security needs;
  • call routing to emergency telephone services, with the exact location of the caller;
  • failover to back up trunks and locations;
  • the ability to provide trunks through a web-based interface;
  • interconnection with cellular networks hence calls via mobile phones also ring on desktop phones;
  • protection against denial-of-service (DoS) attacks;

Also read: Six SIP Trunk Cost Components You Need to Know