What is an SBC

SBC stands for Session Border Controller

  • Simplified Explanation
    • SIP Firewall
    • SIP Security Device


  • Real time interactive communications
  • Voice, Video, multimedia
  • SIP or H323 Signaling


  • IP to IP network border
  • SIP trunks to service providers
  • Remote worker access
  • Internal Enterprise / External Enteprise


  • Security & SLA assurance
  • Revenue & cost optimization
  • Compliance

Why use an SBC

SBC are installed at the edge of VoIP Networks to facilitate end to end VoIP transmission without compromising network security

Essential for Several reasons:

  • New security issues introduced with SIP protocol
  • Fix Interoperability issues
  • Implementation of UC/Collaboration features

SBC are typically implemented as Back to Back User Agents (B2BUA)

  • All SIP and Media (voice) traffic transit through SBCs

B2BUA Explained

  • A back to back user agent (B2BUA) is a logical network element in the Session Initiation Protocol (SIP) applications
  • It operates between two endpoints in a communication session and divides the communication channel into two different call legs
  • It mediates SIP signalling between both ends of the call
  • B2BUAs are often implemented within media gateways

Sangoma SBC B2BUA

What are User Agents?

Sangoma SBC User Agent

Theory Subtopics

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