voice quality

Using the OSI network layer model as a basis, here’s how to derive a simplified three-layer model for SIP-based VoIP and corresponding threats and defenses. The resurgence of interest in VoIP to provide telephone services worldwide is often credited to the use of session initiation protocol (SIP) for signaling. Both residential and enterprise VoIP services are widely deployed. IP telephony may be used either to replace the primary telephone service or to provide additional telephone […]