L08
VoIP: call setup, speech and quality
Cram this first — memory hook
Session Initiation Protocol rings; Real-time Transport Protocol talks; RTP Control Protocol reports. 5060 says hello, 5061 locks the call setup.
Exam trap
A phone that rings successfully can still have a blocked media path. There is no single universal port.
The slide facts
sets up calls, carries voice, and reports quality. Deployment includes voice VLANs, tagging, power, address settings and quality of service. One-way audio points toward routing/firewall/address-translation checks.
If you have time — extra
Voice over Internet Protocol () turns sound into data packets. A Private Branch Exchange () supplies office functions such as extensions, voicemail, transfer and call queues. Session Initiation Protocol () establishes and manages calls, commonly on Transmission Control Protocol or User Datagram Protocol 5060. protected by Transport Layer Security (), often called SIPS, commonly uses 5061. Real-time Transport Protocol () carries the media, normally over negotiated ports; Control Protocol () reports reception/quality information. Secure () is used to protect media; securing signaling alone does not encrypt every voice packet. A Virtual Local Area Network () can separate voice traffic, while Quality of Service () can prioritize delay-sensitive traffic. Power over Ethernet () can power a phone using its network cable.
Walkthrough
The phone gets power and correct network settings, registers with its call system, uses to establish a call, exchanges media, and supplies/receives quality feedback through . Troubleshoot the failed stage.