Tools like Wireshark use PCAP to capture SIP signaling and RTP media packets between endpoints. Engineers rely on PCAP files to troubleshoot call failures, latency, codec mismatches, jitter, one-way audio, or dropped calls. A typical PCAP shows each step of a VoIP call – from SIP INVITE to BYE – along with RTP streams carrying the actual voice data. By examining timestamps, packet sizes, and jitter, technicians can pinpoint quality issues with surgical precision. PCAP files are also useful in security investigations, as they can reveal unauthorized access attempts or SIP-based attacks. However, capturing and storing VoIP traffic must comply with privacy regulations, especially when it contains live voice content. In essence, PCAP provides a window into the heartbeat of a VoIP system and is indispensable for deep-dive troubleshooting and performance analysis.
What is PCAP (Packet Capture)?
PCAP is a file format and technique used to record network traffic for analysis. It’s widely used in VoIP diagnostics to trace call flows, signaling, and media streams.
