What type of data is commonly captured to troubleshoot endpoint registration issues?

• A. Packet captures
• B. System metrics
• C. DNS lookups
• D. CPU temperature

Answer: (A)

Packet captures are the most effective data to troubleshoot endpoint registration issues because registration relies on real-time signaling between the endpoint and the registrar. A capture shows the actual REGISTER messages, the registrar’s responses, and any authentication challenges (such as 401/407) or TLS handshakes if secure signaling is used. It also reveals DNS resolution steps if the endpoint is locating the registrar, including DNS queries and the resulting IPs or SRV records. With this visibility you can pinpoint where the flow breaks—whether the endpoint isn’t sending REGISTER at all, the registrar replies with an error, TLS certificates don’t match, or traffic is being blocked by a firewall or NAT. System metrics or CPU temperatures don’t show the signaling problems, and DNS lookups alone don’t expose the full SIP exchange. This holistic view from a packet capture helps diagnose misconfigurations, connectivity issues, and authentication problems that prevent registration.