What logs help troubleshoot call routing?

• A. CUCM SDL/SDI traces and SIP/call logs on gateways.
• B. Network packet captures on switches only.
• C. System uptime and CPU usage charts.
• D. User authentication logs.

Answer: (A)

Troubleshooting call routing requires visibility into how a call is processed and routed across the signaling path. The most valuable evidence comes from the signaling traces inside CUCM and the gateway-side logs that show how the call is being invited, routed, and negotiated across trunks. This is where you can see digit analysis, route patterns, gateway selections, and any SIP signaling errors that prevent a call from completing as intended.

CUCM SDL/SDI traces give granular insight into the call processing decisions inside the system, showing how digits are analyzed, which route patterns are chosen, and how dialing plans are applied. SIP/call logs on gateways capture the signaling exchanged with CUCM and other peers (INVITE, 100 Trying, 180 Ringing, 200 OK, BYE, etc.), plus any gateway-specific issues like codec negotiation or trunk problems. Together, they provide an end-to-end view of how a call should route versus what actually happens, making it possible to pinpoint where a misrouting or failure occurs.

Logs like network packet captures on switches alone miss the internal call processing decisions and signaling details. System uptime and CPU usage charts reflect health, not the specifics of call routing decisions. User authentication logs don’t reveal how calls are routed or why a call might fail during setup.

So the best approach is to consult the CUCM signaling traces (SDL/SDI) along with gateway SIP/call logs to accurately troubleshoot call routing.