I can’t connect to Zoom meeting on h323/sip, what are the troubleshooting steps?

  1. Was there a recent change (to network, firewall, codec, CUCM, VCS, etc) made prior to incident?
  2. Is it an audio only h323/sip call? This will not connect because the Zoom Room Connectors expect a video channel and will hang up call if video channel is not available (in SDP).
  3. Is your CUCM configured correctly for Zoom? Is “Early Offer” enabled on SIP trunk and SIP device profile?
  4. Is your firewall blocking h323/sip signal and media?
  5. Can you make non Zoom H323/SIP calls to internal and external endpoints?
  6. Have you checked the logs on the video endpoint, VCS, CUCM, etc?
  7. Is the problem happening on all devices or specific endpoints? What are the affected endpoints?
  8. Contact with the following information
    1. What is the description of the problem? Is it no video only or no audio only or video stops, etc?
    2. What are the troubleshooting steps already completed from the above list?
    3. Is it a H323 or SIP (TLS) call?
    4. What is the called address or string?
    5. What is the calling endpoint? Is it a codec or VCS or CUCM or something else?
    6. What is the source IP address sending calls to Zoom, e.g. VCS-E external interface?
    7. Is the issue reproducible? If yes, what are the steps to reproduce?
    8. When did the issue start and disappear?
    9. Is it an on-going issue (which may need urgent support)?