Troubleshooting Webex Contact Center calls that drop after the agent answers

See also

Sources

1. 1
   Webex Contact Center agents can receive calls on a Webex Calling device (Extension), in the browser (Desktop or WebRTC), on a PSTN or premises PBX number (Dial Number), or in Microsoft Teams through a Local Gateway.

   Set up voice channels for Webex Contact Center · Agent telephony options · Checked 2026-10-02
2. 2
   The Analyzer Termination Reason field (used in the Dropped call summaries report) takes the values Agent Left, Customer Busy, Customer Left, Customer Unavailable, Not Found and Participant Invite Timer Expired.

   Cisco Webex Contact Center Analyzer User Guide · Stock Reports > Historical Reports > Agent Reports > Dropped call summaries; field Termination Reason · Checked 2026-10-02
3. 3
   In Webex Contact Center Analyzer, the Termination Type field is a text string that specifies how a call was terminated.

   Cisco Webex Contact Center Analyzer User Guide · Field definitions: Termination Type · Checked 2026-10-02
4. 4
   For a Desktop (WebRTC) agent, a drop at or just after answer can come from the browser side (WebRTC session loss or desktop connectivity loss) and not only from the PSTN trunk, so both the webrtc-internals data and the trunk-side signalling need checking.inferred

   Manage your calls in Agent Desktop · Desktop mode (WebRTC) · Checked 2026-10-02
5. 5
   Control Hub Webex Calling call troubleshooting reports call outcome reasons grouped as Success (for example Normal, UserBusy, NoAnswer), Refusal (for example CallRejected, UnassignedNumber) and Failure (for example DestinationOutOfOrder, NoRouteToDestination, Internal).

   Troubleshoot Webex Calling calls in Control Hub · Call outcome reasons table · Checked 2026-10-02
6. 6
   Control Hub call troubleshooting for Webex Calling shows calls from the past 21 days and lets you search by email, phone number, MAC address, Call ID or Correlation ID.

   Troubleshoot Webex Calling calls in Control Hub · Troubleshoot Webex Calling calls: search and time range · Checked 2026-10-02
7. 7
   Opening the Control Hub Webex Calling troubleshooting view requires the full admin, read-only admin or support admin role.

   Troubleshoot Webex Calling calls in Control Hub · Prerequisites / required roles · Checked 2026-10-02
8. 8
   The Control Hub call troubleshooting article covers Webex Calling calls and does not mention Webex Contact Center, so it should not be assumed to show the contact-center leg of a call; at most it may show the Webex Calling legs (for example an Extension agent's device).inferred

   Troubleshoot Webex Calling calls in Control Hub · Article scope (whole article) · Checked 2026-10-02
9. 9
   If a consulted agent does not answer the consult call, or the consulted agent's device is malfunctioning, the system changes the consulted agent's state to Idle.

   Manage your calls in Agent Desktop · Consult a call: consulted agent does not answer · Checked 2026-10-02
10. 10
    By default the customer is put on hold when the primary agent starts a consult, unless other participants are already in a conference.

    Manage your calls in Agent Desktop · Consult a call · Checked 2026-10-02
11. 11
    Cisco's CUBE session timer documentation states that if a refreshing re-INVITE gets no response before the session expires, the user agent sends a BYE to end the call before expiry.

    Cisco Unified Border Element Configuration Guide (IOS XE) - SIP Session Timer Support · SIP Session Timer Support: information about session timers · Checked 2026-10-02
12. 12
    On Cisco Unified Border Element (IOS XE 17.6 onwards), the min-se value defaults to 1800 seconds and can be set from 90 to 86400 seconds.

    Cisco Unified Border Element Configuration Guide (IOS XE) - SIP Session Timer Support · SIP Session Timer Support: Min-SE configuration · Checked 2026-10-02
13. 13
    The IOS timer receive-rtcp media inactivity timer accepts 0 to 1000 multiples of the RTCP report interval and defaults to 0 (disabled).

    Cisco IOS Voice Command Reference - T through Z - timeouts call-disconnect through timing clear-wait · timer receive-rtcp: Syntax Description and Command Default · Checked 2026-10-02
14. 14
    With the IOS timer receive-rtcp command, the gateway multiplies the configured value by the RTCP report interval, and if no RTP or RTCP packets arrive in that time it disconnects the call, sending a SIP BYE toward the VoIP side.

    Cisco IOS Voice Command Reference - T through Z - timeouts call-disconnect through timing clear-wait · timer receive-rtcp: Usage Guidelines · Checked 2026-10-02
15. 15
    The CUBE command show sip-ua min-se displays the current Min-SE value.

    Cisco Unified Border Element Configuration Guide (IOS XE) - SIP Session Timer Support · SIP Session Timer Support: verification · Checked 2026-10-02
16. 16
    If the customer leaves during an active consult or conference, the call enters a Post Call state: remaining participants can keep talking but no new participants can be added, and the agent is notified that the customer left.

    Manage your calls in Agent Desktop · Consult and conference: customer leaves · Checked 2026-10-02
17. 17
    The Agent Desktop error report (Download Error Report) can be downloaded whether the desktop is connected or disconnected.

    Troublshoot Agent Desktop Disconnect Issues · Troubleshoot: logs to collect, Error Report · Checked 2026-10-02
18. 18
    Agent Desktop sends keepalive messages to the Webex Contact Center backend every 4 seconds, and the backend notification service sends keepalives back in parallel.

    Troublshoot Agent Desktop Disconnect Issues · Background information: keepalive mechanism · Checked 2026-10-02
19. 19
    In Desktop mode, Agent Desktop uses WebRTC to terminate both the call and its media directly in the browser.

    Manage your calls in Agent Desktop · Desktop mode (WebRTC) · Checked 2026-10-02
20. 20
    If no messages complete for 16 seconds from either Agent Desktop or the notification service, Agent Desktop starts its connection recovery process.

    Troublshoot Agent Desktop Disconnect Issues · Background information: recovery trigger · Checked 2026-10-02
21. 21
    During recovery, Agent Desktop tries to reconnect for the interval set by the tenant's Desktop Lost Connection Recovery Timeout.

    Troublshoot Agent Desktop Disconnect Issues · Background information: connection recovery · Checked 2026-10-02
22. 22
    To inspect desktop connectivity, Cisco says to use the browser developer tools Network tab filtered to WebSocket (WS) traffic to the api.wxcc-<datacenter>.cisco.com domain, and to capture keepalive traffic with Wireshark or similar if needed.

    Troublshoot Agent Desktop Disconnect Issues · Troubleshoot: browser logs and network capture · Checked 2026-10-02
23. 23
    Analyzer provides a stock report named Dropped call summaries under Stock Reports > Historical Reports > Agent Reports.

    Cisco Webex Contact Center Analyzer User Guide · Stock Reports > Historical Reports > Agent Reports > Dropped call summaries · Checked 2026-10-02
24. 24
    In Agent Desktop the agent cannot end a call while it is on hold; the End button is disabled during hold.

    Manage your calls in Agent Desktop · Put a call on hold · Checked 2026-10-02
25. 25
    The Agent Desktop End Call voice feature, which adds an End button for terminating active voice calls, is disabled by default in Desktop tenant settings.

    Desktop settings for Webex Contact Center · Tenant Settings > Desktop > Voice Features: End Call · Checked 2026-10-02
26. 26
    The Agent Desktop End Consult voice feature, which lets agents end consult calls during an active customer interaction, is enabled by default.

    Desktop settings for Webex Contact Center · Tenant Settings > Desktop > Voice Features: End Consult · Checked 2026-10-02
27. 27
    A call that consistently drops at a fixed duration, such as just under the session interval or at half of it, points to a session-timer refresh (re-INVITE or UPDATE) that is not sent, not delivered or not answered on some leg, rather than to an agent or desktop action.inferred

    RFC 4028: Session Timers in the Session Initiation Protocol (SIP) · Section 10 (Performing refreshes) · Checked 2026-10-02
28. 28
    Cisco's Local Gateway configuration for a Webex Calling registration-based trunk includes no session refresh in the tenant configuration, which disables SIP session refresh for calls between CUBE and Webex.

    Configure Local Gateway on Cisco IOS XE for Webex Calling · Configure Webex Calling registration-based trunk: voice class tenant · Checked 2026-10-02
29. 29
    The Lost Connection Recovery Timeout is set in Control Hub under Services > Contact Center > Tenant Settings > Desktop, in the System Settings section.

    Desktop settings for Webex Contact Center · Tenant Settings > Desktop > System Settings · Checked 2026-10-02
30. 30
    The Webex Contact Center Lost Connection Recovery Timeout defaults to 120 seconds and accepts 120 to 600 seconds.

    Desktop settings for Webex Contact Center · Tenant Settings > Desktop > System Settings: Lost Connection Recovery Timeout · Checked 2026-10-02
31. 31
    If an agent's network outage lasts longer than the Lost Connection Recovery Timeout, the agent is signed out of Agent Desktop.

    Desktop settings for Webex Contact Center · Tenant Settings > Desktop > System Settings: Lost Connection Recovery Timeout · Checked 2026-10-02
32. 32
    Webex Contact Center requires any codec other than G.711 (for example G.729, iLBC or Opus) to be transcoded before it reaches the Webex Contact Center media edge.

    Set up voice channels for Webex Contact Center · SIP and media requirements: codec · Checked 2026-10-02
33. 33
    On a Local Gateway with media inactivity detection enabled, a call that sends no RTP or RTCP for long enough, as can happen during some hold or consult states, may be released by the gateway; hold-time drops on BYO PSTN should be checked against that timer.inferred

    Cisco IOS Voice Command Reference - T through Z - timeouts call-disconnect through timing clear-wait · timer receive-rtcp: Usage Guidelines · Checked 2026-10-02
34. 34
    Webex Contact Center voice can reach the PSTN through Webex Contact Center PSTN (contiguous US and Canada only), Cloud Connected PSTN through certified providers, Cisco Calling Plan, or a premises Webex Calling Local Gateway.

    Set up voice channels for Webex Contact Center · PSTN connectivity options · Checked 2026-10-02
35. 35
    Under RFC 4028, a 422 (Session Interval Too Small) response must carry a Min-SE header with the minimum timer the server will accept.

    RFC 4028: Session Timers in the Session Initiation Protocol (SIP) · Section 6 (422 response code definition) · Checked 2026-10-02
36. 36
    Under RFC 4028, if no session refresh arrives before the session expires, the side that is not the refresher should send a BYE slightly before expiry, recommended at the lesser of 32 seconds and one third of the session interval before it.

    RFC 4028: Session Timers in the Session Initiation Protocol (SIP) · Section 10 (Performing refreshes), session expiration paragraph · Checked 2026-10-02
37. 37
    Under RFC 4028, the Min-SE value must not be less than 90 seconds and defaults to 90 seconds when the header is absent.

    RFC 4028: Session Timers in the Session Initiation Protocol (SIP) · Section 5 (Min-SE header field definition) · Checked 2026-10-02
38. 38
    RFC 4028 recommends a session interval (Session-Expires) of 1800 seconds.

    RFC 4028: Session Timers in the Session Initiation Protocol (SIP) · Section 4 (Session-Expires header field definition) · Checked 2026-10-02
39. 39
    RFC 4028 recommends sending the session refresh once half the session interval has elapsed.

    RFC 4028: Session Timers in the Session Initiation Protocol (SIP) · Section 10 (Performing refreshes) · Checked 2026-10-02
40. 40
    The RFC 4028 refresher parameter of Session-Expires, set to uac or uas, names which side of the dialog performs the session refreshes.

    RFC 4028: Session Timers in the Session Initiation Protocol (SIP) · Section 4 (refresher parameter) · Checked 2026-10-02
41. 41
    When an agent does not respond to an offered contact within the RONA time, the contact returns to the queue and the agent's state for that channel changes from Available to Idle.

    Understand agent states · RONA (Ring No Answer) Behavior Optimization · Checked 2026-10-02
42. 42
    The Webex Contact Center telephony RONA timeout defaults to 18 seconds and is configurable from 1 to 120 seconds.

    Desktop settings for Webex Contact Center · Tenant Settings > Desktop > RONA Timeouts: Telephony · Checked 2026-10-02
43. 43
    The Webex Contact Center Short Call Threshold, set under Tenant Settings > Voice, determines whether a call is classed as short or abandoned and defaults to 0 seconds.

    Set up voice settings for Webex Contact Center · Tenant Settings > Voice: Short Call Threshold · Checked 2026-10-02
44. 44
    In the Analyzer Agent Details, Agent Trace and Agent Details by Social Channels stock reports, the Sudden Disconnected Count field is documented as currently not used and not populated.

    Webex Contact Center Analyzer Stock Reports · Agent Details report; Agent Trace report; Agent Details by Social Channels report: Sudden Disconnected Count note · Checked 2026-10-02
45. 45
    An empty or zero Sudden Disconnected Count in the agent-level Analyzer reports should not be read as evidence that no calls dropped at answer, because Cisco documents that field as unpopulated in those reports; termination fields are the better evidence.inferred

    Webex Contact Center Analyzer Stock Reports · Agent Details report and Agent Trace report: Sudden Disconnected Count note · Checked 2026-10-02
46. 46
    The Webex Contact Center Sudden Disconnect Threshold is a time interval in seconds that decides whether a call that ends soon after reaching a destination counts as handled by the agent or as a sudden disconnect; its default for a new tenant is 30 seconds.

    Set up voice settings for Webex Contact Center · Tenant Settings > Voice: Sudden Disconnect Threshold · Checked 2026-10-02
47. 47
    The Sudden Disconnect Threshold is set in Control Hub under Services > Contact Center > Tenant Settings > Voice.

    Set up voice settings for Webex Contact Center · Tenant Settings > Voice: Sudden Disconnect Threshold · Checked 2026-10-02
48. 48
    Analyzer defines Sudden Disconnect as calls that were answered (connected to an agent or accepted by a destination site) but then disconnected within the Sudden Disconnect threshold provisioned for the enterprise.

    Cisco Webex Contact Center Analyzer User Guide · Agent Details report field definitions: Sudden Disconnect · Checked 2026-10-02
49. 49
    When opening a TAC case for Agent Desktop problems, Cisco asks for the Customer Org ID, shown at the bottom of the Control Hub page, plus details of the environment (VDI, work from home, VPN) and of recent configuration changes.

    Troubleshoot Webex Contact Center Agent Desktop · Information to collect before contacting TAC · Checked 2026-10-02
50. 50
    For a troubled Webex Contact Center call, Cisco TAC asks for the ANI or Contact Session ID, the exact timestamp of the failure, the agent information and a screenshot of any error.

    Data Requirements to Troubleshoot Webex Contact Center Calls · Data to collect for inbound and outbound call failures · Checked 2026-10-02
51. 51
    Cisco documents that CUCM-registered video devices disconnect exactly 15 minutes into a Webex meeting when the session refresh due at half of the 1800-second SIP Session Expires Timer is not received by the far side, which it attributes to network devices in between.

    Video Calls to Webex Meeting Disconnect after 15 Minutes · Problem; Cause · Checked 2026-10-02
52. 52
    The Webex Contact Center voice channel requirements list SIP Early Offer as not supported and SIP Delayed Offer as supported.

    Set up voice channels for Webex Contact Center · SIP and media requirements table · Checked 2026-10-02
53. 53
    Webex Contact Center Desktop WebRTC calling supports Google Chrome 144 or later, Microsoft Edge 144 or later and Mozilla Firefox 140 or later.

    System requirements for Webex Contact Center Desktop · Supported browsers for WebRTC · Checked 2026-10-02
54. 54
    For WebRTC calls in Agent Desktop, Cisco describes opening chrome://webrtc-internals in a new tab during the active call, selecting the session for the desktop.wxcc domain, and using Create a WebRTC-Internals dump to download the statistics.

    Exploring WebRTC Data and Statistics in WxCC Agent Desktop · Accessing WebRTC statistics; Log collection · Checked 2026-10-02
55. 55
    If WebRTC disconnects after an agent signs in, Agent Desktop moves the voice channel to Idle and disables the Available options for voice until WebRTC reconnects, so voice calls that cannot connect are not routed.

    Understand agent states · WebRTC and Browser-Based Desktop · Checked 2026-10-02
56. 56
    Agent Desktop is supported in VDI environments, but WebRTC (Desktop) calling is not.

    System requirements for Webex Contact Center Desktop · VDI support · Checked 2026-10-02
57. 57
    The WebRTC tenant voice setting lets agents and supervisors make and receive calls in the browser, and it is enabled by default for new tenants.

    Set up voice settings for Webex Contact Center · Tenant Settings > Voice: WebRTC · Checked 2026-10-02

Documents

Cite this page

WarmTransfer. (2026, October 2). Troubleshooting Webex Contact Center calls that drop after the agent answers. WarmTransfer. https://warmtransfer.net/knowledge/wxcc-call-drop-troubleshooting

@misc{warmtransfer-wxcc-call-drop-troubleshooting,
  title  = {Troubleshooting Webex Contact Center calls that drop after the agent answers},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/wxcc-call-drop-troubleshooting},
  note   = {Verified 2026-10-02}
}