Troubleshooting inbound calls that fail to reach Webex Contact Center

See also

Sources

1. 1
   A valid Webex Calling subscription is required for agents who use Webex devices or the Webex App.

   Set up voice channels for Webex Contact Center · Webex Calling Configuration Checklist > Active Subscriptions · Checked 2026-09-30
2. 2
   Cloud Connected PSTN providers are provisioned to support +E.164 format numbers for both DID and toll-free numbers used with Webex Contact Center.

   Set up voice channels for Webex Contact Center · Cloud Connected PSTN number requirements · Checked 2026-09-30
3. 3
   Control Hub's Webex Calling call troubleshooting view shows calls from the past 21 days and includes PSTN legs through Cloud Connected PSTN and Local Gateway with trunk and route group details.

   Troubleshoot Webex Calling calls in Control Hub · Troubleshoot calls > search and call legs · Checked 2026-09-30
4. 4
   Access to 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 · Before you begin / required roles · Checked 2026-09-30
5. 5
   Webex Contact Center PSTN media requires G.711 u-law or A-law, and any other codec such as G.729, iLBC or Opus must be transcoded before reaching Webex Contact Center.

   Set up voice channels for Webex Contact Center · PSTN Media and Signaling Requirements > Codec · Checked 2026-09-30
6. 6
   Flow Designer's Debug flows feature shows the call control path a production interaction took and can be filtered by interaction or session ID.

   Build and manage flows with Flow Designer · Debug flows · Checked 2026-09-30
7. 7
   Dial numbers are mapped to entry points in Control Hub under Contact Center > Tenant Settings > Voice by selecting an available number or DN and the target entry point.

   Set up voice settings for Webex Contact Center · Map dial numbers to entry points (Tenant Settings > Voice) · Checked 2026-09-30
8. 8
   Webex Contact Center PSTN requirements specify RFC 2833 DTMF and a 20 ms packetization time in the SDP.

   Set up voice channels for Webex Contact Center · PSTN Media and Signaling Requirements > DTMF; Packetization Timer in SIP SDP · Checked 2026-09-30
9. 9
   Webex Contact Center PSTN signaling requirements list SIP Early Offer as not supported and SIP Delayed Offer as supported.

   Set up voice channels for Webex Contact Center · PSTN Media and Signaling Requirements > SIP Early Offer / Delay Offer · Checked 2026-09-30
10. 10
    The Set up a channel article states that Webex Contact Center supports mapping only PSTN numbers in globalized +E.164 format to entry points and that extensions are not supported for this mapping.disputed

    Set up a channel · Set up a channel > inbound telephony entry point > Support Number step · Checked 2026-09-30
11. 11
    The Webex Calling based voice channel setup article states that an inbound entry point requires a Webex Calling location and a PSTN region, and can be populated with a PSTN number, an extension number, or both.disputed

    Set up voice channels for Webex Contact Center · Configuration of Inbound Entry Points to Webex Contact Center · Checked 2026-09-30
12. 12
    Cisco's architecture article describes the phone number as the key configuration of a voice entry point, typically a valid PSTN number from the chosen PSTN provider.

    Webex Contact Center Architecture · Entry point (voice ingress) · Checked 2026-09-30
13. 13
    A July 24 2026 admin update added the ability to search and sort phone numbers associated with an entry point in Control Hub.

    What's new for administrators in Webex Contact Center · July 24 2026 entry > admin experience improvements · Checked 2026-09-30
14. 14
    Entry point configuration includes a routing flow selection and a Version Label field that chooses which version of that flow the entry point runs.

    Set up a channel · Set up a channel > Entry point settings > Routing Flow; Version Label · Checked 2026-09-30
15. 15
    When entry points use extensions Cisco says to avoid mixing prefixed and non-prefixed locations and to avoid overlapping extensions across locations because both can cause unexpected call routing.

    Set up voice channels for Webex Contact Center · Important considerations for extension numbers · Checked 2026-09-30
16. 16
    In Flow Designer a flow must be validated and its errors fixed before it can be published.

    Build and manage flows with Flow Designer · Flow Designer interface > Footer pane (validation and publish) · Checked 2026-09-30
17. 17
    Flow developers can branch flow logic on the version label in execution using the NewContact.FlowVersionLabel variable.

    Build and manage flows with Flow Designer · Create and manage flows > Apply version labels to a flow (NewContact variables) · Checked 2026-09-30
18. 18
    Voice calls are routed into Webex Contact Center using Webex Calling PSTN services and Webex edge access services, then answered by voice ingress services that run the flow assigned to the entry point.

    Webex Contact Center Architecture · Voice ingress / Calls are routed into Webex Contact Center · Checked 2026-09-30
19. 19
    Cisco warns administrators to configure only the numbers allocated to their Webex Contact Center PSTN connection because entering invalid numbers may result in call routing failures.

    Set up voice channels for Webex Contact Center · Configuration of Webex Contact Center PSTN numbers (warning note) · Checked 2026-09-30
20. 20
    A defensible isolation order for an inbound failure is: confirm the PSTN path works with a plain Webex Calling number, check trunk status for Local Gateway, confirm the DN is mapped to the intended entry point, then confirm the entry point's flow and version label and review the flow debug path.inferred

    Webex Contact Center Architecture · Voice ingress path (combined with nhy3codb checklist and nhovcy4 Debug flows) · Checked 2026-09-30
21. 21
    When a flow is published it can carry version labels such as Live, Test or Dev, and Latest is a default version label that cannot be removed from a flow version.

    Build and manage flows with Flow Designer · Create and manage flows > Apply version labels to a flow · Checked 2026-09-30
22. 22
    Premises-based PSTN DIDs or toll-free numbers configured in Control Hub for Local Gateway are saved in +E.164 format.

    Set up voice channels for Webex Contact Center · Local Gateway number requirements · Checked 2026-09-30
23. 23
    The Webex Contact Center system limits table sets a maximum of 6000 active entry points per tenant.

    System limits in Webex Contact Center · Table 1. Maximum system limits for configuration entities and attributes > Entry points > Active · Checked 2026-09-30
24. 24
    The Webex Contact Center system limits table allows at most 500 dialed numbers per entry point and 15000 dialed number to entry point mappings per tenant.

    System limits in Webex Contact Center · Table 1 > Dialed numbers > Entry Point; Per entry point · Checked 2026-09-30
25. 25
    The Webex Contact Center system limits article as fetched gives no calls-per-second or per-entry-point concurrent call capacity figure.inferred

    System limits in Webex Contact Center · Tables 1 and 3 (absence of CPS or entry point capacity rows) · Checked 2026-09-30
26. 26
    The Webex Calling location main number does not appear in the list of numbers available for dial number to entry point mapping.

    Set up voice settings for Webex Contact Center · Map dial numbers to entry points (note under Available numbers/DN) · Checked 2026-09-30
27. 27
    Cisco advises limiting the number of PSTN carriers involved in routing to no more than two before the call reaches Webex Contact Center to keep latency low.

    Set up voice channels for Webex Contact Center · PSTN Call Forwarding Scenarios and Best Practices (best practice note) · Checked 2026-09-30
28. 28
    Cisco does not support endpoint devices in the same Webex Calling location as Webex Contact Center PSTN and warns this may cause unexpected overage charges.

    Set up voice channels for Webex Contact Center · Configuration of Webex Contact Center PSTN Locations · Checked 2026-09-30
29. 29
    Webex Contact Center does not provide transcoding or media termination point services for calls using unsupported codecs.

    Set up voice channels for Webex Contact Center · PSTN Media and Signaling Requirements · Checked 2026-09-30
30. 30
    When an activity has no error path configured the flow uses the default path defined in the OnGlobalError event handler on the Event Flows tab.

    Build and manage flows with Flow Designer · Event flows > OnGlobalError · Checked 2026-09-30
31. 31
    A dial number must be mapped to an entry point to be available as the default outdial ANI, and the Default Outdial ANI field shows Not Configured when the number is not mapped.

    Set up voice settings for Webex Contact Center · Call Settings > Default Outdial ANI · Checked 2026-09-30
32. 32
    Webex Contact Center voice supports four PSTN options: Webex Contact Center PSTN, Webex Calling Cloud Connected PSTN, Cisco Calling Plan, and Webex Calling Local Gateway.

    Set up voice channels for Webex Contact Center · PSTN connectivity options · Checked 2026-09-30
33. 33
    Introducing a second upstream PSTN carrier that forwards calls to an intermediary carrier before Webex Contact Center is not a supported configuration for Cloud Connected PSTN, Local Gateway or Webex Contact Center PSTN.

    Set up voice channels for Webex Contact Center · PSTN Call Forwarding Scenarios and Best Practices · Checked 2026-09-30
34. 34
    Cisco's Webex Calling configuration checklist for Webex Contact Center says to confirm under Contact Center > Settings > Service Details that the voice media platform is Real Time Media Service and telephony is Webex Calling.

    Set up voice channels for Webex Contact Center · Webex Calling Configuration Checklist > Service Details · Checked 2026-09-30
35. 35
    No retrieved Cisco source states what a caller hears (fast busy, reorder, announcement or silence) when a dialed number is not mapped to an entry point or the flow errors, so symptom-to-cause mapping by audible tone cannot be sourced.inferred

    Set up voice settings for Webex Contact Center · Map dial numbers to entry points (no caller-experience statement) · Checked 2026-09-30
36. 36
    Cisco TAC asks for the ANI or Contact Session ID of the failed call, exact timestamps, agent information and full error screenshots when troubleshooting Webex Contact Center calls.

    Data Requirements to Troubleshoot Webex Contact Center Calls · Call-specific data · Checked 2026-09-30
37. 37
    For inbound failures the TAC data note asks whether the agent phone rings or the agent gets an error on Agent Desktop, and whether the problem is limited to specific sites or newly added extensions.

    Data Requirements to Troubleshoot Webex Contact Center Calls · Call-specific data > Inbound call failures · Checked 2026-09-30
38. 38
    Cisco says to make successful inbound and outbound calls over the chosen Webex Calling PSTN option before completing the remaining Webex Contact Center deployment tasks.

    Set up voice channels for Webex Contact Center · Webex Calling Configuration Checklist (pre-deployment note) · Checked 2026-09-30
39. 39
    For Cisco-provided Webex Contact Center PSTN, mapping toll-free numbers requires the Bundle 2 inbound toll-free number access add-on; without it toll numbers must be used.

    Set up voice settings for Webex Contact Center · Map dial numbers to entry points (entitlement note) · Checked 2026-09-30
40. 40
    Control Hub shows a Local Gateway trunk as Online, Offline, Impaired (at least one Webex Calling Edge proxy cannot connect) or Unknown (connection in progress for a new gateway).

    Configure trunks, route groups, and dial plans for Webex Calling · Trunk status · Checked 2026-09-30
41. 41
    Local Gateway trunk status in Control Hub updates every 3 minutes.

    Configure trunks, route groups, and dial plans for Webex Calling · Trunk status · Checked 2026-09-30
42. 42
    If an entry point points at a version label other than the one the administrator recently published, callers will run the older flow version, so a republished fix may appear not to take effect.inferred

    Set up a channel · Set up a channel > Entry point settings > Version Label · Checked 2026-09-30
43. 43
    Cisco's technote on incoming call problems for Webex Calling users covers user-level settings such as number assignment, forwarding, DND and incoming permissions and does not cover Contact Center, Local Gateway trunk status or SIP response codes.

    Troubleshoot Incoming Call Problems for Webex Calling Users · Troubleshoot sections (whole document) · Checked 2026-09-30
44. 44
    Webex Contact Center PSTN is available in the contiguous United States and Canada only.

    Set up voice channels for Webex Contact Center · PSTN connectivity options > Webex Contact Center PSTN · Checked 2026-09-30

Documents

Cite this page

WarmTransfer. (2026, September 30). Troubleshooting inbound calls that fail to reach Webex Contact Center. WarmTransfer. https://warmtransfer.net/knowledge/wxcc-inbound-call-failures

@misc{warmtransfer-wxcc-inbound-call-failures,
  title  = {Troubleshooting inbound calls that fail to reach Webex Contact Center},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/wxcc-inbound-call-failures},
  note   = {Verified 2026-09-30}
}