# Troubleshooting Webex Contact Center agents on a Webex Calling extension

Canonical: https://warmtransfer.net/knowledge/wxcc-webex-calling-station-troubleshooting

Last verified: 2026-10-02

At Agent Desktop sign-in, a Webex Contact Center agent chooses 1 of 3 calling preferences: Desktop (browser WebRTC), Extension, or Dial Number, and the Extension option is for Webex Calling users[^28][^20]. Sign-in checks that the selected extension or dial number is valid and assigned to the agent's Webex Calling profile, but it does not confirm that the agent's device is online[^43][^34].

## How extension sign-in works

When an agent has a single configured extension, the Extension option fills it in automatically, and when the agent has multiple extensions, they appear in a drop-down of pre-validated extensions[^20]. The Dial Number option accepts international numbers entered in the format + [Country Code] [Phone Number][^13]. If an agent's saved Dial Number or Extension is invalid, sign-in returns the agent to the interaction preferences screen, with the saved preferences already filled in, so the details can be corrected[^27]. Since the simplified sign-in released on 2025-10-29, Webex Contact Center validates that the extension or dial number is valid and assigned to the agent's Webex Calling profile[^43]. That validation does not confirm that the device is online, so the agent is responsible for making sure the extension or dial number is on an active and available device[^34].

Agents who use Webex devices or Webex App as their Contact Center voice endpoint need a valid Webex Calling subscription[^8]. Agent Desktop cannot be used in multiple browsers or in multiple tabs of the same browser at once; the agent is asked to choose which instance continues[^44].

## Answering Webex Calling calls from Agent Desktop

From the 2025-10-29 release, an agent can answer Webex Calling calls on their device from Agent Desktop by turning on Manage Webex Calling Calls and selecting a preferred device[^29]. This feature has the following prerequisites and limits:[^6][^56][^5]

- It requires Webex App 44.12 or later[^6].
- Webex Calling must be enabled in Control Hub[^56].
- It is available only to users signed in with the Agent role, and a Supervisor plus Agent user cannot answer calls while monitoring or barging[^5].

An agent with only 1 Webex Calling device does not need to set a preferred device[^35]. When an agent changes extension, the preferred-device list refreshes, and if no devices are available, the preferred-device selection is disabled[^21].

Turning on Manage Webex Calling calls adds a way to answer through Contact Center notifications[^46]. It does not stop the call from ringing in the primary Webex App or on linked devices[^46]. We infer that a desk phone and Webex App both ringing for a Contact Center call is expected behaviour for an agent with several Webex Calling devices, not a fault in itself[^32]. A 2025-03-04 release combined the Webex Calling notification and the Agent Desktop popover, so an agent who turns on Hide Webex Calling Notifications answers from the desktop without overlapping windows[^23].

## Embedded Webex App and presence sync

The Webex App embedded in Agent Desktop does not handle external calls, so the agent still needs the external, non-embedded Webex App to make and receive them[^19]. An agent running both the embedded Webex App and the standalone Webex App receives notifications in both[^17]. While Do Not Disturb is active in the embedded Webex App, voice calls and conversation notifications are not displayed[^18].

Presence sync between Webex App and Webex Contact Center agent state can take up to 2 seconds to take effect[^37]. Known presence-sync problems occur in these situations:[^48]

- simultaneous calls that use hold and resume[^48]
- direct calls received during wrap-up[^48]
- ACD calls answered in Webex App during wrap-up[^48]

Webex App state sync with Agent Desktop does not work with Webex Calling Dedicated Instance or with the Extensible Supervisor Desktop[^49].

## Diagnosing failed call delivery

Each system-assigned agent state points to a different delivery failure[^4][^2][^12][^42].

| State | What it indicates |
|---|---|
| Agent_Unavailable | The device for the agent's dial number was offline or unreachable when the call was delivered[^4] |
| Agent_Busy | The agent's device was busy, which prevented call delivery[^2] |
| Channel_Failure | A temporary problem, such as a network failure or unknown error, prevented call delivery[^12] |
| RONA | The agent did not respond when the call was delivered, so the offer timed out[^42] |

In a RONA after ring event, the call reaches the agent endpoint and the endpoint returns SIP 180 Ringing, but no 200 OK (answer) arrives before the RONA timeout, which defaults to 18 seconds[^39]. An immediate RONA happens when the system detects a problem while presenting the call to the agent endpoint; the agent goes straight to RONA without the usual missed-call popup[^24]. If a PSTN dial number is entered without the International Dialing Format box checked, it is treated as non-E.164 and the system fails to ring it, which causes an instant RONA[^26].

We infer that, because sign-in does not check device status, an agent who signs in successfully and then hits Agent_Unavailable or an immediate RONA most likely has an offline or unregistered Webex Calling device[^36]. When the WebRTC connection of a Desktop-option agent disconnects, the system disables Set as Available (all channels) to stop voice calls routing to that agent[^50].

## Checking the Webex Calling side of the extension

For incoming-call problems, Cisco's Webex Calling technote first checks that the device shows as registered in Control Hub Devices, or that Webex App shows Phone Services as connected[^38]. The same checklist then includes these steps:[^57][^54][^7][^45][^55]

- Confirm that call forwarding is turned off in the user's Calling settings in Control Hub[^57].
- Uncheck All calls to voicemail and review the ring count before voicemail answers[^54].
- Verify that Call Intercept is off in the user's advanced call settings[^7].
- Disable Single Number Reach (Office Anywhere) in the user portal's incoming call settings[^45].
- Confirm that Do Not Disturb is disabled in the user portal's incoming call settings[^55].

Cisco does not recommend enabling voicemail on an agent line, because a customer call forwarded to voicemail can look to the contact center like a correctly answered call[^33]. For Webex Calling users, DND set on Webex App syncs automatically to the desk phone, and DND set on the desk phone syncs to Webex App[^16]. With Webex Calling DND on, the user gets no notification of incoming calls, and if voicemail is not configured, the caller hears busy[^14].

## Using the Control Hub call troubleshooting view

The Control Hub Webex Calling troubleshooting view searches successful, failed, and refused calls from the past 21 days, with hop-by-hop media statistics[^9]. Only Control Hub full, read-only, or support administrators can open this view[^10]. WarmTransfer's reading of the sources is that the article for this view does not say whether the agent leg of a Webex Contact Center call appears in it, so its use for Contact Center no-audio cases is unconfirmed[^11].

## Collecting evidence for support

For a RONA case, Cisco asks for the following[^47]:

- the ANI or session ID[^47]
- the exact failure timestamp[^47]
- agent details[^47]
- any error screenshot[^47]
- the Agent Desktop error report (Ctrl+Shift+2)[^47]

## See also

- [Troubleshooting Webex Contact Center Agent Desktop sign-in and station login](https://warmtransfer.net/knowledge/wxcc-agent-login-troubleshooting)
- [Troubleshooting Webex Contact Center agents stuck in wrap-up or RONA or unable to go available](https://warmtransfer.net/knowledge/wxcc-agent-state-troubleshooting)
- [Webex Contact Center RONA and agent state handling](https://warmtransfer.net/knowledge/webex-cc-rona-agent-state)
- [Troubleshooting inbound calls to Webex Calling numbers](https://warmtransfer.net/knowledge/webex-calling-inbound-call-failures)
- [Troubleshooting agent audio on the Webex Contact Center desktop](https://warmtransfer.net/knowledge/wxcc-desktop-audio-troubleshooting)
- [Webex Contact Center voice channel and PSTN options](https://warmtransfer.net/knowledge/webex-cc-voice-channels)
- [Webex Contact Center Agent Desktop and widgets](https://warmtransfer.net/knowledge/webex-cc-agent-desktop)

## Applicability

Applies to: Cisco Webex Contact Center and Cisco Webex Calling. Deployments: multi-tenant. Sources checked 2026-10-02. The simplified sign-in validation and Manage Webex Calling Calls apply from the 2025-10-29 release onward[^43][^29]. The Hide Webex Calling Notifications behaviour applies from the 2025-03-04 release onward[^23]. Answering through Agent Desktop notifications requires Webex App 44.12 or later[^6]. The WebRTC Desktop voice option is unavailable for Webex Contact Center tenants hosted in the Japan data center[^52]. Webex App state sync does not apply to Webex Calling Dedicated Instance[^49]. Agent Desktop does not currently support headset control actions for WebRTC (Desktop option) calls[^51].

## What remains uncertain

How Webex Calling call forwarding treats calls that Webex Contact Center routes to an agent is not covered by the sources below. The incoming-call checklist only says to confirm that forwarding is off[^57]. The media path between Webex Contact Center and Webex Calling, which matters when there is no audio after answer, is not covered by the sources below. WarmTransfer's reading of the sources is that it is unconfirmed whether the Control Hub troubleshooting view shows the agent leg[^11]. The effect of Single Number Reach and other ring-multiple-destinations features on Contact Center agent calls is not covered by the sources below. The checklist only says to disable Single Number Reach[^45]. The scope of any statement that call forwarding does not work for agents is not covered by the sources below. We infer that an agent on a Webex Calling extension who joins a Webex Meeting while Available may have Contact Center calls fail as busy or RONA because of implicit DND; this should be verified[^31]. Whether the menu paths in the Webex Calling incoming-call checklist still match current Control Hub and user portal menus is not covered by the sources below. Per-channel RONA timer limits are not covered by the sources below. The RONA timeout defaults to 18 seconds[^39]. Which reporting view exposes call-event errors for the connection to the agent is not covered by the sources below.

## Sources

[^1]: When a desktop profile restricts Agent DN validation to provisioned or dial-plan rules, an ad hoc DN that does not meet the sign-in syntax rules causes the agent sign-in to be rejected. Source: [Manage desktop profiles](https://help.webex.com/en-us/article/nvaf71f/Manage-desktop-profiles), Manage desktop profiles > Voice Channel Options > Agent DN Validation. Checked 2026-10-02.
[^2]: The Agent_Busy state indicates the agent's device was busy, which prevented call delivery. Source: [Understand agent states](https://help.webex.com/en-us/article/nvg4gu6/Understand-agent-states), Understand agent states > RONA behaviour optimization (system-assigned states). Checked 2026-10-02.
[^3]: Cisco guidance places agents' Webex Calling devices in dedicated Control Hub locations representing how agents connect into the Webex media cloud, and allows multiple agent locations. Source: [Set up voice channels for Webex Contact Center](https://help.webex.com/en-us/article/2dputx/Set-up-voice-channel-for-Webex-Contact-Center), Set up voice channels for Webex Contact Center > Webex Calling agent locations. Checked 2026-10-02.
[^4]: The Agent_Unavailable state indicates the device associated with the agent's dial number was offline or unreachable when the call was delivered. Source: [Understand agent states](https://help.webex.com/en-us/article/nvg4gu6/Understand-agent-states), Understand agent states > RONA behaviour optimization (system-assigned states). Checked 2026-10-02.
[^5]: The desktop call-answer feature is available only to users signed in with the Agent role; a Supervisor plus Agent user cannot answer calls while monitoring or barging. Source: [Optimize Webex Contact Center Desktop call notifications](https://help.webex.com/en-us/article/u5dbtfb), Optimize Webex Contact Center Desktop call notifications > prerequisites and limitations. Checked 2026-10-02.
[^6]: Answering Webex Calling calls through Agent Desktop notifications requires Webex App 44.12 or later. Source: [Optimize Webex Contact Center Desktop call notifications](https://help.webex.com/en-us/article/u5dbtfb), Optimize Webex Contact Center Desktop call notifications > prerequisites. Checked 2026-10-02.
[^7]: The Webex Calling incoming-call checklist includes verifying Call Intercept is off in the user's advanced call settings. Source: [Troubleshoot Incoming Call Problems for Webex Calling Users](https://www.cisco.com/c/en/us/support/docs/unified-communications/webex-calling/218153-troubleshoot-incoming-call-problems-for.html), Troubleshoot Incoming Call Problems > Call Intercept. Checked 2026-10-02.
[^8]: Agents who use Webex devices or Webex App as their Contact Center voice endpoint need a valid Webex Calling subscription. Source: [Set up voice channels for Webex Contact Center](https://help.webex.com/en-us/article/2dputx/Set-up-voice-channel-for-Webex-Contact-Center), Set up voice channels for Webex Contact Center > Webex Calling agent endpoints. Checked 2026-10-02.
[^9]: The Control Hub Webex Calling troubleshooting view searches successful, failed and refused calls with hop-by-hop media statistics for the past 21 days. Source: [Troubleshoot Webex Calling calls in Control Hub](https://help.webex.com/en-us/article/frj1efb/Troubleshoot-Webex-Calling-Media-Quality-in-Control-Hub), Troubleshoot Webex Calling calls in Control Hub > Overview and Search View. Checked 2026-10-02.
[^10]: Only Control Hub full, read-only or support administrators can open the Webex Calling call troubleshooting view. Source: [Troubleshoot Webex Calling calls in Control Hub](https://help.webex.com/en-us/article/frj1efb/Troubleshoot-Webex-Calling-Media-Quality-in-Control-Hub), Troubleshoot Webex Calling calls in Control Hub > access requirements. Checked 2026-10-02.
[^11]: The Control Hub Webex Calling troubleshooting article does not say whether the agent leg of a Webex Contact Center call appears in that view, so its use for WxCC no-audio cases is unconfirmed (inferred). Source: [Troubleshoot Webex Calling calls in Control Hub](https://help.webex.com/en-us/article/frj1efb/Troubleshoot-Webex-Calling-Media-Quality-in-Control-Hub), Troubleshoot Webex Calling calls in Control Hub > whole article (absence of contact center coverage). Checked 2026-10-02.
[^12]: The Channel_Failure state indicates a temporary problem such as a network failure or unknown error prevented call delivery to the agent. Source: [Understand agent states](https://help.webex.com/en-us/article/nvg4gu6/Understand-agent-states), Understand agent states > RONA behaviour optimization (system-assigned states). Checked 2026-10-02.
[^13]: The Dial Number option supports international numbers entered with a country code in the format + [Country Code] [Phone Number]. Source: [Sign in to Agent Desktop](https://help.webex.com/en-us/article/n6lmci8/Sign-in-to-Agent-Desktop), Sign in to Agent Desktop > Dial Number option. Checked 2026-10-02.
[^14]: With Webex Calling DND on, the user gets no notification of incoming calls, and if voicemail is not configured the caller hears busy. Source: [Do not disturb sync between Webex App and desk phone](https://help.webex.com/en-us/article/d307vb/Do-Not-Disturb-Sync-(DND)-between-Webex-App-and-desk-phone), Do not disturb sync between Webex App and desk phone > overview. Checked 2026-10-02.
[^15]: Webex Calling DND is turned on implicitly while the user is in a Webex Meeting. Source: [Do not disturb sync between Webex App and desk phone](https://help.webex.com/en-us/article/d307vb/Do-Not-Disturb-Sync-(DND)-between-Webex-App-and-desk-phone), Do not disturb sync between Webex App and desk phone > overview. Checked 2026-10-02.
[^16]: For Webex Calling users, Do Not Disturb set on Webex App syncs automatically to the desk phone and DND set on the desk phone syncs to Webex App. Source: [Do not disturb sync between Webex App and desk phone](https://help.webex.com/en-us/article/d307vb/Do-Not-Disturb-Sync-(DND)-between-Webex-App-and-desk-phone), Do not disturb sync between Webex App and desk phone > overview. Checked 2026-10-02.
[^17]: An agent running both the embedded Webex App in Agent Desktop and the standalone Webex App receives notifications in both applications. Source: [Use Webex App in Webex Contact Center Desktop](https://help.webex.com/en-us/article/n444dol/Use-Webex-App-in-Webex-Contact-Center-Desktop), Use Webex App in Webex Contact Center Desktop > limitations. Checked 2026-10-02.
[^18]: With Do Not Disturb active in the embedded Webex App, voice calls and conversation notifications are not displayed. Source: [Use Webex App in Webex Contact Center Desktop](https://help.webex.com/en-us/article/n444dol/Use-Webex-App-in-Webex-Contact-Center-Desktop), Use Webex App in Webex Contact Center Desktop > limitations (Do Not Disturb). Checked 2026-10-02.
[^19]: The Webex App embedded in Agent Desktop does not handle external calls; the agent still needs the external, non-embedded Webex App to make and receive external calls. Source: [Use Webex App in Webex Contact Center Desktop](https://help.webex.com/en-us/article/n444dol/Use-Webex-App-in-Webex-Contact-Center-Desktop), Use Webex App in Webex Contact Center Desktop > limitations. Checked 2026-10-02.
[^20]: The Extension option is for Webex Calling users; a single configured extension is pre-filled automatically and multiple extensions are offered as a drop-down of pre-validated extensions. Source: [Sign in to Agent Desktop](https://help.webex.com/en-us/article/n6lmci8/Sign-in-to-Agent-Desktop), Sign in to Agent Desktop > Extension option. Checked 2026-10-02.
[^21]: When an agent changes extension the preferred-device list refreshes, and if no devices are available the preferred-device selection is disabled. Source: [Optimize Webex Contact Center Desktop call notifications](https://help.webex.com/en-us/article/u5dbtfb), Optimize Webex Contact Center Desktop call notifications > preferred device. Checked 2026-10-02.
[^22]: Signing in with a Webex Calling extension enables device features such as preferred-device selection, whereas a free-form dial number sign-in works but without those device controls. Source: [Set up voice channels for Webex Contact Center](https://help.webex.com/en-us/article/2dputx/Set-up-voice-channel-for-Webex-Contact-Center), Set up voice channels for Webex Contact Center > agent sign-in with extension or dial number. Checked 2026-10-02.
[^23]: A 2025-03-04 release consolidated the Webex Calling notification and the Agent Desktop popover so an agent who turns on Hide Webex Calling Notifications answers from the desktop without overlapping windows. Source: [What's new for agents in Webex Contact Center](https://help.webex.com/en-us/article/n3v7ldh/What's-new-for-agents-in-Webex-Contact-Center), March 4, 2025 > Better together with Webex: Enhanced call handling experience in Agent Desktop. Checked 2026-10-02.
[^24]: An immediate RONA occurs when the system detects a problem while presenting the call to the agent endpoint; the agent goes straight to RONA without the usual missed-call popup. Source: [Troubleshoot and Understand RONA Issues in Webex Contact Center](https://help.webex.com/en-us/article/WBX9000037382), Troubleshoot and Understand RONA Issues > Immediate RONA. Checked 2026-10-02.
[^25]: The Webex Calling incoming-call checklist includes checking the user's incoming call permissions (incoming dial plan toggle) under advanced call settings. Source: [Troubleshoot Incoming Call Problems for Webex Calling Users](https://www.cisco.com/c/en/us/support/docs/unified-communications/webex-calling/218153-troubleshoot-incoming-call-problems-for.html), Troubleshoot Incoming Call Problems > Incoming Dial Plans. Checked 2026-10-02.
[^26]: A PSTN dial number entered without the International Dialing Format box checked is treated as non-E.164; the system then fails to ring it, giving an instant RONA. Source: [Troubleshoot RONA Issue When Agents Enter Dial Number in Wrong Tab](https://help.webex.com/article/WBX9000037383), Troubleshoot RONA Issue When Agents Enter Dial Number in Wrong Tab > PSTN numbers. Checked 2026-10-02.
[^27]: If an agent's previously saved Dial Number or Extension is invalid, sign-in returns the agent to the interaction preferences screen pre-populated with the saved preferences so the details can be corrected. Source: [Sign in to Agent Desktop](https://help.webex.com/en-us/article/n6lmci8/Sign-in-to-Agent-Desktop), Sign in to Agent Desktop > enhanced validation during sign-in (Webex Calling users). Checked 2026-10-02.
[^28]: At Agent Desktop sign-in the agent chooses one of three calling preferences: Desktop (browser WebRTC), Extension, or Dial Number. Source: [Sign in to Agent Desktop](https://help.webex.com/en-us/article/n6lmci8/Sign-in-to-Agent-Desktop), Sign in to Agent Desktop > station login / interaction preferences options. Checked 2026-10-02.
[^29]: From the 2025-10-29 release an agent can answer Webex Calling calls on their device from Agent Desktop by turning on Manage Webex Calling Calls and selecting a preferred device. Source: [What's new for agents in Webex Contact Center](https://help.webex.com/en-us/article/n3v7ldh/What's-new-for-agents-in-Webex-Contact-Center), October 29, 2025 > Answer calls on your device directly from Agent Desktop. Checked 2026-10-02.
[^30]: When an agent types an extension or dial number manually instead of choosing from the drop-down, the system still checks that the credential is assigned to that agent. Source: [What's new for agents in Webex Contact Center](https://help.webex.com/en-us/article/n3v7ldh/What's-new-for-agents-in-Webex-Contact-Center), October 29, 2025 > Simplified agent sign-in experience. Checked 2026-10-02.
[^31]: An agent on a Webex Calling extension who joins a Webex Meeting while Available may have Contact Center calls fail as busy or RONA because of implicit DND (inferred). Source: [Do not disturb sync between Webex App and desk phone](https://help.webex.com/en-us/article/d307vb/Do-Not-Disturb-Sync-(DND)-between-Webex-App-and-desk-phone), Do not disturb sync between Webex App and desk phone > overview; combined with Understand agent states > Agent_Busy. Checked 2026-10-02.
[^32]: An agent's desk phone and Webex App both ringing for a Contact Center call is expected behaviour when the agent has several Webex Calling devices, not a fault in itself (inferred). Source: [Optimize Webex Contact Center Desktop call notifications](https://help.webex.com/en-us/article/u5dbtfb), Optimize Webex Contact Center Desktop call notifications > call answer behaviour. Checked 2026-10-02.
[^33]: Cisco does not recommend enabling voicemail on an agent line, because a customer call forwarded to voicemail can look to the contact center like a correctly answered call. Source: [Set up voice channels for Webex Contact Center](https://help.webex.com/en-us/article/2dputx/Set-up-voice-channel-for-Webex-Contact-Center), Set up voice channels for Webex Contact Center > voicemail on agent lines. Checked 2026-10-02.
[^34]: Sign-in validation does not confirm the agent's device is online; the agent is responsible for ensuring the selected or entered extension or dial number is on an active and available device. Source: [What's new for agents in Webex Contact Center](https://help.webex.com/en-us/article/n3v7ldh/What's-new-for-agents-in-Webex-Contact-Center), October 29, 2025 > Simplified agent sign-in experience. Checked 2026-10-02.
[^35]: An agent with only one Webex Calling device does not need to set a preferred device. Source: [Optimize Webex Contact Center Desktop call notifications](https://help.webex.com/en-us/article/u5dbtfb), Optimize Webex Contact Center Desktop call notifications > preferred device. Checked 2026-10-02.
[^36]: Because sign-in does not check device status, an agent who signs in successfully and then hits Agent_Unavailable or immediate RONA most likely has an offline or unregistered Webex Calling device (inferred). Source: [What's new for agents in Webex Contact Center](https://help.webex.com/en-us/article/n3v7ldh/What's-new-for-agents-in-Webex-Contact-Center), October 29, 2025 > Simplified agent sign-in experience; combined with Understand agent states > Agent_Unavailable. Checked 2026-10-02.
[^37]: Presence synchronisation between Webex App and Webex Contact Center agent state can take up to 2 seconds to propagate. Source: [Use Webex App in Webex Contact Center Desktop](https://help.webex.com/en-us/article/n444dol/Use-Webex-App-in-Webex-Contact-Center-Desktop), Use Webex App in Webex Contact Center Desktop > presence synchronization. Checked 2026-10-02.
[^38]: For incoming-call problems Cisco's Webex Calling technote checks first that the device shows registered in Control Hub Devices, or that Webex App shows Phone Services connected. Source: [Troubleshoot Incoming Call Problems for Webex Calling Users](https://www.cisco.com/c/en/us/support/docs/unified-communications/webex-calling/218153-troubleshoot-incoming-call-problems-for.html), Troubleshoot Incoming Call Problems > Validation of Hardphone or Softclient Registration. Checked 2026-10-02.
[^39]: In a RONA after ring event, the call reaches the agent endpoint and it returns SIP 180 Ringing, but no 200 OK (answer) arrives before the RONA timeout, which defaults to 18 seconds. Source: [Troubleshoot and Understand RONA Issues in Webex Contact Center](https://help.webex.com/en-us/article/WBX9000037382), Troubleshoot and Understand RONA Issues > RONA after ring event. Checked 2026-10-02.
[^40]: Cisco's RONA troubleshooting article lists an unregistered device, call forwarding rules, Do Not Disturb, a busy phone and a DN entered in the wrong Dial Number or Extension tab among RONA causes. Source: [Troubleshoot and Understand RONA Issues in Webex Contact Center](https://help.webex.com/en-us/article/WBX9000037382), Troubleshoot and Understand RONA Issues > common RONA causes. Checked 2026-10-02.
[^41]: If voicemail is kept on an agent line, the RONA timer (default 18 seconds) should be shorter than the time before voicemail answers, so unanswered calls requeue instead of going to voicemail. Source: [Set up voice channels for Webex Contact Center](https://help.webex.com/en-us/article/2dputx/Set-up-voice-channel-for-Webex-Contact-Center), Set up voice channels for Webex Contact Center > voicemail on agent lines and RONA timer. Checked 2026-10-02.
[^42]: The RONA state indicates the agent did not respond when a call was delivered, so the offer timed out. Source: [Understand agent states](https://help.webex.com/en-us/article/nvg4gu6/Understand-agent-states), Understand agent states > RONA behaviour optimization (system-assigned states). Checked 2026-10-02.
[^43]: Since the simplified agent sign-in released 2025-10-29, Webex Contact Center validates that a selected extension or dial number is valid and assigned to the agent's Webex Calling profile. Source: [What's new for agents in Webex Contact Center](https://help.webex.com/en-us/article/n3v7ldh/What's-new-for-agents-in-Webex-Contact-Center), October 29, 2025 > Simplified agent sign-in experience. Checked 2026-10-02.
[^44]: Agent Desktop cannot be used in multiple browsers or multiple tabs of the same browser at once; the agent is prompted to choose which instance continues. Source: [Sign in to Agent Desktop](https://help.webex.com/en-us/article/n6lmci8/Sign-in-to-Agent-Desktop), Sign in to Agent Desktop > notes on multiple browsers and tabs. Checked 2026-10-02.
[^45]: The Webex Calling incoming-call checklist includes disabling Single Number Reach (Office Anywhere) in the user portal's incoming call settings. Source: [Troubleshoot Incoming Call Problems for Webex Calling Users](https://www.cisco.com/c/en/us/support/docs/unified-communications/webex-calling/218153-troubleshoot-incoming-call-problems-for.html), Troubleshoot Incoming Call Problems > Single Number Reach (Office Anywhere). Checked 2026-10-02.
[^46]: Turning on Manage Webex Calling calls adds a way to answer through Contact Center notifications but does not stop the call ringing in the primary Webex App or on linked devices. Source: [Optimize Webex Contact Center Desktop call notifications](https://help.webex.com/en-us/article/u5dbtfb), Optimize Webex Contact Center Desktop call notifications > call answer behaviour. Checked 2026-10-02.
[^47]: For a RONA case Cisco asks for the ANI or session ID, the exact failure timestamp, agent details, any error screenshot and the Agent Desktop error report (Ctrl+Shift+2). Source: [Troubleshoot and Understand RONA Issues in Webex Contact Center](https://help.webex.com/en-us/article/WBX9000037382), Troubleshoot and Understand RONA Issues > information to collect. Checked 2026-10-02.
[^48]: Known presence-sync problems occur with simultaneous calls using hold and resume, direct calls received during wrap-up, and ACD calls answered in Webex App during wrap-up. Source: [Use Webex App in Webex Contact Center Desktop](https://help.webex.com/en-us/article/n444dol/Use-Webex-App-in-Webex-Contact-Center-Desktop), Use Webex App in Webex Contact Center Desktop > known issues. Checked 2026-10-02.
[^49]: Webex App state synchronisation with Agent Desktop does not work with Webex Calling Dedicated Instance or with the Extensible Supervisor Desktop. Source: [Use Webex App in Webex Contact Center Desktop](https://help.webex.com/en-us/article/n444dol/Use-Webex-App-in-Webex-Contact-Center-Desktop), Use Webex App in Webex Contact Center Desktop > constraints. Checked 2026-10-02.
[^50]: When the WebRTC connection of a Desktop-option agent disconnects, the system disables Set as Available (all channels) to stop voice calls routing to that agent. Source: [Understand agent states](https://help.webex.com/en-us/article/nvg4gu6/Understand-agent-states), Understand agent states > system-assigned agent states. Checked 2026-10-02.
[^51]: Agent Desktop does not currently support headset control actions for WebRTC (Desktop option) calls. Source: [Sign in to Agent Desktop](https://help.webex.com/en-us/article/n6lmci8/Sign-in-to-Agent-Desktop), Sign in to Agent Desktop > Desktop option note. Checked 2026-10-02.
[^52]: The WebRTC Desktop voice option is unavailable for Webex Contact Center tenants hosted in the Japan data center. Source: [Set up voice channels for Webex Contact Center](https://help.webex.com/en-us/article/2dputx/Set-up-voice-channel-for-Webex-Contact-Center), Set up voice channels for Webex Contact Center > WebRTC desktop support note. Checked 2026-10-02.
[^53]: Choosing the wrong station credential option at sign-in (for example a dial number entered under the wrong tab) can make every offered call fail immediately as RONA. Source: [Troubleshoot RONA Issue When Agents Enter Dial Number in Wrong Tab](https://help.webex.com/article/WBX9000037383), Troubleshoot RONA Issue When Agents Enter Dial Number in Wrong Tab > core issue. Checked 2026-10-02.
[^54]: The Webex Calling incoming-call checklist includes unchecking All calls to voicemail and reviewing the ring count before voicemail answers. Source: [Troubleshoot Incoming Call Problems for Webex Calling Users](https://www.cisco.com/c/en/us/support/docs/unified-communications/webex-calling/218153-troubleshoot-incoming-call-problems-for.html), Troubleshoot Incoming Call Problems > Voicemail Settings. Checked 2026-10-02.
[^55]: The Webex Calling incoming-call checklist includes confirming Do Not Disturb is disabled in the user portal's incoming call settings. Source: [Troubleshoot Incoming Call Problems for Webex Calling Users](https://www.cisco.com/c/en/us/support/docs/unified-communications/webex-calling/218153-troubleshoot-incoming-call-problems-for.html), Troubleshoot Incoming Call Problems > Do Not Disturb (DND). Checked 2026-10-02.
[^56]: The Agent Desktop Webex Calling call-answer feature requires Webex Calling to be enabled in Control Hub. Source: [Optimize Webex Contact Center Desktop call notifications](https://help.webex.com/en-us/article/u5dbtfb), Optimize Webex Contact Center Desktop call notifications > prerequisites. Checked 2026-10-02.
[^57]: Cisco's Webex Calling incoming-call checklist includes confirming call forwarding is turned off on the user's Calling settings in Control Hub. Source: [Troubleshoot Incoming Call Problems for Webex Calling Users](https://www.cisco.com/c/en/us/support/docs/unified-communications/webex-calling/218153-troubleshoot-incoming-call-problems-for.html), Troubleshoot Incoming Call Problems > Call Forwarding Configuration. Checked 2026-10-02.