Troubleshooting Amazon Connect softphone and CCP audio

See also

Sources

1. 1
   Audio Enhancement is not supported together with Amazon Connect audio optimization (WebRTC redirection), though it is supported with VDI local-browser access; configuring both is called out as a likely cause of audio problems.

   Troubleshoot audio quality issues in Connect Customer · Step 5, subsection 'Workstation (paths 1/2)', bullet 'Audio Enhancement' · Checked 2026-10-02
2. 2
   AWS describes the .awsapps.com instance domain as an old domain that is going away and documents my.connect.aws allowlist entries (ccp-v2, api, auth/authorize, awas/api plus *.cloudfront.net) as the current minimum.

   Set up your network to use the Connect Customer Contact Control Panel (CCP) · Section 'Option 1 (recommended)', allowlist table second row · Checked 2026-10-02
3. 3
   Amazon Connect supports the latest three versions of Chrome, Edge Chromium and Firefox plus Firefox ESR until end of life; Safari and other browsers are unsupported, and AWS requires an issue to be reproduced in a supported browser before investigating.

   Browsers supported by Connect Customer · Opening table and the Note beneath it · Checked 2026-10-02
4. 4
   AWS's CCP-only workstation minimums are 54 Kbps up and down per 1:1 audio call, 2 GB RAM and a 2 GHz CPU, with a USB headset recommended though any headset type is compatible.

   Agent headset and workstation requirements for using the Contact Control Panel (CCP) · Sections 'Headset requirements' and 'Workstation minimum requirements' · Checked 2026-10-02
5. 5
   CCP logs are downloaded from the CCP via Settings then Download logs as agent-log.txt, and they persist only for the current browser session, so a tab refresh or close discards them.

   Download and review Connect Customer Contact Control Panel (CCP) logs · Section 'Download CCP logs' steps 1-2; Note in 'Review CCP logs using Connect Customer CCP Log Parser' step 3 · Checked 2026-10-02
6. 6
   AWS warns that Local Network Access prompts introduced in Chrome 147 and Edge 147 can block Citrix UCSDK audio optimization until a Citrix-documented workaround (CTX696569) is applied.

   Optimize Connect Customer audio for Citrix cloud desktops · Section 'System requirements', Important box · Checked 2026-10-02
7. 7
   For Citrix audio optimization AWS advises VDIPlatform CITRIX_413 instead of CITRIX and Citrix Workspace App 2508.10 or later on Windows, Linux and Mac (2507 or later on ChromeOS) to fix dead air and dropped calls during mute; the stated minimum is CWA 2305.

   Optimize Connect Customer audio for Citrix cloud desktops · Section 'System requirements', 'Upgrade Citrix Workspace App to improve call quality' and 'Citrix Workspace Application Version' · Checked 2026-10-02
8. 8
   For Citrix audio optimization the native CCP is listed as an unsupported deployment, and the agent's thin client needs its own media path to Amazon Connect on UDP 3478.

   Optimize Connect Customer audio for Citrix cloud desktops · Section 'System requirements', bullets 'Networking/Firewall Configurations' and 'Unsupported CCP Deployment' · Checked 2026-10-02
9. 9
   Citrix server setup for the UC SDK needs a REG_MULTI_SZ ProcessWhitelist value (Chrome.exe and msedge.exe) under HKLM\SOFTWARE\WOW6432Node\Citrix\WebSocketService followed by a restart of CitrixHdxWebSocketService; VDA 2203 LTSR or later is recommended.

   Optimize Connect Customer audio for Citrix cloud desktops · Section 'System requirements', bullets 'Citrix Server Version' and 'Citrix Server Setup' · Checked 2026-10-02
10. 10
    Because desk phone mode delivers call audio as a PSTN call to the agent's number rather than over browser WebRTC, it probably sidesteps browser microphone, UDP 3478 and VDI media problems, at the cost of telephony charges and PSTN-side quality that CCP WebRTC diagnostics would not see.inferred

    Set up your network to use the Connect Customer Contact Control Panel (CCP) · Section 'Rerouting audio'; combined with configure-agents step 5 and forward-calls-to-mobile-device procedure · Checked 2026-10-02
11. 11
    When an agent's phone type is Desk phone, Amazon Connect incurs outbound telephony charges for inbound calls answered on that phone.

    Configure agent settings in Connect Customer · 'To configure agent settings' step 5, Important note under Desk phone · Checked 2026-10-02
12. 12
    An agent can set Phone type to Desk phone in CCP settings with a mobile number, so call audio goes to the mobile device while the call is managed in the CCP on the computer.

    Forward calls in the Connect Customer CCP to a mobile device (iPhone, Android) · Numbered procedure steps 1 to 3 · Checked 2026-10-02
13. 13
    If the Amazon Connect IP ranges are already allowlisted and DNS resolution is unrestricted, the TurnNlb domain need not be allowlisted; AWS suggests checking resolution with nslookup against a TurnNlb hostname and allowlisting the TurnNlb endpoints if it fails.

    Set up your network to use the Connect Customer Contact Control Panel (CCP) · Section 'Allow DNS resolution for softphones' · Checked 2026-10-02
14. 14
    AWS's fix for the Edge autoplay problem is to add the exact instance URL (https://<instance>.my.connect.aws, or the govcloud.connect.aws form) to the Edge AutoplayAllowlist policy, plus the hosting domain for custom CCPs using connect-rtc-js; the wildcard * is not accepted.

    Browsers supported by Connect Customer · Section 'Microsoft Edge v146 autoplay policy change', 'Recommended action for browser administrators' · Checked 2026-10-02
15. 15
    With the Microsoft Edge AutoplayAllowed enterprise policy set to Disabled on affected Edge versions, Amazon Connect agents may not hear ringtones or audio on incoming voice contacts (one-way audio) or see and hear customers on video calls.

    Browsers supported by Connect Customer · Section 'Microsoft Edge v146 autoplay policy change', list of issues · Checked 2026-10-02
16. 16
    According to AWS, Edge 146 (released 2026-03-13) and later map AutoplayAllowed=Disabled to Block, whereas Edge 92 through 144 mapped it to Limit, which allowed audio on active WebRTC streams.disputed

    Browsers supported by Connect Customer · Section 'Microsoft Edge v146 autoplay policy change', first paragraph and Note · Checked 2026-10-02
17. 17
    According to Microsoft's AutoplayAllowed policy page, Disabled maps to Limit in Edge 92 through 145 and in 148 and later, and to Block only in Edge 146 and 147.disputed

    Microsoft Edge Browser Policy Documentation AutoplayAllowed · Section 'Description', fourth and fifth paragraphs · Checked 2026-10-02
18. 18
    The Amazon Connect Endpoint Test Utility checks browser WebRTC support, browser access to media devices, latency to all active Connect Regions and optionally to a specific instance, and connectivity on the ports required for media streams.

    Validate connectivity to Connect Customer with the Endpoint Test Utility · Opening section, bulleted list of checks · Checked 2026-10-02
19. 19
    The Endpoint Test Utility is hosted at https://tools.connect.aws/endpoint-test/ and accepts URL parameters lng (en, es, fr), autoRun (true or false), connectInstanceUrl (must start with https) and regions (comma-separated Region codes).

    Validate connectivity to Connect Customer with the Endpoint Test Utility · Section 'Parameters to customize the Endpoint Test Utility' · Checked 2026-10-02
20. 20
    In Firefox the CCP gets microphone access only while the CCP or agent workspace tab is in focus, so agents must focus that tab when accepting a voice contact or the call can be missed.

    Contact Control Panel (CCP) Issues · Section 'CCP browser microphone access', second bullet and 'How to fix' · Checked 2026-10-02
21. 21
    The ice_collection_timeout error ('Call failed due to a browser-side WebRTC issue') occurs when the CCP's request to the TurnNlb softphone media endpoint on UDP 3478 times out so ICE candidates cannot be collected; AWS's fix is to allow outbound UDP 3478 through firewalls and NAT.

    Contact Control Panel (CCP) Issues · Section 'CCP WebRTC issues' and its 'How to fix' · Checked 2026-10-02
22. 22
    The CCP banner 'Initialization Failed' is most commonly caused by missing domain or port/IP allowlist entries in the agent environment and results in missed calls.

    Contact Control Panel (CCP) Issues · Section 'CCP initialization issues' · Checked 2026-10-02
23. 23
    New Amazon Connect IP ranges appear in ip-ranges.json at least 30 days before the service uses them, after which softphone traffic shifts onto them over about two weeks, so IP-range allowlists must be updated within 30 days to avoid intermittent failures.

    Set up your network to use the Connect Customer Contact Control Panel (CCP) · Section 'About Connect Customer IP address ranges', last paragraph; section 'Port and protocol considerations', fourth bullet · Checked 2026-10-02
24. 24
    In CCP log WebRTC metrics, AWS treats JitterBufferMillis above 30 ms and RoundTripTime above 300 ms as abnormal.

    Troubleshoot audio quality issues in Connect Customer · Step 4 'Collect diagnostic data', item 3 'CCP logs' · Checked 2026-10-02
25. 25
    AWS states that average latency between the agent browser and the Amazon Connect instance, as measured by the Endpoint Test Utility, should not exceed 300 ms and that higher latency might cause audio quality issues.

    Troubleshoot your network for call quality and disconnect problems · Section 'Run the Endpoint Test Utility', first bullet · Checked 2026-10-02
26. 26
    The CCP Log Parser at https://tools.connect.aws/ccp-log-parser/ shows Snapshots and Logs plus a Metrics tab with skew metrics, API call latency and, for CCP calls, WebRTC media stream metrics.

    Download and review Connect Customer Contact Control Panel (CCP) logs · Section 'Review CCP logs using Connect Customer CCP Log Parser', steps 1 and 6 · Checked 2026-10-02
27. 27
    A custom CCP built with the Amazon Connect Streams API can run media-less, which needs no ports opened for media but still needs connectivity to the Amazon EC2 and CloudFront endpoints.

    Set up your network to use the Connect Customer Contact Control Panel (CCP) · Section 'Port and protocol considerations', last bullet · Checked 2026-10-02
28. 28
    The CCP red banner 'Microphone is not accessible' means the CCP cannot access the agent's microphone, and this condition can cause missed calls.

    Contact Control Panel (CCP) Issues · Introductory error list, entry 'Microphone is not accessible'; section 'CCP browser microphone access' · Checked 2026-10-02
29. 29
    The CCP can connect to the agent's microphone only when permission has been granted for the current browser session; the permission is held in the browser's memory.

    Contact Control Panel (CCP) Issues · Section 'CCP browser microphone access', first bullet · Checked 2026-10-02
30. 30
    AWS lists improperly configured NAT traversal as a cause of one-way or no audio and recommends static NAT where possible with keep-alives enabled.

    Troubleshoot your network for call quality and disconnect problems · Section 'Investigate network components and devices', bullet 'Network address translation (NAT) devices' · Checked 2026-10-02
31. 31
    When the agent can hear the customer but the customer cannot hear the agent, AWS says the cause might be another application taking exclusive control of the agent's microphone or speaker.

    Contact Control Panel (CCP) Issues · Section 'One-way audio from customers' · Checked 2026-10-02
32. 32
    AWS recommends testing the domain-allowlist option with more than 200 calls and says an error rate above 2 percent may indicate a proxy resolution issue, in which case the IP-range option can be considered.

    Set up your network to use the Connect Customer Contact Control Panel (CCP) · Section 'Option 1 (recommended)', second paragraph · Checked 2026-10-02
33. 33
    AWS uses a CloudWatch ToInstancePacketLossRate above 20 percent as a sign of a severe network issue, while noting audio can degrade at packet loss rates well below 20 percent.

    Troubleshoot audio quality issues in Connect Customer · Step 4 'Collect diagnostic data', item 4 'Amazon CloudWatch' · Checked 2026-10-02
34. 34
    Persistent connection works on supported Chrome and Edge but not Firefox, can be used with VDI audio optimization, and only an administrator, not the agent, can turn it on or off.

    Enable persistent connection for Connect Customer agents · FAQ entries 'Can the agent opt-out', 'Are there any browser restrictions', 'Can this feature be used when VDI audio optimization is enabled?' · Checked 2026-10-02
35. 35
    With persistent connection enabled, the agent softphone keeps its media connection for a few minutes after login and after each call so the next call connects faster; after extended idle time it drops and silently re-establishes on the next call.

    Enable persistent connection for Connect Customer agents · Opening paragraph; FAQ 'Does the softphone connection persist for the entire agent session?' · Checked 2026-10-02
36. 36
    As of 2026-10-02 the AWS administrator guide brands the product as Amazon Connect Customer and refers to it in text as Connect Customer, including in CCP troubleshooting pages.

    Contact Control Panel (CCP) Issues · Page body text throughout (e.g. 'Connect Customer softphone media' in the error list) · Checked 2026-10-02
37. 37
    QualityMetrics are returned by the DescribeContact API and in Kinesis contact record events, but are not shown when viewing the contact record in the admin website and are not part of EventBridge events.

    Troubleshoot audio quality issues by using QualityMetrics in the contact record · Section 'Where to find QualityMetrics' · Checked 2026-10-02
38. 38
    A HighPacketLoss value in QualityMetrics indicates packet loss on the participant's outbound (egress) audio stream.

    Troubleshoot audio quality issues by using QualityMetrics in the contact record · Section 'Use QualityMetrics', HighPacketLoss bullet · Checked 2026-10-02
39. 39
    Contact record QualityMetrics give Agent and Customer audio a QualityScore from 1.00 (poor) to 5.00 (high) and a PotentialQualityIssues list whose values are HighPacketLoss, HighRoundTripTime and HighJitterBuffer; an empty list means no issue was detected.

    Troubleshoot audio quality issues by using QualityMetrics in the contact record · Sections 'Where to find QualityMetrics' and 'Use QualityMetrics' · Checked 2026-10-02
40. 40
    Amazon Connect records calls at the Connect service, so degradation audible in the recording happened before audio reached Connect, while a clean recording means degradation occurred after Connect on the path to the listener.

    Troubleshoot audio quality issues in Connect Customer · Step 3 'Localize the problem using the call path' · Checked 2026-10-02
41. 41
    When agent audio is rerouted to a device, Amazon Connect places an outbound call to that device for each contact, and if the agent does not answer, the agent goes into a missed contact state until the agent or a supervisor sets them available again.

    Set up your network to use the Connect Customer Contact Control Panel (CCP) · Section 'Rerouting audio' · Checked 2026-10-02
42. 42
    If the agent's audio device does not support 48 kHz while the browser asserts 48 kHz, an audible hum can appear in the agent's outgoing audio; AWS has seen this with Firefox but not Chrome.

    Humming sound in the agent's audio device: Verify the headset and browser sample rates · Opening paragraph · Checked 2026-10-02
43. 43
    During a live call, the sample rate is checked at about:support under Media in Firefox or on the Audio tab of chrome://media-internals in Chrome; both input and output should read 48000, and the rate is changed in operating system sound settings or by replacing the headset.

    Humming sound in the agent's audio device: Verify the headset and browser sample rates · Sections 'Verify Firefox sample rate' and 'Verify Chrome sample rate' · Checked 2026-10-02
44. 44
    The CCP error 'Failed to establish softphone connection' means the browser could not establish a media channel with Amazon Connect softphone media, often because the agent network blocks the TurnNlb domain or cannot resolve it in DNS.

    Contact Control Panel (CCP) Issues · Introductory error list, entry 'Failed to establish softphone connection' · Checked 2026-10-02
45. 45
    For VDI, AWS recommends a split CCP model, with a media-less Streams-based CCP inside the VDI for data and call control and a standard CCP on the local PC carrying media; Firefox cannot be used for the local CCP in split mode.

    Use Connect Customer in a VDI environment · Section 'Use a split CCP model' and its Firefox note · Checked 2026-10-02
46. 46
    With a stateless firewall, the browser's ephemeral port range must also be allowed inbound from the AMAZON_CONNECT ranges: 49152-65535 UDP on Windows and 32768-61000 on Linux.

    Set up your network to use the Connect Customer Contact Control Panel (CCP) · Section 'Stateless firewalls', table · Checked 2026-10-02
47. 47
    AWS asks audio quality support cases to include 3 to 5 example ContactIds no older than 24 hours, with UTC timestamps, recordings, the instance ARN, Endpoint Test Utility JSON, ping and MTR observations, and CCP logs.

    Troubleshoot audio quality issues in Connect Customer · Section 'Before you begin: gather this information' and 'Step 7: Before you contact AWS Support' · Checked 2026-10-02
48. 48
    CCP v2 signalling uses *.transport.connect.<region>.amazonaws.com on outbound TCP 443, and AWS warns that web socket handling in some proxies can break this and must be tested before production.

    Set up your network to use the Connect Customer Contact Control Panel (CCP) · Section 'Option 1 (recommended)', allowlist table row *.transport.connect.{region}.amazonaws.com and the Tip following the table · Checked 2026-10-02
49. 49
    CCP softphone media requires outbound UDP 3478 send/receive to TurnNlb-*.elb.<region>.amazonaws.com for the instance's Region (or the listed per-Region NLB hostnames).

    Set up your network to use the Connect Customer Contact Control Panel (CCP) · Section 'Option 1 (recommended)', allowlist table row TurnNlb-*.elb.{region}.amazonaws.com; subsection 'NLB endpoints' · Checked 2026-10-02
50. 50
    AWS lists routing audio through a virtualized desktop, instead of redirecting the WebRTC session to the agent workstation, as a cause of high round trip time.

    Troubleshoot audio quality issues by using QualityMetrics in the contact record · Section 'Use QualityMetrics', HighRoundTripTime causes, last bullet · Checked 2026-10-02
51. 51
    With VDI audio optimization, media device information is relayed at contact start, so an agent who switches audio device mid-contact cannot get audio on the new device.

    Use the agent workspace to optimize audio for Amazon WorkSpaces, Citrix, Omnissa, Azure Virtual Desktop, and Windows 365 cloud desktops · Section 'Important things to know', fourth bullet · Checked 2026-10-02
52. 52
    VDIPlatform is appended directly to the /agent-app-v2 URL (removing any referrer=admin parameter), or for SSO to the relay state destination, and should not be appended when the agent workspace is not running inside a VDI.

    Use the agent workspace to optimize audio for Amazon WorkSpaces, Citrix, Omnissa, Azure Virtual Desktop, and Windows 365 cloud desktops · Section 'Important things to know' bullets 1 and 3; subsection 'Use with SSO based login' · Checked 2026-10-02
53. 53
    Agent workspace VDI audio optimization is selected with the VDIPlatform query parameter, whose documented values are CITRIX_413 (Citrix), AWS_WORKSPACE (Amazon WorkSpaces), OMNISSA (Omnissa) and AZURE (Azure Virtual Desktop or Windows 365).

    Use the agent workspace to optimize audio for Amazon WorkSpaces, Citrix, Omnissa, Azure Virtual Desktop, and Windows 365 cloud desktops · Section 'How to use audio optimization in the agent workspace', subsection 'Use without SSO based login', step 2 · Checked 2026-10-02
54. 54
    Voice Isolation should only be used with a wired headset (Noise Suppression for wireless or mixed setups), and Audio Enhancement requires at least a 4-core CPU or 4 vCPU.

    Troubleshoot audio quality issues in Connect Customer · Step 5, subsection 'Workstation (paths 1/2)', bullet 'Audio Enhancement' sub-bullets · Checked 2026-10-02
55. 55
    AWS recommends that CCP media between the agent workstation and AWS not traverse VPNs or network accelerator hops, and its audio troubleshooting asks whether the issue reproduces without VPN and whether split tunnelling is enabled for real-time traffic.

    Troubleshoot audio quality issues in Connect Customer · Step 5, subsection 'Network (path 3)', bullet 'Virtual private network (VPN)' · Checked 2026-10-02
56. 56
    After a Windows 11 reboot, agents using Chrome or Edge can get complete two-way audio failure (dead air) on the first CCP call.

    Contact Control Panel (CCP) Issues · Section 'CCP audio issues on first call after system reboot when using Windows 11', Issue Description and Affected Systems · Checked 2026-10-02
57. 57
    AWS attributes the Windows 11 first-call dead air to the network interface card restarting when Chrome or Edge requests audio packet prioritization, and to volume control changes triggering network services that can restart the NIC.

    Contact Control Panel (CCP) Issues · Section 'CCP audio issues on first call after system reboot when using Windows 11', Root Cause · Checked 2026-10-02
58. 58
    The documented fix for Windows 11 first-call dead air is to change the startup type from Manual to Automatic for qWAVE, ndisuio.sys, dmwAppushSvc, SstpSvc and RasMan, which requires administrative privileges.

    Contact Control Panel (CCP) Issues · Section 'CCP audio issues on first call after system reboot when using Windows 11', Resolution · Checked 2026-10-02

Documents

Cite this page

WarmTransfer. (2026, October 2). Troubleshooting Amazon Connect softphone and CCP audio. WarmTransfer. https://warmtransfer.net/knowledge/amazon-connect-ccp-audio-troubleshooting

@misc{warmtransfer-amazon-connect-ccp-audio-troubleshooting,
  title  = {Troubleshooting Amazon Connect softphone and CCP audio},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/amazon-connect-ccp-audio-troubleshooting},
  note   = {Verified 2026-10-02}
}