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Troubleshooting Five9 softphone and station connection problems

Verified 2026-10-02 · 58 sources · tier 2

Also known as five9-softphone-registration-issues, five9-station-connection-troubleshooting.

Five9 Agent Desktop Plus connects to one of 4 station types (softphone, WebRTC, PSTN or gateway) to process voice interactions, and a No Station option also exists 2. The Softphone station uses the agent's computer for calls and is the default station option 47.

How station connections work

In Five9, the administrator creates station pools, and a supervisor or administrator assigns station IDs 49. An agent assigned to more than one pool can change pools during station setup 49.

Some devices limit which station type an agent can use: 50 10 53

Agent Desktop Plus users on tablets must select WebRTC as the station connection type 50.
Chromebooks are supported for Five9 WebRTC only, because the Five9 Softphone plug-in cannot be installed on them 10.
Users on Citrix workstations cannot use WebRTC and the Five9 Softphone in the same browser 53.

WebRTC station

Setting up a Five9 WebRTC station requires granting the browser microphone access when prompted and confirming the speaker and microphone selections 55. A successful WebRTC station connection plays 3 tones on the audio device and shows 'WebRTC Connected' in Agent Desktop Plus 54. The browser tab also shows a red recording dot 54.

PSTN station

For a Five9 PSTN station, U.S. agents enter a standard 10-digit number 26. European contact centers enter the number in ITU-T E.164 international format, including the country code 26. The agent answers the phone when it rings, and 3 tones on the PSTN device indicate a successful station connection 23. Five9 advises agents to get administrator permission before logging into a PSTN station or forwarding calls between sessions, because high long-distance fees may be incurred 24.

Gateway station

Five9 gateway stations are used with IP phone systems, and calls to and from the Five9 contact center are processed across the Internet 14. The administrator supplies the gateway station address, which combines a port number with the public IP address designated for the domain's gateway access 16. The agent answers the gateway phone when it rings and listens for 3 tones 14.

Installing and checking the Five9 Softphone

Five9 documents installing the browser extension as a prerequisite to installing the Five9 Softphone for Agent Desktop Plus 40.

Windows. The Five9 Softphone is installed by running the setup wizard in the file Five9Softphone.msi 44. After installation, the Station Check page confirms that the extensions are installed 44.

macOS. The Five9 Softphone is installed from Five9Softphone.dmg by choosing 'For me only' in the wizard 39. Finder access must be granted when prompted 39. The installer removes an existing softphone automatically 39.

Supported versions. As of 2026-09-30, Five9 lists these supported voice client versions 41:

Softphone Installer 14.0.5 41
Chrome/Edge extension 13.1.2 (recommended) or 13.1.1 41
Firefox extension 11.6.0 41

Tray status. After installation, a Five9 Softphone icon in the system tray shows the connection status between the browser and the softphone as waiting, connected or error 48.

Port 8083. The Five9 Softphone Service on agent workstations requires TCP port 8083, and no other process may use that port 45. An exception for this port is needed when an HTTP proxy is used 45.

Memory. Five9 warns that agents running many browser tabs besides Five9 need adequate RAM, or session disconnects could occur 31. Five9 lists 8 GB of RAM as the minimum and 16 GB as recommended 31.

Network and firewall requirements

Ports	Direction and use
TCP 8083	Required by the Five9 Softphone Service on agent workstations; no other process may use it 45
UDP 5060-5067	Outbound, for the agent application's SIP connection (softphone customers) 46
UDP 5080 / TCP 5081	Outbound from the customer network to the Five9 SIP proxy: UDP 5080 for SIP signaling, TCP 5081 for SIP over TLS 38
UDP 1024-65535	Outbound, for softphone RTP; inbound rules are needed for return traffic if the firewall is not stateful 33
UDP 8000-8015	Source port range for RTP traffic on the agent desktop (softphone customers) 34
TCP 443, UDP 1024-65535	Outbound, for WebRTC customers; the UDP range carries RTP, and all ports opened for RTP must also allow STUN 56
UDP 5060 (default)	Inbound SIP to the agent's endpoint for gateway customers; the actual port depends on what the customer uses for the SIP endpoint 15

Reserved ports. Five9 tells customers not to use TCP/UDP ports 8080, 9998, 11000 or 30059 for any third-party services or applications on agent desktop computers 32.

PSTN stations. WarmTransfer's reading of the sources is that the agent's voice path on a PSTN station does not depend on workstation VoIP firewall rules 25. This is inferred from the PSTN-customer port table, which lists only web, Java RMI, download and test ports, with no SIP or RTP range 25.

SIP inspection features. Five9 asks that SIP ALG, SIP Inspection and Control, SIP Traversal and SIP Transformation be disabled for Five9 traffic, because default firewall inspect settings alter SIP/VoIP traffic 37. Five9's SIP Firewall Note cautions that the site may run other SIP services or applications that require these SIP inspection features to stay enabled 36.

Intrusion prevention. Five9 warns that an intrusion prevention system that overreacts to normal SIP and RTP traffic to and from Five9 can cause service interruptions 18.

Allow list. Five9 requires customers to add Five9 Internet domains and IP address ranges to their allow list 4. These domains and ranges are published per region: US, Canada, EU/UK and India 4.

NAT. Five9 supports NAT/PAT on the customer network but does not support Double NAT 12.

VPN. Customers using split-tunnel VPN should not exclude Five9 domains from their VPN, to keep DNS resolution consistent 52.

Bandwidth and latency. Five9 lists 128 kbps per agent for Agent Desktop Plus and Plus adapters 6. Agents connecting over VPN need an additional 64 kbps per agent 6. Five9 requires one-way latency from the customer system to the Five9 data center to be under 150 ms 19.

Connection type. Five9 recommends wired connections for best results but supports wireless LANs (Wi-Fi) for agents 57. Satellite and wireless Internet connections, such as 5G and cellular, are not supported for Five9 9.

QoS. Five9 VCC applies DiffServ markings to SIP and RTP packets for VoIP calls leaving Five9 toward the customer or provider network 28. Five9 VCC does not set the DSCP header on packets leaving the agent workstation toward the Five9 network 30. For upstream voice marking, Five9 recommends either a Windows QoS policy on the workstation or QoS tagging on network equipment, configured with the equipment vendor or an internal network engineer 29.

Audio devices and headsets

Device selection. Five9 recommends selecting the system default audio devices in Agent Desktop Plus, because system defaults can override Five9 settings 35. With the system defaults selected, call notifications and voicemail are heard 35. Five9 does not recommend built-in audio devices for Agent Desktop Plus, because they can cause extreme audio interference 7. If a headset does not appear or cannot be selected in the Agent Desktop Plus audio device menu, Five9 suggests updating the device drivers from the manufacturer 11.

Device settings. Agent Desktop Plus audio device settings include Audio Output, Microphone, Automatic Gain Control and Acoustic Echo Cancellation 3. Changes to these settings are saved with Apply 3.

Headsets. Five9 recommends USB-connected headsets with noise-cancelling features for agents and supervisors 17. Analog headsets are not supported for Five9 agents and supervisors 5. Five9 does not recommend wireless headsets when more than 10 agents are active at the same time 58. Five9 cites voice-quality degradation and audio delay from wireless LAN technology as the reason 58.

Diagnosing it

Maximum active sessions error. If Agent Desktop Plus reports that the maximum number of active sessions has been exceeded, Five9 tells the agent to wait up to 30 minutes before logging in again 20. The wait lets stations expire and return to the available pool 20.

Built-in tests

Echo call. An echo call records the agent's speech and plays it back 13. The agent starts it from Help > Echo Call while in the Not Ready state 13.
Voice Connectivity Test. Agent Desktop Plus offers Help > Voice Connectivity Test, which Five9 says to run when instructed by the administrator or Five9 51.
Network Assessment Test. The Five9 Network Assessment Test on quality.five9.com uses outbound TCP 8080/8081 to verify that the customer network is ready for Five9 traffic 21.
Connectivity Assessment Test. This test needs the following outbound and test ports 8:
- outbound TCP 80 and 443 8
- TCP/UDP 5060, for SIP simulation 8
- TCP 8080-8081 8
- UDP 8090, for capacity and bandwidth testing 8
- TCP 20000-20001, for speed tests 8
- UDP 20000-20001, for VoIP tests 8

One-way audio. WarmTransfer's reading of the sources is that one-way audio on a Five9 softphone or gateway station most plausibly traces to blocked RTP return traffic on a non-stateful firewall, an active SIP ALG or inspection feature, an overreacting IPS, or Double NAT 22. This is inferred from the fact that these are the media-path conditions Five9's own requirements single out 22.

Isolating the fault with a PSTN station. We infer that temporarily logging an agent in on a PSTN station is a reasonable isolation step 27. We infer that if audio becomes clean on the PSTN station, the fault is likely in the workstation network, softphone or headset path rather than in Five9 call handling 27.

Collecting logs

Softphone logs. Five9 Softphone logs are collected from the system tray icon with 'Collect logs into a ZIP file' 43. The file is saved to Downloads as five9-softphone-report-.zip and is retained on the computer for 4 days 43.
Windows log folder. On Windows, Five9 Softphone logs are also found under C:\Users<user>\AppData\Local\Five9\Five9Softphone-10.0\logs 42.
Agent Desktop Plus event logs. These are gathered from Help > Show Application Logs and take 30-60 seconds to collect 1. They can be downloaded or attached to a support ticket with Log Issue 1.

Applicability

Applies to: Five9 Agent Desktop Plus, Five9 Softphone, and Five9 Virtual Contact Center. Deployments: multi-tenant. Sources checked 2026-10-02. The supported voice client versions listed in this article are those Five9 lists as of 2026-09-30 41. Five9 publishes its allow-list domains and IP address ranges for the US, Canada, EU/UK and India regions 4.

What remains uncertain

WebRTC no-audio and permission failures. How to recover from a Five9 WebRTC station with no audio, or from a denied browser permission, is not covered by the sources below.
Recommended headset models. The contents of Five9's Recommended Headsets list are not covered by the sources below.
Browser extension installation. The steps of the Five9 Softphone browser extension installation page are not covered by the sources below.
Jitter and packet loss. Five9 jitter and packet-loss thresholds for agents are not covered by the sources below.
Connectivity Assessment Test procedure. The Connectivity Assessment Test entry URL and procedure are not covered by the sources below.
DSCP values. The specific DSCP code points Five9 applies to egress SIP and RTP are not covered by the sources below.
Voice Connectivity Test scope. What the Agent Desktop Plus Voice Connectivity Test measures is not covered by the sources below.
Log folder version mismatch. Why the Five9Softphone-10.0 folder name in the Windows log path differs from the Softphone Installer 14.0.5 version is not covered by the sources below.

Sources

1
Agent Desktop Plus event logs are gathered from Help > Show Application Logs, take 30-60 seconds to collect, and can be downloaded or attached to a support ticket with Log Issue.
Troubleshooting Your Application · Troubleshooting Your Application; Event Logs · Checked 2026-10-02
2
To process voice interactions, Five9 Agent Desktop Plus connects to one of four station types (softphone, WebRTC, PSTN or gateway), and a No Station option also exists.
Selecting a Station (Agent Desktop Plus) · Selecting a Station; opening paragraph · Checked 2026-10-02
3
Agent Desktop Plus audio device settings include Audio Output, Microphone, Automatic Gain Control and Acoustic Echo Cancellation, and changes are saved with Apply.
Audio Device Settings · Audio Device Settings; Audio Devices list · Checked 2026-10-02
4
Five9 requires customers to add Five9 Internet domains and IP address ranges, published per region (US, Canada, EU/UK, India), to their allow list.
Five9 Internet Domains and IP Addresses · Five9 Internet Domains and IP Addresses; opening and regional tables · Checked 2026-10-02
5
Analog headsets are not supported for Five9 agents and supervisors.
Headset for Agents and Supervisors · Headset for Agents and Supervisors; sentence 2 · Checked 2026-10-02
6
Five9 lists 128 kbps per agent for Agent Desktop Plus and Plus adapters, plus an additional 64 kbps per agent when connecting over VPN.
Five9 Network Requirements (LAN and WAN) · Five9 Network Requirements (LAN and WAN); bandwidth table · Checked 2026-10-02
7
Five9 does not recommend built-in audio devices for Agent Desktop Plus because they can cause extreme audio interference.
Selecting Audio Devices · Selecting Audio Devices; warning · Checked 2026-10-02
8
The Five9 Connectivity Assessment Test needs outbound TCP 80 and 443, TCP/UDP 5060 for SIP simulation, TCP 8080-8081, UDP 8090 for capacity and bandwidth testing, TCP 20000-20001 for speed tests and UDP 20000-20001 for VoIP tests.
TCP and UDP Ports for Connectivity Assessment Test · TCP and UDP Ports for Connectivity Assessment Test; port table · Checked 2026-10-02
9
Satellite and wireless Internet connections such as 5G and cellular are not supported for Five9.
Five9 Network Requirements (LAN and WAN) · Five9 Network Requirements (LAN and WAN); Satellite and wireless Internet · Checked 2026-10-02
10
Chromebooks are supported for Five9 WebRTC only because the Five9 Softphone plug-in cannot be installed on them.
Workstation Requirements for Web-Based Applications · Workstation Requirements for Web-Based Applications; Chromebook note · Checked 2026-10-02
11
If a headset does not appear or cannot be selected in the Agent Desktop Plus audio device menu, Five9 suggests updating the device drivers from the manufacturer.
Selecting Audio Devices · Selecting Audio Devices; device not listed paragraph · Checked 2026-10-02
12
Five9 supports NAT/PAT on the customer network but does not support Double NAT.
Five9 Network Requirements (LAN and WAN) · Five9 Network Requirements (LAN and WAN); NAT/PAT · Checked 2026-10-02
13
In Agent Desktop Plus an echo call, which records the agent's speech and plays it back, is started from Help > Echo Call while the agent is in the Not Ready state.
Testing and Adjusting Your Headset · Testing and Adjusting Your Headset; echo test · Checked 2026-10-02
14
Five9 gateway stations are used with IP phone systems, and calls to and from the Five9 contact center are processed across the Internet; the agent answers the gateway phone when it rings and listens for three tones.
Gateway Station (Agent Desktop Plus) · Gateway Station; introduction and steps 5-6 · Checked 2026-10-02
15
For Five9 gateway customers, SIP to the agent's endpoint is inbound UDP with a default of 5060, but the actual port depends on what the customer uses for the SIP endpoint.
TCP/UDP Port Requirements for Gateway Customers · TCP/UDP Port Requirements for Gateway Customers; row 5060 · Checked 2026-10-02
16
A Five9 gateway station address is supplied by the administrator and combines a port number with the public IP address designated for the domain's gateway access.
Gateway Station (Agent Desktop Plus) · Gateway Station; procedure step 2 · Checked 2026-10-02
17
Five9 recommends USB-connected headsets with noise-cancelling features for agents and supervisors.
Headset for Agents and Supervisors · Headset for Agents and Supervisors; sentence 1 · Checked 2026-10-02
18
Five9 warns that an intrusion prevention system that overreacts to normal SIP and RTP traffic to and from Five9 can cause service interruptions.
Five9 Internet Domains and IP Addresses · Five9 Internet Domains and IP Addresses; IPS note · Checked 2026-10-02
19
Five9 requires one-way latency from the customer system to the Five9 data center to be under 150 ms.
Five9 Network Requirements (LAN and WAN) · Five9 Network Requirements (LAN and WAN); latency · Checked 2026-10-02
20
If Five9 Agent Desktop Plus reports that the maximum number of active sessions has been exceeded, Five9 tells the agent to wait up to 30 minutes before logging in again so stations can expire and return to the available pool.
Selecting a Station (Agent Desktop Plus) · Selecting a Station; note on maximum active sessions error · Checked 2026-10-02
21
TCP 8080/8081 outbound is used by the Five9 Network Assessment Test on quality.five9.com to verify that the customer network is ready for Five9 traffic.
TCP/UDP Port Requirements for Gateway Customers · TCP/UDP Port Requirements for Gateway Customers; row 8080/8081 · Checked 2026-10-02
22
One-way audio on a Five9 softphone or gateway station most plausibly traces to blocked RTP return traffic on a non-stateful firewall, an active SIP ALG or inspection feature, an overreacting IPS, or Double NAT, since these are the media-path conditions Five9's own requirements single out.inferred
TCP/UDP Port Requirements for Softphone Customers · Row 1024-65535; read with SIP Firewall Note, IPS note and LAN/WAN Double NAT statement · Checked 2026-10-02
23
When connecting a Five9 PSTN station the agent answers the phone when it rings, and three tones on the PSTN device indicate a successful station connection.
PSTN Station (Agent Desktop Plus) · PSTN Station; procedure steps 3-4 · Checked 2026-10-02
24
Five9 advises agents to get administrator permission before logging into a PSTN station or forwarding calls between sessions because high long-distance fees may be incurred.
PSTN Station (Agent Desktop Plus) · PSTN Station; important note · Checked 2026-10-02
25
Because the Five9 PSTN-customer port table lists only web, Java RMI, download and test ports and no SIP or RTP range, the agent's voice path on a PSTN station does not depend on workstation VoIP firewall rules.inferred
TCP/UDP Port Requirements for PSTN Customers · TCP/UDP Port Requirements for PSTN Customers; full table · Checked 2026-10-02
26
For a Five9 PSTN station, U.S. agents enter a standard ten-digit number and European contact centers enter the number in ITU-T E.164 international format including the country code.
PSTN Station (Agent Desktop Plus) · PSTN Station; procedure step 1 · Checked 2026-10-02
27
Temporarily logging an agent in on a PSTN station is a reasonable isolation step: if audio becomes clean, the fault is likely in the workstation network, softphone or headset path rather than in Five9 call handling.inferred
PSTN Station (Agent Desktop Plus) · PSTN Station page read with TCP/UDP Port Requirements for PSTN Customers · Checked 2026-10-02
28
Five9 VCC applies DiffServ markings to SIP and RTP packets for VoIP calls leaving Five9 toward the customer or provider network.
Five9 Quality of Service (QoS) Features · Five9 Quality of Service (QoS) Features; body · Checked 2026-10-02
29
For upstream voice marking Five9 recommends a Windows QoS policy on the workstation, or QoS tagging on network equipment configured with the equipment vendor or an internal network engineer.
Five9 Quality of Service (QoS) Features · Five9 Quality of Service (QoS) Features; recommendations · Checked 2026-10-02
30
Five9 VCC does not set the DSCP header on packets leaving the agent workstation toward the Five9 network.
Five9 Quality of Service (QoS) Features · Five9 Quality of Service (QoS) Features; body · Checked 2026-10-02
31
Five9 warns that agents running many browser tabs besides Five9 need adequate RAM or session disconnects could occur; it lists 8 GB minimum and 16 GB recommended.
Workstation Requirements for Web-Based Applications · Workstation Requirements for Web-Based Applications; hardware tables and note · Checked 2026-10-02
32
Five9 tells customers not to use TCP/UDP ports 8080, 9998, 11000 or 30059 for any third-party services or applications on agent desktop computers.
Other VoIP Services and Phones, Ports, IP Address Ranges, and Network Traffic · Other VoIP Services and Phones...; reserved ports paragraph · Checked 2026-10-02
33
Five9 softphone RTP uses outbound UDP 1024-65535, and if the firewall is not stateful inbound rules must be configured to allow the return traffic.
TCP/UDP Port Requirements for Softphone Customers · TCP/UDP Port Requirements for Softphone Customers; row 1024-65535 · Checked 2026-10-02
34
UDP 8000-8015 is the source port range used for RTP traffic on the agent desktop for Five9 softphone customers.
TCP/UDP Port Requirements for Softphone Customers · TCP/UDP Port Requirements for Softphone Customers; row 8000-8015 · Checked 2026-10-02
35
Five9 recommends selecting the system default audio devices in Agent Desktop Plus so call notifications and voicemail are heard, because system defaults can override Five9 settings.
Selecting Audio Devices · Selecting Audio Devices; main recommendation · Checked 2026-10-02
36
Five9's SIP Firewall Note cautions that the site may run other SIP services or applications that require these SIP inspection features to stay enabled.
SIP Firewall Note · SIP Firewall Note; note · Checked 2026-10-02
37
Five9 asks that SIP ALG, SIP Inspection and Control, SIP Traversal and SIP Transformation be disabled for Five9 traffic because default firewall inspect settings alter SIP/VoIP traffic.
SIP Firewall Note · SIP Firewall Note; body and feature list · Checked 2026-10-02
38
The Five9 SIP proxy uses UDP 5080 for SIP signaling and TCP 5081 for SIP over TLS, both outbound from the customer network.
TCP/UDP Port Requirements for Softphone Customers · TCP/UDP Port Requirements for Softphone Customers; rows 5080 and 5081 · Checked 2026-10-02
39
On macOS the Five9 Softphone is installed from Five9Softphone.dmg choosing 'For me only' in the wizard, Finder access must be granted when prompted, and an existing softphone is removed automatically.
Installing the Softphone · Installing the Softphone; macOS procedure · Checked 2026-10-02
40
Five9 documents installing the browser extension as a prerequisite to installing the Five9 Softphone for Agent Desktop Plus.
Installing the Softphone · Installing the Softphone; prerequisites · Checked 2026-10-02
41
As of 2026-09-30 Five9 lists Softphone Installer 14.0.5, Chrome/Edge extension 13.1.2 (recommended) or 13.1.1, and Firefox extension 11.6.0 as supported voice client versions.
Workstation Requirements for Web-Based Applications · Workstation Requirements for Web-Based Applications; Supported Voice Client Software Versions table · Checked 2026-10-02
42
On Windows, Five9 Softphone logs are also found under C:\Users\<user>\AppData\Local\Five9\Five9Softphone-10.0\logs.
Troubleshooting Your Application · Troubleshooting Your Application; Softphone Logs, Windows path · Checked 2026-10-02
43
Five9 Softphone logs are collected from the system tray icon with 'Collect logs into a ZIP file', saved to Downloads as five9-softphone-report-<date-and-time>.zip, and retained on the computer for four days.
Troubleshooting Your Application · Troubleshooting Your Application; Softphone Logs · Checked 2026-10-02
44
On Windows the Five9 Softphone is installed from the file Five9Softphone.msi by running its setup wizard, after which the Station Check page confirms the extensions are installed.
Installing the Softphone · Installing the Softphone; Windows procedure · Checked 2026-10-02
45
TCP port 8083 is required by the Five9 Softphone Service on agent workstations, no other process may use it, and an exception is needed when an HTTP proxy is used.
TCP/UDP Port Requirements for Softphone Customers · TCP/UDP Port Requirements for Softphone Customers; row 8083 · Checked 2026-10-02
46
Five9 softphone customers must allow outbound UDP 5060-5067 for the agent application's SIP connection.
TCP/UDP Port Requirements for Softphone Customers · TCP/UDP Port Requirements for Softphone Customers; row 5060-5067 · Checked 2026-10-02
47
The Softphone station option in Five9 Agent Desktop Plus uses the agent's computer for calls and is the default station option.
Softphone Station (Agent Desktop Plus) · Softphone Station; option description · Checked 2026-10-02
48
After installation a Five9 Softphone icon in the system tray shows the connection status between the browser and the softphone as waiting, connected or error.
Softphone Status Indicator · Softphone Status Indicator; body paragraph · Checked 2026-10-02
49
In Five9 the administrator creates station pools, and station IDs are assigned by a supervisor or administrator; an agent assigned to more than one pool can change pools during station setup.
Selecting a Station (Agent Desktop Plus) · Selecting a Station; station pool paragraphs · Checked 2026-10-02
50
Five9 Agent Desktop Plus users on tablets must select WebRTC as the station connection type.
Selecting a Station (Agent Desktop Plus) · Selecting a Station; tablet users note · Checked 2026-10-02
51
Agent Desktop Plus offers Help > Voice Connectivity Test, which Five9 says to run when instructed by the administrator or Five9.
Testing and Adjusting Your Headset · Testing and Adjusting Your Headset; voice connectivity test · Checked 2026-10-02
52
Customers using split-tunnel VPN should not exclude Five9 domains from their VPN, to keep DNS resolution consistent.
Five9 Network Connectivity · Five9 Network Connectivity; VPN note · Checked 2026-10-02
53
Users on Citrix workstations cannot use WebRTC and the Five9 Softphone in the same browser.
WebRTC Station (Agent Desktop Plus) · WebRTC Station; Citrix note · Checked 2026-10-02
54
A successful Five9 WebRTC station connection plays three tones on the audio device and shows 'WebRTC Connected' in Agent Desktop Plus, with the browser tab showing a red recording dot.
WebRTC Station (Agent Desktop Plus) · WebRTC Station; result after procedure · Checked 2026-10-02
55
Setting up a Five9 WebRTC station requires granting the browser microphone access when prompted and confirming the speaker and microphone selections.
WebRTC Station (Agent Desktop Plus) · WebRTC Station; procedure steps 3-4 · Checked 2026-10-02
56
Five9 WebRTC customers need outbound TCP 443 and outbound UDP 1024-65535 for RTP, and all ports opened for RTP must also allow STUN.
TCP/UDP Port Requirements for WebRTC Customers · TCP/UDP Port Requirements for WebRTC Customers; both rows · Checked 2026-10-02
57
Five9 recommends wired connections for best results but supports wireless LANs (Wi-Fi) for agents.
Five9 Network Requirements (LAN and WAN) · Five9 Network Requirements (LAN and WAN); Wireless LANs · Checked 2026-10-02
58
Citing voice-quality degradation and audio delay from wireless LAN technology, Five9 does not recommend wireless headsets when more than 10 agents are active at the same time.
Headset for Agents and Supervisors · Headset for Agents and Supervisors; sentences 3-4 · Checked 2026-10-02

Documents

tier 2 current vendor documentation

Cite this page

APA

WarmTransfer. (2026, October 2). Troubleshooting Five9 softphone and station connection problems. WarmTransfer. https://warmtransfer.net/knowledge/five9-softphone-troubleshooting

BibTeX

@misc{warmtransfer-five9-softphone-troubleshooting,
  title  = {Troubleshooting Five9 softphone and station connection problems},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/five9-softphone-troubleshooting},
  note   = {Verified 2026-10-02}
}