Troubleshooting Guides

8.6 Troubleshooting Procedures

8.6.1 Troubleshooting Decision Tree

+-----------------------------------------------------------------+
|  WEBEX CALLING TROUBLESHOOTING DECISION TREE                     |
+-----------------------------------------------------------------+
|                                                                 |
|  USER REPORTS ISSUE                                            |
|  |                                                              |
|  +-> No dial tone / Phone not working                          |
|  |   +-> Check phone registration -> 8.6.2                      |
|  |   +-> Check network connectivity -> 8.6.3                    |
|  |                                                              |
|  +-> Cannot make calls                                         |
|  |   +-> Internal calls fail -> 8.6.4                           |
|  |   +-> PSTN calls fail -> 8.6.5                               |
|  |                                                              |
|  +-> Cannot receive calls                                      |
|  |   +-> DID not ringing -> 8.6.6                               |
|  |   +-> Extension not ringing -> 8.6.7                         |
|  |                                                              |
|  +-> Poor call quality                                         |
|  |   +-> One-way audio -> 8.6.8                                 |
|  |   +-> Choppy/robotic audio -> 8.6.9                          |
|  |   +-> Echo -> 8.6.10                                         |
|  |                                                              |
|  +-> Voicemail issues                                          |
|  |   +-> Voicemail not working -> 8.6.11                        |
|  |                                                              |
|  +-> Feature not working                                       |
|      +-> Specific feature troubleshooting -> 8.6.12             |
|                                                                 |
+-----------------------------------------------------------------+

8.6.2 Phone Registration Issues

Procedure: Troubleshoot Phone Not Registering

Step	Check	Action if Failed
1	Phone powered on?	Check PoE / power adapter
2	Network link light on?	Check cable / switch port
3	Phone has IP address?	Settings -> Network -> IPv4
4	Phone can ping gateway?	Network test on phone
5	Phone can reach Webex?	DNS / firewall check
6	Phone in Control Hub?	Add device if missing
7	MAC address correct?	Verify in Control Hub
8	Correct firmware?	May need factory reset

Control Hub Verification:

Step	Action	Notes
1	Navigate to Devices	Device list
2	Search by MAC or user	Find device
3	Check Status	Should be "Online"
4	If Offline: Check "Last Seen"	Recent = network issue
5	Click device -> Troubleshoot	Diagnostic tools
6	Run connectivity test	From Control Hub

Reference: https://help.webex.com/article/n2wfv0j (Troubleshoot Devices)

8.6.3 Network Connectivity Issues

Procedure: Troubleshoot Network Path

Step	Check	Command/Tool
1	Phone IP configuration	Phone Settings -> Network
2	VLAN assignment correct	show mac address-table on switch
3	DNS resolution	nslookup webex.com from phone subnet
4	Firewall rules	Check FW logs for blocks
5	Proxy bypass	Verify Webex domains excluded
6	SSL inspection	Must be disabled for Webex
7	QoS marking	Packet capture / show policy-map

Network Test from Phone:

Step	Action
1	On phone: Settings -> Admin Settings -> Network
2	Run Network Test
3	Review results: DNS, HTTP, Media
4	Note any failures

8.6.4 Internal Call Failures

Procedure: Troubleshoot Internal Calls

Step	Check	Action
1	Caller phone registered?	Control Hub device status
2	Callee phone registered?	Control Hub device status
3	Extensions correct?	User -> Calling -> Numbers
4	Same location?	Verify dial plan
5	Different location?	Check site-to-site routing
6	Webex-to-CUCM call?	Check coexistence trunk
7	Check call history	User -> Calling -> Call History
8	Check error code	Analytics -> Troubleshooting

Common Error Codes:

Code	Meaning	Resolution
404	User not found	Check extension/routing
480	Temporarily unavailable	Device offline
486	Busy	User on another call
503	Service unavailable	Platform issue - check status

8.6.5 PSTN Call Failures

Procedure: Troubleshoot PSTN Outbound

Step	Check	Action
1	User has PSTN access?	Calling permissions
2	Correct dial string?	Include country code
3	PSTN trunk active?	Control Hub -> PSTN
4	For India: Correct Zone?	Toll bypass routing
5	LGW registered? (India)	show voice register status
6	PSTN provider up?	Check provider portal
7	DIDs ported complete?	Number inventory
8	Check CDR for error	Call history

India-Specific PSTN Troubleshooting:

Symptom	Likely Cause	Resolution
Call fails to connect	Wrong LGW routing	Verify Zone assignment
Call connects but no audio	NAT/firewall	Check media ports
PSTN rejection	Provider trunk down	Contact Tata/Airtel
Caller ID wrong	LGW dial-peer	Check calling party transform

8.6.6 Inbound DID Issues

Procedure: Troubleshoot DID Not Ringing

Step	Check	Action
1	DID assigned to user?	Control Hub -> Numbers
2	User phone registered?	Device status
3	DID active with provider?	Provider portal
4	Number porting complete?	Check porting status
5	Call forward active?	May be forwarding elsewhere
6	DND enabled?	User setting
7	Test from different PSTN	Carrier issue?

8.6.7 Extension Not Ringing

Procedure: Troubleshoot Extension Issues

Step	Check	Action
1	Extension assigned?	User -> Calling
2	Extension unique?	No duplicates
3	Phone registered?	Device status
4	Do Not Disturb?	Disable DND
5	Call forward set?	Check forward settings
6	Ring setting correct?	Phone audio settings
7	Webex App signed in?	May ring App not phone

8.6.8 One-Way Audio

Procedure: Troubleshoot One-Way Audio

Step	Check	Likely Cause
1	Consistent direction?	Inbound vs outbound media
2	Specific users/locations?	Site-specific issue
3	Firewall symmetric?	Stateful inspection
4	NAT configuration	ALG disabled?
5	Media ports open	UDP 19560-65535
6	LGW media binding	Check bind statements

Common Resolutions:

Cause	Resolution
Firewall blocking media	Open UDP 19560-65535 outbound
SIP ALG enabled	Disable SIP ALG on firewall
NAT issue on LGW	Verify media bind interface
QoS dropping packets	Check QoS policy

8.6.9 Choppy/Robotic Audio

Procedure: Troubleshoot Audio Quality

Step	Check	Tool
1	Check call quality metrics	Control Hub Analytics
2	MOS score for call	Call details
3	Jitter values	Should be <30ms
4	Packet loss	Should be <1%
5	Network path	Traceroute to Webex
6	Local network congestion	Switch/router utilization
7	QoS applied?	Check DSCP marking
8	WiFi vs wired	WiFi more prone to issues

Quality Resolution Matrix:

Metric Issue	Likely Cause	Resolution
High jitter	Network congestion	QoS prioritization
High latency	Long path / congestion	Review routing
Packet loss	Congestion / errors	Check interface errors
Low MOS	Combination above	Comprehensive review

8.6.10 Echo Issues

Procedure: Troubleshoot Echo

Step	Check	Resolution
1	Which end hears echo?	Echo is at OTHER end
2	Speakerphone in use?	Use handset or headset
3	Headset quality?	Replace if poor quality
4	Phone volume too high?	Reduce speaker volume
5	Acoustic environment?	Add dampening
6	LGW echo cancellation	Enable echo-cancel

8.6.11 Voicemail Issues

Procedure: Troubleshoot Voicemail

Step	Check	Action
1	Voicemail enabled?	User -> Calling -> Voicemail
2	User knows PIN?	May need reset
3	Forward to VM working?	Check no-answer forward
4	VM pilot number correct?	Location settings
5	VM notification working?	Check email settings
6	Mailbox full?	Clear old messages

Reset Voicemail PIN:

Step	Action
1	Navigate to Users -> find user
2	Calling -> Voicemail
3	Click "Reset PIN"
4	User receives temporary PIN via email
5	User must set new PIN on first access

Reference: https://help.webex.com/article/n5qc5u4 (Voicemail Troubleshooting)

8.6.12 Feature Troubleshooting Quick Reference

Feature	Common Issue	Check
Hunt Group	Calls not distributing	Verify members registered
Call Park	Cannot retrieve	Park extension range correct?
Call Forward	Not forwarding	Feature enabled? Destination valid?
BLF	Status not updating	Monitored user registered?
Shared Line	Not ringing all	Virtual line assigned to all devices?
Call Recording	Not recording	Policy enabled? License assigned?

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