Grandstream IPPBX UCM63XX – Failed to Bind a LDAP session

Grandstream UCM IP PBX Failed to bind a LDAP Session

Description This article describes the error Failed to bind LDAP session when configuring Phonebook Download Configuration in Grandstream IPPBX UCM63XX. The example shown on the phonebook Download Configuration page is not up-to-date. To avoid the binding error in UCM63XX, make sure you fill in cn=admin,dc=pbx,dc=com in the Username field. Go back to the LDAP Phonebook … Read more

Common Analog Trunk issues in Grandstream UCM63XX/62XX/6510


Description This article describes common Analog or PSTN trunk issues that happen in Grandstream PBX UCM63XX/62XX/6510. A list of suggestions is stated to deal with different scenarios in the customer’s setup. Issue 1: Noise or Echo Issue 2: Caller ID not showing or Undetected 0000 Issue 3: FXO port status is not reflected correctly in … Read more

Delays in Receiving Inbound Calls (Analog/VoIP Trunk)

Description The users experience 10 – 20s delays when receiving inbound calls, either through Analog or VoIP trunk. Outbound and internal calls (between extensions) work as expected. The More You Know Please ensure that the Call Control option under the Value-added Features > API Configuration page is disabled. When this option is enabled, the UCM will wait … Read more

Call Fails with 403 Forbidden (Invalid domain in From header) Error

403 Forbidden - feature image

Description We have configured the HA feature with two UCM630X successfully. We also configure a SIP Peer trunk with an Avaya PBX. However, when the phones are registered with HA Cluster IP address, the outbound calls fail with an error: The call is rejected by the server. The outbound call works if the phones are … Read more

Call Drop With Grandstream GXV3350 And Fanvil SIP Indoor Station

Description There is a call drop issue that involves Fanvil Indoor Station and Grandstream GXV3350 registered through UCM63XX. Missed calls are shown on the Fanvil SIP Indoor Station. However, a call goes through if it is dialed from GXV3240. Analysis We manage to capture the packets from UCM and analyze both good and bad calls … Read more

Error “LAN Port disconnected. Please connect LAN port to discover again.” in UCM’s Zero Config

Issue Zero Config that is unable to auto-detect different subnets. Error “LAN port is disconnected. Please connect LAN port to discover again” pops up each time running the scan Scenario or System InfoSystem Info: UCM6510 Range: UCM IP: GAC2500: Troubleshooting steps– UCM62XX can ping GAC2500 – GAC2500 can access UCM62XX. – Manual registration … Read more

Understanding Grandstream UCM Troubleshooting Tools and Syslog Modules

Grandstream UCM Syslog Modules for troubleshooting

Description Grandstream UCM has built-in troubleshooting tools under the Maintenance tab. They are : Process Log & Syslog Level CDR API Log: Monitors processes related to CDR API configuration and function. PBX MID Log: Monitors processes related to the CTI module. This includes CRM and PMS features, as well as web pages that use WebSocket … Read more

How to create UCM62XX’s backup config file with UCM63XX

To do create UCM62XX‘s backup config file with UCM63XX, please follow the steps below:

a. Create a config backup from the UCM62XX, attach the file as compressed to a support ticket. (If you are migrating from UCM6208 to UCM6304, remove the Analog configurations when you create the backup file)

b. Provide your UCM63XX’s SSH access

Navigate UCM63xx Web > System Settings > Security > SSH Access tab > Enable SSH Access: Check > Save & Apply.

c. Provide the UCM63XX’s public IP and login credentials of the super admin account

Our developers will check and attempt to create a compatible backup for UCM63XX.

If you have a firewall, please whitelist these IPs: , &


You can convert the configuration file of UCM62xx/UCM65xx to the configuration file of UCM63xx via GDMS portal. Login into your GDMS account, nagivate to UCM Backup and upload the configuration to perform the conversion.

Figure 1: Nagivate to UCM Backup and upload the configuration to perform the conversion.

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