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When the Cisco CallManager 4.x IPMA is in proxy mode configuration, and the service button is pressed on the IP phone of an assistant, the "HTTP ERROR [500]" error message appears

Core Issue

In IP Manager Assistant (IPMA) proxy mode, the phone of the manager and the assistant console work properly, and an assistant can log on to the phone and be seen online by the manager. But, when the assistant tries to access the IPMA service, the IP phone displays the HTTP ERROR [500] error message.

All of the other services run fine.


The appearance of the HTTP Error [500] is a normal behavior when an assistant user tries to access the IPMA Phone Service on the assistant phone, because assistants do not have access to this service. If an assistant is subscribed to that service, complete these steps:

  1. Navigate to http://[CCM_address]/CCMUser.

    Log in as the assistant.

  2. Choose Configure your Cisco IP Phone Services, and unsubscribe from IPMA Phone Service.

Refer to these sections of Cisco IP Manager Assistant With Proxy Line Support for more information about the interfaces that are available to the manager and the assistant: