Agent Login Failure using Open Interface

Could you please help on the below error receiving on OI_RefClient.
The same OI_RefClient is working fine on CCT server and the .NET RefClient working fine from CCT server as well as from my workstation.

Error:

com.nortel.soa.oi.cct.faults.LoginAgentToTerminalException: [com.nortelnetworks.portal.cmf.core.ErrorCode@3c0bc388][A request response has returned with an error: sendRequestAndAwaitCompletion():Error - An Error has been returned by the Service Provider for the request Id[49277641-936b-401c-b2d0-cf734bfe6a2c] and Request Type[AddAgentAgentTerminalRequest] with errCode[Error - An agent terminal has failed to login. and sp errCode[0] and sp exMessage[Login failed because Agent Phoneset is unavailable. Please make sure the Phoneset is logged in.]][0] : SP Message :Login failed because Agent Phoneset is unavailable. Please make sure the Phoneset is logged in.

Thanks

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