Calls in queue, agent is ready and calls are not coming

[bghayad]

Hello;

vicibox 4.0.3, vicidial 2.8-404a, Build 130605-0841, asterisk 1.4.39.1-vici, Single Machine, Vtiger 5.4

I am facing a problem that sometimes the agent is ready and there is calls in the queue, and the call does not come to the agent ! The agent is OnHook and this stay for long time .. But when the agent do pause and then resume, the call come for it.

I have some settings and situation that understanding it maybe will help to reach to the reason of the problem:

1) There is call-limit=1 for each agent sip configuration to avoid getting call while the agent has another outbound call placed directly from the Phone (not from the application). This most probably is causing the queue to send the call to the agent but because of not allowed if the Phone is busy in outbound call, that cause the call to stay (or maybe return to the queue .. I do not know).
2) There is problem with these IP Phones GulfSIP phones, if the call came from the queue (and only from the queue, but it is coming as normal call "not from the queue .. but normal transfer call"), the agent press answer, but the call look like dropped (answered and then drop again). I placed the agent auto answer, it is better working "it is answering the calls" but some calls also dropped !!
HOW I CAN FORCE THE PHONE TO AUTO ANSWER FROM ASTERISK OR VICIDIAL CONFIGURATION?
Note: if agent Off Hook, all calls come to the Phone is answered properly and automatically.

My point: Does any of those above factors are affecting to not let the agent get a calls and he has to pause and then resume? Is it related to a settings that consider the agent in bad situation (after a lot of drop calls for example ..) so it is not sending the calls for it?

I read in the below link for a question at the forum that it was required to add some silent for the ON-HOOK lines at the extensions.conf:

viewtopic.php?p=79724

How I can overcome this?

I am fully thanks if someone can help me.
Regards
Bilal