I am using a PBX with a Analogue card that currently has 4 lines. In the trunk I have set the maximum channel to 1. I understand from some reading and the tooltip that inbound calls are not counted in this.
I have had complaints of cross lines and being able to hear other people talking in the background when making calls and I believe it is related to this issue. I have also read another post by someone who had pretty much the same issue and he mentioned it was due to this. He goes on to say that he had to change the context but does not provide further details.
My question is simply, how do I have a maximum of one call per trunk counting both outbound and inbound calls?
If you have a butt set (or a regular analog phone) check your lines and your wiring outside of the PBX to see if you have cross talk, eliminate that first before looking elsewhere.
What happens is a call out collides with a call in and the 2 calls are connected.
Here is how you attempt to correct this, Dial out opposite of the telco hunt.
If the telco hunt is 1->4 you call out 4->1
Your trunk is likely g0 which dials 1->4
Make it G0 which dials 4->1
This should reduce glare. If this does not then you need more lines. You can add additional analog lines or add sip lines.
It may not be a bad Idea to add a sip trunk for outbound calling. Let all your inbound calls come in to the current line and push all outbound calls over sip.
I should have mentioned in my initial post I have tested the lines and can hear nothing unexpected. I have taken the issue to the provider of the line and their engineer who came to the property about one of the other lines we have for ADSL, confirmed he found no issue with the lines.
Many thanks for you answer. This certainly makes sense to me that there would be a clash when two people call at the same time. Also as it is a call centre this makes the situation all the more likely as well as the fact the issue is not constant. I will look into implementing your solution, but at the risk of sounding daft, how would I go about implementing this. Do I simply say change the trunk order in Outbound routes.