Have just installed a 2820 IPPBX.
Have configured 2 extensions (yealink t22) and the SIP trunk which has successfully registered.
I can make outgoing calls but all incoming calls give a busy signal.
Have set-up an alias for the DDI on the trunk.

There are logs for the outgoing calls but nothing listed for incoming.
The ITSP is saying it's my set-up.
Not sure where to go from here.
Any help would be appreciated.

Frank

In the first instance I suggest you disable the alias on the SIP Trunk, and set the Answer mode to "Forward to Extension" and select one of the extensions you have set-up. This is the basic set-up. If this works, you can then look at the DDI if you have multiple numbers or set up a Hunt Group.

Thanks. doctord for your prompt reply.
I had setup all incomming calls to foward to a configured extension.
I removed the alias but still no joy.

However after some research I found that calls can be delivered in a number of ways (a bit of newbie with VOIP)
The call was being delivered to the PBX in the format SIP/user/DDI.
The ITSP removed the user/DDI bit and delivered the call to the SIP URL only.....and it worked.
My only concern is if I get additional DDI's in the future, I will have to ask them to add the DDI bit back in the call delivery.

I went on the SEG course which was great to get me of the ground, but am now hunting for practical resources to extend my knowledge.