236 Callback initiation too early
Callback initiation denied because it is too early from the initiation call from same CallerID.
E.g. First call is made from same CallerID and all other attempts to initiate callback are denied if they are too early.
It is not allowed to initiate more callback attempts from same CallerID in the time period, which is necessary to wait after Callback Initiation Call and Call Leg A. This period is set in Callback Dial-Plan Edit window (Wait (s)).
Such callback initiation control is implemented due to the case when providers send several INVITE packets for the same call.
Using this protection, only first INVITE will initiate the callback. All other attempts will be dropped with such HGC: 236
If you see such HGC near your call - also check for the good call, which should be made for first INVITE.
And you can ignore all these following call attempts or you can contact your DID Provider by asking to fix they call sending routines to avoid several INVITES.
By our experience DID Providers do not care to do that.
