In a recent KB article, Yeastar elected to eliminate the call waiting setting for extensions in the PBX instead relying on the user to make the needed settings in the phones associated to the extensions.
In my opinion, the was/is a poor move on Yeastar's part -
Yeastar has apparently forgotten that by removing the function from the PBX, that the PBX must now rely upon the phone to respond to any INVITE sent and that even if the phone is on a call already, the PBX must still send the call which is causing unneeded network traffic and the phone may still chirp or ring upon seeing the INVITE before it then sends a 486 busy. Had it been a setting at the PBX, then the PBX would know a call is already in progress and it would not send the call, but rather follow the rules for the busy extension.
It also means that for those extensions with multiple concurrent registrations, that each phone must be set to disable call waiting, but even so that the PBX will still send even more worthless messaging and that it is possibly even more confusing to set the parameter in each and every phone where call waiting is not to be enabled (and especially troublesome for remote phones). Further, if any phone associated to an extension is not set the same, then those will still ring despite the intent not being able to have call waiting.
Additionally as this was a change that was made mid-stream, there was nothing to suggest what might be the impact to those extensions already provisioned with the call waiting disabled at the PBX level. Is it still in place? Is it gone and now folks need to make a change to the phones?
This was an extremely short-sighted decision on the part of Yeastar.
I would like to see the setting re-instated. I and many others are fully aware of the function and if some users are not and it causes some issues, then they can read the manual, post to the forum, submit a ticket, learn how it works, but as it stands now, those of us that do know how it works and could/can use the function as Asterisk and the phone manufacturers intended....can't. I do not like the idea of any functionality being deprecated or removed.