Hello i have an issue with Yealinks (Yealink SIP-T22P FM 7.72.18.5 )
our compeny have only 3 yealinks and the rest is Grandstream.
for some reasone the Yealinks does not give us a busy signal if im calling to
a busy phone number (like somone is allready on the phone) or if there is a music instad of a ring tone in some numbers we do not hear them.
we hear a regular dial tone.
can you please help?
somone reccomended me to change Early media setting so i did from disable to enable and it did not help.
The problem is that, sometimes, it is not an easy task for a UAC to
know whether it will be receiving early media or it should generate
local ringing. A UAS can send early media without using reliable
provisional responses (very simple UASs do that) or it can send an
answer in a reliable provisional response without any intention of
sending early media (this is the case when preconditions are used).
Therefore, by only looking at the SIP signalling, a UAC cannot be
sure whether or not there will be early media for a particular
session. The UAC needs to check if media packets are arriving at a
given moment.