A comment on our last post
Today I called my colleague Michael to ask him if bad quality at the end of a call wouldn’t also be visible in the signaling. His answer: “Maybe, but only if you look very closely.”
A call that is ended by the call parties due to bad voice quality will show as normal call clearing from the signaling perspective. However, network performance issues cause packet loss and jitter (see picture: signaling quality “Sig Q”– green, transport quality “TQ” – red).
This may lead to longer than usual Session Disconnect Delays due to retransmission of SIP messages. Yet, even if this increase is noticeable it may also have other reasons, such as overloaded signaling devices.
The QUIT indicator provides a much more convenient and reliable way of detecting bad in-call user experience.