[asterisk-users] What are "non critical" invites?

[Stefan Viljoen]

Hi All

I'm getting tens of thousands of these messages ever hour in the Asterisk
CLI for Asterisk 13.22.0:

[Apr 20 15:59:46] WARNING[45462]: chan_sip.c:4127 retrans_pkt: Timeout on
1924200000-502043860-301870737 on non-critical invite transaction.
[Apr 20 15:59:46] WARNING[45462]: chan_sip.c:4127 retrans_pkt: Timeout on
301794058-652332923-1834701069 on non-critical invite transaction.
[Apr 20 15:59:47] WARNING[45462]: chan_sip.c:4127 retrans_pkt: Timeout on
393288224-685421081-2030967079 on non-critical invite transaction.
[Apr 20 15:59:48] WARNING[45462]: chan_sip.c:4127 retrans_pkt: Timeout on
1724665510-1751083232-677093666 on non-critical invite transaction.
[Apr 20 15:59:49] WARNING[45462]: chan_sip.c:4127 retrans_pkt: Timeout on
1958221882-69806522-85947083 on non-critical invite transaction.
[Apr 20 15:59:49] WARNING[45462]: chan_sip.c:4127 retrans_pkt: Timeout on
1013186441-666073546-1030482332 on non-critical invite transaction.

If an invite is non-critical, why do it then?

What is the purpose of a "non-critical" invite.

My server mostly works, with occassional channels that get stuck and need to
be hung up manually, but otherwise is working fine.

I'm trying to identify what a non-critrical invite is, and if it is
non-critical, can it be turned off somehow?

Since it is explictily shown as "non-critical" - it means it can be
dispensed with, as it is non-critical.

Clearly, it IS critical, since it exists, but why the strange semantic of
calling it "non critical" - why do something that is non-critical and
therefore not necessary.

Thanks!

Stefan