16 Feb
2021
16 Feb
'21
3:43 p.m.
Björn Bylander writes:
My problem is this: When the Perimeta SBC sends its
first INVITE (I
can't say anything about any succeeding INVITEs yet) it's added a
Record-Route header with the "lr" parameter included which, as far as
I can see makes Kamailio think it should use loose routing which is
all well I think. But when the SBC sends an ACK for the "200 OK" from
the Kamailio side it doesn't include any Route headers and I think
that makes it hard for Kamailio (at least with the standard script
which is basically what I'm using) to know where to relay the ACK, at
least it makes the t_check_trans() call in WITHINDLG after
'is_method("ACK")' return false which makes the script ignore the
ACK.
Any thoughts or suggestions on how to handle this?
If the SBC does not include Route headers it learned from 200 OK R-R
headers into in-dialog requests (e.g. ACK) it break SIP RFC3261 and you
should ask them to fix their code or get your money back.
-- Juha