Found my answer, use correct version of doc: https://kamailio.org/docs/modules/5.2.x/modules/ims_usrloc_pcscf.html#idm10… From: sr-users &lt;sr-users-bounces(a)lists.kamailio.org&gt; On Behalf Of Martin W Woscek Sent: Wednesday, June 17, 2020 8:47 AM To: Kamailio (SER) - Users Mailing List &lt;sr-users(a)lists.kamailio.org&gt; Subject: [SR-Users] kamailio 5.2.2 enabling hashing_type Hello, I'm revisiting some initial issues I had with P-CSCF. I could not set the hashing type in my PCSCF (kamalio 5.2.2) so I simply commented it out and moved on. But now, I may need it as the P-CSCF is not handling INVITES coming from I-CSCF that originated from external SIP server, where the endpoint (UE) is registered to the IMS but the P-CSCF sends the INVITE back to the S rather that the registered UE and fails. kamailio.cfg: modparam("ims_usrloc_pcscf", "hashing_type", 1) So with that, when I set the hashing_type to 1,1 or 2 I get the following starting the pcscf: Starting the P-CSCF: Jun 17 08:25:30 ubuntu kamailio_pcscf[5753]: * Not starting Kamailio IMS P-CSCF: invalid configuration file! Jun 17 08:25:30 ubuntu kamailio_pcscf[5753]: * Jun 17 08:25:30 ubuntu kamailio_pcscf[5753]: * 0(5766) ERROR: <core> [core/modparam.c:140]: set_mod_param_regex(): parameter <hashing_type> of type <2> not found in module <ims_usrloc_pcscf> Jun 17 08:25:30 ubuntu kamailio_pcscf[5753]: 0(5766) CRITICAL: <core> [core/cfg.y:3510]: yyerror_at(): parse error in config file /etc/kamailio/pcscf/kamailio.cfg, line 364, column 47: Can't set module parameter Am I missing some module that I did not include at compile time? According to the docs, it has no additional dependencies other than the ims_usrloc_pcscf.so https://kamailio.org/docs/modules/5.0.x/modules/ims_usrloc_pcscf.html#idp35… Any help is appreciated. Thanks, _Martin