Re: [SR-Users] IMS IPSec does use UDP socket?

Hello, not sure why you think that the ims_ipsec_pcscf module is listening only on UDP. It seems to be also listening on TCP: //add listen interfaces for IPv4 if(add_listen_iface(addr4, NULL, ipsec_client_port + i, PROTO_TCP, 0) != 0) { LM_ERR("Error adding listen ipsec client TCP interface for IPv4\n"); return -1; } if(add_listen_iface(addr4, NULL, ipsec_server_port + i, PROTO_TCP, 0) != 0) { LM_ERR("Error adding listen ipsec server TCP interface for IPv4\n"); return -1; } if(add_listen_iface(addr4, NULL, ipsec_client_port + i, PROTO_UDP, 0) != 0) { LM_ERR("Error adding listen ipsec client UDP interface for IPv4\n"); return -1; } if(add_listen_iface(addr4, NULL, ipsec_server_port + i, PROTO_UDP, 0) != 0) { LM_ERR("Error adding listen ipsec server UDP interface for IPv4\n"); return -1; } Cheers, Henning -- Henning Westerholt – https://skalatan.de/blog/ Kamailio services – https://gilawa.com<https://gilawa.com/> From: sr-users &lt;sr-users-bounces(a)lists.kamailio.org&gt; On Behalf Of H Yavari Sent: Thursday, May 20, 2021 3:01 AM To: Kamailio (SER) - Users Mailing List &lt;sr-users(a)lists.kamailio.org&gt; Subject: [SR-Users] IMS IPSec does use UDP socket? Hi to all, I am interested in the implementation of IPsec module. When I run Kamailio, it is creating processes based on the below formulate: UDP children * IPSEC_MAX_CONN * interfaces (v4 and v6) + (TCP+UD) processes for each interface. For example: children = 16 tcp_children=16 IPSEC_MAX_CONN = 25 and two interface : IPv6 and V4 Kamailio process count = (16 * 25 * 2 ) + 16 + 16 = 832 But why IPsec module is listening to UDP not TCP? this is an internal connection? Thank you. Regards, Hossein