modules: readme files regenerated - nathelper ... [skip ci]

src/modules/nathelper/README

@@ -1,796 +1,2 @@
-nathelper Module
 
-Maxim Sobolev
 
-   Sippy Software, Inc.
-
-Juha Heinanen
-
-   TuTPro, Inc.
-
-Edited by
-
-Maxim Sobolev
-
-Edited by
-
-Bogdan-Andrei Iancu
-
-Edited by
-
-Juha Heinanen
-
-Edited by
-
-Ovidiu Sas
-
-   Copyright © 2003-2008 Sippy Software, Inc.
-
-   Copyright © 2005 Voice Sistem SRL
-
-   Copyright © 2009 TuTPro Inc.
-
-   Copyright © 2010 VoIPEmbedded Inc.
-     __________________________________________________________________
-
-   Table of Contents
-
-   1. Admin Guide
-
-        1. Overview
-        2. NAT pinging types
-        3. Dependencies
-
-              3.1. Kamailio Modules
-              3.2. External Libraries or Applications
-
-        4. Parameters
-
-              4.1. force_socket (string)
-              4.2. natping_interval (integer)
-              4.3. ping_nated_only (integer)
-              4.4. natping_processes (integer)
-              4.5. natping_socket (string)
-              4.6. received_avp (str)
-              4.7. sipping_bflag (integer)
-              4.8. sipping_from (string)
-              4.9. sipping_method (string)
-              4.10. natping_disable_bflag (integer)
-              4.11. nortpproxy_str (string)
-              4.12. keepalive_timeout (int)
-              4.13. udpping_from_path (int)
-              4.14. append_sdp_oldmediaip (int)
-              4.15. filter_server_id (int)
-
-        5. Functions
-
-              5.1. fix_nated_contact()
-              5.2. fix_nated_sdp(flags [, ip_address])
-              5.3. add_rcv_param([flag]),
-              5.4. fix_nated_register()
-              5.5. nat_uac_test(flags)
-              5.6. is_rfc1918(ip_address)
-              5.7. add_contact_alias([ip_addr, port, proto])
-              5.8. handle_ruri_alias()
-              5.9. set_contact_alias()
-
-        6. Exported Pseudo Variables
-
-              6.1. $rr_count
-              6.2. $rr_top_count
-
-        7. RPC Commands
-
-              7.1. nathelper.enable_ping
-
-        8. Selects
-
-              8.1. @nathelper.rewrite_contact[n]
-
-   2. Frequently Asked Questions
-
-   List of Examples
-
-   1.1. Set force_socket parameter
-   1.2. Set natping_interval parameter
-   1.3. Set ping_nated_only parameter
-   1.4. Set natping_processes parameter
-   1.5. Set natping_socket parameter
-   1.6. Set received_avp parameter
-   1.7. Set sipping_bflag parameter
-   1.8. Set sipping_from parameter
-   1.9. Set sipping_method parameter
-   1.10. Set natping_disable_bflag parameter
-   1.11. Set nortpproxy_str parameter
-   1.12. Set keepalive_timeout parameter
-   1.13. Set udpping_from_path parameter
-   1.14. Set append_sdp_oldmediaip parameter
-   1.15. Set filter_server_id parameter
-   1.16. fix_nated_contact usage
-   1.17. fix_nated_sdp usage
-   1.18. add_rcv_paramer usage
-   1.19. fix_nated_register usage
-   1.20. nat_uac_test usage
-   1.21. is_rfc1918 usage
-   1.22. add_contact_alias usage
-   1.23. handle_ruri_alias usage
-   1.24. set_contact_alias usage
-   1.25. $rr_count usage
-   1.26. $rr_top_count usage
-   1.27. nathelper.enable_ping usage
-   1.28. @nathelper.rewrite_contact usage
-
-Chapter 1. Admin Guide
-
-   Table of Contents
-
-   1. Overview
-   2. NAT pinging types
-   3. Dependencies
-
-        3.1. Kamailio Modules
-        3.2. External Libraries or Applications
-
-   4. Parameters
-
-        4.1. force_socket (string)
-        4.2. natping_interval (integer)
-        4.3. ping_nated_only (integer)
-        4.4. natping_processes (integer)
-        4.5. natping_socket (string)
-        4.6. received_avp (str)
-        4.7. sipping_bflag (integer)
-        4.8. sipping_from (string)
-        4.9. sipping_method (string)
-        4.10. natping_disable_bflag (integer)
-        4.11. nortpproxy_str (string)
-        4.12. keepalive_timeout (int)
-        4.13. udpping_from_path (int)
-        4.14. append_sdp_oldmediaip (int)
-        4.15. filter_server_id (int)
-
-   5. Functions
-
-        5.1. fix_nated_contact()
-        5.2. fix_nated_sdp(flags [, ip_address])
-        5.3. add_rcv_param([flag]),
-        5.4. fix_nated_register()
-        5.5. nat_uac_test(flags)
-        5.6. is_rfc1918(ip_address)
-        5.7. add_contact_alias([ip_addr, port, proto])
-        5.8. handle_ruri_alias()
-        5.9. set_contact_alias()
-
-   6. Exported Pseudo Variables
-
-        6.1. $rr_count
-        6.2. $rr_top_count
-
-   7. RPC Commands
-
-        7.1. nathelper.enable_ping
-
-   8. Selects
-
-        8.1. @nathelper.rewrite_contact[n]
-
-1. Overview
-
-   This is a module to help with NAT traversal and reuse of TCP
-   connections. In particular, it helps symmetric UAs that don't advertise
-   they are symmetric and are not able to determine their public address.
-
-   The function fix_nated_contact() rewrites the “Contact” header field
-   with request's source address:port pair. The function fix_nated_sdp()
-   adds the active direction indication to SDP (flag 0x01) and updates the
-   source IP address too (flag 0x02). The function fix_nated_register()
-   exports exports the request's source address:port into an AVP to be
-   used during save() and should be used for “REGISTER” requests.
-
-   Note: fix_nated_contact changes the “Contact” header, thus it breaks
-   the RFC. Although usually this is not an issue, it may cause problems
-   with strict SIP clients. An alternative is to use add_contact_alias()
-   that together with the handle_ruri_alias() is standards conforming and
-   also supports reuse of TCP/TLS connections.
-
-2. NAT pinging types
-
-   Currently, the nathelper module supports two types of NAT pings:
-     * UDP packet - 4 bytes (zero filled) UDP packets are sent to the
-       contact address.
-          + Advantages: low bandwidth traffic, easy to generate by
-            Kamailio;
-          + Disadvantages: unidirectional traffic through NAT (inbound -
-            from outside to inside); As many NATs do update the bind
-            timeout only on outbound traffic, the bind may expire and
-            closed.
-     * SIP request - a stateless SIP request is sent to the UDP contact
-       address.
-          + Advantages: bidirectional traffic through NAT, since each PING
-            request from Kamailio (inbound traffic) will force the SIP
-            client to generate a SIP reply (outbound traffic) - the NAT
-            bind will be surely kept open.
-          + Disadvantages: higher bandwidth traffic, more expensive (as
-            time) to generate by Kamailio;
-
-3. Dependencies
-
-   3.1. Kamailio Modules
-   3.2. External Libraries or Applications
-
-3.1. Kamailio Modules
-
-   The following modules must be loaded before this module:
-     * usrloc module - only if the NATed contacts are to be pinged.
-
-3.2. External Libraries or Applications
-
-   The following libraries or applications must be installed before
-   running Kamailio with this module loaded:
-     * None.
-
-4. Parameters
-
-   4.1. force_socket (string)
-   4.2. natping_interval (integer)
-   4.3. ping_nated_only (integer)
-   4.4. natping_processes (integer)
-   4.5. natping_socket (string)
-   4.6. received_avp (str)
-   4.7. sipping_bflag (integer)
-   4.8. sipping_from (string)
-   4.9. sipping_method (string)
-   4.10. natping_disable_bflag (integer)
-   4.11. nortpproxy_str (string)
-   4.12. keepalive_timeout (int)
-   4.13. udpping_from_path (int)
-   4.14. append_sdp_oldmediaip (int)
-   4.15. filter_server_id (int)
-
-4.1. force_socket (string)
-
-   Socket to be used when sending NAT pings for UDP communication. If no
-   one specified, the OS will choose a socket.
-
-   Default value is “NULL”.
-
-   Example 1.1. Set force_socket parameter
-...
-modparam("nathelper", "force_socket", "127.0.0.1:5060")
-...
-
-4.2. natping_interval (integer)
-
-   Period of time in seconds between sending the NAT pings to all
-   currently registered UAs to keep their NAT bindings alive. Value of 0
-   disables this functionality.
-
-Note
-
-   Enabling the NAT pinging functionality will force the module to bind
-   itself to USRLOC module.
-
-   Default value is 0.
-
-   Example 1.2. Set natping_interval parameter
-...
-modparam("nathelper", "natping_interval", 10)
-...
-
-4.3. ping_nated_only (integer)
-
-   If this parameter is set to 1 then only contacts that have “behind_NAT”
-   flag in user location database set will get ping.
-
-   If it is 0 and sipping_flag is not set, then the 4-bytes UDP ping is
-   sent to all contacts. If it is 0 and sipping_flag parameter is set,
-   then SIP-request-based pinging is sent to all contacts.
-
-   Default value is 0.
-
-   Example 1.3. Set ping_nated_only parameter
-...
-modparam("nathelper", "ping_nated_only", 1)
-...
-
-4.4. natping_processes (integer)
-
-   How many timer processes should be created by the module for the
-   exclusive task of sending the NAT pings.
-
-   Default value is 1.
-
-   Example 1.4. Set natping_processes parameter
-...
-modparam("nathelper", "natping_processes", 3)
-...
-
-4.5. natping_socket (string)
-
-   Spoof the natping's source-ip to this address. Works only for IPv4.
-
-   Default value is NULL.
-
-   Example 1.5. Set natping_socket parameter
-...
-modparam("nathelper", "natping_socket", "192.168.1.1:5006")
-...
-
-4.6. received_avp (str)
-
-   The name of the Attribute-Value-Pair (AVP) used to store the URI
-   containing the received IP, port, and protocol. The URI is created by
-   fix_nated_register function of nathelper module and the attribute is
-   then used by the registrar to store the received parameters. Do not
-   forget to change the value of corresponding parameter in registrar
-   module if you change the value of this parameter.
-
-Note
-
-   You must set this parameter if you use fix_nated_register. In such case
-   you must set the parameter with same name in the “registrar” module to
-   same value.
-
-   Default value is "NULL" (disabled).
-
-   Example 1.6. Set received_avp parameter
-...
-modparam("nathelper", "received_avp", "$avp(i:42)")
-...
-
-4.7. sipping_bflag (integer)
-
-   Which branch flag should be used by the module to identify NATed
-   contacts for which it should perform NAT ping via a SIP request instead
-   of dummy UDP packet.
-
-   Default value is -1 (disabled).
-
-   Example 1.7. Set sipping_bflag parameter
-...
-modparam("nathelper", "sipping_bflag", 7)
-...
-
-4.8. sipping_from (string)
-
-   The parameter sets the SIP URI to be used in generating the SIP
-   requests for NAT ping purposes. To enable the SIP request pinging
-   feature, you have to set this parameter. The SIP request pinging will
-   be used only for requests marked so.
-
-   Default value is “NULL”.
-
-   Example 1.8. Set sipping_from parameter
-...
-modparam("nathelper", "sipping_from", "sip:[email protected]")
-...
-
-4.9. sipping_method (string)
-
-   The parameter sets the SIP method to be used in generating the SIP
-   requests for NAT ping purposes.
-
-   Default value is “OPTIONS”.
-
-   Example 1.9. Set sipping_method parameter
-...
-modparam("nathelper", "sipping_method", "INFO")
-...
-
-4.10. natping_disable_bflag (integer)
-
-   What branch flag should be used by the module to disable NAT pings on a
-   per-registration basis. If the given flag is set for a particular
-   registration, then no NAT pings will be sent at all, regardless of any
-   other conditions.
-
-   Default value is -1 (disabled).
-
-   Example 1.10. Set natping_disable_bflag parameter
-...
-modparam("nathelper", "natping_disable_bflag", 8)
-...
-
-4.11. nortpproxy_str (string)
-
-   The parameter sets the SDP attribute used by nathelper to mark the
-   packet SDP that information have already been mangled.
-
-   If empty string, no marker will be added or checked.
-
-Note
-
-   The string must be a complete SDP line, including the EOH (\r\n).
-
-   Default value is “a=nortpproxy:yes\r\n”.
-
-   Example 1.11. Set nortpproxy_str parameter
-...
-modparam("nathelper", "nortpproxy_str", "a=sdpmangled:yes\r\n")
-...
-
-4.12. keepalive_timeout (int)
-
-   The parameter sets the interval in seconds after which a natted contact
-   is removed from location table if it does not reply to SIP keepalives
-   (usually OPTIONS ping requests).
-
-   The features is available only for UDP contacts that are stored in
-   memory (not working for db only mode for usrloc module).
-
-   Keepalives are sent stateless, not using TM module. The value of this
-   parameter has to be few times higher than natping_interval.
-
-   Default value is “0” (feature disabled).
-
-   Example 1.12. Set keepalive_timeout parameter
-...
-modparam("nathelper", "keepalive_timeout", 120)
-...
-
-4.13. udpping_from_path (int)
-
-   Enable sending UDP pings (keepalives) using raw socket from Path
-   address.
-
-   Default value is “0” (feature disabled).
-
-   Example 1.13. Set udpping_from_path parameter
-...
-modparam("nathelper", "udpping_from_path", 1)
-...
-
-4.14. append_sdp_oldmediaip (int)
-
-   The parameter controls if oldmediaip field should be appended to the
-   SDP.
-
-   Default value is “1” (feature enabled).
-
-   Example 1.14. Set append_sdp_oldmediaip parameter
-...
-modparam("nathelper", "append_sdp_oldmediaip", 1)
-...
-
-4.15. filter_server_id (int)
-
-   Filter contacts by “server_id” core parameter. Use this parameter to
-   limit pinging. When set to “1”, only proxy instances which send packets
-   are those where core server_id matches server_id saved in usrloc.
-   Default value is “0” (disabled).
-
-   Example 1.15. Set filter_server_id parameter
-...
-modparam("nathelper", "filter_server_id", 1)
-...
-
-5. Functions
-
-   5.1. fix_nated_contact()
-   5.2. fix_nated_sdp(flags [, ip_address])
-   5.3. add_rcv_param([flag]),
-   5.4. fix_nated_register()
-   5.5. nat_uac_test(flags)
-   5.6. is_rfc1918(ip_address)
-   5.7. add_contact_alias([ip_addr, port, proto])
-   5.8. handle_ruri_alias()
-   5.9. set_contact_alias()
-
-5.1.  fix_nated_contact()
-
-   Rewrites the “Contact” header to contain the request's source
-   address:port.
-
-   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
-   BRANCH_ROUTE.
-
-   Example 1.16. fix_nated_contact usage
-...
-if (search("User-Agent: Cisco ATA.*") {fix_nated_contact();};
-...
-
-5.2.  fix_nated_sdp(flags [, ip_address])
-
-   Alters the SDP information in order to facilitate NAT traversal. What
-   changes to be performed may be controlled via the “flags” parameter.
-   Return value is -1 if error occurred, 1 if ip's were replaced, 2 if no
-   ip's were replaced.
-
-   Meaning of the parameters is as follows:
-     * flags - the value may be a bitwise OR of the following flags:
-          + 0x01 - adds “a=direction:active” SDP line;
-          + 0x02 - rewrite media IP address (c=) with source address of
-            the message or the provided IP address (the provide IP address
-            take precedence over the source address).
-          + 0x04 - adds “a=nortpproxy:yes” SDP line;
-          + 0x08 - rewrite IP from origin description (o=) with source
-            address of the message or the provided IP address (the provide
-            IP address take precedence over the source address).
-     * ip_address - IP to be used for rewriting SDP. If not specified, the
-       received signalling IP will be used. The parameter allows
-       pseudo-variables usage. NOTE: For the IP to be used, you need to
-       use 0x02 or 0x08 flags, otherwise it will have no effect.
-
-   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
-   FAILURE_ROUTE, BRANCH_ROUTE.
-
-   Example 1.17. fix_nated_sdp usage
-...
-if (search("User-Agent: Cisco ATA.*") {fix_nated_sdp("3");};
-...
-
-5.3.  add_rcv_param([flag]),
-
-   Add a received parameter to the “Contact” header fields (available for
-   all transports) or to the Contact URI (available only for UDP traffic).
-
-   The parameter will contain the URI created from the source IP, port,
-   and protocol (if different than UDP) of the packet containing the SIP
-   message. The parameter can be then processed by another registrar. This
-   is useful, for example, when replicating register messages using
-   t_replicate function to another registrar.
-
-   Meaning of the parameters is as follows:
-     * flag - flags to indicate if the parameter should be added to
-       Contact URI or Contact header. If the flag is non-zero, the
-       parameter will be added to the Contact URI. If not used or equal to
-       zero, the parameter will go to the Contact header.
-
-   This function can be used from REQUEST_ROUTE.
-
-   Example 1.18. add_rcv_paramer usage
-...
-add_rcv_param(); # add the parameter to the Contact header
-....
-add_rcv_param("1"); # add the parameter to the Contact URI
-...
-
-5.4.  fix_nated_register()
-
-   The function creates a URI consisting of the source IP, port, and
-   protocol and stores the URI in an Attribute-Value-Pair. The URI will be
-   appended as "received" parameter to Contact in 200 OK and registrar
-   will store it in the received column in the location table.
-
-   Note: You have to set the “received_avp” parameter of the nathelper
-   module and the registrar module (both module parameters must have the
-   same value) to use this function.
-
-   This function can be used from REQUEST_ROUTE.
-
-   Example 1.19. fix_nated_register usage
-...
-fix_nated_register();
-...
-
-5.5.  nat_uac_test(flags)
-
-   Tries to guess if client's request originated behind a nat. The
-   parameter determines what heuristics is used.
-
-   Meaning of the flags is as follows:
-     * 1 - The “Contact” header field is searched for occurrence of
-       RFC1918 or RFC6598 addresses.
-     * 2 - the "received" test is used: address in the “Via” header is
-       compared against source IP address of signaling. If the “Via”
-       header contains no port, it uses the default SIP port 5060
-     * 4 - The Top Most “Via” is searched for occurrence of RFC1918 or
-       RFC6598 addresses
-     * 8 - The SDP is searched for occurrence of RFC1918 or RFC6598
-       addresses
-     * 16 - Test if the source port is different from the port in the
-       “Via” header. If the “Via” header contains no port, it uses the
-       default SIP port 5060
-     * 32 - Test if the source IP address of signaling is a RFC1918 or
-       RFC6598 address
-     * 64 - Test if the source connection of signaling is a WebSocket
-     * 128 - Test if the “Contact” header URI port differs from the source
-       port of the request (Warning: this is might be legal or even
-       intended combination in non NATted scenarios)
-
-   All flags can be bitwise combined, the test returns true if any of the
-   tests identified a NAT.
-
-   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
-   FAILURE_ROUTE, BRANCH_ROUTE.
-
-   Example 1.20. nat_uac_test usage
-...
-if(nat_uac_test("19")) {
-    rtpproxy_manage("co");
-}
-...
-
-5.6.  is_rfc1918(ip_address)
-
-   Determines if the address in the parameter is an rfc1918 or rfc6598
-   address. The parameter allows pseudo-variables usage.
-
-   This function can be used from ANY_ROUTE.
-
-   Example 1.21. is_rfc1918 usage
-...
-if(is_rfc1918("$rd")) {
-    # domain in r-uri is private address
-}
-...
-
-5.7.  add_contact_alias([ip_addr, port, proto])
-
-   Adds an “;alias=ip~port~transport” parameter to the contact URI
-   containing either received ip, port, and transport protocol or those
-   given as parameters. If called without parameters, “;alias” parameter
-   is only added if received ip, port, or transport protocol differs from
-   that in contact URI.
-
-   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
-   BRANCH_ROUTE, and LOCAL_ROUTE.
-
-   Example 1.22. add_contact_alias usage
-...
-    if (!is_present_hf("Record-Route")) {
-        if (!add_contact_alias("$var(src_ip)", "$Rp", "tcp")) {
-            xlog("L_ERR", "Error in aliasing contact $ct\n");
-            send_reply("400", "Bad request");
-            exit;
-        };
-    };
-...
-
-5.8.  handle_ruri_alias()
-
-   Checks if the Request URI has an “alias” parameter and if so, removes
-   it and sets the “$du” based on its value. Note that this means that
-   routing of request is based on “;alias” parameter value of the Request
-   URI rather than the Request URI itself. If you call handle_ruri_alias()
-   on a request, make sure that you screen the alias parameter value of
-   Request URI the same way as you would screen the Request URI itself.
-
-   Returns 1 if “;alias” parameter was found and “$du” was set and the
-   “$ru” rewritten, 2 if the alias parameter was not found and nothing was
-   done, or -1 in case of error.
-
-   This function can be used from REQUEST_ROUTE, BRANCH_ROUTE, and
-   LOCAL_ROUTE.
-
-   Example 1.23. handle_ruri_alias usage
-...
-    if ($du == "") {
-        handle_ruri_alias();
-        switch ($rc) {
-        case -1:
-            xlog("L_ERR", "Failed to handle alias of R-URI $ru\n");
-            send_reply("400", "Bad request");
-            exit;
-        case 1:
-            xlog("L_INFO", "Routing in-dialog $rm from $fu to $du\n");
-            break;
-        case 2:
-            xlog("L_INFO", "Routing in-dialog $rm from $fu to $ru\n");
-            break;
-         };
-    };
-...
-
-5.9.  set_contact_alias()
-
-   Adds an “;alias=ip~port~transport” parameter to the contact URI
-   containing the received ip, port, and transport protocol. The new
-   contact URI is immediately visible to other modules in the way the
-   fix_nated_contact() does it.
-
-   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
-   BRANCH_ROUTE, and FAILURE_ROUTE.
-
-   Example 1.24. set_contact_alias usage
-...
-    if (!is_present_hf("Record-Route")) {
-        if (!set_contact_alias()) {
-            xlog("L_ERR", "Error in aliasing contact $ct\n");
-            send_reply("400", "Bad request");
-            exit;
-        };
-    };
-...
-
-6. Exported Pseudo Variables
-
-   6.1. $rr_count
-   6.2. $rr_top_count
-
-6.1. $rr_count
-
-   Number of Record Routes in received SIP request or reply.
-
-   Example 1.25. $rr_count usage
-...
-    $avp(rr_count) = $rr_count;
-...
-
-6.2. $rr_top_count
-
-   If topmost Record Route in received SIP request or reply is a double
-   Record Route, value of $rr_top_count is 2. If it a single Record Route,
-   value of $rr_top_count is 1. If there is no Record Route(s), value of
-   $rr_top_count is 0.
-
-   Example 1.26. $rr_top_count usage
-...
-    if ($rr_count == $avp(rr_count) + $rr_top_count) {
-        route(ADD_CONTACT_ALIAS);
-    };
-...
-
-7. RPC Commands
-
-   7.1. nathelper.enable_ping
-
-7.1. nathelper.enable_ping
-
-   Enables natping if parameter value different than 0. Disables natping
-   if parameter value is 0.
-
-   The function takes only one parameter - a number in decimal format.
-
-   Example 1.27. nathelper.enable_ping usage
-...
-$ kamcmd nathelper.enable_ping 1
-...
-
-8. Selects
-
-   8.1. @nathelper.rewrite_contact[n]
-
-8.1. @nathelper.rewrite_contact[n]
-
-   Get n-th Contact value with IP:Port rewritten to source ip:port. N is
-   counted from 1. Only IP:port is rewritten, remaining part are left
-   unchanged. Full nameaddr is supported.
-
-   Example 1.28. @nathelper.rewrite_contact usage
-...
-$c = @nathelper.rewrite_contact[1];
-...
-$c2 = @nathelper.rewrite_contact[1].nameaddr.uri;
-
-Chapter 2. Frequently Asked Questions
-
-   2.1. What happened with “rtpproxy_disable” parameter?
-   2.2. Where can I find more about Kamailio?
-   2.3. Where can I post a question about this module?
-   2.4. How can I report a bug?
-
-   2.1.
-
-       What happened with “rtpproxy_disable” parameter?
-
-       It was removed as it became obsolete - now “rtpproxy_sock” can take
-       empty value to disable the rtpproxy functionality.
-
-   2.2.
-
-       Where can I find more about Kamailio?
-
-       Take a look at https://www.kamailio.org/.
-
-   2.3.
-
-       Where can I post a question about this module?
-
-       First at all check if your question was already answered on one of our
-       mailing lists:
-         * User Mailing List -
-           https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
-         * Developer Mailing List -
-           https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-dev
-
-       E-mails regarding any stable Kamailio release should be sent to
-       <[email protected]> and e-mails regarding development
-       versions should be sent to <[email protected]>.
-
-   2.4.
-
-       How can I report a bug?
-
-       Please follow the guidelines provided at:
-       https://github.com/kamailio/kamailio/issues.