SipCapture Module

Alexandr Dubovikov

Edited by

Alexandr Dubovikov

Table of Contents

1. Admin Guide
1. Overview
2. Dependencies
2.1. Kamailio Modules
2.2. External Libraries or Applications
3. Parameters
3.1. db_url (str)
3.2. table_name (str)
3.3. mt_mode (str)
3.4. hash_source (str)
3.5. db_insert_mode (integer)
3.6. capture_on (integer)
3.7. capture_mode (str)
3.8. hep_capture_on (integer)
3.9. raw_ipip_capture_on (integer)
3.10. raw_moni_capture_on (integer)
3.11. raw_socket_listen (string)
3.12. raw_interface (string)
3.13. raw_sock_children (integer)
3.14. promiscuous_on (integer)
3.15. raw_moni_bpf_on (integer)
3.16. capture_node (str)
3.17. insert_retries (integer)
3.18. insert_retry_timeout (integer)
3.19. callid_aleg_header (str)
3.20. topoh_unmask (int)
3.21. nonsip_hook (int)
3.22. event_callback (str)
3.23. capture_bad_msgs (int)
4. Functions
4.1. sip_capture([table], [cmode])
4.2. report_capture([table], [cid], [data])
4.3. float2int(fval, ival)
4.4. sip_capture_forward(uri)
5. Event Routes
5.1. event_route[sipcapture:request]
6. RPC Commands
6.1. sipcapture.status param
7. Database setup
8. Limitations

List of Examples

1.1. Set db_url parameter
1.2. Set sip_capture parameter
1.3. Set mt_mode parameter
1.4. Set mt_mode parameter
1.5. db_insert_mode example
1.6. Set capture_on parameter
1.7. capture_mode example
1.8. Set hep_capture_on parameter
1.9. Set raw_ipip_capture_on parameter
1.10. Set raw_moni_capture_on parameter
1.11. Set raw_socket_listen parameter
1.12. Set raw_interface parameter
1.13. Set raw_sock_children parameter
1.14. Set promiscuous_on parameter
1.15. Set raw_moni_bpf_on parameter
1.16. Set capture_node parameter
1.17. Set insert_retries parameter
1.18. Set insert_retry_timeout parameter
1.19. Set callid_aleg_header parameter
1.20. Set topoh_unmask parameter
1.21. Set nonsip_hook parameter
1.22. Set event_callback parameter
1.23. Set capture_bad_msgs parameter
1.24. sip_capture() usage
1.25. report_capture() usage
1.26. report_capture() usage
1.27. sip_capture_forward() usage
1.28. event_route[sipcapture:request] usage

Chapter 1. Admin Guide

1. Overview

The sipcapture module stores incoming/outgoing SIP messages in database.

Kamailio can capture SIP messages in three modes

  • IPIP encapsulation. (ETHHDR+IPHDR+IPHDR+UDPHDR).

  • Monitoring/mirroring port.

  • Homer encapsulation protocol mode (HEP v1, v2, v3).

The capturing can be turned on/off using rpc commands. Example:

kamctl rpc sipcapture.status on

kamctl rpc sipcapture.status off

2. Dependencies

2.1. Kamailio Modules

The following modules must be loaded before this module:

  • database module - mysql, postgres, dbtext, unixodbc...

2.2. External Libraries or Applications

The following libraries or applications must be installed before running Kamailio with this module loaded:

  • None.

3. Parameters

3.1. db_url (str)

Database URL.

Default value is "".

Example 1.1. Set db_url parameter

modparam("sipcapture", "db_url", "mysql://user:passwd@host/dbname")

3.2. table_name (str)

Name of the table's name used to store the SIP messages. Can contain multiple tables, separated by "|".

Default value is "sip_capture". Only for Homer 3. For Homer 5, please use an argument for the sip_capture function.

Example 1.2. Set sip_capture parameter

modparam("sipcapture", "table_name", "homer_capture")
modparam("sipcapture", "table_name", "homer_capture1|homer_capture2");

3.3. mt_mode (str)

Name of the mode used for storing data in multiple tables. Modes can be "rand" (random), "round_robin" (use a round_robin algorithm) or "hash" (use hashing to determine the table to store). These modes are only triggered if there is more than one table specified in table_name parameter, separated by "|".

Default value is "rand".

Example 1.3. Set mt_mode parameter

modparam("sipcapture", "mt_mode", "hash")

3.4. hash_source (str)

The field of the SIP message used for hashing, when mt_mode is set to "hash". The value can be "call_id", "to_user" or "from_user".

Default value is "call_id".

Example 1.4. Set mt_mode parameter

modparam("sipcapture", "hash_source", "to_user")

3.5. db_insert_mode (integer)

If set to 1, use INSERT DELAYED to store sip message into capture table when the DB driver has support for it. If no INSERT DELAYED support is offered by DB driver, then standard INSERT is used.

If set to 2, use ASYNC INSERT to store sip message into capture table when the DB driver has support for it. If no ASYNC INSERT support is offered by DB driver, then standard INSERT is used.

Default value is 0 (no INSERT DELAYED).

Example 1.5. db_insert_mode example

modparam("sipcapture", "db_insert_mode", 1)

3.6. capture_on (integer)

Parameter to enable/disable capture globally (on(1)/off(0))

Default value is "0".

Example 1.6. Set capture_on parameter

modparam("sipcapture", "capture_on", 1)

3.7. capture_mode (str)

This parameter can be used for defining a capture mode which can be used in the sip_capture calls as a parameter. A capture mode has a name and some parameters. It must be defined in the format: name=>param1=val1;param2=val2;... The parameters are db_url, table_name, mt_mode and hash_source (optional). Multiple capture modes can be defined by using this parameter multiple times. After this, the capture modes can be used like: sip_capture ("", "CAPTURE_MODE");

Example 1.7. capture_mode example

modparam("sipcapture", "capture_mode", "mode1=>db_url=mysql://user:passwd@host/dbname1;table_name=homer_capture1|homer_capture2;mt_mode=hash;hash_source=call_id;")
modparam("sipcapture", "capture_mode", "mode2=>db_url=mysql://user:passwd@host/dbname2;table_name=homer_capture3|homer_capture4;mt_mode=rand;")

3.8. hep_capture_on (integer)

Parameter to enable/disable capture of HEP (on(1)/off(0))

Default value is "0".

Example 1.8. Set hep_capture_on parameter

modparam("sipcapture", "hep_capture_on", 1)

3.9. raw_ipip_capture_on (integer)

Parameter to enable/disable IPIP capturing (on(1)/off(0))

Default value is "0".

Example 1.9. Set raw_ipip_capture_on parameter

modparam("sipcapture", "raw_ipip_capture_on", 1)

3.10. raw_moni_capture_on (integer)

Parameter to enable/disable monitoring/mirroring port capturing (on(1)/off(0)) Only one mode on raw socket can be enabled! Monitoring port capturing currently supported only on Linux.

Default value is "0".

Example 1.10. Set raw_moni_capture_on parameter

modparam("sipcapture", "raw_moni_capture_on", 1)

3.11. raw_socket_listen (string)

Parameter indicate a listen IP address of RAW socket for IPIP capturing. You can also define a port/portrange for IPIP/Mirroring mode, to capture SIP messages in specific ports:

"" - the source/destination port of the SIP message must be equal 5060

"" - the source/destination port of the SIP message must be equal or be between 5060 and 5090.

The port/portrange must be defined if you are planning to use mirroring capture! In this case, the part with IP address will be ignored, but to make parser happy, use i.e.

Default value is "".

Example 1.11. Set raw_socket_listen parameter

modparam("sipcapture", "raw_socket_listen", "")
modparam("sipcapture", "raw_socket_listen", "")

3.12. raw_interface (string)

Name of the interface to bind on the raw socket.

Default value is "".

Example 1.12. Set raw_interface parameter

modparam("sipcapture", "raw_interface", "eth0")

3.13. raw_sock_children (integer)

Parameter define how many children that must be created to listen the raw socket.

Default value is "1".

Example 1.13. Set raw_sock_children parameter

modparam("sipcapture", "raw_sock_children", 6)

3.14. promiscuous_on (integer)

Parameter to enable/disable promiscuous mode on the raw socket. Linux only.

Default value is "0".

Example 1.14. Set promiscuous_on parameter

modparam("sipcapture", "promiscuous_on", 1)

3.15. raw_moni_bpf_on (integer)

Activate Linux Socket Filter (LSF based on BPF) on the mirroring interface. The structure is defined in linux/filter.h. The default LSF accept a port/portrange from the raw_socket_listen param. Currently LSF supported only on Linux.

Default value is "0".

Example 1.15. Set raw_moni_bpf_on parameter

modparam("sipcapture", "raw_moni_bpf_on", 1)

3.16. capture_node (str)

Name of the capture node.

Default value is "homer01".

Example 1.16. Set capture_node parameter

modparam("sipcapture", "capture_node", "homer03")

3.17. insert_retries (integer)

The number of times Kamailio should retry to write to the Homer database in case the first attempt failed. The retry is also limited timewise by the insert_retry_timeout parameter. Values allowed range from 0 to 500.

Default value is 0 (no retries).

Example 1.17. Set insert_retries parameter

modparam("sipcapture", "insert_retries", 5)

3.18. insert_retry_timeout (integer)

The time limit in seconds Kamailio retries to write to the Homer database in case the first attempt failed. This parameter is only used together with the insert_retries parameter. Values allowed range from 0 to 300.

Default value is 60 seconds.

Example 1.18. Set insert_retry_timeout parameter

modparam("sipcapture", "insert_retry_timeout", 10)

3.19. callid_aleg_header (str)

Header name used to correlate A-leg with B-leg. It can take a list of headers, separated by semicolon, e.g. "X-CID0;X-CID1". First match wins.

Default value is "X-CID".

Example 1.19. Set callid_aleg_header parameter

modparam("sipcapture", "callid_aleg_header", "X-CallIDALeg")

3.20. topoh_unmask (int)

If set to 1, call-id will be unmasked using topoh module api (topoh module must be loaded in this case).

Default value is 0.

Example 1.20. Set topoh_unmask parameter

modparam("sipcapture", "topoh_unmask", 1)

3.21. nonsip_hook (int)

If set to 1, event route sipcapture:siprequest is run when HEP message is received.

Default value is 0.

Example 1.21. Set nonsip_hook parameter

modparam("sipcapture", "nonsip_hook", 1)

3.22. event_callback (str)

The name of the function in the kemi configuration file (embedded scripting language such as Lua, Python, ...) to be executed instead of event_route[...] blocks.

The function receives a string parameter with the name of the event, the values can be: 'sipcapture:request'.

Default value is 'empty' (no function is executed for events).

Example 1.22. Set event_callback parameter

modparam("sipcapture", "event_callback", "ksr_sipcapture_event")
-- event callback function implemented in Lua
function ksr_sipcapture_event(evname)"===== sipcapture module triggered event: " .. evname .. "\n");
	return 1;

3.23. capture_bad_msgs (int)

If set to something different than 0, tries to capture also the broken SIP messages.

Default value is 0.

Example 1.23. Set capture_bad_msgs parameter

modparam("sipcapture", "capture_bad_msgs", 1)

4. Functions

4.1.  sip_capture([table], [cmode])

Store the current processed HEP/IPIP SIP message in database. It is stored in the form prior applying changes made to it.

Meaning of the parameters is as follows:

  • table - The table where HEP SIP message will be stored. Homer 5 use now tables with datestamp. To generate an automatic table's name please use strftime parameters. I.e. $var(table) = "sip_capture_call_%Y%m%d" and set the variable as an argument of the sip_capture function.

  • cmode - The reference to the capture_mode parameter.

This function can be used from ANY_ROUTE.

Default value is "NULL".

Example 1.24. sip_capture() usage

sip_capture("", "cmode");

4.2.  report_capture([table], [cid], [data])

Store the current processed HEP REPORT message in database.

Meaning of the parameters is as follows:

  • table - The table where REPORT message will be stored.

  • cid - The correlation id.

  • data - The custom report data in JSON format.

This function can be used from ANY_ROUTE.

Default value is "NULL".

Example 1.25. report_capture() usage

report_capture("report_data", "$ci");
report_capture("report_data", "$ci", "{\"MOS\":4.1,\"PACKET_LOST\":100"});

4.3.  float2int(fval, ival)

Return the value of atof(fval) * atoi(ival). On case the result is 0, then -1 is returned.

This function can be used from ANY_ROUTE.

Example 1.26. report_capture() usage

$var(res) = float2int("10.5", "1");

4.4.  sip_capture_forward(uri)

Forward the HEP packet to an address specified by the parameter uri (it has to be a sip uri format). The function should be used inside event_route[sipcapture:request]. After using this function, add a return 0 in order to stop processing further the packet in the local Kamailio instance.

This function can be used from ANY_ROUTE.

Example 1.27. sip_capture_forward() usage

    event_route[sipcapture:request] {
        if(src_ip== {
            return 0;

5. Event Routes

5.1. event_route[sipcapture:request]

Event route block to be executed when HEP packet is received. It requires module parameter 'nonsip_hook' to be set to 1.

Example 1.28. event_route[sipcapture:request] usage

# new event sipcapture socket
modparam("sipcapture", "nonsip_hook", 1)

event_route[sipcapture:request] {

	xlog("HEP Request!\n");
	xlog("received sipcapture request from $si:$sp\n");
	xlog("HEP VERSION $hep(version) request from $si:$sp\n");
	xlog("HEP CHUNK Source IP $hep(0x002) request from $si:$sp\n");

	# is it SIP ?
	if($hep(0x00b) == 1) {

		# do parsing internal
		return 1;
	} else {
		# if report lets proceed here with payload
		xlog("HEP CHUNK PAYLOAD $hep(0x00f) request from $si:$sp\n");
		return 0;

6. RPC Commands

6.1.  sipcapture.status param

Name: sipcapture.status


  • on or off: turns on/off SIP message capturing. Possible values are:

    • on

    • off

  • check does not change sipcapture status, just reports the current status.

RPC Command Format:

kamcmd sipcapture.status on
kamcmd sipcapture.status off
kamcmd sipcapture.status check

7. Database setup

Before running Kamailio with the sipcapture module, you have to setup the database tables where the module will store the data. For that, if the table were not created by the installation script or you choose to install everything by yourself you can use the homer_databases.sql, SQL script in the sql folder of sipcapture module as template. You can also find the complete database documentation on the project webpage,

8. Limitations

  • 1. Only one capturing mode on RAW socket is supported: IPIP or monitoring/mirroring port. Don't activate both at the same time. Obsolete. Please use HEP mirroring now.
  • 2. Mirroring port capturing works only on Linux.