
Acc Module

Jiri Kuthan

   iptel.org

   Copyright © 2002, 2003 FhG FOKUS
     _________________________________________________________

   Table of Contents
   1. User's Guide

        1.1. Overview

              1.1.1. General Example

        1.2. Dependencies
        1.3. Exported Parameters

              1.3.1. secret (string)
              1.3.2. log_level (integer)
              1.3.3. log_fmt (string)
              1.3.4. early_media (integer)
              1.3.5. failed_transactions (integer)
              1.3.6. log_flag (integer)
              1.3.7. log_missed_flag (integer)
              1.3.8. report_ack (integer)
              1.3.9. report_cancels (integer)
              1.3.10. radius_config (string)
              1.3.11. service_type (integer)
              1.3.12. radius_flag (integer)
              1.3.13. radius_missed_flag (integer)
              1.3.14. db_url (string)
              1.3.15. db_flag (integer)
              1.3.16. db_missed_flag (integer)

        1.4. Exported Functions

              1.4.1. acc_log_request(comment)
              1.4.2. acc_db_request(comment, table)
              1.4.3. acc_rad_request(comment)

   2. Developer's Guide
   3. Frequently Asked Questions

   List of Examples
   1-1. Setting secret module parameter
   1-2. log_level example
   1-3. log_fmt example
   1-4. early_media example
   1-5. failed_transactions example
   1-6. log_flag example
   1-7. log_missed_flag example
   1-8. report_ack example
   1-9. report_cancels example
   1-10. radius_config example
   1-11. service_type example
   1-12. radius_flag example
   1-13. radius_missed_flag example
   1-14. db_url example
   1-15. db_flag example
   1-16. db_missed_flag example
   1-17. acc_log_request usage
   1-18. acc_db_request usage
   1-19. acc_rad_request usage
     _________________________________________________________

Chapter 1. User's Guide

1.1. Overview

   acc module is used to report on transactions to syslog, SQL
   and RADIUS.

   To report on a transaction using syslog, use "setflag" to mark
   a transaction you are interested in with a flag, load
   accounting module and set its "log_flag" to the same flag
   number. The acc module will then report on completed
   transaction to syslog. A typical usage of the module takes no
   acc-specific script command -- the functionality binds
   invisibly through transaction processing. Script writers just
   need to mark the transaction for accounting with proper
   setflag.

   What is printed depends on module's "log_fmt" parameter. It's
   a string with characters specifying which parts of request
   should be printed:

     * c = Call-Id
     * d = To tag (Dst)
     * f = From
     * i = Inbound Request-URI
     * m = Method
     * o = Outbound Request-URI
     * r = fRom
     * s = Status
     * t = To
     * u = digest Username
     * p = username Part of inbound Request-URI

   If a value is not present in request, "n/a" is accounted
   instead.

   Note that:

     * A single INVITE may produce multiple accounting reports --
       that's due to SIP's forking feature
     * Subsequent ACKs and other requests do not hit the server
       and can't be accounted unless record-routing is enforced.
       The ACKs assert very little useful information anyway and
       reporting on INVITE's 200 makes most accounting scenarios
       happy.
     * There is no session accounting -- ser maintains no
       sessions. If one needs to correlate INVITEs with BYEs for
       example for purpose of billing, then it is better done in
       the entity which collects accounting infromation.
       Otherwise, SIP server would have to become
       sessions-stateful, which would very badly impact its
       scalability.
     * If a UA fails in middle of conversation, a proxy will
       never learn it. In general, a better practice is to
       account from an end-device (such as PSTN gateway), which
       best knows about call status (including media status and
       PSTN status in case of the gateway).

   Support for SQL and RADIUS works analogously. You need to
   enable it by recompiling the module with properly set defines.
   Uncomment the SQL_ACC and RAD_ACC lines in
   modules/acc/Makefile. To compile SQL support, you need to have
   mysqlclient package on your system. To compile RADIUS support,
   you need to have radiusclient installed on your system
   (version 0.4.1 or higher is required) which is available from
   http://developer.berlios.de/projects/radiusclient-ng/. The
   radius client needs to be configured properly. To do so, use
   the template at etc/radiusclient.conf and make sure that
   module's radius_config parameter points to its location. In
   particular, accounting secret must match that one configured
   in server and proper dictionary is used (one is available at
   etc/sip_dictionary). Uses along with FreeRadius
   (http://www.freeradius.org/) and Radiator
   (http://www.open.com.au/radiator/) servers have been reported
   to us.

   Both mysql and radius libraries must be dynamically linkable.
   You need to configure your OS so that SER, when started, will
   find them. Typically, you do so by manipulating
   LD_LIBRARY_PATH environment variable or condiguring ld.so.
     _________________________________________________________

1.1.1. General Example

loadmodule "modules/acc/acc.so"
modparam("acc", "log_level", 1)
modparam("acc", "log_flag", 1)

if (uri=~"sip:+49") /* calls to Germany */ {
    if (!proxy_authorize("iptel.org" /* realm */,
                         "subscriber" /* table name */))  {
        proxy_challenge("iptel.org" /* realm */, "0" /* no qop */ );
        break;
    }

    if (method=="INVITE" & !check_from()) {
        log("from!=digest\n");
        sl_send_reply("403","Forbidden");
        break;
    }

    setflag(1); /* set for accounting (the same value as in log_flag!)
    t_relay();  /* enter stateful mode now */
};
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1.2. Dependencies

   The module depends on the following modules (in the other
   words the listed modules must be loaded before this module):

     * tm -- Transaction Manager
     * a database module -- If compiled with database support.
     _________________________________________________________

1.3. Exported Parameters

1.3.1. secret (string)

   Default value is randomly generated string.

   Example 1-1. Setting secret module parameter
modparam("auth", "secret", "johndoessecretphrase")
     _________________________________________________________

1.3.2. log_level (integer)

   Log level at which accounting messages are issued to syslog.

   Default value is L_NOTICE.

   Example 1-2. log_level example
modparam("acc", "log_level", 2)   # Set log_level to 2
     _________________________________________________________

1.3.3. log_fmt (string)

   Defines what parts of header fields will be printed to syslog,
   see "overview" for list of accepted values.

   Default value is "miocfs".

   Example 1-3. log_fmt example
modparam("acc", "log_fmt", "mfs")
     _________________________________________________________

1.3.4. early_media (integer)

   Should be early media (183) accounted too ?

   Default value is 0 (no).

   Example 1-4. early_media example
modparam("acc", "early_media", 1)
     _________________________________________________________

1.3.5. failed_transactions (integer)

   Should be failed transactions (status>=300) accounted too ?

   Default value is 0 (no).

   Example 1-5. failed_transactions example
modparam("acc", "failed_transactions", 1)
     _________________________________________________________

1.3.6. log_flag (integer)

   Request flag which needs to be set to account a transaction.

   Default value is 1.

   Example 1-6. log_flag example
modparam("acc", "log_flag", 2)
     _________________________________________________________

1.3.7. log_missed_flag (integer)

   Request flag which needs to be set to account missed calls.

   Default value is 2.

   Example 1-7. log_missed_flag example
modparam("acc", "log_missed_flag", 3)
     _________________________________________________________

1.3.8. report_ack (integer)

   Shall acc attempt to account e2e ACKs too ? Note that this is
   really only an attempt, as e2e ACKs may take a different path
   (unless RR enabled) and mismatch original INVITE (e2e ACKs are
   a separate transaction).

   Default value is 1 (yes).

   Example 1-8. report_ack example
modparam("acc", "report_ack", 0)
     _________________________________________________________

1.3.9. report_cancels (integer)

   By default, CANCEL reporting is disabled -- most accounting
   applications are happy to see INVITE's cancellation status.
   Turn on if you explicitely want to account CANCEL
   transactions.

   Default value is 0 (no).

   Example 1-9. report_cancels example
modparam("acc", "report_cancels", 1)
     _________________________________________________________

1.3.10. radius_config (string)

   This parameter is radius specific. Path to radius client
   configuration file, set the referred config file correctly and
   specify there address of server, shared secret (should equal
   that in /usr/local/etc/raddb/clients for freeRadius servers)
   and dictionary, see etc for an example of config file and
   dictionary.

   Default value is
   "/usr/local/etc/radiusclient/radiusclient.conf".

   Example 1-10. radius_config example
modparam("acc", "radius_config", "/etc/radiusclient/radiusclient.conf")
     _________________________________________________________

1.3.11. service_type (integer)

   Radius service type used for accounting.

   Default value is 15 (SIP).

   Example 1-11. service_type example
modparam("acc", "service_type", 16)
     _________________________________________________________

1.3.12. radius_flag (integer)

   Request flag which needs to be set to account a transaction --
   RADIUS specific.

   Default value is 1.

   Example 1-12. radius_flag example
modparam("acc", "radius_flag", 2)
     _________________________________________________________

1.3.13. radius_missed_flag (integer)

   Request flag which needs to be set to account missed calls --
   RADIUS specific.

   Default value is 2.

   Example 1-13. radius_missed_flag example
modparam("acc", "radius_missed_flag", 3)
     _________________________________________________________

1.3.14. db_url (string)

   SQL address -- database specific.

   Default value is "mysql://ser:heslo@localhost/ser"

   Example 1-14. db_url example
modparam("acc", "db_url", "mysql://user:password@localhost/ser")
     _________________________________________________________

1.3.15. db_flag (integer)

   Request flag which needs to be set to account a transaction --
   database specific.

   Default value is 1.

   Example 1-15. db_flag example
modparam("acc", "db_flag", 2)
     _________________________________________________________

1.3.16. db_missed_flag (integer)

   Request flag which needs to be set to account missed calls --
   database specific.

   Default value is 2.

   Example 1-16. db_missed_flag example
modparam("acc", "db_missed_flag", 3)
     _________________________________________________________

1.4. Exported Functions

1.4.1. acc_log_request(comment)

   acc_request reports on a request, for example, it can be used
   to report on missed calls to off-line users who are replied
   404. To avoid multiple reports on UDP request retranmission,
   you would need to embed the action in stateful processing.

   Meaning of the parameters is as follows:

     * comment - Comment to be appended.

   Example 1-17. acc_log_request usage
...
acc_log_request("Some comment");
...
     _________________________________________________________

1.4.2. acc_db_request(comment, table)

   Like acc_log_request, acc_db_request reports on a request. The
   report is sent to database at "db_url", in the table referred
   to in the second action parameter

   Meaning of the parameters is as follows:

     * comment - Comment to be appended.
     * table - Database table to be used.

   Example 1-18. acc_db_request usage
...
acc_log_request("Some comment", "Some table");
...
     _________________________________________________________

1.4.3. acc_rad_request(comment)

   Like acc_log_request, acc_rad_requst reports on a request. It
   reports to radius server as configured in "radius_config".

   Meaning of the parameters is as follows:

     * comment - Comment to be appended.

   Example 1-19. acc_rad_request usage
...
acc_rad_request("Some comment");
...
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Chapter 2. Developer's Guide

   To be done.
     _________________________________________________________

Chapter 3. Frequently Asked Questions

   3.1. What is the meaning of life ?

   3.1. What is the meaning of life ?

   42
