ACC module

Admin Guide

Overview

ACC module is used to account transactions information to different backends like syslog, SQL, AAA and DIAMETER (beta version).

To account a transaction and to choose which set of backends to be used, the script writer just has to use mark the transaction for accouting by using the do accounting script function. Note that the function is not actually doing the accounting at that very process, it is just setting a marker - the actual accouting will be done later when the transaction or dialog will be completed.

Even so, the module allows the script writter to force accounting on the spot in special cases via some other script functions.

The accounting module will log by default a fixed set of attributes for the transaction - if you customize your accounting by adding more information to be logged, please see the next chapter about extra accounting - ACC extra id.

The fixed minimal accounting information is:

Request Method name
From header TAG parameter
To header TAG parameter
Call-Id
3-digit Status code from final reply
Reason phrase from final reply
Time stamp when transaction was completed

If a value is not present in request, the empty string is accounted instead.

Note that:

A single INVITE may produce multiple accounting reports — that’s due to SIP forking feature.
Since version 2.2 all flags used for accounting have been replaced by the do_accounting function. No need to worry anymore of whether you have set the flags or not, or be confused by various flag names, now you only have to call the function and it will do all the work for you.
OpenSIPS now supports session/dialog accounting. It can automatically correlate INVITEs with BYEs for generating proper CDRs, for example for purpose of billing.
If a UA fails in middle of conversation, a proxy will never find out about 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).

The SQL, Event Interface and AAA backend support are compiled in the module.

A very comprehensive description of how the accounting module works in terms accounting scope, accounting events and accounting backends can be found in this online Advanced Accounting Tutorial.

General Example

loadmodule "modules/acc/acc.so"

if (uri=~"sip:+40") /* calls to Romania */ {
    if (!proxy_authorize("sip_domain.net" /* realm */,
    "subscriber" /* table name */))  {
        proxy_challenge("sip_domain.net" /* realm */, "0" /* no qop */ );
        exit;
    }

    if (is_method("INVITE") && !db_check_from()) {
        xlog("FROM URI != digest username\n");
        sl_send_reply("403","Forbidden");
    }

    do_accounting("log"); /* set for accounting via syslog */
    t_relay(); /* enter stateful mode now */
};

Extra accounting

Overview

Along the static default information, ACC modules allows dynamical selection of extra information to be logged. This allows you to log any pseudo-variable (AVPs, parts of the request, parts of the reply, etc).

Definitions and syntax

Selection of extra information is done via xxx_extra parameters by specifying the names of additional information you want to log. This information is defined via pseudo-variables and may include headers, AVPs values or other message or system values. The syntax of the parameter is:

xxx_extra = extra_definition (’;‘extra_definition)*
extra_definition = log_name ’=’ pseudo_variable [‘/reply’]

Each PV (pseudo variable) may be evaluated in the context of the request message (to access info from it) or in the context of the reply message (final reply for the request).

Using “/reply” marker, the PV will be evaluated in the context of the reply; by default (without the marker), the evaluation is done in the contect of the request. This will allow you to automatically account information (message or network related) from both request and reply in the same time.

The full list of supported pseudo-variables in OpenSIPS is availabe at: /manual/2-2/script-corevar/

Via log_name you define how/where the data will be logged. Its meaning depends of the accounting support which is used:

LOG accounting - log_name will be just printed along with the data in log_name=data format;
DB accounting - log_name will be the name of the DB column where the data will be stored.

Add in db acc table the columns corresponding to each extra data.
AAA accounting - log_name will be the AVP name used for packing the data into AAA message. The log_name will be translated to AVP number via the dictionary.

Add in AAA dictionary the log_name attribute.
DIAMETER accounting - log_name will be the AVP code used for packing the data into DIAMETER message. The AVP code is given directly as integer, since DIAMETER has no dictionary support yet.

log_name must be a number.
Events accounting - log_name will be the name of the parameter in the event raised.

How it works

Some pseudo variables may return more than one value (like headers or AVPs). In this case, the returned values are embedded in a single string in a comma-separated format.

Radius accounting dependencies

If radius accounting is used, except from a radius client library which is mandatory, dictionary.rfc2866 must be included for the module to work properly.

Multi Call-Legs accounting

Overview

A SIP call can have multiple legs due forwarding actions. For example user A calls user B which forwards the call to user C. There is only one SIP call but with 2 legs ( A to B and B to C). Accounting the legs of a call is required for proper billing of the calls (if C is a PSTN number and the call is billed, user B must pay for the call - as last party modifing the call destination-, and not A - as initiator of the call. Call forwarding on server is only one example which shows the necessity of the having an accounting engine with multiple legs support.

Configuration

First how it works: The idea is to have a set of AVPs and for each call leg to store a set of values in the AVPs. The meaning of the AVP content is stricly decided by the script writer - it can be the origin and source of the leg, its status or any other related information. If you have a set of 4 AVPS (AVP1, AVP2, AVP3, AVP4), then for the “A call B and B forwards to C” example, you need to set a different set of values for the AVPs for each leg ([A,B] and [B,C]) . The script writer must take care and properly insert all these AVP from the script (in proper order and with the correct type).

When the accounting information for the call will be written/sent, all the call-leg pairs will be added (based on the found AVP sets).

By default, the multiple call-leg support is disabled - it can be enabled just by setting the per-leg set of AVPs via the multi_leg_info and/or multi_leg_bye_info module parameters. Note that the last one only makes sense only for CDRs that are generated automatically by OpenSIPS.

Important: when both multi-leg accounting is done (for INVITE and BYE), you have to make sure that the AVPs are populated with the same number of legs, otherwise the multi-leg accounting will have an unexpected behavior (values may no longer match the leg number).

Logged data

For each call, all the values of the AVP set (which defines a call-leg) will be logged. How the information will be actually logged, depends of the data backend:

syslog — all leg-sets will be added to one record string as AVP1=xxx, AVP2=xxxx ,… sets.
database — each pair will be separately logged (due DB data structure constraints); several records will be written, the difference between them being only the fields corresponding to the call-leg info.

AAA — all sets will be added to the same AAA accounting message as AAA AVPs - for each call-leg a set of AAA AVPs will be added (corresponding to the per-leg AVP set)

Diameter same as for AAA.
events — each pair will appear as a different parameter-value pair in the event. Similar to the database behavior, multiple events will be raised, and the only difference between them is the leg information.

CDRs accounting

Overview

ACC module can now also maintain session/dialog accounting. This allows you to log useful information like call duration, call start time and setup time.

Configuration

In order to have CDRs accounting, first you need to set the cdr flag when calling do accounting script function for the initial INVITE of the dialog.

How it works

This type of accounting is based on the dialog module. When an initial INVITE is received, if the cdr flag is set, then the dialog creation time is saved. Once the call is answered and the ACK is received, other information like extra values or leg values are saved. When the corresponding BYE is received, the call duration is computed and all information is stored to the desired backend.

Dependencies

OpenSIPS Modules

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 SQL support is used.
rr — Record Route, if “detect_direction” module parameter is enabled.
an aaa module
dialog — Dialog, if “cdr” option is used

External Libraries or Applications

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

none.

Exported Parameters

early_media (integer)

Should be early media (any provisional reply with body) accounted too ?

Default value is 0 (no).

modparam("acc", "early_media", 1)

report_cancels (integer)

By default, CANCEL reporting is disabled — most accounting applications wants to see INVITE’s cancellation status. Turn on if you explicitly want to account CANCEL transactions.

Default value is 0 (no).

modparam("acc", "report_cancels", 1)

detect_direction (integer)

Controls the direction detection for sequential requests. If enabled (non zero value), for sequential requests with upstream direction (from callee to caller), the FROM and TO will be swapped (the direction will be preserved as in the original request).

It affects all values related to TO and FROM headers (body, URI, username, domain, TAG).

Default value is 0 (disabled).

modparam("acc", "detect_direction", 1)

multi_leg_info (string)

Defines the AVP set to be used in per-call-leg accounting. See multi call legs for a detailed description of the Multi Call-Legs accounting.

If empty, the multi-leg accounting support will be disabled.

Default value is 0 (disabled).

# for syslog-based accounting, use any text you want to be printed
modparam("acc", "multi_leg_info",
    "text1=$avp(src);text2=$avp(dst)")
# for mysql-based accounting, use the names of the columns
modparam("acc", "multi_leg_info",
    "leg_src=$avp(src);leg_dst=$avp(dst)")
# for AAA-based accounting, use the names of the AAA AVPs
modparam("acc", "multi_leg_info",
    "AAA_LEG_SRC=$avp(src);AAA_LEG_DST=$avp(dst)")
# for DIAMETER-based accounting, use the DIAMETER AVP ID (as integer)
modparam("acc", "multi_leg_info",
    "2345=$avp(src);2346=$avp(dst)")

multi_leg_bye_info (string)

Defines the AVP set to be used in per-call-leg accounting. See multi call legs for a detailed description of the Multi Call-Legs accounting. This parameter evaluates the AVPs set for BYE requests. It makes sense only when the CDRs are automatically generated, using the dialog support. Note: since the CDR is generated when the BYE message matches the dialog, these variables need to be populated before calling loose_route() or match_dialog().

If empty, the multi-leg support for BYE requests is disabled.

Default value is 0 (disabled).

# for syslog-based accounting, use any text you want to be printed
modparam("acc", "multi_leg_bye_info",
    "text1=$avp(src);text2=$avp(dst)")
# for mysql-based accounting, use the names of the columns
modparam("acc", "multi_leg_bye_info",
    "leg_src=$avp(src);leg_dst=$avp(dst)")
# for AAA-based accounting, use the names of the AAA AVPs
modparam("acc", "multi_leg_bye_info",
    "AAA_LEG_SRC=$avp(src);AAA_LEG_SRC=$avp(dst)")

log_level (integer)

Log level at which accounting messages are issued to syslog.

Default value is L_NOTICE.

modparam("acc", "log_level", 2)   # Set log_level to 2

log_facility (string)

Log facility to which accounting messages are issued to syslog. This allows to easily seperate the accounting specific logging from the other log messages.

Default value is LOG_DAEMON.

modparam("acc", "log_facility", "LOG_DAEMON")

log_extra (string)

Extra values to be logged.

Default value is NULL.

modparam("acc", "log_extra",
  "uaA=$hdr(User-Agent);uaB=$hdr(Server)/reply;uuid=$avp(123)")

log_extra_bye (string)

Extra values to be logged to logfile. Note that this parameter makes sense only when the cdr option is used with do_accounting(). Note: since the CDR is generated when the BYE message matches the dialog, these variables need to be populated before calling loose_route() or match_dialog().

Default value is NULL.

modparam("acc", "log_extra_bye",
  "uaA=$hdr(User-Agent);uaB=$hdr(Server)/reply;uuid=$avp(123)")

aaa_url (string)

This is the url representing the AAA protocol used and the location of the configuration file of this protocol.

If the parameter is set to empty string, the AAA accounting support will be disabled.

Default value is “NULL”.

...
modparam("acc", "aaa_url", "radius:/etc/radiusclient-ng/radiusclient.conf")
...

service_type (integer)

AAA service type used for accounting.

Default value is not-set.

# Default value of service type for SIP is 15
modparam("acc", "service_type", 15)

aaa_extra (string)

Extra values to be logged via AAA - AAA specific.

Default value is NULL.

modparam("acc", "aaa_extra",
  "via=$hdr(Via[*]); email=$avp(email); Bcontact=$ct / reply")

aaa_extra_bye (string)

Extra values to be logged via AAA when a BYE message is received - AAA specific. Note that this parameter makes sense only when the cdr option is used with do_accounting. Note: since the CDR is generated when the BYE message matches the dialog, these variables need to be populated before calling loose_route() or match_dialog().

Default value is NULL.

modparam("acc", "aaa_extra_bye",
  "via=$hdr(Via[*]); email=$avp(email); Bcontact=$ct / reply")

db_table_acc (string)

Table name of accounting successfull calls — database specific.

Default value is “acc”

modparam("acc", "db_table_acc", "myacc_table")

db_table_missed_calls (string)

Table name for accounting missed calls — database specific.

Default value is “missed_calls”

modparam("acc", "db_table_missed_calls", "myMC_table")

db_url (string)

SQL address — database specific. If is set to NULL or empty string, the SQL support is disabled.

Default value is “NULL” (SQL disabled).

modparam("acc", "db_url", "mysql://user:password@localhost/opensips")

acc_method_column (string)

Column name in accounting table to store the request’s method name as string.

Default value is “method”.

modparam("acc", "acc_method_column", "method")

acc_from_tag_column (string)

Column name in accounting table to store the From header TAG parameter.

Default value is “from_tag”.

modparam("acc", "acc_from_tag_column", "from_tag")

acc_to_tag_column (string)

Column name in accounting table to store the To header TAG parameter.

Default value is “to_tag”.

modparam("acc", "acc_to_tag_column", "to_tag")

acc_callid_column (string)

Column name in accounting table to store the request’s Callid value.

Default value is “callid”.

modparam("acc", "acc_callid_column", "callid")

acc_sip_code_column (string)

Column name in accounting table to store the final reply’s numeric code value in string format.

Default value is “sip_code”.

modparam("acc", "acc_sip_code_column", "sip_code")

acc_sip_reason_column (string)

Column name in accounting table to store the final reply’s reason phrase value.

Default value is “sip_reason”.

modparam("acc", "acc_sip_reason_column", "sip_reason")

acc_time_column (string)

Column name in accounting table to store the time stamp of the transaction completion in date-time format.

Default value is “time”.

modparam("acc", "acc_time_column", "time")

db_extra (string)

Extra values to be logged into database - DB specific.

Default value is NULL.

modparam("acc", "db_extra", "ct=$hdr(Content-type); email=$avp(email)")

db_extra_bye (string)

Extra values to be logged into database when a BYE message is received - DB specific. Note that this parameter makes sense only when the cdr option is used with do_accounting. Note: since the CDR is generated when the BYE message matches the dialog, these variables need to be populated before calling loose_route() or match_dialog().

Default value is NULL.

modparam("acc", "db_extra_bye", "ct=$hdr(Content-type); email=$avp(email)")

diameter_client_host (string)

Hostname of the machine where the DIAMETER Client is running — DIAMETER specific.

Default value is “localhost”.

modparam("acc", "diameter_client_host", "3a_server.net")

diameter_client_port (int)

Port number where the Diameter Client is listening — DIAMETER specific.

Default value is “3000”.

modparam("acc", "diameter_client_port", 3000)

diameter_extra (string)

Extra values to be logged via DIAMETER - DIAMETER specific.

Default value is NULL.

modparam("acc", "diameter_extra", "7846=$hdr(Content-type);7847=$avp(email)")

evi_extra (string)

Extra values to be attached as event’s parameters.

Default value is NULL.

modparam("acc", "evi_extra",
  "uaA=$hdr(User-Agent);uaB=$hdr(Server)/reply;uuid=$avp(123)")

evi_extra_bye (string)

Extra values to be attached as event’s parameters for BYE messages. Note that this parameter makes sense only when the cdr option is used with do_accounting. Note: since the CDR is generated when the BYE message matches the dialog, these variables need to be populated before calling loose_route() or match_dialog().

Default value is NULL.

modparam("acc", "evi_extra_bye",
  "uaA=$hdr(User-Agent);uaB=$hdr(Server)/reply;uuid=$avp(123)")

acc_created_avp_name (string)

The name of the openSips avp that will be used to hold the time when the call was created. This time will only be logged on missed calls.

Default value is “accX_created”.

modparam("acc", "acc_created_avp_name", "call_created_avp")

Exported Functions

do_accounting(type, flags, table)

do_accounting() replace all the *_flag and, *_missed_flag, cdr_flag, failed transaction_flag and the db_table_avp modpara. Just call do_accounting(), select where you want to do accounting and how and the function will do all the job for you.

Meaning of the parameters is as follows:

type - the type of accounting you want to do. All the types have to be separated by ’|’. The following parameters can be used:
- log - syslog accounting;
- db - database accounting;
- aaa - aaa specific accounting;
- evi - Event Interface accounting;
- diam - Diameter accounting;
flags - flags for the accouting type you have selected. All the types have to be separated by ’|’. The following parameters can be used:
- cdr - also set CDR details when doing accounting; DIALOG MODULE HAS TO BE LOADED;
- missed - log missed calls;
- failed - flag which says if the transaction should be accounted also in case of failure (status>=300);
table - table where to do the accounting; it replaces old table_avp parameter;