The following module must be loaded before this module:

The name of the table containing the subscribers

Default value is “subscriber”.

...
modparam("carrierroute", "subscriber_table", "subscriber")
...

The name of the column in the subscriber table containing the usernames.

Default value is “username”.

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modparam("carrierroute", "subscriber_user_col", "username")
...

The name of the column in the subscriber table containing the domain of the subscriber.

Default value is “domain”.

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modparam("carrierroute", "subscriber_domain_col", "domain")
...

The name of the column in the subscriber table containing the carrier id of the subscriber.

Default value is “cr_preferred_carrier”.

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modparam("carrierroute", "subscriber_carrier_col", "cr_preferred_carrier")
...

Specifies whether the module loads its config data from a file or from a database. Possible values are “file” and “db”.

Default value is “file”.

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modparam("carrierroute", "config_source", "file")
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Specifies the path to the config file. The file has to be owned by the user and group used to run Kamailio.

Default value is “/etc/kamailio/carrierroute.conf”.

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modparam("carrierroute", "config_file", "/etc/kamailio/carrierroute.conf")
...

The name of the carrier tree used per default (if the current subscriber has no preferred tree)

Default value is “default”.

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modparam("carrierroute", "default_tree", "default")
...

When using tree lookup per user, this parameter specifies whether to use the domain part for user matching or not. This parameter is tunable via the ser cfg framework.

Default value is “0”.

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modparam("carrierroute", "use_domain", 0)
...

This parameter defines the behaviour when using user-based tree lookup. If the user has a non-existing tree set and fallback_default is set to 1, the default tree is used. Otherwise, cr_user_rewrite_uri returns an error. This parameter is tunable via the ser cfg framework.

Default value is “1”.

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modparam("carrierroute", "fallback_default", 1)
...

The number of the rows to be fetched at once from database when loading the routing data. This value can be used to tune the load time at startup. For 1MB of private memory (default) it should be below 3750. The database driver must support the fetch_result() capability. This parameter is tunable via the ser cfg framework.

Default value is “2000”.

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modparam("carrierroute", "fetch_rows", 3000)
...

Toggle on/off loading in memory the description column in the carrierroute/carrierfailureroute database tables. This reduces the shared memory used by the module.

Default value is “1”.

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modparam("carrierroute", "db_load_description", 0)
...

The number of individual characters that are used for matching. Valid values are 10 or 128. When you specify 10, only digits will be used for matching, this operation mode is equivalent to the old behaviour. When configured with 128, all standard ascii chars are available for matching. Please be aware that memory requirements for storing the routing tree in shared memory will also increase by a factor of 12.8.

Default value is “10”.

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modparam("carrierroute", "match_mode", 10)
...

Integer parameter to toggle on/off the possibility that in the failurerouting cases destinations that previously failed are avoided. Possible values are 0 (off), 1 (on). Also see cr_route section.

Default value is “1”.

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modparam("carrierroute", "avoid_failed_destinations", 0)
...

This function loads the carrier and stores it in a config variable. It cannot be used in the config file mode, as it needs a mapping of the given user to a certain carrier. The is drived from a database entry belonging to the user parameter. This mapping must be available in the table that is specified in the “subscriber_table” variable. This data is not cached in memory, that means for every execution of this function a database query will be done.

Meaning of the parameters is as follows:

This function searches for the longest match for the user given in prefix_matching with the given domain in the given carrier tree. The Request URI is rewritten using rewrite_user and the given hash source and algorithm. Returns -1 if there is no data found or an empty rewrite host on the longest match is found. On success, it also stores the carrier description in the given AVP (if present). This is useful if you need some additional informations that belongs to each gw, like the destination uri, force socket or any arbitrary info.

Depending on the value of the avoid_failed_destinations module parameter, the function pays special attention to the failurerouting cases, so that any destination that has failed to provide a successful response will not be reused in a subsequent call of this function. This situation can appear when different route domains contain a set of common gateways.

This function is only usable with rewrite_user and prefix_matching containing a valid string. This string needs to be numerical if the match_mode parameter is set to 10. It uses the standard CRC32 algorithm to calculate the hash values.

If flags and masks values are specified in the routing rule, they will be compared by this function to the message flags. Specify a flag and mask value of “0” to match to all possible message flags (this is the default value). If flags and mask are not zero, and no match to the message flags is possible, no routing will be done. The calculation of the hash and the load-balancing is done after the flags matching.

Meaning of the parameters is as follows:

This function searches for the longest match for the user given in prefix_matching with the given domain in the given carrier tree. The Request URI is rewritten using rewrite_user and the given hash source and algorithm. Returns -1 if there is no data found or an empty rewrite host on the longest match is found. On success it also stores the carrier description in the given AVP (if present). This is useful if you need some additional informations that belongs to each gw, like the destination uri, force socket or any arbitrary info.

This function is only usable with rewrite_user and prefix_matching containing a valid string. This string needs to be numerical if the match_mode parameter is set to 10.

It uses the standard CRC32 algorithm to calculate the hash values. In contrast to the normal cr_route function, the backup rules of (now obsolete) cr_prime_route is used. This means none of the configured probabilities will be used, only a fixed hash distribution is used. This makes sense to distribute incoming register requests e.g. to a bunch of registrar servers. If one of the hash targets is not available and backup rule is configured, the function will return -1.

Meaning of the parameters is as follows:

This function searches for the longest match for the user given in prefix_matching with the given domain in the given carrier failure tree. It tries to find a next domain matching the given host, reply_code and the message flags. The matching is done in this order: “host” then “reply_code” and then “flags”. The more wildcards in reply_code and the more bits used in flags, the lower the priority will be. Returns -1, if there is no data found or if the next_domain on the longest match is empty. Otherwise the next domain is stored in the given variable.

This function is only usable if rewrite_user and prefix_matching contains a valid string. This string must be numerical if the match_mode parameter is set to 10.

Meaning of the parameters is as follows:

This command reloads the routing data from the data source.

Name: cr.reload_routes

Parameters:

Important: When new domains have been added, a restart of the server must be done, because the mapping of the ids used in the config script cannot be updated at runtime at the moment. So a reload could result in a wrong routing behaviour, because the ids used in the script could differ from the one used internally from the server. Modifying of already existing domains is no problem.

This command prints the route rules on the command line.

Name: cr.dump_routes

Parameters:

This command adds a new host to the route rules

Name: cr.add_host

Parameters:

Example:

This command deletes a host from the route rules

Name: cr.delete_host

Parameters:

Example:

This command activates a host from the route rules

Name: cr.activate_host

Parameters:

Example:

This command deactivates a host from the route rules

Name: cr.deactivate_host

Parameters:

Example:

This command replaces a host from the route rules

Name: cr.replace_host

Parameters:

Example:

Before running Kamailio with carrierroute, you have to setup the database table where the module will store the routing data. For that, if the table was not created by the installation script or you choose to install everything by yourself you can use the carrierroute-create.sql SQL script in the database directories in the kamailio/scripts folder as template. Database and table name can be set with module parameters so they can be changed, but the name of the columns must be as they are in the SQL script. You can also find the complete database documentation on the project webpage, https://www.kamailio.org/docs/db-tables/kamailio-db-devel.html. The flags and mask columns have the same function as in the carrierfailureroute table. A zero value in the flags and mask column means that any message flags will match this rule.

For a minimal configuration either use the config file given above, or insert some data into the tables of the module.

...
+----+---------+--------+-------------+-------+------+---------------+
| id | carrier | domain | scan_prefix | flags | prob | rewrite_host  |
+----+---------+--------+-------------+-------+------+---------------+
| 1  |       1 |      1 | 49          |     0 |  0.5 | de-1.carrier1 |
| 2  |       1 |      1 | 49          |     0 |  0.5 | de-2.carrier1 |
| 3  |       1 |      1 | 49          |    16 |    1 | de-3.carrier1 |
| 4  |       1 |      1 |             |     0 |    1 | gw.carrier1-1 |
| 5  |       1 |      2 | 49          |     0 |    1 | gw.carrier1-1 |
| 6  |       1 |      3 |             |     0 |    1 | gw.carrier1-2 |
| 7  |       1 |      4 |             |     0 |    1 | gw.carrier1-3 |
| 8  |       2 |      1 | 49          |     0 |  0.5 | de-1.carrier2 |
| 9  |       2 |      1 | 49          |     0 |  0.5 | de-2.carrier2 |
| 10 |       2 |      1 |             |     0 |    1 | gw.carrier2   |
| 11 |       2 |      2 | 49          |     0 |    1 | gw.carrier2   |
| 12 |       3 |      8 | 49          |     0 |    1 | de-gw.default |
| 13 |       3 |      8 |             |     0 |    1 | gw.default    |
+----+---------+--------+-------------+-------+------+---------------+
...

This table contains three routes to two gateways for the “49” prefix, and a default route for other prefixes over carrier 2 and carrier 1. The gateways for the default carrier will be used for functions that don't support the user specific carrier lookup. The routing rules for carrier 1 and carrier 2 for the “49” prefix contains an additional rule with the domain 2, that can be used for example as fallback if the gateways in domain 1 are not reachable. Two more fallback rules (domain 3 and 4) for carrier 1 are also supplied to support the functionality of the carrierfailureroute table example that is provided in the next section.

This table provides also a “carrier 1” routing rule for the “49” prefix, that is only chosen if some message flags are set. If this flags are not set, the other two rules are used. The “strip”, “mask” and “comment” columns are omitted for brevity.

...
+----+---------+--------+---------------+------------+-------------+
| id | carrier | domain | host_name     | reply_code | next_domain |
+----+---------+--------+---------------+------------+-------------+
|  1 |       1 | 1      | gw.carrier1-2 | ...        | 3           |
|  2 |       1 | 1      | gw.carrier1-3 | ...        | 2           |
+----+---------+--------+---------------+------------+-------------+
...

This table contains two failure routes for the “gw.carrier1-1” and “-2” gateways. For any (failure) reply code the respective next domain is chosen. After that no more failure routes are available, an error will be returned from the “cr_next_domain” function. Not all table columns are shown here for brevity.

For each failure route domain and carrier that is added to the carrierfailureroute table there must be at least one corresponding entry in the carrierroute table, otherwise the module will not load the routing data.

...
+----+---------+-----------+------------+--------+-----+-------------+
| id | domain  | host_name | reply_code | flags | mask | next_domain |
+----+---------+-----------+------------+-------+------+-------------+
|  1 |      99 |           | 408        |    16 |   16 |             |
|  2 |      99 | gw1       | 404        |     0 |    0 | 100         |
|  3 |      99 | gw2       | 50.        |     0 |    0 | 100         |
|  4 |      99 |           | 404        |  2048 | 2112 | 101         |
+----+---------+-----------+------------+-------+------+-------------+
...

This table contains four failure routes that shows the usage of more advanced features. The first route matches to a 408, and to some flag for example that indicates that ringing has happened. If this flag is set, there will be no further forwarding, because next_domain is empty. In the second and third routes are certain gateway errors matched, if this errors have occurred, then the next domain will be chosen. Note that the reply_code must be 3 characters wide, and only the "." character is accepted as wildcard. The last route does forwarding according some flags, e.g. the customer came from a certain carrier, and has call-forwarding deactivated. In order to use the routing that is specified above, a matching carrierroute table must be provided, that holds domain entries for this routing rules. Not all table columns are shown here for brevity.

...
+----+----------+
| id | carrier  |
+----+----------+
|  1 | carrier1 |
|  2 | carrier2 |
|  3 | default  |
+----+----------+
...

This table contains the mapping of the carrier id to actual names.

...
+----+----------+
| id | domain   |
+----+----------+
|  1 | domain1  |
|  2 | domain2  |
|  3 | domain3  |
+----+----------+
...

This table contains the mapping of the domain id to actual names.

For a functional routing the “cr_preferred_carrier” column must be added to the subscriber table (or to the table and column that you specified as module parameter) to choose the actual carrier for the users.

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ALTER TABLE subscriber ADD cr_preferred_carrier int(10) default NULL;
...