carrierroute

Henning Westerholt

1&1 Internet AG

Edited by

Lucian Balaceanu

1&1 Internet AG

Table of Contents

1. Admin Guide
1. Overview
2. Dependencies
2.1. Kamailio Modules
3. Parameters
3.1. subscriber_table (string)
3.2. subscriber_user_col (string)
3.3. subscriber_domain_col (string)
3.4. subscriber_carrier_col (string)
3.5. config_source (string)
3.6. config_file (string)
3.7. default_tree (string)
3.8. use_domain (int)
3.9. fallback_default (int)
3.10. fetch_rows (integer)
3.11. db_load_description (integer)
3.12. match_mode (integer)
3.13. avoid_failed_destinations (integer)
4. Functions
4.1. cr_user_carrier(user, domain, dstavp)
4.2. cr_route(carrier, domain, prefix_matching, rewrite_user, hash_source, descavp)
4.3. cr_nofallback_route(carrier, domain, prefix_matching, rewrite_user, hash_source, descavp)
4.4. cr_next_domain(carrier, domain, prefix_matching, host, reply_code, dstavp)
5. RPC Commands
5.1. cr.reload_routes
5.2. cr.dump_routes
6. MI Commands
6.1. cr_reload_routes
6.2. cr_dump_routes
6.3. cr_replace_host
6.4. cr_deactivate_host
6.5. cr_activate_host
6.6. cr_add_host
6.7. cr_delete_host
7. Configuration examples
8. Installation and Running
8.1. Database setup
8.2. Database examples
8.3. User specific routing
2. Module parameter for database access.
1. db_url (String)
2. carrierroute_table (String)
3. carrierroute_id_col (string)
4. carrierroute_carrier_col (string)
5. carrierroute_domain_col (string)
6. carrierroute_scan_prefix_col (string)
7. carrierroute_flags_col (string)
8. carrierroute_mask_col (string)
9. carrierroute_prob_col (string)
10. carrierroute_strip_col (string)
11. carrierroute_rewrite_host_col (string)
12. carrierroute_rewrite_prefix_col (string)
13. carrierroute_rewrite_suffix_col (string)
14. carrierroute_description_col (string)
15. carrierfailureroute_table (String)
16. carrierfailureroute_id_col (string)
17. carrierfailureroute_carrier_col (string)
18. carrierfailureroute_domain_col (string)
19. carrierfailureroute_scan_prefix_col (string)
20. carrierfailureroute_host_name_col (string)
21. carrierfailureroute_reply_code_col (string)
22. carrierfailureroute_flags_col (string)
23. carrierfailureroute_mask_col (string)
24. carrierfailureroute_next_domain_col (string)
25. carrierfailureroute_description_col (string)
26. carrier_name_table (String)
27. carrier_name_id_col (string)
28. carrier_name_carrier_col (string)
29. domain_name_table (String)
30. domain_name_id_col (string)
31. domain_name_domain_col (string)

List of Examples

1.1. Set subscriber_table parameter
1.2. Set subscriber_user_col parameter
1.3. Set subscriber_domain_col parameter
1.4. Set subscriber_carrier_col parameter
1.5. Set config_source parameter
1.6. Set config_file parameter
1.7. Set default_tree parameter
1.8. Set use_domain parameter
1.9. Set fallback_default parameter
1.10. Set fetch_rows parameter
1.11. Unset db_load_description parameter
1.12. Set match_mode parameter
1.13. Set avoid_failed_destinations parameter
1.14. cr_replace_host usage
1.15. cr_deactivate_host usage
1.16. cr_activate_host usage
1.17. cr_add_host usage
1.18. cr_delete_host usage
1.19. Configuration example - Routing to default tree
1.20. Configuration example - Routing to user tree
1.21. Configuration example - module configuration
1.22. Example database content - carrierroute table
1.23. Example database content - simple carrierfailureroute table
1.24. Example database content - more complex carrierfailureroute table
1.25. Example database content - carrier_name table
1.26. Example database content - domain_name table
1.27. Necessary extensions for the user table
2.1. Set db_url parameter
2.2. Set carrierroute_table parameter
2.3. Set carrierroute_id_col parameter
2.4. Set carrierroute_carrier_col parameter
2.5. Set carrierroute_domain_col parameter
2.6. Set carrierroute_scan_prefix_col parameter
2.7. Set carrierroute_flags_col parameter
2.8. Set carrierroute_mask_col parameter
2.9. Set carrierroute_prob_col parameter
2.10. Set carrierroute_strip_col parameter
2.11. Set carrierroute_rewrite_host_col parameter
2.12. Set carrierroute_rewrite_prefix_col parameter
2.13. Set carrierroute_rewrite_suffix_col parameter
2.14. Set carrierroute_description_col parameter
2.15. Set carrierfailureroute_table parameter
2.16. Set carrierfailureroute_id_col parameter
2.17. Set carrierfailureroute_carrier_col parameter
2.18. Set carrierfailureroute_domain_col parameter
2.19. Set carrierfailureroute_scan_prefix_col parameter
2.20. Set carrierfailureroute_host_name_col parameter
2.21. Set carrierfailureroute_reply_code_col parameter
2.22. Set carrierfailureroute_flags_col parameter
2.23. Set carrierfailureroute_mask_col parameter
2.24. Set carrierfailureroute_next_domain_col parameter
2.25. Set carrierfailureroute_description_col parameter
2.26. Set carrier_name_table parameter
2.27. Set carrier_name_id_col parameter
2.28. Set carrier_name_carrier_col parameter
2.29. Set domain_name_table parameter
2.30. Set domain_name_id_col parameter
2.31. Set domain_name_domain_col parameter

Chapter 1. Admin Guide

1. Overview

A module which provides routing, balancing and blacklisting capabilities.

The module provides routing, balancing and blacklisting capabilities. It reads routing entries from a database source or from a config file at Kamailio startup. It can uses one routing tree (for one carrier), or if needed for every user a different routing tree (unique for each carrier) for number prefix based routing. It supports several route tree domains, e.g. for failback routes or different routing rules for VoIP and PSTN targets.

Based on the tree, the module decides which number prefixes are forwarded to which gateway. It can also distribute the traffic by ratio parameters. Furthermore, the requests can be distributed by a hash funcion to predictable destinations. The hash source is configurable, two different hash functions are available.

This modules scales up to more than a few million users, and is able to handle more than several hundred thousand routing table entries. We received reports of some setups that used more than a million routing table entries. It also supports a large number of carriers and domains which can be efficiently looked up in most of the cases (see below for more informations). In load balancing scenarios the usage of the config file mode is recommended, to avoid the additional complexity that the database driven routing creates.

Routing tables can be reloaded and edited (in config file mode) with the RPC interface, the config file is updated according the changes. This is not implemented for the db interface, because its easier to do the changes directly on the db. But the reload and dump functions works of course here too.

Some module functionality is not fully available in the config file mode, as it is not possible to specify all information that can be stored in the database tables in the config file. Further information about these limitations is given in later sections. For user based routing or LCR you should use the database mode.

In database mode, this module supports names and IDs for the carriers and domains. When using IDs for the routing functions, efficient binary search is used to find the needed data structures. If you are using constant strings as parameter, these will be converted to IDs during the fixup procedure. However, if you are using AVPs as parameter and they contain strings, this cannot be converted to IDs during the fixup procedure. In that case linear search is performed to find the needed data structures. So from a performance point of view it is better to pass only IDs in AVPs to the routing functions.

Basically this module could be used as an replacement for the lcr and the dispatcher module, if you have certain flexibility, integration and/or performance requirements that can't be satisfied with these modules. But for smaller installations it probably make more sense to use the lcr and dispatcher module.

Starting with version 3.1 , if you want to use this module in failure routes, it is not needed to callappend_branch() after rewriting the request URI in order to relay the message to the new target. Its also supportes the usage of database derived failure routing descisions with the carrierfailureroute table.

2. Dependencies

2.1. Kamailio Modules

The following module must be loaded before this module:

  • a database module, when a database is used as configuration data source. Only SQL based databases are supported, as this module needs the capability to issue raw queries. Its not possible to use the dbtext or db_berkeley module at the moment.

  • The tm module, when you want to use the $T_reply_code pseudo-variable in the cr_next_domain function.

3. Parameters

3.1. subscriber_table (string)

The name of the table containing the subscribers

Default value is subscriber.

Example 1.1. Set subscriber_table parameter

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

3.2. subscriber_user_col (string)

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

Default value is username.

Example 1.2. Set subscriber_user_col parameter

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

3.3. subscriber_domain_col (string)

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

Default value is domain.

Example 1.3. Set subscriber_domain_col parameter

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

3.4. subscriber_carrier_col (string)

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

Default value is cr_preferred_carrier.

Example 1.4. Set subscriber_carrier_col parameter

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

3.5. config_source (string)

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

Default value is file.

Example 1.5. Set config_source parameter

...
modparam("carrierroute", "config_source", "file")
...

3.6. config_file (string)

Specifies the path to the config file.

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

Example 1.6. Set config_file parameter

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

3.7. default_tree (string)

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

Default value is default.

Example 1.7. Set default_tree parameter

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

3.8. use_domain (int)

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.

Example 1.8. Set use_domain parameter

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

3.9. fallback_default (int)

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.

Example 1.9. Set fallback_default parameter

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

3.10. fetch_rows (integer)

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.

Example 1.10. Set fetch_rows parameter

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

3.11. db_load_description (integer)

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.

Example 1.11. Unset db_load_description parameter

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

3.12. match_mode (integer)

The number of individual characters that are used for matching. Valid values are 10 or 128. When you specifiy 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.

Example 1.12. Set match_mode parameter

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

3.13. avoid_failed_destinations (integer)

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.

Example 1.13. Set avoid_failed_destinations parameter

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

4. Functions

Previous versions of carrierroute had some more function. All the old semantics can be achieved by using the few new functions like this:

cr_rewrite_uri(domain, hash_source)
-> cr_route("default", domain, "$rU", "$rU", hash_source)

cr_rewrite_by_to(domain, hash_source)
-> cr_route("default", domain, "$tU", "$rU", hash_source)

cr_rewrite_by_from(domain, hash_source)
-> cr_route("default", domain, "$fU", "$rU", hash_source)

cr_user_rewrite_uri(uri, domain)
-> cr_user_carrier(user, domain, "$avp(tree_avp)")
-> cr_route("$avp(tree_avp)", domain, "$rU", "$rU", "call_id")

cr_tree_rewrite_uri(tree, domain)
-> cr_route(tree, domain, "$rU", "$rU", "call_id")

4.1.  cr_user_carrier(user, domain, dstavp)

This function loads the carrier and stores it in an AVP. It cannot be used in the config file mode, as it needs a mapping of the given user to a certain carrier. The is derived 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:

  • user - Name of the user for the carrier tree lookup. Additional to a string any pseudo-variable could be used as input.

  • domain - Name of the routing domain to be used. Additional to a string any pseudo-variable could be used as input.

  • dstavp - Name of the AVP where to store the carrier id.

4.2.  cr_route(carrier, domain, prefix_matching, rewrite_user, hash_source, descavp)

This function searches for the longest match for the user given in prefix_matching at 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 also the description is stored in the given AVP (if obmitted, nothing is stored in an AVP). This is useful if you need some additional informations that belongs to each gw, like the destination or the number of channels.

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 cr_route. 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:

  • carrier - The routing tree to be used. Additional to a string any pseudo-variable could be used as input.

  • domain - Name of the routing domain to be used. Additional to a string any pseudo-variable could be used as input.

  • prefix_matching - User name to be used for prefix matching in the routing tree. Additional to a string any pseudo-variable could be used as input.

  • rewrite_user - The user name to be used for applying the rewriting rule. Usually this is the user part of the request URI. Additional to a string any pseudo-variable could be used as input.

  • hash_source - The hash values of the destination set must be a contiguous range starting at 1, limited by the configuration parameter max_targets. Possible values for hash_source are: call_id, from_uri, from_user, to_uri, to_user and rand

  • decsavp - AVP where to store the description. This parameter is optional.

4.3.  cr_nofallback_route(carrier, domain, prefix_matching, rewrite_user, hash_source, descavp)

This function searches for the longest match for the user given in prefix_matching at 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 also the description is stored in the given AVP (if obmitted, nothing is stored in an AVP). This is useful if you need some additional informations that belongs to each gw, like the destination or the number of channels. 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 obselete) cr_prime_route is used. This means not the configured probabilities will be used, only a fixed hash distribution. 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:

  • carrier - The routing tree to be used. Additional to a string any pseudo-variable could be used as input.

  • domain - Name of the routing domain to be used. Additional to a string any pseudo-variable could be used as input.

  • prefix_matching - User name to be used for prefix matching in the routing tree. Additional to a string any pseudo-variable could be used as input.

  • rewrite_user - The user name to be used for applying the rewriting rule. Usually this is the user part of the request URI. Additional to a string any pseudo-variable could be used as input.

  • hash_source - The hash values of the destination set must be a contiguous range starting at 1, limited by the configuration parameter max_targets. Possible values for hash_source are: call_id, from_uri, from_user, to_uri and to_user.

  • descavp - Name of the AVP where to store the description. This parameter is optional.

4.4.  cr_next_domain(carrier, domain, prefix_matching, host, reply_code, dstavp)

This function searches for the longest match for the user given in prefix_matching at 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, reply_code and then flags. The more wildcards in reply_code and the more bits used in flags, the lower the priority. Returns -1 if there is no data found or an empty next_domain on the longest match is found. Otherwise the next domain is stored in the given AVP. 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.

Meaning of the parameters is as follows:

  • carrier - The routing tree to be used. Additional to a string any pseudo-variable could be used as input.

  • domain - Name of the routing domain to be used. Additional to a string any pseudo-variable could be used as input.

  • prefix_matching - User name to be used for prefix matching in the routing tree. Additional to a string any pseudo-variable could be used as input.

  • host - The host name to be used for failure route rule matching. Usually this is the last tried routing destination stored in an avp by cr_route. Additional to a string any pseudo-variable could be used as input.

  • reply_code - The reply code to be used for failure route rule matching. Additional to a string any pseudo-variable could be used as input.

  • dstavp - Name of the AVP where to store the next routing domain.

5. RPC Commands

5.1.  cr.reload_routes

This command reloads the routing data from the data source.

Name: cr.reload_routes

Parameters:

  • none

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.

5.2.  cr.dump_routes

This command prints the route rules on the command line.

Name: cr.dump_routes

Parameters:

  • none

6. MI Commands

All commands understand the "-?" parameter to print a short help message. The options have to be quoted as one string to be passed to MI interface. Each option except host and new host can be wildcarded by * (but only * and not things like "-d prox*").

6.1. cr_reload_routes

6.2. cr_dump_routes

6.3. cr_replace_host

This command can replace the rewrite_host of a route rule, it is only usable in file mode. Following options are possible:

  • -d - the domain containing the host

  • -p - the prefix containing the host

  • -h - the host to be replaced

  • -t - the new host

Use the "null" prefix to specify an empty prefix.

Example 1.14. cr_replace_host usage

...
kamctl fifo cr_replace_host "-d proxy -p 49 -h proxy1 -t proxy2"
...

6.4. cr_deactivate_host

This command deactivates the specified host, i.e. it sets its status to 0. It is only usable in file mode. Following options are possible:

  • -d - the domain containing the host

  • -p - the prefix containing the host

  • -h - the host to be deactivated

  • -t - the new host used as backup

When -t (new_host) is specified, the portion of traffic for the deactivated host is routed to the host given by -t. This is indicated in the output of dump_routes. The backup route is deactivated if the host is activated again.

Use the "null" prefix to specify an empty prefix.

Example 1.15. cr_deactivate_host usage

...
kamctl fifo cr_deactivate_host "-d proxy -p 49 -h proxy1"
...

6.5. cr_activate_host

This command activates the specified host, i.e. it sets its status to 1. It is only usable in file mode. Following options are possible:

  • -d - the domain containing the host

  • -p - the prefix containing the host

  • -h - the host to be activated

Use the "null" prefix to specify an empty prefix.

Example 1.16. cr_activate_host usage

...
kamctl fifo cr_activate_host "-d proxy -p 49 -h proxy1"
...

6.6. cr_add_host

This command adds a route rule, it is only usable in file mode. Following options are possible:

  • -d - the domain containing the host

  • -p - the prefix containing the host

  • -h - the host to be added

  • -w - the weight of the rule

  • -P - an optional rewrite prefix

  • -S - an optional rewrite suffix

  • -i - an optional hash index

  • -s - an optional strip value

Use the "null" prefix to specify an empty prefix.

Example 1.17. cr_add_host usage

...
kamctl fifo cr_add_host "-d proxy -p 49 -h proxy1 -w 0.25"
...

6.7. cr_delete_host

This command delete the specified hosts or rules, i.e. remove them from the route tree. It is only usable in file mode. Following options are possible:

  • -d - the domain containing the host

  • -p - the prefix containing the host

  • -h - the host to be added

  • -w - the weight of the rule

  • -P - an optional rewrite prefix

  • -S - an optional rewrite suffix

  • -i - an optional hash index

  • -s - an optional strip value

Use the "null" prefix to specify an empty prefix.

Example 1.18. cr_delete_host usage

...
kamctl fifo cr_delete_host "-d proxy -p 49 -h proxy1 -w 0.25"
...

7. Configuration examples

Example 1.19. Configuration example - Routing to default tree

...
route {
	# route calls based on hash over callid
	# choose route domain 0 of the default carrier
	
	if(!cr_route("default", "0", "$rU", "$rU", "call_id")){
		sl_send_reply("403", "Not allowed");
	} else {
		# In case of failure, re-route the request
		t_on_failure("1");
		# Relay the request to the gateway
		t_relay();
	}
}

failure_route[1] {
	revert_uri();
	# In case of failure, send it to an alternative route:
	if (t_check_status("408|5[0-9][0-9]")) {
	#choose route domain 1 of the default carrier
	if(!cr_route("default", "1", "$rU", "$rU", "call_id")){
			t_reply("403", "Not allowed");
		} else {
			t_on_failure("2");
			t_relay();
		}
	}
}

failure_route[2] {
	# further processing
}

Example 1.20. Configuration example - Routing to user tree

...
route[1] {
	cr_user_carrier("$fU", "$fd", "$avp(s:carrier)");

	# just an example domain
	$avp(s:domain)="start";
	if (!cr_route("$avp(s:carrier)", "$avp(s:domain)", "$rU", "$rU",
			"call_id")) {
		xlog("L_ERR", "cr_route failed\n");
		exit;
	}
	# if you store also the port as part of the rewrite host,
	# otherwise you can just use $rd later
	$avp(s:host)= $rd+":"+$rp;
	t_on_failure("1");
		if (!t_relay()) {
			sl_reply_error();
	};
}

failure_route[1] {
	revert_uri();
	if (!cr_next_domain("$avp(s:carrier)", "$avp(s:domain)", "$rU",
			"$avp(s:host)", "$T_reply_code", "$avp(s:domain)")) {
		xlog("L_ERR", "cr_next_domain failed\n");
		exit;
	}
	if (!cr_route("$avp(s:carrier)", "$avp(s:domain)", "$rU", "$rU",
			"call_id")) {
		xlog("L_ERR", "cr_route failed\n");
		exit;
	}
	$avp(s:host)= $rd+":"+$rp;
	t_on_failure("1");
	if (!t_relay()) {
		xlog("L_ERR", "t_relay failed\n");
		exit;
	};
}
...

Example 1.21. Configuration example - module configuration

The following config file specifies within the default carrier two domains, each with an prefix that contains two hosts. It is not possible to specify another carrier if you use the config file as data source.

All traffic will be equally distributed between the hosts, both are active. The hash algorithm will working over the [1,2] set, messages hashed to one will go to the first host, the other to the second one. Don't use a hash index value of zero. If you ommit the hash completly, the module gives them a autogenerated value, starting from one.

Use the NULL prefix to specify an empty prefix in the config file. Please note that the prefix is matched against the request URI (or to URI), if they did not contain a valid (numerical) URI, no match is possible. So for loadbalancing purposes e.g. for your registrars, you should use an empty prefix.

...
domain proxy {
   prefix 49 {
     max_targets = 2
      target proxy1.localdomain {
         prob = 0.500000
         hash_index = 1
         status = 1
         comment = "test target 1"
      }
      target proxy2.localdomain {
         prob = 0.500000
         hash_index = 2
         status = 1
         comment = "test target 2"
      }
   }
}

domain register {
   prefix NULL {
     max_targets = 2
      target register1.localdomain {
         prob = 0.500000
         hash_index = 1
         status = 1
         comment = "test target 1"
      }
      target register2.localdomain {
         prob = 0.500000
         hash_index = 2
         status = 1
         comment = "test target 2"
      }
   }
}
...

8. Installation and Running

8.1. Database setup

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.

8.2. Database examples

Example 1.22. Example database content - carrierroute table

...
+----+---------+--------+-------------+-------+------+---------------+
| 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 a 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 choosen if some message flags are set. If this flags are not set, the other two rules are used. The strip, mask and comment colums are omitted for brevity.

Example 1.23. Example database content - simple carrierfailureroute table

...
+----+---------+--------+---------------+------------+-------------+
| 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 choosen. After that no more failure routes are available, an error will be returned from the cr_next_domain function. Not all table colums are show 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.

Example 1.24. Example database content - more complex carrierfailureroute table

...
+----+---------+-----------+------------+--------+-----+-------------+
| 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 choosen. 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 colums are show here for brevity.

Example 1.25. Example database content - carrier_name table

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

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

Example 1.26. Example database content - domain_name table

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

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

8.3. User specific routing

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 modul parameter) to choose the actual carrier for the users.

Example 1.27. Necessary extensions for the user table

Suggested changes:

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

Chapter 2. Module parameter for database access.

1. db_url (String)

URL to the database containing the data.

Default value is mysql://kamailioro:kamailioro@localhost/kamailio.

Example 2.1. Set db_url parameter

...
modparam("carrierroute", "db_url", "dbdriver://username:password@dbhost/dbname")
...

2. carrierroute_table (String)

Name of the carrierroute table for the carrierroute module.

Default value is carrierroute.

Example 2.2. Set carrierroute_table parameter

...
modparam("carrierroute", "carrierroute_table", "carrierroute")
...

3. carrierroute_id_col (string)

Name of the column contains the unique identifier of a route.

Example 2.3. Set carrierroute_id_col parameter

...
modparam("carrierroute", "carrierroute_id_col", "id")
...

4. carrierroute_carrier_col (string)

This column contains the carrier id.

Example 2.4. Set carrierroute_carrier_col parameter

...
modparam("carrierroute", "carrierroute_carrier_col", "carrier")
...

5. carrierroute_domain_col (string)

This column contains the routing domain id. You can define several routing domains to have different routing rules. Maybe you use domain 0 for normal routing and domain 1 if domain 0 failed.

Example 2.5. Set carrierroute_domain_col parameter

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

6. carrierroute_scan_prefix_col (string)

Name of column contains the scan prefixes. Scan prefixes define the matching portion of a phone number, e.g. when we have the scan prefixes 49721 and 49, the called number is 49721913740, it matches 49721, because the longest match is taken. If no prefix matches, the number is not routed. To prevent this, an empty prefix value of could be added.

Example 2.6. Set carrierroute_scan_prefix_col parameter

...
modparam("carrierroute", "carrierroute_scan_prefix_col", "scan_prefix")
...

7. carrierroute_flags_col (string)

This column contains the flags used for rule matching.

Example 2.7. Set carrierroute_flags_col parameter

...
modparam("carrierroute", "carrierroute_flags_col", "flags")
...

8. carrierroute_mask_col (string)

This column contains the mask that is applied to the message flags before rule matching.

Example 2.8. Set carrierroute_mask_col parameter

...
modparam("carrierroute", "carrierroute_mask_col", "mask")
...

9. carrierroute_prob_col (string)

Name of column contains the probability. The probability value is used to distribute the traffic between several gateways. Let's say 70 % of the traffic shall be routed to gateway A, the other 30 % shall be routed to gateway B, we define a rule for gateway A with a prob value of 0.7 and a rule for gateway B with a prob value of 0.3. If all probabilities for a given prefix, tree and domain don't add to 100%, the prefix values will be adjusted according the given prob values. E.g. if three hosts with prob values of 0.5, 0.5 and 0.4 are defined, the resulting probabilities are 35.714, 35.714 and 28.571%. But its better to choose meaningful values in the first place because of clarity.

Example 2.9. Set carrierroute_prob_col parameter

...
modparam("carrierroute", "carrierroute_prob_col", "prob")
...

10. carrierroute_strip_col (string)

Name of the column contains the number of digits to be stripped of the userpart of an URI before prepending rewrite_prefix.

Example 2.10. Set carrierroute_strip_col parameter

...
modparam("carrierroute", "carrierroute_strip_col", "strip")
...

11. carrierroute_rewrite_host_col (string)

Name of column contains the rewrite prefixes. Here you can define a rewrite prefix for the localpart of the SIP URI. An empty field represents a blacklist entry, anything else is put as domain part into the Request URI of the SIP message.

Example 2.11. Set carrierroute_rewrite_host_col parameter

...
modparam("carrierroute", "carrierroute_rewrite_host_col", "rewrite_host")
...

12. carrierroute_rewrite_prefix_col (string)

Name of column contains the rewrite prefixes. Here you can define a rewrite prefix for the localpart of the SIP URI.

Example 2.12. Set carrierroute_rewrite_prefix_col parameter

...
modparam("carrierroute", "carrierroute_rewrite_prefix_col", "rewrite_prefix")
...

13. carrierroute_rewrite_suffix_col (string)

Name of column contains the rewrite suffixes. Here you can define a rewrite suffix for the localpart of the SIP URI.

Example 2.13. Set carrierroute_rewrite_suffix_col parameter

...
modparam("carrierroute", "carrierroute_rewrite_suffix_col", "rewrite_suffix")
...

14. carrierroute_description_col (string)

A comment for the route entry, useful for larger routing tables. The comment is also displayed by the fifo cmd "cr_dump_routes".

Example 2.14. Set carrierroute_description_col parameter

...
modparam("carrierroute", "carrierroute_description_col", "description")
...

15. carrierfailureroute_table (String)

Name of the carrierfailureroute table for the carrierroute module.

Default value is carrierfailureroute.

Example 2.15. Set carrierfailureroute_table parameter

...
modparam("carrierroute", "carrierfailureroute_table", "carrierfailureroute")
...

16. carrierfailureroute_id_col (string)

This column contains the unique identifier of a failure route.

Example 2.16. Set carrierfailureroute_id_col parameter

...
modparam("carrierroute", "carrierfailureroute_id_col", "id")
...

17. carrierfailureroute_carrier_col (string)

This column contains the carrier id.

Example 2.17. Set carrierfailureroute_carrier_col parameter

...
modparam("carrierroute", "carrierfailureroute_carrier_col", "carrier")
...

18. carrierfailureroute_domain_col (string)

This column contains the routing domain id. You can define several routing domains to have different routing rules. Maybe you use domain 0 for normal routing and domain 1 if domain 0 failed.

Example 2.18. Set carrierfailureroute_domain_col parameter

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

19. carrierfailureroute_scan_prefix_col (string)

Name of column contains the the scan prefixes. Scan prexies define the matching portion of a phone number, e.g. we have the scan prefixes 49721 and 49, the called number is 49721913740, it matches 49721, because the longest match is taken. If no prefix matches, the number is not failure routed. To prevent this, an empty prefix value of could be added.

Example 2.19. Set carrierfailureroute_scan_prefix_col parameter

...
modparam("carrierroute", "carrierfailureroute_scan_prefix_col", "scan_prefix")
...

20. carrierfailureroute_host_name_col (string)

Name of the column containing the host name of the last routing destination, using for rules matching.

Example 2.20. Set carrierfailureroute_host_name_col parameter

...
modparam("carrierroute", "carrierfailureroute_host_name_col", "host_name")
...

21. carrierfailureroute_reply_code_col (string)

This column contains the reply code used for rule matching.

Example 2.21. Set carrierfailureroute_reply_code_col parameter

...
modparam("carrierroute", "carrierfailureroute_reply_code_col", "reply_code")
...

22. carrierfailureroute_flags_col (string)

This column contains the flags used for rule matching.

Example 2.22. Set carrierfailureroute_flags_col parameter

...
modparam("carrierroute", "carrierfailureroute_flags_col", "flags")
...

23. carrierfailureroute_mask_col (string)

This column contains the mask that is applied to the message flags before rule matching.

Example 2.23. Set carrierfailureroute_mask_col parameter

...
modparam("carrierroute", "carrierfailureroute_mask_col", "mask")
...

24. carrierfailureroute_next_domain_col (string)

This column contains the route domain id that should be used for the next routing attempt.

Example 2.24. Set carrierfailureroute_next_domain_col parameter

...
modparam("carrierroute", "carrierfailureroute_next_domain_col", "next_domain")
...

25. carrierfailureroute_description_col (string)

A comment for the route entry, useful for larger routing tables.

Example 2.25. Set carrierfailureroute_description_col parameter

...
modparam("carrierroute", "carrierfailureroute_description_col", "description")
...

26. carrier_name_table (String)

Name of the carrier_name table for the carrierroute module.

Default value is carrier_name.

Example 2.26. Set carrier_name_table parameter

...
modparam("carrierroute", "carrier_name_table", "carrier_name")
...

27. carrier_name_id_col (string)

Name of the column containing the unique identifier of a carrier.

Example 2.27. Set carrier_name_id_col parameter

...
modparam("carrierroute", "carrier_name_id_col", "id")
...

28. carrier_name_carrier_col (string)

This column contains the carrier name.

Example 2.28. Set carrier_name_carrier_col parameter

...
modparam("carrierroute", "carrier_name_carrier_col", "carrier")
...

29. domain_name_table (String)

Name of the domain_name table for the carrierroute module.

Default value is domain_name.

Example 2.29. Set domain_name_table parameter

...
modparam("carrierroute", "domain_name_table", "domain_name")
...

30. domain_name_id_col (string)

Name of the column containing the unique identifier of a domain.

Example 2.30. Set domain_name_id_col parameter

...
modparam("carrierroute", "domain_name_id_col", "id")
...

31. domain_name_domain_col (string)

This column contains the domain name.

Example 2.31. Set domain_name_domain_col parameter

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