1.2.1. OpenSER modules

The following modules must be loaded before this module:

• none.

1.2.2. External libraries or applications

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

• none.

1.3.1. list_file (string)

Path to the file with destination sets.

Default value is "/etc/ser/dispatcher.list" or "/usr/local/etc/ser/dispatcher.list".

...
modparam("dispatcher", "list_file", "/var/run/ser/dispatcher.list")
...

1.3.2. force_dst (int)

If set to 1, force overwriting of destination address when that is already set.

Default value is "0".

...
modparam("dispatcher", "force_dst", 1)
...

1.3.3. flags (int)

Various flags that affect the hashing behaviour. For now only the flag 1 is defined. If flag 1 is set only the username part of the uri will be used when computing an uri based hash. If no flags are set the username, hostname and port will be used The port is used only if different from 5060 (normal sip uri) or 5061 (in the sips case).

Default value is "0".

 ...
 modparam("dispatcher", "flags", 1)
 ...
 

1.4.1. ds_select_dst(set, alg)

The method selects a destination from addresses set.

Meaning of the parameters is as follows:

• set - the id of the set from where to pick up destination address. It is the first column in destination list file.

• alg - the algorithm used to select the destination address.

  • "0" - hash over callid

  • "1" - hash over from uri.

  • "2" - hash over to uri.

  • "3" - hash over request-uri.

  • "4" - round-robin (next destination).

  • "X" - if the algorithm is not implemented, the first entry in set is chosen.

This function can be used from REQUEST_ROUTE.

...
ds_select_dst("1", "0");
...

1.4.2. ds_select_domain(set, alg)

The method selects a destination from addresses set and rewrites the host and port from R-URI. The parameters have same meaning as for ds_select_dst().

This function can be used from REQUEST_ROUTE.

1.5.1. Destination List File

Each destination point must be on one line. First token is the set id and next is destination address. The set id must be an integer value. Destination address must be a valid SIP URI. Empty lines or lines starting with "#" are ignored.

...
# $Id: dispatcher.list,v 1.1.1.1 2005/06/13 16:47:37 bogdan_iancu Exp $
# dispatcher destination sets
#

# proxies
2 sip:127.0.0.1:5080
2 sip:127.0.0.1:5082

# gateways
1 sip:127.0.0.1:7070
1 sip:127.0.0.1:7072
1 sip:127.0.0.1:7074
...

1.5.2. OpenSER config file

Next picture displays a sample usage of dispatcher.

...
# $Id: dispatcher.cfg,v 1.1.1.1 2005/06/13 16:47:37 bogdan_iancu Exp $
# sample config file for dispatcher module
#

debug=9          # debug level (cmd line: -dddddddddd)
fork=no
log_stderror=yes  # (cmd line: -E)

children=2
check_via=no      # (cmd. line: -v)
dns=off           # (cmd. line: -r)
rev_dns=off       # (cmd. line: -R)
port=5060

# for more info: sip_router -h

# ------------------ module loading ----------------------------------

loadmodule "modules/maxfwd/maxfwd.so"
loadmodule "modules/sl/sl.so"
loadmodule "modules/dispatcher/dispatcher.so"

# ----------------- setting module-specific parameters ---------------
# -- dispatcher params --

modparam("dispatcher", "list_file", "../etc/dispatcher.list")
# modparam("dispatcher", "force_dst", 1)

route{
	if ( !mf_process_maxfwd_header("10") )
	{
	 	sl_send_reply("483","To Many Hops");
	 	drop();
	};
	
	ds_select_dst("2", "0");
	
	forward(uri:host, uri:port);
	# t_relay();
}

...