---
title: "mi_datagram Module"
description: "This is a module which provides a UNIX/UDP SOCKET transport layer implementation for the Management Interface."
---

## Admin Guide


### Overview


This is a module which provides a UNIX/UDP SOCKET transport layer
implementation for the Management Interface.


### DATAGRAM command syntax


The MI requests and replies follow the
[JSON-RPC](http://www.jsonrpc.org/specification) syntax.


If case of an error generated by the MI engine, mostly internal
errors, an error message in plain text is sent back in the datagram.


### Dependencies


#### OpenSIPS Modules


The following modules must be loaded before this module:


- *No dependencies on other OpenSIPS modules*.


#### External Libraries or Applications


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


- *none*


### Exported Parameters


#### socket_name (string)


The name of a UNIX SOCKET or an IP address.
The UNIX datagram or UDP socket will be created using this parameter
in order to read the external commands.
Both IPv4 and IPv6 are supported.


*Default value is NONE.*


```opensips title="Set socket_name parameter"
...
modparam("mi_datagram", "socket_name", "/tmp/opensips.sock")
...
modparam("mi_datagram", "socket_name", "udp:192.168.2.133:8080")
...
```


#### children_count (string)


The number of child processes to be created. Each child process
will be a datagram server.


*Default value is 1.*


```opensips title="Set children_count parameter"
...
modparam("mi_datagram", "children_count", 3)
...
```


#### unix_socket_mode (integer)


Permission to be used for creating the listening UNIX datagram socket.
Not necessary for a UDP socket.
It follows the UNIX conventions.


*Default value is 0660 (rw-rw----).*


```opensips title="Set unix_socket_mode parameter"
...
modparam("mi_datagram", "unix_socket_mode", 0600)
...
```


#### unix_socket_group (integer) unix_socket_group (string)


Group to be used for creating the listening UNIX socket.


*Default value is the inherited one.*


```opensips title="Set unix_socket_group parameter"
...
modparam("mi_datagram", "unix_socket_group", 0)
modparam("mi_datagram", "unix_socket_group", "root")
...
```


#### unix_socket_user (integer) unix_socket_group (string)


User to be used for creating the listening UNIX socket.


*Default value is the inherited one.*


```opensips title="Set unix_socket_user parameter"
...
modparam("mi_datagram", "unix_socket_user", 0)
modparam("mi_datagram", "unix_socket_user", "root")
...
```


#### socket_timeout (integer)


The reply will expire after trying to sent it for socket_timeout
milliseconds.


*Default value is 2000.*


```opensips title="Set socket_timeout parameter"
...
modparam("mi_datagram", "socket_timeout", 2000)
...
```


#### trace_destination (string)


Trace destination as defined in the tracing module. Currently
the only tracing module is **proto_hep**.
This is where traced mi messages will go.


**WARNING:**A tracing module must be
loaded in order for this parameter to work. (for example
**proto_hep**).


*Default value is none(not defined).*


```opensips title="Set trace_destination parameter"
...
modparam("proto_hep", "trace_destination", "[hep_dest]10.0.0.2;transport=tcp;version=3")

modparam("mi_datagram", "trace_destination", "hep_dest")
...
```


#### trace_bwlist (string)


Filter traced mi commands based on a blacklist or a whitelist.
**trace_destination** must be defined for
this parameter to have any purpose. Whitelists can be defined using
'w' or 'W', blacklists using 'b' or 'B'. The type is separate by the
actual blacklist by ':'. The mi commands in the list must be separated
by ','.


Defining a blacklists means all the commands that are not blacklisted
will be traced. Defining a whitelist means all the commands that are
not whitelisted will not be traced.
**WARNING:** One can't define both
a whitelist and a blacklist. Only one of them is allowed. Defining
the parameter a second time will just overwrite the first one.


**WARNING:**A tracing module must be
loaded in order for this parameter to work. (for example
**proto_hep)**.


*Default value is none(not defined).*


```opensips title="Set trace_destination parameter"
...
## blacklist ps and which mi commands
## all the other commands shall be traced
modparam("mi_datagram", "trace_bwlist", "b: ps, which")
...
## allow only sip_trace mi command
## all the other commands will not be traced
modparam("mi_datagram", "trace_bwlist", "w: sip_trace")
...
```


#### pretty_printing (int)


Indicates whether the JSONRPC responses sent through MI should
be pretty-printed or not.


*Default value is "0 - no pretty-printing".*


```opensips title="Set pretty_printing parameter"
...
modparam("mi_fifo", "pretty_printing", 1)
...
```


#### socket_buf_size (integer)


Maximum buffer size used when receiving and sending.


*Default value is 65457.*


```opensips title="Set socket_buf_size parameter"
...
modparam("mi_datagram", "socket_buf_size", 131072)
...
```


### Exported Functions


No function exported to be used from configuration file.


### Example


This is an example showing the DATAGRAM format for the
"get_statistics dialog: tm:" MI commad:
request.


```json title="DATAGRAM request"
{"jsonrpc":"2.0","method":"get_statistics","id":"1065","params":[["dialog:","tm:"]]}
```


## Frequently Asked Questions


**Q: Both UNIX and UDP type of socket can be created 
simultaneusly?**


This version supports only one kind of socket at a time.
If there are more than one value set for socket_name the last one
will take effect.


**Q: Is there a limit in the datagram request's size?**


The maximum length of a datagram request or reply is 65457 bytes.


**Q: Where can I find more about OpenSIPS?**


Take a look at [https://opensips.org/](https://opensips.org/).


**Q: Where can I post a question about this module?**


First at all check if your question was already answered on one of
our mailing lists:

E-mails regarding any stable OpenSIPS release should be sent to 
users@lists.opensips.org and e-mails regarding development versions
should be sent to devel@lists.opensips.org.

If you want to keep the mail private, send it to 
users@lists.opensips.org.


**Q: How can I report a bug?**


Please follow the guidelines provided at:
[https://github.com/OpenSIPS/opensips/issues](https://github.com/OpenSIPS/opensips/issues).
<!-- CONTRIBUTORS -->

### License

All documentation files (i.e. .md extension) are licensed under the Creative Common License 4.0
