rtpengine Module


Table of Contents

1. Admin Guide
1.1. Overview
1.2. Multiple RTP proxy usage
1.3. Dependencies
1.3.1. OpenSIPS Modules
1.3.2. External Libraries or Applications
1.4. Exported Parameters
1.4.1. rtpengine_sock (string)
1.4.2. rtpengine_disable_tout (integer)
1.4.3. rtpengine_tout (integer)
1.4.4. rtpengine_retr (integer)
1.4.5. extra_id_pv (string)
1.4.6. setid_avp (string)
1.4.7. db_url (string)
1.4.8. db_table (string)
1.4.9. socket_column (string)
1.4.10. set_column (string)
1.5. Exported Functions
1.5.1. rtpengine_use_set(setid)
1.5.2. rtpengine_offer([flags[, sock_var[, sdp_pvar[, body]]]])
1.5.3. rtpengine_answer([flags[, sock_pvar[, sdp_pvar[, body]]]])
1.5.4. rtpengine_delete([flags[, sock_var]])
1.5.5. rtpengine_manage([flags[, sock_var[, sdp_var[, body]]]])
1.5.6. rtpengine_start_recording([flags [, sock_var]])
1.5.7. rtpengine_stop_recording([flags [, sock_var]])
1.5.8. rtpengine_play_media(flags, [duration_spec[, sock_var[, sockvar]]])
1.5.9. rtpengine_stop_media([flags[, sockvar]])
1.5.10. rtpengine_block_media([flags[, sockvar]])
1.5.11. rtpengine_unblock_media([flags[, sockvar]])
1.5.12. rtpengine_block_dtmf([flags[, sockvar]])
1.5.13. rtpengine_unblock_dtmf([flags[, sockvar]])
1.5.14. rtpengine_start_forwarding([flags[, sockvar]])
1.5.15. rtpengine_stop_forwarding([flags[, sockvar]])
1.5.16. rtpengine_play_dtmf(code, [flags[, sockvar]])
1.6. Exported Pseudo-Variables
1.6.1. $rtpstat
1.6.2. $rtpstat(STAT)[index]
1.6.3. $rtpquery
1.7. Exported MI Functions
1.7.1. rtpengine_enable
1.7.2. rtpengine_show
1.7.3. rtpengine_reload
1.7.4. teardown
2. Frequently Asked Questions
3. Contributors
3.1. By Commit Statistics
3.2. By Commit Activity
4. Documentation
4.1. Contributors

List of Tables

3.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
3.2. Most recently active contributors(1) to this module

List of Examples

1.1. Set rtpengine_sock parameter
1.2. Set rtpengine_disable_tout parameter
1.3. Set rtpengine_tout parameter
1.4. Set rtpengine_retr parameter
1.5. Set extra_id_pv parameter
1.6. Set setid_avp parameter
1.7. Set db_url parameter
1.8. Set db_table parameter
1.9. Set socket_column parameter
1.10. Set set_column parameter
1.11. rtpengine_use_set usage
1.12. rtpengine_offer usage
1.13. rtpengine_offer usage with body replace
1.14. rtpengine_offer usage with call recording
1.15. rtpengine_offer usage for transcoding
1.16. rtpengine_answer usage
1.17. rtpengine_delete usage
1.18. rtpengine_manage usage
1.19. rtpengine_start_recording usage
1.20. rtpengine_stop_recording usage
1.21. Ringback tone using rtpengine_play_media
1.22. Manage music on hold using rtpengine_play_media
1.23. Ringback tone stop using rtpengine_stop_media
1.24. Example of rtpengine_block_media usage
1.25. Example of rtpengine_unblock_media usage
1.26. Example of rtpengine_block_dtmf usage
1.27. Example of rtpengine_unblock_dtmf usage
1.28. Example of rtpengine_start_forwarding usage
1.29. Example of rtpengine_stop_forwarding usage
1.30. Example of rtpengine_play_dtmf usage
1.31. $rtpstat Usage
1.32. $rtpstat(STAT)
1.33. $rtpquery Usage
1.34. rtpengine_enable usage
1.35. rtpengine_show usage
1.36. rtpengine_reload usage
1.37. teardown usage

Chapter1.Admin Guide

1.1.Overview

This is a module that enables media streams to be proxied via an RTP proxy. The only RTP proxy currently known to work with this module is the Sipwise rtpengine https://github.com/sipwise/rtpengine. The rtpengine module is a modified version of the original rtpproxy module using a new control protocol. The module is designed to be a drop-in replacement for the old module from a configuration file point of view, however due to the incompatible control protocol, it only works with RTP proxies which specifically support it.

1.2.Multiple RTP proxy usage

The rtpengine module can support multiple RTP proxies for balancing/distribution and control/selection purposes.

The module allows definition of several sets of rtpengines. Load-balancing will be performed over a set and the admin has the ability to choose what set should be used. The set is selected via its id - the id being defined with the set. Refer to the rtpengine_sock module parameter definition for syntax description.

The balancing inside a set is done automatically by the module based on the weight of each RTP proxy from the set.

The selection of the set is done from script prior using rtpengine_delete(), rtpengine_offer() or rtpengine_answer() functions - see the rtpengine_use_set() function.

Another way to select the set is to define setid_avp module parameter and assign setid to the defined avp before calling rtpengine_offer() or rtpengine_manage() function. If forwarding of the requests fails and there is another branch to try, remember to unset the avp after calling rtpengine_delete() function.

For backward compatibility reasons, a set with no id take by default the id 0. Also if no set is explicitly set before rtpengine_delete(), rtpengine_offer() or rtpengine_answer() the 0 id set will be used.

IMPORTANT: if you use multiple sets, take care and use the same set for both rtpengine_offer()/rtpengine_answer() and rtpengine_delete()!! If the set was selected using setid_avp, the avp needs to be set only once before rtpengine_offer() or rtpengine_manage() call.

1.3.Dependencies

1.3.1.OpenSIPS Modules

The following modules must be loaded before this module:

  • tm module - (optional) if you want to have rtpengine_manage() fully functional

1.3.2.External Libraries or Applications

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

  • None.

1.4.Exported Parameters

1.4.1.rtpengine_sock (string)

Definition of socket(s) used to connect to (a set) RTP proxy. It may specify a UNIX socket or an IPv4/IPv6 UDP socket.

Default value is NONE (disabled).

Example1.1.Set rtpengine_sock parameter

...
# single rtproxy
modparam("rtpengine", "rtpengine_sock", "udp:localhost:12221")
# multiple rtproxies for LB
modparam("rtpengine", "rtpengine_sock",
	"udp:localhost:12221 udp:localhost:12222")
# multiple sets of multiple rtproxies
modparam("rtpengine", "rtpengine_sock",
	"1 == udp:localhost:12221 udp:localhost:12222")
modparam("rtpengine", "rtpengine_sock",
	"2 == udp:localhost:12225")
...

1.4.2.rtpengine_disable_tout (integer)

Once an RTP proxy was found unreachable and marked as disabled, the rtpengine module will not attempt to establish communication to that RTP proxy for rtpengine_disable_tout seconds.

Default value is 60.

Example1.2.Set rtpengine_disable_tout parameter

...
modparam("rtpengine", "rtpengine_disable_tout", 20)
...

1.4.3.rtpengine_tout (integer)

Timeout value in waiting for reply from RTP proxy.

Default value is 1.

Example1.3.Set rtpengine_tout parameter

...
modparam("rtpengine", "rtpengine_tout", 2)
...

1.4.4.rtpengine_retr (integer)

How many times the module should retry to send and receive after timeout was generated.

Default value is 5.

Example1.4.Set rtpengine_retr parameter

...
modparam("rtpengine", "rtpengine_retr", 2)
...

1.4.5.extra_id_pv (string)

The parameter sets the PV defination to use when the b parameter is used on rtpengine_delete(), rtpengine_offer(), rtpengine_answer() or rtpengine_manage() command.

Default is empty, the b parameter may not be used then.

Example1.5.Set extra_id_pv parameter

...
modparam("rtpengine", "extra_id_pv", "$avp(extra_id)")
...

1.4.6.setid_avp (string)

The parameter defines an AVP that, if set, determines which RTP proxy set rtpengine_offer(), rtpengine_answer(), rtpengine_delete(), and rtpengine_manage() functions use.

There is no default value.

Example1.6.Set setid_avp parameter

...
modparam("rtpengine", "setid_avp", "$avp(setid)")
...

1.4.7.db_url (string)

Database URL, used to load RTPEngines sockets from db, instead of specifying them in the script (rtpengine_sock module parameter).

Default value is NULL, no database is used.

Example1.7.Set db_url parameter

...
modparam("rtpengine", "db_url", 
		"mysql://opensips:opensipsrw@localhost/opensips")
...

1.4.8.db_table (string)

The table where the RTPEngines sockets are stored. Used when Database URL is provisioned.

Default value is rtpengines.

Example1.8.Set db_table parameter

...
modparam("rtpengine", "db_table", "rtpengine_new")
...

1.4.9.socket_column (string)

The name of the rtpengine socket column in the database table.

Default value is socket.

Example1.9.Set socket_column parameter

...
modparam("rtpengine", "socket_column", "sock")
...

1.4.10.set_column (string)

The name of the rtpengine set column in the database table.

Default value is set_id.

Example1.10.Set set_column parameter

...
modparam("rtpengine", "set_column", "set_new")
...

1.5.Exported Functions

1.5.1. rtpengine_use_set(setid)

Sets the ID of the RTP proxy set to be used for the next rtpengine_delete(), rtpengine_offer(), rtpengine_answer() or rtpengine_manage() command. The parameter is an integer.

This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE.

Example1.11.rtpengine_use_set usage

...
rtpengine_use_set(2);
rtpengine_offer();
...

1.5.2. rtpengine_offer([flags[, sock_var[, sdp_pvar[, body]]]])

Rewrites SDP body to ensure that media is passed through an RTP proxy. To be invoked on INVITE for the cases the SDPs are in INVITE and 200 OK and on 200 OK when SDPs are in 200 OK and ACK.

Meaning of the parameters is as follows:

  • flags(string, optional) - flags to turn on some features.

    The flags string is a list of space-separated items. Each item is either an individual token, or a token in key=value format. The possible tokens are described below.

    When passing an option that OpenSIPS is not aware of, it will be blindly sent to the rtpengine daemon to be processed.

    • via-branch=... - Include the branch value of one of the Via headers in the request to the RTP proxy. Possible values are: 1 - use the first Via header; 2 - use the second Via header; auto - use the first Via header if this is a request, or the second one if this is a reply; extra - don't take the value from a header, but instead use the value of the extra_id_pv variable. This can be used to create one media session per branch on the RTP proxy. When sending a subsequent delete command to the RTP proxy, you can then stop just the session for a specific branch when passing the flag '1' or '2' in the rtpengine_delete, or stop all sessions for a call when not passing one of those two flags there. This is especially useful if you have serially forked call scenarios where the RTP proxy gets an offer command for a new branch, and then a delete command for the previous branch, which would otherwise delete the full call, breaking the subsequent answer for the new branch. This flag is only supported by the Sipwise rtpengine RTP proxy at the moment!

    • asymmetric - flags that UA from which message is received doesn't support symmetric RTP. (automatically sets the 'r' flag)

    • force-answer - force answer, that is, only rewrite SDP when corresponding session already exists in the RTP proxy. By default is on when the session is to be completed.

    • in-iface=..., out-iface=... - these flags specify the direction the SIP message. These flags only make sense when the RTP proxy is running in bridge mode. in-iface should indicate the proxy's inbound interface, and out-iface corresponds to the RTP proxy's outbound interface. You always have to specify two flags to define the incoming network and the outgoing network. For example, in-iface=internal out-iface=external should be used for SIP message received from the local interface and sent out on the external interface.

    • internal, external - these the old flags used to specify the direction of call. They are now obsolate, being replaced by the in-iface=internal out-iface=external configuration.

    • auto-bridge - this flag an alternative to the internal and external flags in order to do automatic bridging between IPv4 on the "internal network" and IPv6 on the "external network". Instead of explicitly instructing the RTP proxy to select a particular address family, the distinction is done by the given IP in the SDP body by the RTP proxy itself. Not supported by Sipwise rtpengine.

    • address-family=... - instructs the RTP proxy that the recipient of this SDP body expects to see addresses of a particular family. Possible values are IP4 and IP6. For example, if the SDP body contains IPv4 addresses but the recipient only speaks IPv6, you would use address-family=IP6 to bridge between the two address families.

      Sipwise rtpengine remembers the address family preference of each party after it has seen an SDP body from them. This means that normally it is only necessary to explicitly specify the address family in the offer, but not in the answer.

      Note: Please note, that this will only work properly with non-dual-stack user-agents or with dual-stack clients according to RFC6157 (which suggest ICE for Dual-Stack implementations). This short-cut will not work properly with RFC4091 (ANAT) compatible clients, which suggests having different m-lines with different IP-protocols grouped together.

    • force - instructs the RTP proxy to ignore marks inserted by another RTP proxy in transit to indicate that the session is already goes through another proxy. Allows creating a chain of proxies. Not supported and ignored by Sipwise rtpengine.

    • trust-address - flags that IP address in SDP should be trusted. Without this flag, the RTP proxy ignores address in the SDP and uses source address of the SIP message as media address which is passed to the RTP proxy.

    • replace-origin - flags that IP from the origin description (o=) should be also changed.

    • replace-session-connection - flags to change the session-level SDP connection (c=) IP if media description also includes connection information.

    • symmetric - flags that for the UA from which message is received, support symmetric RTP must be forced. You do not need to explicitly specify this value, as it is the default, and the behavior is only changed when the asymmetric is used.

    • repacketize=NN - requests the RTP proxy to perform re-packetization of RTP traffic coming from the UA which has sent the current message to increase or decrease payload size per each RTP packet forwarded if possible. The NN is the target payload size in ms, for the most codecs its value should be in 10ms increments, however for some codecs the increment could differ (e.g. 30ms for GSM or 20ms for G.723). The RTP proxy would select the closest value supported by the codec. This feature could be used for significantly reducing bandwith overhead for low bitrate codecs, for example with G.729 going from 10ms to 100ms saves two thirds of the network bandwith. Not supported by Sipwise rtpengine.

    • loop-protect - flag that instructs RTP to avoid rewriting the SDP when looping the same message.

    • ICE=... - controls the RTP proxy's behaviour regarding ICE attributes within the SDP body. Possible values are: force - discard any ICE attributes already present in the SDP body and then generate and insert new ICE data, leaving itself as the only ICE candidates; remove instructs the RTP proxy to discard any ICE attributes and not insert any new ones into the SDP. The default (if no ICE=... is given at all), new ICE data will only be generated if no ICE was present in the SDP originally; otherwise the RTP proxy will only insert itself as an additional ICE candidate. Other SDP substitutions (c=, m=, etc) are unaffected by this flag.

    • RTP, SRTP, AVP, AVPF - These flags control the RTP transport protocol that should be used towards the recipient of the SDP. If none of them are specified, the protocol given in the SDP is left untouched. Otherwise, the SRTP flag indicates that SRTP should be used, while RTP indicates that SRTP should not be used. AVPF indicates that the advanced RTCP profile with feedback messages should be used, and AVP indicates that the regular RTCP profile should be used. See also the next set of flags below.

    • RTP/AVP, RTP/SAVP, RTP/AVPF, RTP/SAVPF - these serve as an alternative, more explicit way to select between the different RTP protocols and profiles supported by the RTP proxy. For example, giving the flag RTP/SAVPF has the same effect as giving the two flags SRTP AVPF.

    • to-tag - force inclusion of the To tag. Normally, the To tag is always included when present, except for delete messages. Including the To tag in a delete messages allows you to be more selective about which dialogues within a call are being torn down.

    • to-tag=... - use the specified string as To tag instead of the actual To tag from the SIP message, and force inclusion of the tag in the message as per above.

    • from-tag=... - use the specified string as From tag instead of the actual From tag from the SIP message.

    • call-id=... - use the specified string as Call-ID instead of the actual Call-ID from the SIP message.

    • rtcp-mux-demux - if rtcp-mux (RFC 5761) was offered, make the RTP proxy accept the offer, but not offer it to the recipient of this message.

    • rtcp-mux-reject - if rtcp-mux was offered, make the RTP proxy reject the offer, but still offer it to the recipient. Can be combined with rtcp-mux-offer to always offer it.

    • rtcp-mux-offer - make the RTP proxy offer rtcp-mux to the recipient of this message, regardless of whether it was offered originally or not.

    • rtcp-mux-require - Similar to offer but pretends that the client has accepted rtcp-mux. This breaks RFC 5761 and will not advertise seperate RTCP ports. This option is necessary for WebRTC clients.

    • rtcp-mux-accept - if rtcp-mux was offered, make the RTP proxy accept the offer and also offer it to the recipient of this message. Can be combined with rtcp-mux-offer to always offer it.

    • media-address=... - force a particular media address to be used in the SDP body. Address family is detected automatically.

    • record-call=yes/no - indicates whether rtpengine should record the call or not. When using this parameter, you may pass further information in the metadata.

    • transcode-CODEC - used only for offer, indicates that rtpengine should transcode the CODEC towards the B-side. Example: transcode-PCMA will present to the B-side the PCMA codec.

    • codec-strip-CODEC - used only for offer, indicates that the A-side of the call will not end up talking CODEC. Example: codec-strip-PCMA will prevent the A-side from receiving the PCMA codec.

    • codec-mask-CODEC - used only for offer, indicates that the A-side will use the CODEC, but it will not be presented to the B-side. Example: codec-mask-PCMA will make the A-side receive the PCMA codec, but B-side will use something else.

  • sock_var(var, optional) - variable used to store the rtpengine socket chosen for this call.

  • sdp_var(var, optional) - variable used to store the full SDP received from rtpengine. You can perform any additional changes on this string. Important: when providing this variable, the message body is no longer changed, so you have to manually replace it!.

  • body(string, optional) - used to provide a specific body to the rtpengine_* function. If this parameter is missing the body of the current message is used.

This function can be used from ALL_ROUTES.

Example1.12.rtpengine_offer usage

route {
...
    if (is_method("INVITE")) {
        if (has_body("application/sdp")) {
            if (rtpengine_offer())
                t_on_reply("1");
        } else {
            t_on_reply("2");
        }
    }
    if (is_method("ACK") && has_body("application/sdp"))
        rtpengine_answer();
...
}

onreply_route[1]
{
...
    if (has_body("application/sdp"))
        rtpengine_answer();
...
}

onreply_route[2]
{
...
    if (has_body("application/sdp"))
        rtpengine_offer();
...
}

Example1.13.rtpengine_offer usage with body replace

...
if (rtpengine_offer(, $var(socket), $var(body), $rb)) {
    xlog("Used rtpengine $var(socket)\n");
    # make all the changes on the resulted SDP in $var(body)
    ...
    remove_body_part();
    add_body_part($var(body), "application/sdp");
}
...

Example1.14.rtpengine_offer usage with call recording

...
$var(rtpengine_flags) = $var(rtpengine_flags) + " record-call=yes";

$json(recording_keys) := "{}";
$json(recording_keys/callId) = $ci;
$json(recording_keys/fromUser) = $dlg_val(recording_from_user);
$json(recording_keys/fromDomain) = $dlg_val(recording_from_domain);
$json(recording_keys/fromTag) = $dlg_val(recording_from_tag);
$json(recording_keys/toUser) = $dlg_val(recording_to_user);
$json(recording_keys/toDomain) = $dlg_val(recording_to_domain);

$var(rtpengine_flags) = $var(rtpengine_flags) + " metadata=" + $(json(recording_keys){s.encode.hexa});
rtpengine_offer($var(rtpengine_flags));
...

Example1.15.rtpengine_offer usage for transcoding

...
# Goal: make A-side talk PCMA and B-side talk opus
# * do not present PCMA to B-side: codec-mask-PCMA, but use it on A-side
# * do not use opus for A-side: codec-strip-opus
# * offer opus to B-side: transcode-opus
rtpengine_offer("... codec-mask-PCMA codec-strip-opus transcode-opus ...");
...

1.5.3. rtpengine_answer([flags[, sock_pvar[, sdp_pvar[, body]]]])

Rewrites SDP body to ensure that media is passed through an RTP proxy. To be invoked on 200 OK for the cases the SDPs are in INVITE and 200 OK and on ACK when SDPs are in 200 OK and ACK.

See rtpengine_offer() function description above for the meaning of the parameters.

This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example1.16.rtpengine_answer usage

See rtpengine_offer() function example above for examples.


1.5.4. rtpengine_delete([flags[, sock_var]])

Tears down the RTPProxy session for the current call.

See rtpengine_offer() function description above for the meaning of the parameters. Note that not all flags make sense for a delete.

This function can be used from ALL_ROUTES.

Example1.17.rtpengine_delete usage

...
rtpengine_delete();
...

1.5.5. rtpengine_manage([flags[, sock_var[, sdp_var[, body]]]])

Manage the RTPProxy session - it combines the functionality of rtpengine_offer(), rtpengine_answer() and rtpengine_delete(), detecting internally based on message type and method which one to execute.

It can take the same parameters as rtpengine_offer(). The flags parameter to rtpengine_manage() can be a configuration variable containing the flags as a string.

Functionality:

  • If INVITE with SDP, then do rtpengine_offer()

  • If INVITE with SDP, when the tm module is loaded, mark transaction with internal flag FL_SDP_BODY to know that the 1xx and 2xx are for rtpengine_answer()

  • If ACK with SDP, then do rtpengine_answer()

  • If BYE or CANCEL, or called within a FAILURE_ROUTE[], then do rtpengine_delete()

  • If reply to INVITE with code >= 300 do rtpengine_delete()

  • If reply with SDP to INVITE having code 1xx and 2xx, then do rtpengine_answer() if the request had SDP or tm is not loaded, otherwise do rtpengine_offer()

This function can be used from ALL_ROUTES.

Example1.18.rtpengine_manage usage

...
rtpengine_manage();
...

1.5.6. rtpengine_start_recording([flags [, sock_var]])

This function will send a signal to the RTP proxy to record the RTP stream on the RTP proxy.

Meaning of the parameters is as follows:

  • flags(string, optional) - flags used to change the behavior of the recorder. An importat value to set is the call-id value, which can be used to start recording a different call than the requested one.

  • sock_var(var, optional) - variable used to store the rtpengine socket chosen for this call.

This function can be used from any route.

Example1.19.rtpengine_start_recording usage

...
rtpengine_start_recording();
...
		

1.5.7. rtpengine_stop_recording([flags [, sock_var]])

This function will send a signal to the RTP proxy to stop recording the RTP stream on the RTP proxy.

Meaning of the parameters is as follows:

  • flags(string, optional) - flags used to change the behavior of the recorder. An importat value to set is the call-id value, which can be used to start recording a different call than the requested one.

  • sock_var(var, optional) - variable used to store the rtpengine socket chosen for this call.

This function can be used from any route.

Example1.20.rtpengine_stop_recording usage

...
rtpengine_stop_recording();
...
		

1.5.8. rtpengine_play_media(flags, [duration_spec[, sock_var[, sockvar]]])

This function will start playing a media file to one of the endpoints.

Meaning of the parameters is as follows:

  • flags(string) - a list of flags simialar to the other functions. One of the file, blob or db-id parameters is mandatory to indicate the content of the media file to be played. file is a common choice for specifying rtpengine to get media from a file path, blob to take the content from an inline string and db-id to get the content from the database.

    The direction of the media stream is controlled by the from-tag parameter, address (media address from the SDP), or label, if the media stream contains a label. If all of them are missing, the media file is played to the initiator of the SIP request, and will work similar to a ringback tone.

  • duration_spec(var, optional) - a pseudo variable that will contain the duration of the played file. It will be set to -1 if the duration could not be determined.

  • sock_var(var, optional) - variable used to store the rtpengine socket chosen for this call.

This function can be used from any route.

Example1.21.Ringback tone using rtpengine_play_media

...
if (is_method("INVITE") && !has_totag())
	rtpengine_play_media("file=/path/to/ringback_tone_file.wav");
...
		

Example1.22.Manage music on hold using rtpengine_play_media

...
if (is_method("INVITE") && has_totag()) {
	if (is_audio_on_hold()) {
		$dlg_val(on_hold) = "1";
		rtpengine_play_media("from-tag=$tt file=/path/to/moh_file.wav");
	} else if ($dlg_val(on_hold) == "1") {
		$dlg_val(on_hold) = "0";
		rtpengine_stop_media("from-tag=$tt");
	}
}
...
		

1.5.9. rtpengine_stop_media([flags[, sockvar]])

This function will stop playing a media file previously started by a rtpengine_play_media() call. The meaning of its parameters is similar to the previous functions. Note that this function should be called with similar parameters as its matching rtpengine_play_media() call, otherwise RTPEngine will not be able to stop media playing.

This function can be used from any route.

Example1.23.Ringback tone stop using rtpengine_stop_media

...
if (is_method("INVITE") && $rs == 200)
	rtpengine_stop_media();
...
		

1.5.10. rtpengine_block_media([flags[, sockvar]])

This function will block the media sent from one of the endpoints. The direction to be blocked is controled by the flags parameter, the from-tag value.

This function can be used from any route.

Example1.24.Example of rtpengine_block_media usage

...
rtpengine_block_media();
...
		

1.5.11. rtpengine_unblock_media([flags[, sockvar]])

This function will resume/unblock the media sent from one of the endpoints. The direction to be blocked is controled by the flags parameter, the from-tag value.

This function can be used from any route.

Example1.25.Example of rtpengine_unblock_media usage

...
rtpengine_unblock_media();
...
		

1.5.12. rtpengine_block_dtmf([flags[, sockvar]])

This function will block the DTMF media sent from one of the endpoints. The direction to be blocked is controled by the flags parameter, the from-tag value.

This function can be used from any route.

Example1.26.Example of rtpengine_block_dtmf usage

...
rtpengine_block_dtmf();
...
		

1.5.13. rtpengine_unblock_dtmf([flags[, sockvar]])

This function will resume/unblock the DTMF media sent from one of the endpoints. The direction to be blocked is controled by the flags parameter, the from-tag value.

This function can be used from any route.

Example1.27.Example of rtpengine_unblock_dtmf usage

...
rtpengine_unblock_dtmf();
...
		

1.5.14. rtpengine_start_forwarding([flags[, sockvar]])

This function will start forwarding the media to a TLS destination specified in the tls-send-to parmeter of RTPEngine. This function allows you to select the media stream to forward, by specifing the from-tag of the entity you want to forward the media. If missing, all media streams are forwarded.

This function can be used from any route.

Example1.28.Example of rtpengine_start_forwarding usage

...
rtpengine_start_forwarding();
...
		

1.5.15. rtpengine_stop_forwarding([flags[, sockvar]])

This function will stop forwarding of the media previously started using the rtpengine_start_forwarding() function.

This function can be used from any route.

Example1.29.Example of rtpengine_stop_forwarding usage

...
rtpengine_stop_forwarding();
...
		

1.5.16. rtpengine_play_dtmf(code, [flags[, sockvar]])

This function instructs RTP to send the DTMF code to the participant of the call. The code can be a digit (0-9) or a special character (one of *,#,A,B,C,D). Additional parameters can be configured using the flags parameter. For more information, please consult the RTP documentation.

NOTE: if you are planning to inject DTMF in a session, you have to specify the inject-DTMF flag when the session is created.

This function can be used to convert SIP INFO DTMF keys to RTP DTMF.

This function can be used from any route.

Example1.30.Example of rtpengine_play_dtmf usage

...
rtpengine_play_dtmf("0"); # send the 0 code upstream
...
		

1.6.Exported Pseudo-Variables

1.6.1.$rtpstat

Returns the RTP statistics from the RTP proxy. The RTP statistics from the RTP proxy are provided as a string and it does contain several packet counters.

Example1.31.$rtpstat Usage

...
    append_hf("X-RTP-Statistics: $rtpstat\r\n");
...
		

1.6.2.$rtpstat(STAT)[index]

Returnes one of the pre-fined statistics listed below:

  • MOS-average - without an index, it returns the average MOS value, expressed in an integer between 0 and 50, of all the RTP streams involved in the call, both caller and callee. If index is specified, it has to be one of the from-tag or to-tag involved in the call. In this case, the variable will return the average MOS of all the streams generated by that endpoint with the associated tag value. If you need more granular statistics, check the $rtpquery variable.

  • jitter-average - similar behavior with MOS-average, but returnes the average jitter.

  • roundtrip-average - similar behavior with MOS-average, but returnes the average roundtrip.

  • packetloss-average - similar behavior with MOS-average, but returnes the average packet loss.

  • MOS-min - without an index, it returns the minimum MOS value (integer value between 0 and 50) of all RTP streams involved in the call, both caller and callee. If the index is specified, it has the same effect as for MOS-average.

  • jitter-min - similar behavior with MOS-min, but returnes the minimum jitter of a leg/call.

  • roundtrip-min - similar behavior with MOS-min, but returnes the minimum roundtrip of a leg/call.

  • packetloss-min - similar behavior with MOS-min, but returnes the minimum packet loss of a leg/call.

  • MOS-max - without an index, it returns the maximum MOS value (integer value between 0 and 50) of all RTP streams involved in the call, both caller and callee. If the index is specified, it has the same effect as for MOS-average.

  • jitter-max - similar behavior with MOS-max, but returnes the maximum jitter of a leg/call.

  • roundtrip-max - similar behavior with MOS-max, but returnes the maximum roundtrip of a leg/call.

  • packetloss-max - similar behavior with MOS-max, but returnes the maximum packet loss of a leg/call.

  • MOS-min-at - without an index, it returns the time in seconds elapsed from the start of the call when the MOS value is minimum. If the index is specified, it has the same effect as for MOS-average.

  • jitter-min-at - similar behavior with MOS-min-at, but returnes the time when the minimum jitter was detected.

  • roundtrip-min-at - similar behavior with MOS-min-at, but returnes the time when the minimum roundtrip was detected.

  • packetloss-min-at - similar behavior with MOS-min-at, but returnes the time when the minimum packet loss of a leg/call was detected.

  • MOS-max-at - without an index, it returns the time in seconds elapsed from the start of the call when the MOS value is maximum. If the index is specified, it has the same effect as for MOS-average.

  • jitter-max-at - similar behavior with MOS-max-at, but returnes the time when the maximum value of jitter was detected.

  • roundtrip-max-at - similar behavior with MOS-max-at, but returnes the time when the maximum value of roundtrip was detected.

  • packetloss-min-at - similar behavior with MOS-max-at, but returnes the time when the maximum packet loss of a leg/call was detected.

NOTE: all these statistics are computed based on the statistics generated by RTPEngine. Some of them might not be available for all the calls (i.e. MOS cannot be computed if the call is too short, or if the phones do not properly report RTP statistics over RTCP). In these cases the variable returns the NULL value.

Example1.32.$rtpstat(STAT)

...
    xlog("Average MOS of the entire call is $rtpstat(MOS-average)\r\n");
    xlog("Average MOS of caller is $(rtpstat(MOS-average)[$ft])\r\n");
    xlog("Average MOS of callee is $(rtpstat(MOS-average)[$tt])\r\n");
    xlog("Min MOS of caller is $(rtpstat(MOS-min)[$ft]) reported at $(rtpstat(MOS-min-at)[$ft])\r\n");
...
		

1.6.3.$rtpquery

Does a Query command to the RTP proxy and returns the answer in a JSON format. You can use this variable to fetch arbitrary data from the RTP proxy such as raw statistics about the call, or other indicators.

You can use a $json() variable to parse its output and extract any information from the query, such as RTP statistics, or MOS values.

Example1.33.$rtpquery Usage

...
	$json(reply) := $rtpquery;
	xlog("Total RTP Stats: $json(reply/totals)\n");
...
		

1.7.Exported MI Functions

1.7.1.rtpengine_enable

Enables/disables a RTP proxy.

Parameters:

  • url - the RTP proxy url (exactly as defined in the config file).

  • enable - 1 - enable, 0 - disable the RTP proxy.

NOTE: if a RTP proxy is defined multiple times (in the same or different set), all of its instances will be enables/disabled.

Example1.34. rtpengine_enable usage

...
$ opensips-cli -x mi rtpengine_enable udp:192.168.2.133:8081 0
...
			

1.7.2.rtpengine_show

Displays all the RTP proxies and their information: set and status (disabled or not, weight and recheck_ticks).

No parameter.

Example1.35. rtpengine_show usage

...
$ opensips-cli -x mi rtpengine_show
...
			

1.7.3.rtpengine_reload

Reloads all rtpengine sets from the database. Used only when the db_url parameter is set.

No parameter.

Example1.36. rtpengine_reload usage

...
$ opensips-cli -x mi rtpengine_reload
...
			

1.7.4.teardown

Terminates the SIP dialog by the SIP Call-ID given as parameter.

Parameters:

  • callid - SIP Call-ID.

Note this is a just a wrapper function over the dlg_end_dlg MI function provided by the dialog module. This wrapping is done just to make rtpengine happy when trying to terminate SIP calls based on RTP timeouts.

Example1.37. teardown usage

...
$ opensips-cli -x mi teardown Y2IwYjQ2YmE2ZDg5MWVkNDNkZGIwZjAzNGM1ZDY0ZDQ
...
			

Chapter2.Frequently Asked Questions

2.1.

How do I migrate from rtpproxy or rtpproxy-ng to rtpengine?

For the most part, only the names of the functions have changed, with rtpproxy in each name replaced with rtpengine. For example, rtpproxy_manage() has become rtpengine_manage(). A few name duplications have also been resolved, for example there is now a single rtpengine_delete() instead of unforce_rtp_proxy() and the identical rtpproxy_destroy().

The largest difference to the old module is how flags are passed to rtpengine_offer(), rtpengine_answer(), rtpengine_manage() and rtpengine_delete(). Instead of having a string of single-letter flags, they now take a string of space-separated items, with each item being either a single token (word) or a key=value pair.

For example, if you had a call rtpproxy_offer("FRWOC+PS");, this would then become:

rtpengine_offer("force trust-address symmetric replace-origin replace-session-connection ICE=force RTP/SAVPF");
		

Finally, if you were using the second parameter (explicit media address) to any of these functions, this has been replaced by the media-address=... option within the first string of flags.

2.2.

Where can I find more about OpenSIPS?

Take a look at http://www.opensips.org/.

2.3.

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 and e-mails regarding development versions should be sent to .

If you want to keep the mail private, send it to .

2.4.

How can I report a bug?

Please follow the guidelines provided at: https://github.com/OpenSIPS/opensips/issues.

Chapter3.Contributors

3.1.By Commit Statistics

Table3.1.Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)

NameDevScoreCommitsLines ++Lines --
1. Razvan Crainea (@razvancrainea)1375646092629
2. Bogdan-Andrei Iancu (@bogdan-iancu)2915421593
3. Richard Fuchs202640723
4. Liviu Chircu (@liviuchircu)151166131
5. Vlad Patrascu (@rvlad-patrascu)157218330
6. Eric Tamme (@etamme)754219
7. Peter Lemenkov (@lemenkov)752732
8. John Burke4117231
9. Rob Gagnon (@rgagnon24)312222
10. Dan Pascu (@danpascu)31313

All remaining contributors: Oliver Severin Mulelid-Tynes (@olivermt).

(1) DevScore = author_commits + author_lines_added / (project_lines_added / project_commits) + author_lines_deleted / (project_lines_deleted / project_commits)

(2) including any documentation-related commits, excluding merge commits. Regarding imported patches/code, we do our best to count the work on behalf of the proper owner, as per the "fix_authors" and "mod_renames" arrays in opensips/doc/build-contrib.sh. If you identify any patches/commits which do not get properly attributed to you, please submit a pull request which extends "fix_authors" and/or "mod_renames".

(3) ignoring whitespace edits, renamed files and auto-generated files

3.2.By Commit Activity

Table3.2.Most recently active contributors(1) to this module

NameCommit Activity
1. Razvan Crainea (@razvancrainea)Jun 2014 - Jan 2020
2. Vlad Patrascu (@rvlad-patrascu)May 2017 - Nov 2019
3. Peter Lemenkov (@lemenkov)Jun 2018 - Sep 2019
4. Bogdan-Andrei Iancu (@bogdan-iancu)Jun 2014 - Jul 2019
5. John BurkeJun 2019 - Jun 2019
6. Liviu Chircu (@liviuchircu)Jul 2014 - Nov 2018
7. Dan Pascu (@danpascu)Mar 2018 - Mar 2018
8. Oliver Severin Mulelid-Tynes (@olivermt)May 2015 - May 2015
9. Rob Gagnon (@rgagnon24)Mar 2015 - Mar 2015
10. Eric Tamme (@etamme)Dec 2014 - Mar 2015

All remaining contributors: Richard Fuchs.

(1) including any documentation-related commits, excluding merge commits

Chapter4.Documentation

4.1.Contributors

Last edited by: Razvan Crainea (@razvancrainea), Peter Lemenkov (@lemenkov), Vlad Patrascu (@rvlad-patrascu), Liviu Chircu (@liviuchircu), Bogdan-Andrei Iancu (@bogdan-iancu), Richard Fuchs.

Documentation Copyrights:

Copyright 2013-2014 Sipwise GmbH

Copyright 2010 VoIPEmbedded Inc.

Copyright 2009-2014 TuTPro Inc.

Copyright 2005 Voice Sistem SRL

Copyright 2003-2008 Sippy Software, Inc.