SimpleVoipReceiver

simple module

Receives a VoIP stream generated by a SimpleVoipSender, and records statistics. The most important statistic is MOS (Mean Opinion Score, a value between 1 and 5, representing a human user's view of the voice quality), computed using the E Model defined in the ITU-T G.107 standard. The parameters starting with "emodel_" correspond to the parameters of the E model.

The E Model was originally developed within ETSI as a transmission planning tool, described in ETSI technical report ETR 250, and then standardized by the ITU as G.107. The objective of the model was to determine a quality rating that incorporated the "mouth to ear" characteristics of a speech path.

The playout delay, buffer space, the UDP port to listen on, and other input can be specified in module parameters.

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Parameters

Name	Type	Default value	Description
localPort	int
emodelIe	int	5	Equipment impairment factor
emodelBpl	int	10	Packet-loss robustness factor
emodelA	int	5	Advantage factor
emodelRo	double	93.2	Basic signal-to-noise ratio
playoutDelay	double	0s	initial delay for beginning playout after receiving the first packet
adaptivePlayoutDelay	bool	false	if true, adjust playoutDelay after each talkspurt
bufferSpace	int	20	buffer size in packets
mosSpareTime	double	1s	spare time before calculating MOS (after calculated playout time of last packet)

Properties

Name	Value	Description
display	i=block/source

Gates

Name	Direction	Size	Description
socketIn	input
socketOut	output

Signals

Name	Type	Unit
voipPacketDelay	simtime_t
voipPlayoutLossRate	double
voipPlayoutDelay	simtime_t
voipTaildropLossRate	double
voipPacketLossRate	double
voipMosRate	double

Statistics

Name	Title	Source	Record	Unit
mos	VoIP MOS	voipMosRate	stats, vector	MOS
playoutDelay	VoIP Playout Delay	voipPlayoutDelay	stats, vector	s
packetLossRate	VoIP Packet Loss	voipPacketLossRate	stats, vector	ratio
playoutLossRate	VoIP Playout Loss Rate	voipPlayoutLossRate	stats, vector	ratio
taildropLossRate	VoIP Tail Drop Loss Rate	voipTaildropLossRate	stats, vector	ratio
endToEndDelay	VoIP Packet End-to-End Delay	voipPacketDelay	stats, vector	s

Scheduled messages (observed)

msg	kind	ctrl	tags	msgname	context
omnetpp::cMessage	0			selfTalkspurtFinished

Direct method calls (observed)

call to	function	info
MessageDispatcher	inet::MessageDispatcher::arrived	arrived

Incoming messages (observed)

gate	msg	kind	ctrl	srcModule	tags
socketIn	Packet	0 (UdpStatusInd::UDP_I_DATA)		Udp	DscpInd, EcnInd, HopLimitInd, InterfaceInd, L3AddressInd, L4PortInd, NetworkProtocolInd, SocketInd, TosInd, TransportProtocolInd

Outgoing messages (observed)

gate	msg	kind	ctrl	destModule	tags
socketOut	Request	1 (UdpCommandCode::UDP_C_BIND)	UdpBindCommand	Udp	DispatchProtocolReq, SocketReq

Packet operations (observed)

chunkType	packetAction
SimpleVoipPacket	peekAtFront

Shared Tagging operations (observed)

tagType	tagAction
DispatchProtocolReq	addTagIfAbsent
SocketInd	findTag
SocketReq	addTagIfAbsent

Source code

//
// Receives a VoIP stream generated by a ~SimpleVoipSender, and records statistics.
// The most important statistic is MOS (Mean Opinion Score, a value between 1
// and 5, representing a human user's view of the voice quality), computed using
// the E Model defined in the ITU-T G.107 standard. The parameters starting with
// "emodel_" correspond to the parameters of the E model.
//
// The E Model was originally developed within ETSI as a transmission planning tool,
// described in ETSI technical report ETR 250, and then standardized by the ITU as G.107.
// The objective of the model was to determine a quality rating that incorporated the
// "mouth to ear" characteristics of a speech path.
//
// The playout delay, buffer space, the UDP port to listen on, and other input
// can be specified in module parameters.
//
simple SimpleVoipReceiver like IApp
{
    parameters:
        int localPort;
        int emodelIe = default(5);        // Equipment impairment factor
        int emodelBpl = default(10);      // Packet-loss robustness factor
        int emodelA = default(5);         // Advantage factor
        double emodelRo = default(93.2);  // Basic signal-to-noise ratio

        double playoutDelay @unit(s) = default(0s);      // initial delay for beginning playout after receiving the first packet
        bool adaptivePlayoutDelay = default(false);      // if true, adjust playoutDelay after each talkspurt
        int bufferSpace = default(20);      // buffer size in packets
        double mosSpareTime @unit(s) = default(1s); // spare time before calculating MOS (after calculated playout time of last packet)

        @signal[voipPacketDelay](type="simtime_t");      // when receive a frame
        @signal[voipPacketLossRate](type="double");      // at end of talkspurt
        @signal[voipPlayoutDelay](type="simtime_t");    // at end of talkspurt
        @signal[voipPlayoutLossRate](type="double");    // at end of talkspurt
        @signal[voipMosRate](type="double");          // at end of talkspurt
        @signal[voipTaildropLossRate](type="double");   // at end of talkspurt
        @statistic[endToEndDelay](title="VoIP Packet End-to-End Delay"; unit="s"; source="voipPacketDelay"; record=stats,vector);
        @statistic[packetLossRate](title="VoIP Packet Loss"; unit="ratio"; source="voipPacketLossRate"; record=stats,vector);
        @statistic[playoutDelay](title="VoIP Playout Delay"; unit="s"; source="voipPlayoutDelay"; record=stats,vector);
        @statistic[playoutLossRate](title="VoIP Playout Loss Rate"; unit="ratio"; source="voipPlayoutLossRate"; record=stats,vector);
        @statistic[mos](title="VoIP MOS"; unit="MOS"; source="voipMosRate"; record=stats,vector);
        @statistic[taildropLossRate](title="VoIP Tail Drop Loss Rate"; unit="ratio"; source="voipTaildropLossRate"; record=stats,vector);

        @display("i=block/source");
    gates:
        input socketIn @labels(UdpControlInfo/up);
        output socketOut @labels(UdpControlInfo/down);
}

File: src/inet/applications/voip/SimpleVoipReceiver.ned