SimpleVoipSender

simple module

Implements a simple VoIP source. It is a constant bitrate source, with talkspurt support added. Packets do not contain actual voice data. Connection setup/teardown is not modelled. The peer must be a SimpleVoipReceiver.

The source alternates between two states: talk and silence. The length the module spends in each state are controlled by the talkspurtDuration and silenceDuration parameters. In talk state, the module acts as a CBR source, and sends packets of size talkPacketSize every packetizationInterval seconds to the destination over UDP. Silence is implicit: in silence state, no packets are sent, and there is no explicit signalling of silence either.

Packets are of type SimpleVoipPacket. In addition to packet ID and timestamp, packets also contain a talkspurt ID and the total number of packets in the talkspurt to facilitate statistics at the receiver side. (It allows the receiver to detect loss of packets at the end of a talkspurt; a full talkspurt can still be lost unnoticed.)

The destination address/port, the local port, start and stop times can be set via parameters.

Author:: Adriano

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	-1
destPort	int
destAddress	string
talkPacketSize	int	40B	size of talk packets in bytes
talkspurtDuration	double	weibull(1.423s, 0.824s)
silenceDuration	double	weibull(0.899s, 1.089s)
packetizationInterval	double	20ms	interval between sending voice packets
startTime	double	0s	time of start sending
stopTime	double	-1s	time of end of sending, -1 means forever

Properties

Name	Value	Description
display	i=block/source

Gates

Name	Direction	Size	Description
socketIn	input
socketOut	output

Scheduled messages (observed)

msg	kind	ctrl	tags	msgname	context
omnetpp::cMessage	0			selfSender
omnetpp::cMessage	0			selfSource

Direct method calls (observed)

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

Outgoing messages (observed)

gate	msg	kind	ctrl	destModule	tags
socketOut	Packet	0 (UdpCommandCode::UDP_C_DATA)		Udp	DispatchProtocolReq, L3AddressReq, L4PortReq, SocketReq
socketOut	Request	1 (UdpCommandCode::UDP_C_BIND)	UdpBindCommand	Udp	DispatchProtocolReq, SocketReq

Packet operations (observed)

chunkType	packetAction
SimpleVoipPacket	insertAtBack

Shared Tagging operations (observed)

tagType	tagAction
DispatchProtocolReq	addTagIfAbsent
L3AddressReq	addTagIfAbsent
L4PortReq	addTagIfAbsent
SocketReq	addTagIfAbsent

Tagging operations (observed)

tagType	tagAction
inet::Ipv4InterfaceData	findTag

Source code

//
// Implements a simple VoIP source. It is a constant bitrate source, with
// talkspurt support added. Packets do not contain actual voice data.
// Connection setup/teardown is not modelled. The peer must be a
// ~SimpleVoipReceiver.
//
// The source alternates between two states: talk and silence. The length
// the module spends in each state are controlled by the talkspurtDuration and
// silenceDuration parameters. In talk state, the module acts as a CBR source,
// and sends packets of size talkPacketSize every packetizationInterval seconds
// to the destination over UDP. Silence is implicit: in silence state, no packets
// are sent, and there is no explicit signalling of silence either.
//
// Packets are of type SimpleVoipPacket. In addition to packet ID and timestamp,
// packets also contain a talkspurt ID and the total number of packets in the
// talkspurt to facilitate statistics at the receiver side. (It allows the receiver
// to detect loss of packets at the end of a talkspurt; a full talkspurt can still
// be lost unnoticed.)
//
// The destination address/port, the local port, start and stop times can be
// set via parameters.
//
// @author: Adriano
//
simple SimpleVoipSender like IApp
{
    parameters:
        int localPort = default(-1);
        int destPort;
        string destAddress;
        int talkPacketSize @unit(B) = default(40B);     // size of talk packets in bytes
        volatile double talkspurtDuration @unit(s) = default(weibull(1.423s, 0.824s));
        volatile double silenceDuration @unit(s) = default(weibull(0.899s, 1.089s));
        double packetizationInterval @unit(s) = default(20ms);   // interval between sending voice packets
        double startTime @unit(s) = default(0s);   // time of start sending
        double stopTime @unit(s) = default(-1s);  // time of end of sending, -1 means forever

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

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