SimpleVoipSender
Package: inet.applications.voip

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.

@authors: Adriano, Zoltan Bojthe

SimpleVoipSender

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

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.
//
// @authors: Adriano, Zoltan Bojthe
//
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