Client for a generic request-response style protocol over TCP. May be used as a rough model of HTTP or FTP users. Compatible with both IPv4 (Ipv4) and IPv6 (Ipv6).

The model communicates with the server in sessions. During a session, the client opens a single TCP connection to the server, sends several requests (always waiting for the complete reply to arrive before sending a new request), and closes the connection.

The server app should be TcpGenericServerApp; the model sends GenericAppMsg messages.

Example settings:

FTP:

   numRequestsPerSession = exponential(3)
   requestLength = 1B*int(truncnormal(20,5))
   replyLength = 1B*int(exponential(1000000))

Note that this module doesn't open separate TCP connections for commands and data transfer as the FTP protocol.

HTTP:

   numRequestsPerSession = 1 (HTTP 1.0)
   numRequestsPerSession = exponential(5) (HTTP 1.1, with keepalive)
   requestLength = 1B*int(truncnormal(350,20))
   replyLength = 1B*int(exponential(2000))

Note that since most web pages contain images and may contain frames, applets etc, possibly from various servers, and browsers usually download these items in parallel to the main HTML document, this module cannot serve as a realistic web client.

Also, with HTTP 1.0 it is the server that closes the connection after sending the response, while in this model it is the client.

See also: TcpGenericServerApp, GenericAppMsg, TelnetApp

Inheritance diagram

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

Parameters

Name	Type	Default value	Description
localAddress	string	""	may be left empty ("")
localPort	int	-1	port number to listen on
connectAddress	string	""	server address (may be symbolic)
connectPort	int	1000	port number to connect to
startTime	double	1s	time first session begins
stopTime	double	-1s	time of finishing sending, negative values mean forever
numRequestsPerSession	int	1	number of requests sent per session
requestLength	int	200B	length of a request
replyLength	int	1MiB	length of a reply
thinkTime	double		time gap between requests
idleInterval	double		time gap between sessions
reconnectInterval	double	30s	if connection breaks, waits this much before trying to reconnect
timeToLive	int	-1	if not -1, set the TTL (IPv4) or Hop Limit (IPv6) field of sent packets to this value
dscp	int	-1	if not -1, set the DSCP (IPv4/IPv6) field of sent packets to this value
tos	int	-1	if not -1, set the Type Of Service (IPv4) / Traffic Class (IPv6) field of sent packets to this value
stopOperationExtraTime	double	-1s	extra time after lifecycle stop operation finished
stopOperationTimeout	double	2s	timeout value for lifecycle stop operation

Properties

Name	Value	Description
display	i=block/app
lifecycleSupport

Gates

Name	Direction	Size	Description
socketIn	input
socketOut	output

Signals

Name	Type	Unit
packetReceived	inet::Packet
packetSent	inet::Packet
connect	long

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode
packetReceived	packets received	packetReceived	count, sum(packetBytes), vector(packetBytes)		none
numSessions	total number of sessions	sum(connect+1)/2	last
packetSent	packets sent	packetSent	count, sum(packetBytes), vector(packetBytes)		none
numActiveSessions	number of active sessions	warmup(sum(connect))	max, timeavg, vector		sample-hold
endToEndDelay	end-to-end delay	dataAge(packetReceived)	histogram, weightedHistogram, vector	s	none

Scheduled messages (observed)

msg	kind	ctrl	tags	msgname	context
omnetpp::cMessage	0			timer
omnetpp::cMessage	1			timer

Direct method calls (observed)

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

Incoming messages (observed)

gate	msg	kind	ctrl	srcModule	tags
socketIn	Indication	4 (TcpStatusInd::TCP_I_ESTABLISHED)	TcpConnectInfo	Tcp	SocketInd
socketIn	Indication	6 (TcpStatusInd::TCP_I_CLOSED)	TcpCommand	Tcp	SocketInd
socketIn	Packet	1 (TcpStatusInd::TCP_I_DATA)		Tcp	SocketInd

Outgoing messages (observed)

gate	msg	kind	ctrl	destModule	tags
socketOut	Packet	4 (TcpCommandCode::TCP_C_SEND)		Tcp	DispatchProtocolReq, SocketReq
socketOut	Request	1 (TcpCommandCode::TCP_C_OPEN_ACTIVE)	TcpOpenCommand	Tcp	DispatchProtocolReq, SocketReq
socketOut	Request	5 (TcpCommandCode::TCP_C_CLOSE)	TcpCommand	Tcp	DispatchProtocolReq, SocketReq

Packet operations (observed)

chunkType	packetAction
	peekData
GenericAppMsg	insertAtBack

Shared Tagging operations (observed)

tagType	tagAction
DispatchProtocolReq	addTagIfAbsent
SocketInd	findTag
SocketReq	addTagIfAbsent

Region Tagging operations (observed)

tagType	tagAction
CreationTimeTag	addTag, getAllTags

Tagging operations (observed)

tagType	tagAction
inet::Ipv4InterfaceData	findTag

Source code

//
// Client for a generic request-response style protocol over TCP.
// May be used as a rough model of HTTP or FTP users.
// Compatible with both IPv4 (~Ipv4) and IPv6 (~Ipv6).
//
// The model communicates with the server in sessions. During a session,
// the client opens a single TCP connection to the server, sends several
// requests (always waiting for the complete reply to arrive before
// sending a new request), and closes the connection.
//
// The server app should be ~TcpGenericServerApp; the model sends ~GenericAppMsg
// messages.
//
// Example settings:
//
// FTP:
// <pre>
//    numRequestsPerSession = exponential(3)
//    requestLength = 1B*int(truncnormal(20,5))
//    replyLength = 1B*int(exponential(1000000))
// </pre>
//
// Note that this module doesn't open separate TCP connections for commands
// and data transfer as the FTP protocol.
//
// HTTP:
// <pre>
//    numRequestsPerSession = 1 <i>(HTTP 1.0)</i>
//    numRequestsPerSession = exponential(5) <i>(HTTP 1.1, with keepalive)</i>
//    requestLength = 1B*int(truncnormal(350,20))
//    replyLength = 1B*int(exponential(2000))
// </pre>
//
// Note that since most web pages contain images and may contain frames,
// applets etc, possibly from various servers, and browsers usually download
// these items in parallel to the main HTML document, this module cannot
// serve as a realistic web client.
//
// Also, with HTTP 1.0 it is the server that closes the connection after
// sending the response, while in this model it is the client.
//
// @see ~TcpGenericServerApp, ~GenericAppMsg, ~TelnetApp
//
simple TcpBasicClientApp like IApp
{
    parameters:
        string localAddress = default(""); // may be left empty ("")
        int localPort = default(-1); // port number to listen on
        string connectAddress = default("");  // server address (may be symbolic)
        int connectPort = default(1000); // port number to connect to
        double startTime @unit(s) = default(1s); // time first session begins
        double stopTime @unit(s) = default(-1s);  // time of finishing sending, negative values mean forever
        volatile int numRequestsPerSession = default(1);  // number of requests sent per session
        volatile int requestLength @unit(B) = default(200B); // length of a request
        volatile int replyLength @unit(B) = default(1MiB); // length of a reply
        volatile double thinkTime @unit(s); // time gap between requests
        volatile double idleInterval @unit(s); // time gap between sessions
        volatile double reconnectInterval @unit(s) = default(30s);  // if connection breaks, waits this much before trying to reconnect
        int timeToLive = default(-1); // if not -1, set the TTL (IPv4) or Hop Limit (IPv6) field of sent packets to this value
        int dscp = default(-1); // if not -1, set the DSCP (IPv4/IPv6) field of sent packets to this value
        int tos = default(-1); // if not -1, set the Type Of Service (IPv4) / Traffic Class (IPv6) field of sent packets to this value
        @display("i=block/app");
        @lifecycleSupport;
        double stopOperationExtraTime @unit(s) = default(-1s);    // extra time after lifecycle stop operation finished
        double stopOperationTimeout @unit(s) = default(2s);    // timeout value for lifecycle stop operation
        @signal[packetSent](type=inet::Packet);
        @signal[packetReceived](type=inet::Packet);
        @signal[connect](type=long);  // 1 for open, -1 for close
        @statistic[packetReceived](title="packets received"; source=packetReceived; record=count,"sum(packetBytes)","vector(packetBytes)"; interpolationmode=none);
        @statistic[packetSent](title="packets sent"; source=packetSent; record=count,"sum(packetBytes)","vector(packetBytes)"; interpolationmode=none);
        @statistic[endToEndDelay](title="end-to-end delay"; source="dataAge(packetReceived)"; unit=s; record=histogram,weightedHistogram,vector; interpolationmode=none);
        @statistic[numActiveSessions](title="number of active sessions"; source=warmup(sum(connect)); record=max,timeavg,vector; interpolationmode=sample-hold; autoWarmupFilter=false);
        @statistic[numSessions](title="total number of sessions"; source="sum(connect+1)/2"; record=last);
    gates:
        input socketIn @labels(TcpCommand/up);
        output socketOut @labels(TcpCommand/down);
}

File: src/inet/applications/tcpapp/TcpBasicClientApp.ned

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