File: Applications/TCPApp/TCPBasicClientApp.ned
C++ definition: click here
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 and 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 TCPGenericSrvApp; the model sends GenericAppMsg messages.
Example settings:
FTP:
numRequestsPerSession = exponential(3) requestLength = truncnormal(20,5) replyLength = 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 = truncnormal(350,20) replyLength = 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: TCPGenericSrvApp, GenericAppMsg, TelnetApp
The following diagram shows usage relationships between modules, networks and channels. Unresolved module (and channel) types are missing from the diagram. Click here to see the full picture.
Name | Type | Description |
---|---|---|
address | string | may be left empty ("") |
port | numeric const | port number to listen on |
connectAddress | string | server address (may be symbolic) |
connectPort | numeric const | port number to connect to |
startTime | numeric | time first session begins |
numRequestsPerSession | numeric | number of requests sent per session |
requestLength | numeric | length of a request (bytes) |
replyLength | numeric | length of a reply (bytes) |
thinkTime | numeric | time gap between requests |
idleInterval | numeric | time gap between sessions |
reconnectInterval | numeric | if connection breaks, waits this much before trying to reconnect |
Name | Direction | Description |
---|---|---|
tcpIn | input | |
tcpOut | output |
simple TCPBasicClientApp parameters: address: string, // may be left empty ("") port: numeric const, // port number to listen on connectAddress: string, // server address (may be symbolic) connectPort: numeric const, // port number to connect to startTime: numeric, // time first session begins numRequestsPerSession: numeric, // number of requests sent per session requestLength: numeric, // length of a request (bytes) replyLength: numeric, // length of a reply (bytes) thinkTime: numeric, // time gap between requests idleInterval: numeric, // time gap between sessions reconnectInterval: numeric; // if connection breaks, waits this much before trying to reconnect gates: in: tcpIn; out: tcpOut; endsimple