NAME¶
owlttb - one-way light time transmission delay simulator
SYNOPSIS¶
owlttb own_uplink_port# own_downlink_port#
dest_uplink_IP_address dest_uplink_port#
dest_downlink_IP_address dest_downlink_port# owlt_sec.
[-v]
DESCRIPTION¶
owlttb delays delivery of data between an NTTI and a NetAcquire box (or
two, one for uplink and one for downlink) by a specified length of time,
simulating the signal propagation delay imposed by distance between the nodes.
Its operation is configured by the command-line parameters, except that the
delay interval itself may be changed while the program is running.
owlttb offers a command prompt (:), and when a new value of one-way
light time is entered at this prompt the new delay interval takes effect
immediately.
- own_uplink_port# identifies the port on owlttb accepts the
NTTI's TCP connection for uplink traffic (i.e., data destined for the
NetAcquire box).
- own_downlink_port# identifies the port on owlttb accepts the
NTTI's TCP connection for downlink traffic (i.e., data issued by the
NetAcquire box).
- dest_uplink_IP_address is the IP address (a dotted string)
identifying the NetAcquire box to which owlttb will transmit uplink
traffic.
- dest_uplink_port# identifies the TCP port to which owlttb
will connect in order to transmit uplink traffic to NetAcquire.
- dest_downlink_IP_address is the IP address (a dotted string)
identifying the NetAcquire box from which owlttb will receive
downlink traffic.
- dest_downlink_port# identifies the TCP port to which owlttb
will connect in order to receive downlink traffic from NetAcquire.
- owlt specifies the number of seconds to wait before forwarding each
received segment of TCP traffic.
The optional
-v ("verbose") parameter causes
owlttb to
print a message whenever it receives, sends, or discards (due to absence of a
connected downlink client) a segment of TCP traffic.
owlttb is designed to run indefinitely. To terminate the program, just
use control-C to kill it or enter "q" at the prompt.
EXIT STATUS¶
- "0" Nominal termination.
- "1" Termination due to an error condition, as noted in printed
messages.
EXAMPLES¶
Here is a sample owlttb command:
- owlttb 2901 2902 137.7.8.19 10001 137.7.8.19 10002 75
This command indicates that
owlttb will accept an uplink traffic
connection on port 2901, forwarding the received uplink traffic to port 10001
on the NetAcquire box at 137.7.8.19, and it will accept a downlink traffic
connection on port 2902, delivering over that connection all downlink traffic
that it receives from connecting to port 10002 on the NetAcquire box at
137.7.8.19. 75 seconds of delay (simulating a distance of 75 light seconds)
will be imposed on this transmission activity.
FILES¶
Not applicable.
ENVIRONMENT¶
No environment variables apply.
DIAGNOSTICS¶
The following diagnostics may be printed to stdout:
- owlttb can't spawn uplink thread
- The program terminates.
- owlttb can't spawn uplink sender thread
- The program terminates.
- owlttb can't spawn downlink thread
- The program terminates.
- owlttb can't spawn downlink receiver thread
- The program terminates.
- owlttb can't spawn downlink sender thread
- The program terminates.
- owlttb fgets failed
- The program terminates.
- owlttb out of memory.
- The program terminates.
- owlttb lost uplink client.
- This is an informational message. The NTTI may reconnect at any time.
- owlttb lost downlink client
- This is an informational message. The NTTI may reconnect at any time.
- owlttb can't open TCP socket to NetAcquire
- The program terminates.
- owlttb can't connect TCP socket to NetAcquire
- The program terminates.
- owlttb write() error on socket
- The program terminates if it was writing to NetAcquire; otherwise it
simply recognizes that the client NTTI has disconnected.
- owlttb read() error on socket
- The program terminates.
- owlttb can't open uplink dialup socket
- The program terminates.
- owlttb can't initialize uplink dialup socket
- The program terminates.
- owlttb can't open downlink dialup socket
- The program terminates.
- owlttb can't initialize downlink dialup socket
- The program terminates.
- owlttb accept() failed
- The program terminates.
BUGS¶
Report bugs to <ion-bugs@korgano.eecs.ohiou.edu>