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>