Lantronix LPS1-T EPS Reference Manual - Page 78

TCP Socket Connections

Page 78 highlights

TCP Socket Connections TCP/IP Host Setup 7.3.8 RTEL Troubleshooting The job_status diagnostic file in the /usr/spool/rtel directory may help locate problems. The file contains any errors that occurred on a particular print job, such as job aborted, invalid service name, and so on. This file should be examined if the RTEL queue is not performing correctly. Entries are time-stamped to indicate when the error(s) took place; make sure when looking at these error logs that the errors shown are for roughly the same time as the problem(s) occurred. In addition, each error name in the log files has a name that identifies roughly where the error took place, as shown in Table 7-2. Table 7-2: RTEL Errors Error Name Error %Exxxxxx Error reported by the host operating system itself. Error names generally correspond to values for errno. %LAT_xxxx A reject code from the server. Generally indicates a problem with the Server setup or the server_hosts file. %RTEL_xxxxx The host system could not initiate the connection to the server properly. The message should indicate the reason. 7.4 TCP Socket Connections If custom queueing software has been designed, raw TCP/IP (or Telnet) connections can be made directly to the Server ports. Opening a TCP session to port 30nn will attempt a direct connection to port nn on the Server. Note: The 30nn range of ports is 8-bit clean. If Telnet IAC interpretation is needed, form a connection to the 20nn range of ports. If the port is busy or unavailable when the TCP connection attempt is made, a TCP RST will be sent back to the host and the connection attempt will be rejected. It is up to the application software to detect this condition and retry the connection. Connections can also be formed to a specific port on the Server with the Telnet command's port number parameter. For example, to connect to serial port 3 on the Server, first make sure the port is set to either Dynamic Access or Remote Access, then issue the following command: Figure 7-21: Telnet Command to Connect to Specific Port % telnet server_name 2003 A TCP socket number can also be associated with a multi-port service using the Set/Define Service TCPport command. This allows an application program to request a connection to a single socket and be given the next available port. Note: See Set/Define Service TCPport on page 12-60 or Set/Define Service Telnetport on page 12-61 for more information on socket connections. 7-18

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TCP Socket Connections
TCP/IP Host Setup
7-
18
7.3.8
RTEL Troubleshooting
The
job_status
diagnostic file in the /usr/spool/rtel directory may help locate problems. The file contains
any errors that occurred on a particular print job, such as job aborted, invalid service name, and so on. This
file should be examined if the RTEL queue is not performing correctly. Entries are time-stamped to indicate
when the error(s) took place; make sure when looking at these error logs that the errors shown are for
roughly the same time as the problem(s) occurred. In addition, each error name in the log files has a name
that identifies roughly where the error took place, as shown in Table 7-2.
7.4
TCP Socket Connections
If custom queueing software has been designed, raw TCP/IP (or Telnet) connections can be made directly
to the Server ports. Opening a TCP session to port 30
nn
will attempt a direct connection to port
nn
on the
Server.
Note:
The 30nn range of ports is 8-bit clean. If Telnet IAC interpretation is needed,
form a connection to the 20nn range of ports.
If the port is busy or unavailable when the TCP connection attempt is made, a TCP RST will be sent back
to the host and the connection attempt will be rejected. It is up to the application software to detect this
condition and retry the connection.
Connections can also be formed to a specific port on the Server with the Telnet command’s port number
parameter. For example, to connect to serial port 3 on the Server, first make sure the port is set to either
Dynamic Access or Remote Access, then issue the following command:
Figure 7-21:
Telnet Command to Connect to Specific Port
A TCP socket number can also be associated with a multi-port service using the
Set/Define Service
TCPport
command. This allows an application program to request a connection to a single socket and be
given the next available port.
Note:
See
Set/Define Service TCPport on page 12-60
or
Set/Define Service
Telnetport on page 12-61
for more information on socket connections.
Table 7-2:
RTEL Errors
Error Name
Error
%Exxxxxx
Error reported by the host operating system itself. Error
names generally correspond to values for errno.
%LAT_xxxx
A reject code from the server. Generally indicates a problem
with the Server setup or the
server_hosts
file.
%RTEL_xxxxx
The host system could not initiate the connection to the
server properly. The message should indicate the reason.
% telnet server_name 2003