7: Line and Tunnel Settings
EDS-MD® Medical Device Server User Guide
54
Host (Number)
(continued)
TCP User Timeout: s
pecify the amount of time the TCP segments will be
retransmitted before the connection is closed.
AES Encrypt Key:
enter the AES encrypt key to encrypt outgoing data.
Enter the key in the fixed 16, 24, or 32 byte length and either in
Text
or
Hexadecimal
form. Keys are stored and exchanged in Hexadecimal form
only. To remove a key, delete
<Configured>
in the display. All keys are
shared secret keys which are known by both sides of the connection and kept
secret.
AES Decrypt Key:
enter the AES decrypt key to decrypt outgoing data.
Enter the key in the fixed 16, 24, or 32 byte length and either in
Text
or
Hexadecimal
form. Keys are stored and exchanged in Hexadecimal form
only. To remove a key, delete
<Configured>
in the display. All keys are
shared secret keys which are known by both sides of the connection and kept
secret.
I
nitial Send:
enter the Initial Send string for data sent out of the network upon
connection establishment (before any data from the Line). The string may
contain one or more Directives of the form %<char> and can be entered in
Text or Binary form.
Notes:
If the keep alive idle time (the initial keep alive probe) expires, the user
timeout is expired, and there are probes in flight, the connection will be
reset. For this reason, it is recommended that if keep alive is used in
conjunction with the user timeout, the keep alive timeouts be larger than
the user timeout. If they are smaller, what will typically be seen is that the
initial probe will be sent, then at the interval where the next probe would
normally be sent, the connection will be reset, with no additional probes
sent. Also note that the probe count can be disregarded in these cases: if
the keep alive timers are significantly smaller than the user timeout, probes
will continue to be sent for an unreachable host until the user timeout
expires.
If there is data in flight when the TCP retransmission timeout kicks in, the
user timeout is checked as a limiting condition only when the timer
expirations would normally be checked during RTO handling. In other
words, the user timeout will not be an exact limit; in practice, it will always
take somewhat longer for the connection to be closed. The longer the user
timeout is, the more likely it will expire between exponentially slower
retransmissions, and the connection will not experience an error until the
next retransmission timeout is checked. Also note that the user timeout
expiration during retransmission returns an error to the application; it does
not automatically reset the connection as happens with keep alive timeout.
It is up to the application (e.g., tunneling) to close the connection (this
happens almost immediately with tunneling).
Reconnect Timer
Set the value of the reconnect timeout (in milliseconds) for outgoing connections
established by the device. Valid range is 1 to 65535 milliseconds. Default is
15000.
Flush Serial Data
Set whether the serial Line data buffer is flushed upon a new network
connection. Choices are:
Enabled
= serial data buffer is flushed on network connection
Disabled
= serial data buffer is not flushed on network connection (
default
)
Tunnel Connect Mode
Settings (continued)
Description
