Specifications

i50 Manual (5.10)

Page 44

www.datalinksystemsinc.com

10.2 Wi-Fi Configuration

Wi-Fi connections are made using an ad-hoc (computer to computer) link, using the SSID and

encryption key assigned in the i50 settings. The i50 includes a DHCP server, which assigns an IP

address to the connecting computer.

Note: as this is an ad-hoc connection, no indication will be given if the wrong encryption key is

entered. If no IP address is assigned when connecting, first check that the encryption keys are

configured correctly.

10.3 Connection Details

The i50 monitors the dial-up/Wi-Fi connection, looking for data to be sent to the Internet. Any data

packets addressed to the local subnet or multicast addresses are ignored (except transparent/email

data – see sections 10.3.2 and 10.3.3). If the Wi-Fi/Dial-up firewall setting is enabled, only data

packets addressed to the Cellular or Globalstar server IP addresses will be allowed through.

If a cellular or Globalstar network connection is available, the data is then forwarded over the

Internet. Otherwise an ICMP response is returned to indicate there is no route to that address.

Data received from the wireless network is parsed to check whether it is addressed to the i50 itself. If

not, it is forwarded to the attached computer over the dial-up/Wi-Fi link.

Network address translation is used to isolate the computer from the wireless network, allowing the

unit to switch networks transparently if more than one wireless modem is available.

When using Globalstar service, the unit will only establish a satellite connection when data is

received from the computer, and will shut down the connection if no more data is received after the

Globalstar Timeout period. This allows a computer to keep its dial-up/Wi-Fi connection active at all

times. Note: the computer should be configured to reduce network traffic (preferably using a firewall),

as satellite airtime will be used each time a packet is sent.

10.3.1 GPS over UDP

While a dial-up or Wi-Fi connection is established, the i50 will broadcast all internal GPS data to the

PC using UDP packets, allowing the PC to make use of the GPS information independently. The

UDP port used can be adjusted in the i50 settings. If this feature is unwanted, the UDP port can be

set to zero to disable the GPS UDP packets.

10.3.2 Transparent data over UDP

Any UDP packet sent to the i50’s IP address (defined by the “Router IP” option) and transparent UDP

port will be sent to the DataGate server as transparent data. Likewise, any transparent data received

from the DataGate server will be broadcast as UDP data over the dial-up/Wi-Fi connection. Setting

the UDP port to zero will disable this feature.