Moxa ANT-WSB-ANM-05 Manuel D’Utilisation
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2009 Industrial Wireless Guidebook
Cellular Networks
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3.5 How to Connect Ethernet Devices to Cellular Networks
Traditionally, Ethernet-based devices can only establish TCP/IP connections through wired LAN lines. At best, you
may be able to deploy a WLAN environment to communicate with Ethernet devices in the field. A WLAN system can
eliminate wires and cabling problems when installing and operating the devices. It also provides greater mobility,
especially when the Ethernet devices are moving. When it comes to range, however, WLAN systems are still limited
to local area networks and places with hardwire Internet connections.
What if Ethernet devices could be accessed through a cellular network? This would allow Ethernet devices to
be accessible almost anywhere as long as cellular coverage is available. Ethernet to cellular technology can also
provide primary and backup network connectivity. Moxa offers an easy and cost-effective means of connecting
virtually any remote location or device to a corporate IP network. It is ideal for applications where wired networks
(e.g., lease line / frame relay, CSU/DSU, fractional T1) are not feasible or where alternative network connections are
required.
may be able to deploy a WLAN environment to communicate with Ethernet devices in the field. A WLAN system can
eliminate wires and cabling problems when installing and operating the devices. It also provides greater mobility,
especially when the Ethernet devices are moving. When it comes to range, however, WLAN systems are still limited
to local area networks and places with hardwire Internet connections.
What if Ethernet devices could be accessed through a cellular network? This would allow Ethernet devices to
be accessible almost anywhere as long as cellular coverage is available. Ethernet to cellular technology can also
provide primary and backup network connectivity. Moxa offers an easy and cost-effective means of connecting
virtually any remote location or device to a corporate IP network. It is ideal for applications where wired networks
(e.g., lease line / frame relay, CSU/DSU, fractional T1) are not feasible or where alternative network connections are
required.
From WAN to LAN (TCP Server)
In this case, the Ethernet device, when acting as a server, is to be reached from the public domain. The TCP Server
may be an industrial PC server, an I/O device with LAN interface, or any Ethernet routing device. As long as the
device uses a LAN interface running on TCP protocols (even MODBUS TCP), the device can be reached. There may
even be multiple Ethernet devices with different IP addresses connected to the IP gateway.
may be an industrial PC server, an I/O device with LAN interface, or any Ethernet routing device. As long as the
device uses a LAN interface running on TCP protocols (even MODBUS TCP), the device can be reached. There may
even be multiple Ethernet devices with different IP addresses connected to the IP gateway.
When a TCP Client device attempts to connect to the TCP Server, it will first need to make a TCP connection
with the IP modem (OnCell), and then have the OnCell port forward the synchronization request to the TCP
Server connected to it. Basically, the OnCell plays the role of a virtual server to allow clients to make a direct TCP
connection to it before forwarding traffic to the actual server. Much like a WLAN router, the traffic from the WAN port
is directed to the devices connected to the LAN port of the router.
with the IP modem (OnCell), and then have the OnCell port forward the synchronization request to the TCP
Server connected to it. Basically, the OnCell plays the role of a virtual server to allow clients to make a direct TCP
connection to it before forwarding traffic to the actual server. Much like a WLAN router, the traffic from the WAN port
is directed to the devices connected to the LAN port of the router.
It is important to note that your OnCell device will need to obtain a public WAN IP address from your cellular
provider in order for it to be visible to the public domain. Private IP addresses are hidden from the public Internet so
TCP Clients will not be able to find it on a public network. The WAN IP address of your OnCell device may be static
or dynamic, but it must be a public IP address. If the public WAN IP address is a dynamic IP address (changes
every time the OnCell reconnects to the cellular network), a useful function is to enable to DDNS (Dynamic DNS).
DDNS allows the TCP clients to access the OnCell device by domain name. So even as the OnCell device’s WAN IP
address changes, the changed IP addresses continue to map to the same domain name through DDNS updates.
provider in order for it to be visible to the public domain. Private IP addresses are hidden from the public Internet so
TCP Clients will not be able to find it on a public network. The WAN IP address of your OnCell device may be static
or dynamic, but it must be a public IP address. If the public WAN IP address is a dynamic IP address (changes
every time the OnCell reconnects to the cellular network), a useful function is to enable to DDNS (Dynamic DNS).
DDNS allows the TCP clients to access the OnCell device by domain name. So even as the OnCell device’s WAN IP
address changes, the changed IP addresses continue to map to the same domain name through DDNS updates.
In cases where only private IP addresses are available from the cellular provider, the OnCell can still play the server
role by enabling the OnCell Central Manager (see section 3.2 for details) function proprietary to Moxa’s IP gateways.
role by enabling the OnCell Central Manager (see section 3.2 for details) function proprietary to Moxa’s IP gateways.