Cyclone for ARM devices User Manual
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Cyclone for ARM
®
devices
greater detail in the “Configuring the Cyclone” section of this manual.
8.3
Internet Protocol
Once the network has been established, and the IP numbers have been
assigned, data can be transacted over a network with one of several
protocols. By far the most prevalent protocol is the Transmission Control
Protocol (TCP), which runs on top of the Internet Protocol in what is
collectively known as the TCP/IP protocol. The TCP/IP protocol was
developed by the Department of Defense to connect different computers from
different vendors by a “network of networks,” which has become what is
known as the Internet today.
The primary purpose of the TCP/IP protocol was to prevent a complete
network outage in the case of a nuclear attack, by automatically rerouting data
traffic through the functioning part of the network. As such, the TCP/IP
mechanism guaranteed delivery of data packets by introducing a system of
acknowledgements and sequence numbers for the data packets. This
mechanism, while good for transacting large amounts of data (such as email
or file transfers), is unsuitable in the real-time type environment in which the
Cyclone operates. Because the Cyclone needs to transact data as quickly as
possible to the target, it takes advantage of TCP/IP’s alternative, the UDP/IP
protocol.
Unlike TCP/IP, the UDP/IP protocol is a connectionless, single-packet
protocol that sends short data packets at the expense of not guaranteeing
their delivery. This makes the UDP/IP protocol efficient in real-time
applications such as broadcasting video over the Internet, where the
occasional loss of a frame of data is not going to hamper the overall viewing
experience. Left unmodified, the UDP/IP, with its lack of guarantees for packet
delivery, would be unusable in an environment where the delivery of a single
byte of data needs to be guaranteed. The Cyclone firmware adds
mechanisms to the UDP/IP protocol, without affecting its underlying efficiency,
to guarantee delivery of data packets.
8.4
Connecting The Cyclone Device
There are two methods for establishing a connection between a Cyclone and
a PC with an Ethernet cable. The most basic method is to connect the
Cyclone directly to a PC, via a cross-over Ethernet cable. However, the more
common method is to place the Cyclone and the PC on the same network
