VDR1
00 User’s Manual
Page 4
Revision 1.2
1.6.3 TCP/IP Networks
The networking protocol that is used for the communication between the PC running
N2KExtractor
®
software and the VDR100 is the TCP/IP protocol. This protocol is used by the
World Wide Web, FTP (File Transfer Protocol), and many others of the most popular
applications on the Internet. The TCP/IP connection can be made over an Ethernet
connection, a Wi-Fi connection, cellular phone data connection, and many other types of
media. In fact, a single packet of TCP/IP data may traverse multiple types of media on its
journey. The TCP/IP protocol is supported by most operating systems, as well as Internet-
connected cellular phones.
Each computer on a TCP/IP network is identified by an IP address unique to that network. An
IP address consists of four numbers, each ranging between 0 and 255, separated by periods.
This is referred to a dotted decimal notation. Examples of IP addresses in this format are
10.0.0.1, and 62.12.31.188.
The IP address may either be hard coded into the computer (this means that the address is
static which makes the computer easier to find) or assigned at each startup by a DHCP
(Dynamic Host Control Protocol) server, typically found as part of a router. The router can be
configured to reserve a specific address for the computer and then assign that same address
each time at startup. If the router chooses a different address each time, then the computer
may be difficult to find on the network. This is not a problem for a client such as
N2KExtractor
®
,
but servers such as the VDR100 should be at a known address.
1.6.3.1 NAT (Network Address Translation)
If you wish to use
N2KExtractor
®
to view data from a VDR100 on a WAN through an Internet
connection, please read this section. If your
N2KExtractor
®
computer and the VDR100 are on
the same LAN, you may skip this section.
In the early days of the Internet, each computer connected to the Internet had its own
IP
address
. With the explosive growth of the Internet, the number of distinct IP addresses is
starting to run out. It is no longer practical for an Internet Service Provider (ISP) to provide its
customers with individual IP addresses for each component the customer wishes to connect to
the Internet. Rather, the ISP normally assigns each customer a single IP address, and a
router implementing Network Address Translation (NAT) is connected to the Internet
connection (sometimes referred to as the Wide Area Network, or WAN, connection) on one
side, and to the Local Area Network, or LAN, on the other side. Each computer on the LAN
side of the connection will be assigned its own IP address, typically in the ranges 192.168.x.x,
10.x.x.x, and 172.16.x.x through 172.31.x.x, where x can be any number in the range 0-255.
The WAN connection will be assigned a single IP address by the ISP.
Generally, network address translation is performed by a router that is connected to the
Internet via a Cable or DSL connection on the WAN side, and to the local area network (LAN)
via Ethernet or Wi-Fi connections. In order to access a VDR100 on the local area network
from an
N2KExtractor
®
outside of the LAN, you must configure the router to allow incoming
connections on port 6544 and to forward these connections to the IP address of the VDR100.
Consult the documentation that came with your router for details.
