3Com OfficeConnect Series, User Manual

Page: 106 / 129

What is a network?
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What is DHCP?
Dynamic Host Configuration Protocol automatically assigns a unique, temporary IP
address to a newly attached computer on an IP network.
What is DNS?
Domain Name Service translates the common alphabetic name into the numeric IP
address. For example, floyds_PC is translated to 192.168.1.2. If you do not use the
DHCP functionality of the ISDN LAN Modem, you will have to manually configure
the following parameters for each computer on the LAN: IP address, subnet mask,
DNS address and default gateway.
What is NAT?
Network Address Translation, also known as IP address sharing, allows multiple
users to share a single connection such as an Internet connection. For example,
with the ISDN LAN Modem, when users on the LAN launch their Web browser for
Internet access, their computer’s IP address is translated into the IP address
provided by the ISP for access.
You will probably not want to use NAT If your LAN network is static; that is, an IP
address is assigned to your computer by your MIS department or ISP and manually
configured.
What are numbered and
unnumbered links?
Some networks require an IP address to be assigned to a WAN in addition to the
LAN(s). If a WAN has an IP address assigned to it, it is considered to be a
numbered link. If there is not an IP address assigned to a WAN, it is considered to
be an unnumbered link.
How is overall
throughput determined?
The performance of all linked devices must be considered to determine
end-to-end throughput. Connection performance is affected by each device in the
chain. Therefore, the slowest link in the chain determines the maximum
throughput. On the LAN side, computers on a typical network can communicate
with each other at up to 10 Mbps. When dialing up to a long distance location
using ISDN, you can establish a network connection speed of up to 128 Kbps
without compression or up to 384 Kbps with compression. If you are dialing into
the Internet, the speed of the router providing access must also be considered. In
addition, the Internet itself may have speed limitations.