Tcp/Ip Network Addressing; Ip Address - D&R Lyra User Manual

Network Basics
TCP/IP is a protocol that is well known in WAN structures. This means there are many Data Link &
Physical Layers that can carry TCP/IP. In WAN structures the Cobranet protocol is not known, so that will
only function on the Ethernet based networks.
What happens if a destination of a TCP/IP envelope is outside the Ethernet network? The TCP/IP
envelope will be redirected to the 'gateway'. This gateway takes the TCP/IP packet out of the Ethernet
envelope and repacks the TCP/IP envelope in a new envelope for the new protocol (for example DSL or
ISDN)
This explains how it's possible to have TCP/IP data over WANs and Cobranet only over LANs.

7.3 TCP/IP Network Addressing

The TCP/IP protocol is a higher-level networking protocol and has its own system of addresses called IP
addresses. TCP/IP, like other network protocols, has its own addressing scheme and data structure. Thus,
contained within the Ethernet payload is another series of fields containing IP source and destination
address information, as well as another payload containing TCP data. This "nesting" within the Ethernet
payload continues until the protocol(s) being transported is completely defined.
The most important thing to understand is that the networking protocol in use is completely independent of
Ethernet. Ethernet is simply the delivery system, and it doesn't know or care about the networking data that
it's carrying in its payload. This enables Ethernet to carry many different networking protocols on the same
network. It is left up to the networking software running on the receiving system to understand the
networking protocol information extracted from the Ethernet payload field.
7.3.1

IP Address

An IP address is a unique identifier for a device on a TCP/IP network. Within an isolated network, it is
possible to assign IP addresses at random as long as each address is unique. However, connecting a
private network directly to the Internet requires using registered IP addresses (called Internet addresses) to
avoid duplicates. An IP address is a 32-bit numeric address (four sections of 8 bits each) written in "dotted
decimal notation". The number in each section can range from 0 to 255. The address consists of 2 parts,
the network number (or as it is more commonly referred to today, the network prefix) and the host address.
The host address is the unique address of the network node, while the network number identifies the
network on which the host resides. Each host on a network shares the same network number but must
have a unique host address. Likewise, any two hosts can share the same host address as long as they
have different network numbers. The InterNIC Registration Service originally assigned Internet addresses
from three classes, where each class fixes the boundary between the network number and the host
address at a different point within the 32-bit address. This is known as "classful" addressing.
Class A - 16 million hosts on each of 127
Class B - 65,000 hosts on each of 16,000
Class C - 254 hosts on each of 2 million
Unfortunately, no one expected the Internet to grow as quickly as it did, and the limitations and inflexibility
of this method of addressing were unforeseen. Adding another level to the address hierarchy, the subnet,
helped to temporarily overcome many of these shortcomings.
Lyra Digital Mixer from D&R Phone +31 294 418014, email:
networks (1.xxx.xxx.xxx - 126.xxx.xxx.xxx)
networks (128.0.xxx.xxx - 191.255.xxx.xxx)
networks (192.0.0.xxx - 223.255.255.xxx)
info@d-r.nl Page 15