Configuring and Managing Host-Based X.25 Links - Edition 6 (36939-90057)

Preparing to Configure DTCs
Defining the DTC
Chapter 2
41
An IP address is made up of a network portion and a node portion. The
address is formed as four fields of decimal numbers where each
number is a value ranging from 000 to 255.
The following shows examples of three classes of IP addresses:
Class A: nnn.xxx.xxx.xxx
Class B: nnn.nnn.xxx.xxx
Class C: nnn.nnn.nnn.xxx
where nnn represents the network portion and xxx represents the node
portion of the address. The class of the IP address is determined by the
value of the left most group of nnn and has the following ranges:
Class A: 001—126
Class B: 128—191
Class C: 192—254
Network and node portions of all zeroes or 255 are not allowed for DTC
addresses. These are special values. All devices configured with the
same network portion are considered to be on the same network. The
node portion must be unique for all nodes on a network.
You can obtain a Class B or Class C IP address from:
Government Systems, Inc.
Attn: Network Information Center
7990 Boeing Ct.
Vienna, VA 22183
[phone] or FAX: [phone]
For DTC 16RX access to an HP 3000 in an MPE/iX host-based
management environment, the IP address of the DTC16RX is
configured using the DTC 16RX Manager on the HP 9000 host and not
on the HP 3000. Any value entered for the DTC 16RX in NMMGR will
be ignored.
DTC Cards (or DTC Boards) The number and types of connector cards in the DTC.
(The cards are also referred to as boards.) DTC 16 can have up to 2
asynchronous cards and 1 DTC/X.25 Network Access card, DTC 48 up
to 6 cards, and DTC 72MX up to 4 cards.
DTC 16iX/16MX/16RX has its two port connectors built directly onto
its backplane for support of up to 16 asynchronous devices. It does not
have removable cards; you do not specify the number or type of cards
for a DTC 16iX/16MX/16RX.
The valid card types for DTC 72MX are:
L for the LAN card, pre-installed in slot 0
A for asynchronous processor boards (up to 24 ports per
card for direct and modem connections)
X for DTC/X.25 Network Access cards (for X.25
connection).