Ref: 10420012
Title: Release Notes: CS/1 TCP SNA Version 13000
Date: 7/22/87

Copyright 3Com Corporation, 1991.  All rights reserved.

Software Release

SW/1-T-SNA Version 13000

July 22, 1987

Part Number: 86-0045-00
Revision 02


TO:          CS/1-SNA Users

FROM:        Bridge Communications, Inc.

SUBJECT:     SW/1-T-SNA Version 13000

DATE:        July 22, 1987

Enclosed is the SW/1-T-SNA Version 13000 diskette.  This diskette
is your distribution copy and should only be used to copy the
system software onto a master diskette.

Before you make a backup copy of the software, note the
following:

1.  SW/1-T-SNA Version 13000 supports the EC/2 board only.  Be
sure that your CS/1-SNA does not use an EC/1 board.

2.  To perform the copy properly, the MCPU PROMs of your CS/1
or CS/1-SNA should be revision 1B or later.

3.  Because the syntax of the Name and UNName commands has been
changed, you must redefine all the clearinghouse names when
updating your system to SW/1-T-SNA Version 13000.

4.  If your system is equipped with a Shared Buffer Board
(SBB), the shorting plug on the SBB board must be changed
from LK18 to LK17 to prevent the CS/1-SNA from
malfunctioning.  Refer to the Series/1 Installation Guide
for information on SBB board configuration.

Software_Backup

Bridge recommends the following procedure to back up the SW/1-T-
SNA Version 13000 distribution diskette:

1.  Connect your terminal to the console port of the CS/1 or
CS/1-SNA.

2.  Insert the SW/1-T-SNA Version 13000 diskette in the disk
drive of the CS/1-SNA, then press the Reset switch.

3.  After the CS/1-SNA is finished booting, copy the software
from the distribution diskette onto a blank, double-sided,
double-density, 48 TPI diskette using the following
command:

> co <n> <CR> where n is the number of copies to be made.

4.  The following message appears on your screen:

Insert master and hit return key Follow the message



instructions by pressing the return key.



5.  If the read completes successfully, the following messages
appear on your screen:

> reading ...  OK > insert copy #n and hit return key If
the message "read error" appears instead of the message
"OK", contact an authorized Bridge service representative
for assistance.

6.  Remove the SW/1-T-SNA Version 13000 diskette, insert the
blank diskette in the disk drive, then press the return
key.

7.  If the copy completes successfully, the following messages
appear on your screen:

> formatting ...  writing ...  verifying ...  OK > copy
completed

8.  Remove the diskette from the disk drive and label this
diskette "SW/1-T-SNA MASTER VERSION 13000".  Store the
distribution diskette in a safe place.

Operation_Instructions

Refer to the Configuration Guide for detailed information on
system generation parameters and complete system generation
procedures.  For the parameters not included in the Configuration
Guide, refer to the SNA Support Guide.  After the installation
has been completed, boot the system diskette (SW/1-T-SNA Version
13000 diskette).  If a switched line is used, also dial the SDLC
line.  The CS/1-SNA is now ready for operation.

For easy operation, a network manager can define rotaries and
clearinghouse names on the CS/1-SNA in remote mode from a
terminal attached to a CS/1 or a CS/100.

New_Features

The following features, which were not present in SW/1-T-SNA
Version 10000 and not described in the SNA Support Guide, have
been implemented in SW/1-T-SNA Version 13000:

1.  SW/1-T-SNA Version 13000 can operate with the PCS/1 running
PCS3270 Version 10000 or later.  This feature provides the
PC with complete IBM 3278 Model 2 and 3279 Model S2A or S2B
display station emulation, which includes extended color
support.  The CS/1-SNA now also permits file transfer
between the PCS/1 running PCS3270 and an IBM mainframe.

2.  The CS/1-SNA will synthesize an UNBIND command for an LU-LU
session if the session already exists when a positive
response is received.



3.  It now supports the Read Modified All 3270 command.



4.  On the SNA Emulation Level menu in the Sysgen program, a
new option "Negative FMD response if no connection" is
added.  The default value is Support.

Also, the Character set selection parameter has been
replaced by the EBCDIC/ASCII translation table parameter,
which is described in item 5 in this section.

The SNA Emulation Level menu is as follows:
SNA Emulation Level Menu

1. Negative Response selection              No Response

2. LU status Report type selection          LUSTAT

3. Host application logout support          SUPPORT

4. Negative FMD response if no connection   SUPPORT

5. Device Types

6. Default printers

7. Terminal emulation type

8. CS1-SNA banner message

9. EBCDIC/ASCII translation table

A. IBM3270 Terminal/Printer Model

Enter selection: Option 4 determines whether a negative
response is sent from the CS/1-SNA to the IBM host when FM
data is received by a terminal not connected to an LU
session.  This in turn determines whether a VTAMTM logon
screen will be displayed after connection.

The default value of this parameter is Support, which will
result in a negative response.  If you do not want the
CS/1-SNA to send the negative response, select option 4
from the menu, and then change the value of the parameter
to Nosupport.

5.  The following terminal types are now supported:

+ Tandem 653x

Table 1 describes the key correspondence between a
Tandem 653x terminal and a display station.




__________________________________________________________________________
|                 Table 1  Tandem 653x Key Correspondence                 |
|_________________________________________________________________________|
|                                                                         |
| Display Station   Tandem 653x Keys   Display Station    Tandem 653x Keys|
| Function                             Function                           |
|                                                                         |
| PF1               F1                 Right              F14             |
| PF2               F2                 Left               F13 or Backspace|
| PF3               F3                 Up                 F15             |
| PF4               F4                 Down               F16             |
| PF5               F5                 Attention          ESC-a           |
| PF6               F6                 Backtab            ESC-b           |
| PF7               F7                 Clear              ESC-c           |
| PF8               F8                 Delete             DEL             |
| PF9               F9                 Device Cancel      ESC-x           |
| PF10              F10                Duplicate          ESC-d           |
| PF11              F11                Enter              Return          |
| PF12              F12                Erase Input        ESC-e           |
| PF13              SHIFT-F1           Erase EOF          ESC-DEL         |
| PF14              SHIFT-F2           Field Mark         ESC-m           |
| PF15              SHIFT-F3           Home               ESC-h           |
| PF16              SHIFT-F4           Insert Mode        ESC-i           |
| PF17              SHIFT-F5           New Line           ESC-n           |
| PF18              SHIFT-F6           PA1                ESC-1           |
| PF19              SHIFT-F7           PA2                ESC-2           |
| PF20              SHIFT-F8           Print              ESC-p           |
| PF21              SHIFT-F9           Reset              ESC-r           |
| PF22              SHIFT-F10          System Request     ESC-s           |
| PF23              SHIFT-F11          Update Screen      CTRL-u          |
| PF24              SHIFT-F12          Toggle Last Line   CTRL-t          |
| TAB               ESC t                                                 |
|_________________________________________________________________________|

When you use a Tandem 653x terminal with the CS/1-SNA,
note the following:

1.  The terminal must be configured for Conversational
mode.

2.  When the CS/1-SNA prompts for the terminal type,
select item 18 on the terminal type selection menu.

3.  Several keys on the Tandem 653x terminal keyboard must
not be used while the terminal is connected to a
CS/1-SNA.  These keys are listed below.  If you press
one of these keys accidentally, use the Update Screen
(CTRL-u) function to repaint the screen.



.br;HOME
.br;NEXT PAGE
.br;ROLL DOWN
.br;DEL LIN INS
.br;CHAR INS
.br;DOWN ARROW
.br;LEFT ARROW
.br;PREV PAGE
.br;ROLL UP
.br;CHAR DEL
.br;UP ARROW
.br;RIGHT ARROW
.br;BACK TAB / TAB

4.  The rightmost character on the last line on the screen
(row 24, column 80) is not displayed.

+ Alternate VT220TM

Table 2 describes the key correspondence between an
alternate VT220 terminal and a display station. ''



___________________________________________________________________
|            Table 2  Alternate VT220 Key Correspondence           |
|__________________________________________________________________|
|                                                                  |
| Display Station   VT220         Display Station       VT220      |
| Function                        Function                         |
|                                                                  |
| PF1               PF1           Left                  Left Arrow |
| PF2               PF2           Down                  Down Arrow |
| PF3               PF3           Up                    Up Arrow   |
| PF4               PF4           Attention             Select a   |
| PF5               Select F6     Backtab               Select Tab |
| PF6               F6            Clear                 Select c   |
| PF7               F7            Cursor Select         Select l   |
| PF8               F8            Delete                DEL        |
| PF9               F9            Device Cancel         Select x   |
| PF10              F10           Duplicate             Select d   |
| PF11              F11           Enter                 Return     |
| PF12              F12           Erase Input           Select e   |
| PF13              F13           Erase EOF             Select DEL |
| PF14              F14           Field Mark            Select m   |
| PF15              F15           Home                  Find       |
| PF16              F16           Insert Mode           Insert Here|
| PF17              F17           New Line              Select n   |
| PF18              F18           PA1                   Prev Screen|
| PF19              F19           PA2                   Next Screen|
| PF20              F20           Print                 Select p   |
| PF21              Select PF1    Reset                 Select r   |
| PF22              Select PF2    System Request        Select s   |
| PF23              Select PF3    Tab                   Tab        |
| PF24              Select PF4    Update Screen         CTRL-u     |
| Right             Right Arrow   Toggle to 25th line   CTRL-t     |
|__________________________________________________________________|

When you use the alternate VT220 keyboard mapping,
note the following:

1.  The terminal must be set up for VT200, seven-bit
Controls mode.  This can be selected from the VT220
General Set-Up menu.

2.  When you use the alternate VT220 keyboard mapping, you
should select item 17 from the CS/1-SNA terminal
selection menu.

6.  The ASCII-to-EBCDIC and EBCDIC-to-ASCII translation tables
have been expanded to contain 256 entries.  You can sysgen
these tables to perform the translation using this
procedure:

1.  Follow the instructions in the Configuration Guide to run
the Sysgen program on the CS/1-SNA.



2.  Select the SNA Emulation Level Parameters option from the
SNA Parameters menu.

3.  The SNA Emulation Level menu appears on the screen.  Note
that the Character set selection option has been replaced
by the EBCDIC/ASCII translation table option.  The default
translation tables are for the U.S. character set.

Select the EBCDIC/ASCII translation option.  The screen
will display the three sub-options as follows:

0. Reset EBCDIC/ASCII translation table. (U.S.A. character
set) 1. View/Modify EBCDIC to ASCII translation table.  2.
View/Modify ASCII to EBCDIC translation table.

4.  Option 0 resets both the EBCDIC-to-ASCII and ASCII-to-
EBCDIC translation tables to DEFAULT.

Option 1 displays the EBCDIC-to-ASCII translation table,
which is followed by this prompt:

Enter row and column (low limit=0x00, hi limit=0xff):0x If
you need to change a value in the table, enter the address
of the value (the row and column numbers).  Then press the
return key.

The old ASCII value at that address will be displayed.
When a prompt for the new value appears, enter the new
value.

Option 2 is similar to option 1, except that the
translation table is ASCII-to-EBCDIC instead of EBCDIC-to-
ASCII.

The following is an example showing how the tables are
modified when the British character set is used.  Because
it is for illustrative purpose only, the values you enter
in the translation tables can be different from the ones
provided below.  All values used in the example are in
hexadecimal.




___________________________________
|    EBCDIC-to-ASCII Translation   |
|__________________________________|
|                                  |
|     EBCDIC             ASCII     |
|                                  |
|       4A                24       |
|       5B                23       |
|__________________________________|

In this example, the British character set is used.  The
user, therefore, wants the characters not in the U.S.
character set to be translated.

The user enters "4A" as the address of the value in the
EBCDIC-to-ASCII table that needs to be changed.  This
address is actually the EBCDIC value of the cent sign (/),
which is not available in the U.S. character set.

The user then enters "24" as the new value.  This value is
the ASCII code for the character that will be displayed by
an ASCII terminal when the EBCDIC code for "/" is sent from
the host to the CS/1-SNA. The ASCII character to which the
"/" sign will be translated is the dollar sign ($).  The
user chooses another symbol to represent the "/" sign
because there is not an equivalent of this sign in the
ASCII character set.

When you modify your translation table, you are not
required to enter "24" as the new ASCII value for the "/"
sign.  For example, if you want a question mark (?) to
represent the "/" sign on the ASCII terminal, you should
enter "3F" as the new value.
Next, the user enters "5B" as the address, which is the EBCDIC
code for "$".  Then "23" is entered as the new value.  As a
result, the ASCII character "#", which has ASCII value 23, will
appear on the terminal when the EBCDIC code for "$" is sent from
the host to the CS/1-SNA.

Similarly, the entries in the ASCII-to-EBCDIC table can be
changed to provide the same mappings, which are shown in the
following chart.  The address now represents the ASCII code for
the character entered from an ASCII keyboard, and the new value
entered by the user represents the EBCDIC code that will be sent
to the host from the CS/1-SNA.''



___________________________________
|    ASCII-to-EBCDIC Translation   |
|__________________________________|
|                                  |
|      ASCII            EBCDIC     |
|                                  |
|       23                5B       |
|       24                4A       |
|__________________________________|

7.  The cursor select key function is now available.  To use
this function, press <ESC-l>.

8.  The 25th line on the terminal screen now displays an "X NO
COMM" message to signal users if the communication link has
been disconnected.

9.  When the CS/1-SNA prompts you for the terminal type, you
can now use the return key, the enter key, or <CTRL-j>
after you have entered your terminal type.

10.  Both the minus sign and the comma can be used in the
numeric field of the 3270 screen.

11.  The bell signal is now sent to the terminal whenever there
is an input error (e.g., when the user enters an
alphabetical character on the numeric field).  In addition,
the keyboard no longer locks after such an error happens.

12.  The <ESC-R> (Reset) and <ESC-C> (Clear) function keys for
the VT100 terminal now function properly whether the R or C
is in uppercase or lowercase.

13.  Fast cursor is supported on IBM 3278 and IBM 3279
terminals.  Terminals that are compatible with these
terminal types are also supported.  This feature allows a
left or right arrow key to become a double arrow cursor
when the key is pressed.

14.  The following terminals emulate the IBM 3278 (wide screen):

+ Pericom MT200   (27 x 132)

+ DEC VT100   (24 x 132)

+ DEC VT220 (24 x 132)

+ DEC VT240   (24 x 132)

15.  The Name Server no longer needs the !net! field when naming
or unnaming a logical name.  Therefore, you must not use
"!" in a logical name.  In addition, a hyphen (-) is now
allowed in logical names.



16.  The Internet addresses of the Name Server, Default Gateway,
and the Communications Server's physical and rotary ports
can now be defined via User Interface commands listed
below:

- SETDefault (!<port-id>) InternetPort = <Internet
address>

Assigns Internet addresses to individual physical or
rotary ports.

- SETDefault (!<port-id>) InternetPort = 0.0.0.0

Removes the Internet address of an individual physical
or rotary port.

- SETDefault DefaultGateway = <Internet address>

Allows all remote net packets to be sent to the
specified gateway.

- SETDefault PrimaryNameServer = <Internet address>

Assigns an Internet address for the primary Name
Server. The primary Name Server will be queried first
for name resolution.  The primary Name Server's
Internet address can be defined to be on a remote
network.



- SETDefault SecondaryNameServer = <Internet address>

Assigns an Internet address for the secondary Name
Server. The secondary Name Server will be queried if
the primary Name Server does not yield a name to
address resolution.

- SHow InternetPorts

Replaces the SHow InternetMap command. It displays the
Internet address of the Communications Server itself
and all other Internet addresses associated with the
Communications Server (physical and rotary ports).

- SHow InternetServers

Displays Internet addresses of the Name Servers and
Default Gateway.

- SHow VirtualPorts

Displays the connection state (passive or active) of
the physical port to which these virtual ports are
connected.

17.  Subnets are supported.  Refer to the appendix for further
information on subnets.

18.  Passive-end or host-side RLOGIN is supported.  It allows a
login from a UNIX host to a non-UNIX host front-end by the
CS/1-SNA running SW/1-T-SNA.

For example, to perform an RLOGIN from the UNIX host to the
IBM host attached to a CS/1-SNA, enter the following
command: rlogin <Internet address of the port on the
Communications Server
where the host is connected>

19.  There is an additional buffer for disk access.  This
feature reduces the probability of getting the "Can't - No
Memory" message in response to User Interface commands that
require disk I/O.

20.  The FlushVC option in the BReakAction parameter now works,
if the remote host responds to Telnet DO-TIMING-MARK
commands.

21.  The CS/1-SNA now sends audit trail information to the
NCS/150 running SW/150-NCS-TCP.

The following features, which have been implemented in this
version of SW/1-T-SNA but were not present in version 10000, are
described in the SNA Support Guide:

1.  For terminals that display 24 lines on the screen, you can
use the toggle key to change the 24th line to a status
line.

2.  If you are using a terminal that displays 24 lines to
emulate an IBM 3278 Model 5 terminal, you can press <CTRL-
v> to see lines 4 through 27.  If you want to display line
1 through 24, press <CTRL-v> again.

3.  The IBM 3279 and IBM 3279-compatible base-color display is
supported.

4.  If the terminal session is disconnected before the IBM host
application logout procedure is performed, an application
logout for the terminal session will be performed
automatically.



5.  These terminal types are now supported:

+ DEC VT100-Keypad, VT240, VT241

+ Pericom MT200TM

+ IBM 3278

+ Xerox 820TM

+ Honeywell VIP 7200TM, VIP 7201TM, VIP 7305TM, VIP
7801TM, and VIP 7814TM

6.  The number of sessions can now be sysgenned depending on
the number of wide-screen or regular-screen terminal
emulations.  This feature has several hardware
dependencies, which are described in the Configuration
Guide.

7.  The number of physical ports can be limited via sysgen.
Refer to the Configuration Guide for sysgen instructions.

Compatibility

SW/1-T-SNA Version 13000 operates with the following products and
software releases:

.br;CS/1 running SW/1-TCP Version 12000 or later
.br;CS/50 running SW/50-TCP Version 13010 or later
.br;CS/100 running SW/100-TCP Version 12000 or later
.br;CS/200 running SW/200-TCP Version 13000 or later
.br;IVECS running SW/IVECS-TCP Version 13000 or later
.br;GS/3 running SW/3-IP Version 10000 or later
.br;NCS/150 running SW/150-NCS-TCP Version 12000 or later
.br;NCS/AT running SW/AT-NCS Version 10000 or later
.br;PC running TCPTerm Version 10000 or later
.br;PCS/1 running SW/1-PCS Version 10000 or later
.br;In order for SIO-3270 to support the extended VT100 mode when it
works in conjunction with the CS/1-SNA, the CS/1-SNA must run
SW/1-T-SNA Version 11010 or later.



Table 3 illustrates the software and firmware compatibility for
SW/1-T-SNA Version 13000. ''

______________________________________________________________
|           Table 3  Software/Firmware Compatibility          |
|_____________________________________________________________|
|         |               |                                   |
| Product |    Software   |              Firmware             |
|_________|_______________|___________________________________|
|         |               |     SIO   |    MCPU   |    EC/2   |
|         |               |           |           |           |
| CS/1-SNA|  SW/1-T-SNA   |  M1SYNC 1C|  M1MMON 1B|  M0EDL2 0A|
|         |  Version 13000|  or later |  or later |  or later |
|_________|_______________|___________|___________|___________|

In order for the 512K EC/2 to work properly in the CS/1-SNA, the
MCPU PROMs must be M1MMON Rev. 01K or later and the EC/2 PROMs
must be M0EDL2 Rev. 01A or later.

Bugs_Fixed

The following problems, which were present in SW/1-SNA Version
12000, have been fixed in SW/1-T-SNA Version 13000:

1.  The CICSTM printer no longer gives an extra form feed.

2.  The logon screen on VTAM is now displayed after connection
if the sysgen parameter "Negative FMD response if no
connection" has the proper value.

3.  The SPP EOM flag is now always set for compatibility with
the GS/1.

4.  The CS/1-SNA no longer crashes when you repeatedly type
CTRL-u to repaint the screen.

5.  In the past, any non-printing character sent from the host
to the terminal was sent as a null character instead of a
blank.  This caused improper cursor movement.  The problem
has been fixed.

6.  Connections can now be initiated from the DEC20TM machine
to the CS/1-SNA running SW/1-T-SNA Version 11000.

7.  The TCP retransmission algorithm has been improved.

8.  Users can now use the Broadcast 255.255.255.255 command to
broadcast a message.  This command does not work in remote
mode.

9.  The SHow NetMap command now displays the actual number of
server Ethernet addresses on the network.



10.  Improper deletion of characters no longer occurs after a
deletion or insertion has been performed.

11.  When changing from a highlight field to a non-highlight
field, the non-highlight field no longer contains the
highlight attribute.

12.  The PF5 and PF24 keys now work properly for alternate VT220
keyboard mapping.

Limitations

SW/1-T-SNA Version 13000 has the following limitations:

1.  The intensity attribute is not supported in VIP 7814 and
VIP 7305 terminal emulation.

2.  There is no command available to disable the wrap-around
feature in the host terminal mode of the Xerox 820.
Instead, the screen is advanced one line to the next
screen.

3.  A beep sound is always generated by the VIP 7201 when the
screen is cleared.

Miscellaneous

The CS/1-SNA that has an EC/2 with 256 kilobytes of memory
includes the SBB board. This CS/1-SNA can support up to 12
sessions for IBM 3278 Model 5 terminal emulation.  The maximum
number of sessions for IBM 3278 Model 2 terminal emulation is 24.

The CS/1-SNA that has an EC/2 with 512 kilobytes of memory can
support up to 24 sessions for IBM 3278 Model 5 terminal
emulation.  However, the SBB board, which is not supplied with
this CS/1-SNA, must be installed to support the maximum number of
sessions.  You can order the SBB board (part number: 10-0004-01)
from Bridge.  For IBM 3278 Model 2 terminal emulation, it can
support up to 24 sessions.

Procedure_to_Sysgen_SW/1-T-SNA_Version_13000

Refer to the Configuration Guide for the procedure to sysgen
SW/1-T-SNA Version 13000.

Memory_Dump_Procedure

If the CS/1-SNA crashes for any reason, you should follow the
procedure described in the Network Management Guide to obtain a
memory dump.



Documentation

The current manuals for the CS/1-SNA are listed below:

+ Connection Service User's Guide (8/86)
Part Number: 09-0063-01

+ Series/1 Installation Guide (11/86)
Part Number: 09-0022-05

+ Network Management Guide (1/87)
Part Number: 09-0067-01

+ Configuration Guide (1/87)
Part Number: 09-0093-00

+ SNA Support Guide (3/87)
Part Number: 09-0045-01

If you have any questions, please contact an authorized Bridge
service representative for assistance.

Trademarks

IBM is a registered trademark of International Business Machines
Corporation.
CICS and VTAM are trademarks of International Business Machines
Corporation.
MT200 is a trademark of Pericom Corporation.
VIP 7200, VIP 7201, VIP 7305, VIP 7801, and VIP 7814 are
trademarks of Honeywell Communications Systems, Inc.
DEC is a registered trademark of Digital Equipment Corporation.
VT100, VT220, VT240, VT241, and DECnet are trademarks of Digital
Equipment Corporation.
Xerox 820 is a trademark of Xerox Corporation.
UNIX is a registered trademark of AT&T.



APPENDIX

SUBNETS

Overview

If a private network wishes to establish communications to a
public TCP/IP network (e.g., ARPANET), the public network first
assigns a unique network number to the private network. In this
case, all stations on this private network will have this unique
network number. Gateways internal to this network may be used to
further subdivide the network into segments by incorporating
subnetworking as described below.

Definition of Subnets and the Subnet Mask

An Internet address consists of 32 bits divided into four 8-bit
subfields.

Normally, these subfields are divided between the <net> and
<host> fields. Some TCP/IP networks, however, have inserted an
additional field between the <net> and <host> fields called
<subnet>. The subnet field is used to indicate the particular
physical segment. The <subnet> field is formed by taking the
leading bits from the <host> field.

The <subnet> field is assigned in the system program under the
"Server subnet mask" option in the "IP Parameters" menu.
However, if your network does not use subnets, do not assign  a
subnet  mask. When entering the subnet mask, enter the decimal
instead of binary representation.

The subnet mask is then defined as follows:

It is a 32-bit number divided into four equal subfields. Each bit
that coincides with the network field (the 8, 16, and 24 most
significant bits for a class A, B, and C Internet address,
respectively) is always set to 1. The remaining bits in the host
field that are set to 1 define the subnet field to be
incorporated. The subnetwork address is then obtained by
performing the logical AND operation of the Internet address with
the selected subnet mask field.

For the subnet addressing to be meaningful, all the servers on
this private network must be sysgenned with identical subnet
masks.



Example 1:

The subnets of a class A Internet address might be defined as
follows:

126.(11110000) (00000000) (00000000)

In this example, the number of subnets defined on this network is
16 and the subnet mask is (11111111) (11110000) (00000000)
(00000000), which is the binary equivalent of 255.240.000.000
decimal. The possible subnetwork addresses for this network would
then be:

''

.br;126.0.0.0     126.128.0.0
.br;126.16.0.0    126.144.0.0
.br;126.32.0.0    126.160.0.0
.br;126.48.0.0    126.176.0.0
.br;126.64.0.0    126.192.0.0
.br;126.80.0.0    126.208.0.0
.br;126.96.0.0    126.224.0.0
.br;126.112.0.0   126.240.0.0

Example 2:

The subnets of a class B Internet address might be defined as
follows:

129.000.(11100000) (00000000)

In this example, the number of subnets is 8 and the subnet mask
is (11111111) (11111111) (11100000) (00000000), which is the
binary equivalent of 255.255.224.000 decimal. The possible
subnetwork addresses for this network would then be:

''

.br;129.0.0.0    129.0.128.0
.br;129.0.32.0   129.0.160.0
.br;129.0.64.0   129.0.192.0
.br;129.0.96.0   129.0.224.0



Example 3:

The subnets of a class C Internet address might be defined as
follows:

193.129.130.(11000000)

In this example, the number of subnets is 4 and the subnet mask
is (11111111) (11111111) (11111111) (11000000), which is the
binary equivalent of 255.255.255.192 decimal. The possible
subnetwork addresses for this network would then be:

''

.br;193.129.130.0    193.129.130.128
.br;193.129.130.64   193.129.130.192

Note that in the three examples above, the numbers in parentheses
are in binary format.


