Installation Verification

The following sections describe how to perform loopback tests to verify that the X.25/ACC subsystem has been properly installed and is functional.

Loopback Configuration Description

The loopback test configuration is designed for testing pairs of ports or ports/subchannels on a given mux connected to each other with loopback cables. For example, it is designed to test the communication between the following 8-Channel card pairs:

Mux 0 port 0 to	Mux 0 port 1
Mux 0 port 2 to	Mux 0 port 3
etc.
Mux 1 port 0 to	Mux 1 port 1
Mux 1 port 2 to	Mux 1 port 3
etc.

The 4-Channel card features 32 subchannels on each port, but it is suggested that loopback testing on 3 subchannels should be adequate for system verification. The typical setup is shown below.

These assignments of DCE/DTE and Int/Ext conform to those found in the configuration files generated at installation (see “Required Configuration Files”; see also Appendix C “Utilities, Servers, and Scripts”)

Required Configuration Files

There are two types of configuration files that are required: the .answ file which is used to bring up the ACC Mux subsystem, and the x25init file which is used for bringing up the Level 2 connections for X.25 using the x25init utility.

TTGEN .answ File

When the X.25/ACC software is installed, the .answ file is automatically created. The /opt/acc/cfg/x25_loop.answ file is automatically created based on the hardware that was installed when the X.25/ACC software was installed on the system. The ttgen utility is automatically run on /opt/acc/cfg/x25_loop.answ to create the file /opt/acc/cfg/x25_loop.tmem.

If either the .answ or .tmem file does not exist, or no longer reflects the current location of the hardware, recreate this file and run ttgen on this file:

% cd /opt/acc/cfg
% /opt/acc/lbin/acc_bld_lpbk -o x25_loop.answ -t sample_header
                    \-p x25
% /opt/acc/bin/ttgen -o x25_loop.answ x25_loop.tmem

Do not proceed until ttgen has been run successfully.

x25init Configuration Files

The X.25/ACC software provides the utility /opt/acc/bin/make_n2z_x25init to build x25init configuration files, and /opt/acc/bin/make_n2z_route to create a routing script file (See Appendix C “Utilities, Servers, and Scripts”). These are all recommended to perform the loopback tests as described in the following sections. (Login as user root.)

Create the x25init configuration files for the muxes to be tested. Use the /etc/x25/x25init.sample file as a template. For example, to test muxes 0 through 3:
% cd /etc/x25 % /opt/acc/bin/make_n2z_x25init -t x25init.sample -m 0 1 2 3
("0 1 2 3" identifies the ACC cards to test. These numbers are the ordinal position of the cards relative to all ACC cards appearing in an ioscan(M)
If all muxes on a system will be tested, run the script without the -m option:
% /opt/acc/bin/make_n2z_x25init -t x25init.sample
To test subchannels 1-3 on T1E1 ports of (4-Channel) mux 0:
% /opt/acc/bin/make_n2z_x25init -t x25init.sample -s 1:3 -m 0
Files /etc/x25/XXYlooptest (or XXYZZlooptest if 4-Channel) are created, where XX represents the mux number, and Y represents the mux port. (ZZ represents the range of subchannels for 4-Channel.) One file will be created for each port of each specified mux, or for each subchannel per port per mux, if 4-Channel.

Setting Up Loopback Test

A loopback cable must be attached between each pair of ports to be tested.
The default test configuration in /opt/acc/cfg/x25_loop.answ file configures the clocking to be internal on the even ports and external on the odd ports. This means that the loopback cable ends marked INT must be attached to the even numbered ports while the EXT end must be connected to the odd numbered ports. If a different .answ file is to be used, connect the cables to reflect the clocking in that file.
Login as root and bring up the X.25/ACC Mux Subsystem with the file /opt/acc/cfg/x25_loop.tmem:
% zmasterd cold /opt/acc/cfg/x25_loop.tmem
This command takes a short time to run as ACC firmware is downloaded to all ACC cards specified in the .answ file.
Monitor the system console or the appropriate /var/opt/acc/log/XXX.tlog file carefully for errors. If any error is reported during the start up procedure, it may be necessary to stop the X.25/ACC Subsystem by running:
% zmasterd stop
The error should be addressed and then the subsystem should be started up again.

Bring up the Level 2 connections using zx25init on the configuration files created by the make_n2z_x25init script. For an 8-Channel example:

	% x25init -c /etc/x25/00looptest
	% x25init -c /etc/x25/01looptest
	% x25init -c /etc/x25/02looptest
	% x25init -c /etc/x25/03looptest
                 etc.

An example for a 4-Channel interface:

	% x25init -c /etc/x25/00001looptest
	% x25init -c /etc/x25/00002looptest
	% x25init -c /etc/x25/00003looptest
	% x25init -c /etc/x25/00101looptest
	% x25init -c /etc/x25/00102looptest
	% x25init -c /etc/x25/00103looptest

Note that subchannel 0 for the two ports shown is left unitialized, since the loopback is to be performed on only subchannels 1 through 3.

It is important to monitor the appropriate /var/opt/acc/log/XXX.tlog file as the x25init program is run. If the X.25/ACC subsystem is up and running, and if the hardware is properly installed and connected for the loopback tests, a level 2 X.25 connection should be seen to come up as pairs of x25inits are run. Example:

17:12:05 zx25d 00621 Link ZLU 037 HDLC/LAP-B established on enable
17:12:05 zx25d 00621 Link ZLU 046 HDLC/LAP-B established on enable
17:12:05 zx25d 00642 Link ZLU 046 Packet layer (lvl 3) restart complete
17:12:05 zx25d 00642 Link ZLU 037 Packet layer (lvl 3) restart complete

If any x25init fails (after both x25inits in a paired connection have been invoked), you should examine the network log file (/usr/adm/nettl.LOG00) for supporting information, using the system utility netfmt.

Performing Loopback Test

Once the configuration files have been generated and the X.25/ACC subsystem is up and running, the test can be performed.

Note that only access between the paired ports or ports/subchannels will work, i.e., communication between Mux 0 port 0 and Mux 0 port 1 will work, but communication between Mux 0 port 0 and Mux 0 port 3 will not work, even if the cable is connected between these ports. This is due to the port configuration specified in the x25_loop.answ file.

To test the Level 3 access between mux ports, use x25check. Make sure that you have scheduled x25server before x25check is run. The following example shows how x25check can be run to create a Level 3 connection first from port 4 to port 5 of mux 0, and then from port 5 to port 4:
% x25server % x25check 408746500500 -i natacc004 -n 50 -s 100 % x25check 408746500400 -i natacc005 -n 50 -s 100
For each of these x25check invocations a typical message should return:
DATA packet sent ... Data packet received DATA packet sent ... Data packet received ...etc Remote Connection Succeeded
An example for checking Level 3 connection first from subchannel 1/port 2 to subchannel 1/port 3 on 4-Channel mux 2, and then from subchannel 1/port 3 to subchannel 1/port 2 of mux 2:
% x25server % x25check 408746502301 -i natacc02201 -n 50 -s 100 % x25check 408746502201 -i natacc02301 -n 50 -s 100
Refer to the explanation of /opt/acc/bin/make_n2z_x25init in Appendix C “Utilities, Servers, and Scripts” for more information on the loopback test configuration files created by that script.