1. Introduction 2. First steps with Fore ATM Switch 2.1. Login and

1. Introduction 2. First steps with Fore ATM Switch 2.1. Login and

LECTURE:
LECTURER:
YEAR OF STUDY:
SEMESTER:
COURSE:
Systemy i Sieci Telekomunikacyjne
dr inż. Krzysztof Wajda ([email protected]),
mgr inż. Grzegorz Rzym ([email protected])
III
winter
Electronics and Telecommunications
LABORATORY – ATM
1. Introduction
The main goal of this laboratory is to familiarize with the configuration, problems
troubleshooting and management in ATM-LAN network consisting of ATM switch and PCs
with ATM25 cards.
2. First steps with Fore ATM Switch
2.1.
Login and session saving
We log in to the switch using telnet session (e.g. in PuTTY program). Please save yours
PuTTY logs in text file: go to the ‘Logging’ submenu (left side of PuTTY program), next
check ‘Log all session output’, browse directory you want to save logs and change log name
as in picture below:
Thanks these changes all data displayed and typed on the keyboard will be stored in the log
file. Remote IP address, login and password will be given by the teacher.
1
LECTURE:
LECTURER:
YEAR OF STUDY:
SEMESTER:
COURSE:
2.2.
Systemy i Sieci Telekomunikacyjne
dr inż. Krzysztof Wajda ([email protected]),
mgr inż. Grzegorz Rzym ([email protected])
III
winter
Electronics and Telecommunications
AMI help
A new user of the AMI – ATM Management Interface can get quick help with commands:
@::help
@::?
User can change switch name in configuration menu:
@::Configuration switch> name NEW_NAME
where NEW_NAME is new name saved in the switch memory.
2.3.
Ports, channels and virtual channel statistic
Command:
@:: configuration port> show
allows to display current information about all installed network modules. Briefly description
shows their status, carrier, capacity of port link in Mbps, used policing, etc. CTL port is a
logical (not physical) location.
The current configuration of the virtual channels can be displayed from configuration vcc
submenu using the command show:
@::configuration vcc> show
There are displayed: Input Port, Input VPI (Virtual Path Identifier), Output Port, Output VPI,
UPC (refer to specific traffic contract assigned to this VCI), Protocol (e.g. pvc, spvc) and
assigned name.
From menu statistics with command:
@::statistics> vcc
You can observe virtual channel statistics like uptime, received and rejected cells helpful with
problems debugging.
2
LECTURE:
LECTURER:
YEAR OF STUDY:
SEMESTER:
COURSE:
Systemy i Sieci Telekomunikacyjne
dr inż. Krzysztof Wajda ([email protected]),
mgr inż. Grzegorz Rzym ([email protected])
III
winter
Electronics and Telecommunications
3. Virtual channel set-up
To create new virtual channel in presented topology going in port 1d1, vpi 0, vci 100 on the
switch board installed in slot 1 and going out port 1d2, vpi 0, vci 101 on the switch board
installed in slot 2, enter the following command:
@::configuration vcc> new 1d1 0 100 1d2 0 101
Attention: Please remember not to use reserved VCIs (0 – 31)!
4. Useful Linux programs
Linux atm-tools is a package containing the basic tools that are needed for setting up,
monitoring, and tuning ATM networks. Here are presented few command belongs to atmtools package:



ttcp_atm – to send and receive data,
awrite and aread – to send and receive characters data,
atmdump – to observe incoming cells.
During laboratory exercises you will have opportunity to use all of them.
3
LECTURE:
LECTURER:
YEAR OF STUDY:
SEMESTER:
COURSE:
Systemy i Sieci Telekomunikacyjne
dr inż. Krzysztof Wajda ([email protected]),
mgr inż. Grzegorz Rzym ([email protected])
III
winter
Electronics and Telecommunications
5. Data stream observation
Please set-up channel from PC A to PC B. Next, please observe it in two cases: first – when
40 bytes are send in payload, second – with 41 bytes. To perform this exercise use:
On PC A:
$awrite VPI.VCI 012345678901234567890… (48, 41, 40, 81 characters)
On PC B:
$atmdump VPI.VCI (in each case)
Please observe how many cells are transmitted in each case. Compare your result with slides
from lectures – AAL5.
6. Usage Parameter Control
In ForeATM switch you can create virtual connection with SLA (e.g. CBR, VBR). First you
must change UPCs units from cps (cells per second) to kbps with command:
@::configuration system> units
Next, you must create new contract from submenu:
@::configuration upc> new
And new virtual channel. Connect previously created contract ID: use –upc option.
Please observe achieved throughput using ttcp_atm program.
Another way to observe real throughput: send data with ttcp_atm and collect it using:
$atmdump VPI.VCI > file_name
Next, count the number of word ‘VPI’ using Linux grep program:
$grep –c VPI file_name
Next, please observe used channel statistics:
@::statistics> vcc 1d1
4
LECTURE:
LECTURER:
YEAR OF STUDY:
SEMESTER:
COURSE:
Systemy i Sieci Telekomunikacyjne
dr inż. Krzysztof Wajda ([email protected]),
mgr inż. Grzegorz Rzym ([email protected])
III
winter
Electronics and Telecommunications
7. Congestion control
Please create virtual channels to send data in loops like in the picture below:
Use e.g. ttcp_atm program to send and receive data stream. Next observe statistics in each
point of created loops. Please consider why cells are dropped and how can you solve this
problem.
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