Guidance for a measurement titled
“Measurements for local computer networks”
VOL 1
Written by:
Telecommunication pattern laboratory of Department of
Telecommunication and Telematics in September 1995
First edition:
Department of Telecommunication and Telematics
Telecommunication pattern laboratory
September 1995
Composed by:
György Horváth,engineer
Tel.:
18-65
MAIL:
horvaath@bme-tel.ttt.bme.hu
Content
Usage of guidance
Concept of LAN, and the OSI reference model
Building elements of the network of Department
Cabling
Testing of cables
Testing of line signals
IEEE802 series of recommendation
SIEMENS K1102 type of LAN protocol tester
Databases of K1102
Mandatory literature
Recommended literature
Appendix 1. Ethernet Vendor codes
Appendix 2. Codes of the Etherneet Type field
i
About the usage of the guidance
This guidance was prepared for a measurement of Telecommunication and
Communication Networks of “A” module laboratories of Electrical Engineering
Department titled “Measurements for local computer networks”. Its primer t ask is
to introduce students through some examples to the basic methods of testing the
local networks.
On the one hand it presents the network of Department, following the layers of OSI
reference model, and then presents the services of a protocol tester, and the method
of its usage. .
We assume, that the reader has some basic user knowledge of IBM-PC typed
personal computers, and Novell and Unix (TCP/IP) network applications.
This material is a guidance for topics mentioned below:










Concept of LAN, and the OSI reference model
Building elements of network of the Department
Physical layer - Cabling- Testing of cables
Physical layer – Testing of line signals
Series of recommendation IEEE802, LLC/MAC, the 2. layer
SIEMENS K1102 typed protocol tester
Traffic generation, monitoring
Preparation of trends, statistics
Testing of layer III. protocols, routers
Applications, and a correspondent Gateway
This document (plus a measurement record) can be found presently at
N drive of PUB field of servers of the Department in subdirectory of
MERESEK\10\DOC alkönyvtárában (in the case of GUEST, vagy
MERES5,6 topic numbers it is on the L drive) at the name of
LANVIZS.DOC (or MERES10.DOC).
1
Concept of LAN and the OSI reference model
Concept of LAN (Local Area Network) is the following according to the IEEE
(Institute of Electrical and Electronics Engineering):
A kind of datacommunication system, which can make possible for
numerous independent tools to communicate with each other
directly within a medium-sized geographical field, with the help of
a physical communication channel installed for this purpose, with a
medium capacity.
The present computer network of our Department is a typi cal LAN, if the files,
printeable materials, electronic letters arosen during the computer work must be
forwarded with speed of 10...16 Mbit/sec among the approximately 100 pieces of
computers existing in building Stoczek working independently from each ot her,
through thin Ethernet, token-ring, and thick Ethernet cables, that can be found in this
building miscellaneously (see next chapter).
OSI (Open System Interconnection) reference model connects systems, which are
open for a communication with other systems. The model based on a
recommendation worked out by ISO (International Standards Organisation) is a
hierarchic one, and consists of seven layers built onto each other. They are the
following:
7.
Application layer
It provides direct services for the users. In the case of
LANs it is realized by network applications installed to
the workstation, or to the server, which have either a user
surface, or are able to complement the resources of the
given operation system with network resources, e.g. file
transfer, electronic correspondence, remote terminal
service, printing, etc.
6.
Presentation layer
It provides semantically correct information for the
application to ensure the platform-independent
operation. E.g. two different operation systems at the to
ends of the link, code conversion. A typical problem is
the lack of this layer in case of transmission of the file
over the TCP/IP protocol (FTP), where the user must
inform the other side about the type of the transmittable
file.
5.
Session layer
It organizes the cooperation between the graphic entities,
synchronizes their dialogues, and transacts their data
changes.
4.
Transport layer
3.
Network layer
2.
Data link layer
1.
Physical layer
It provides the end-to-end delivery of messages through
the network. This layer can transmit messages
transparently with suitable packaging of the data flow.
E.g. it provides forwarding of the packages to the upper
layers in an appropriate order.
It provides a network connection, maintenance and
dissociation between stations containing communicating
entities besides an appropriate route extraction
(searching or designation). E.g. connecting-transmitting
tools of LAN (router) must give this layer the most
powerful support, using the database describing the
topology of the network dynamically and/or statically.
Tools, with that one, or more data connecting connection
can be generated, maintained, or dissolved. Task of this
layer is to expose, or improve errors occurring in the
physical layer during transmission. According to the
recommendations of IEEE 802.x series, this layer broke
into two parts: one is the LLC (Logical Link Control)
which makes a logical connection control, independently
from the medium connection method; and the other is the
MAC (Media Access Control), which controls the
availability of the given physical layer. E.g. CSMA/CD,
token, connected, etc.
These are the tools and processes, which are necessary
for transmitting data, for generation, maintenance and
dissolving of physical connection between data
connection entities. E.g. this layer shows, that a bit series
with no sense for the layer can be taken away with what
kind of line coding, with what kind of electrical
characteristics with what type of cable, and how far
away.
Operation mode of the layers mentioned above can be conditioned with processes and
methods controlled well, which are suitable for a so called layer protocol.
In a computer connected to a network, unique layers of a reference model can have a
concrete shape. Hardware/software technical elements of layers can occur in different
forms. E.g. 7 layers can be realized by inner or outer commands of the operation
system, complemented with network resources, or by task-oriented applications, the
4..6 layers can be realized by dynamic or static process directories, while the 1..3
layers are realized by driving softwares with BIOS or kernel level, and by the
connecting cards connected with cable.
3
Building elements of network of the Department
Network of the Department relies on the NetWare v3.1x of Novell,
and on its 4.1 series network operation system, and on the network
services of the various UNIX-os platforms (DEC-Alpha, IBM
RS6000, Sun Sparkstation). Basic model of Novell realizes a
typical server/client connection, where the server integrates
resources necessary for the laboratory work (mass storage devices
with fixed disk, printers, data connection with other
servers/networks, etc.) which are used by PC based workstations
with less resources. HSN laboratory of the Department relies on
UNIX workstations with a large capacity, where both the server and
the client applications are used in a given computer. Application of
the Microsoft Windows-based (Workgroup) peer-to-peer model is
not typical.
One of the most evident characteristics of network is the accessing
physical connection, and its topology. It mostly covers the
arrangement of the cable system, the computers, and their network
connecting cards, and other network building elements. Sematic
draft of the department network can be seen on Figure 1 (it is the
state of September 1995).
Transmitting data on the physical network is executed according to
largely standardized protocols. Protocol levels embedded into each
other provide the access to the data transmitting medium, the
logical data connection between the intermediate points, and the
addressing and route searching processes, data security and order of
importance, connection between the ends without any error, and the
incidental code conversion for the user programs.
Novell network prefers IPX/SPX protocols, but it supports also the
TCP/IP protocol preferred by UNIX system among others, which
makes possible the connection to the department computers
(IBM/RISC, DEC/ALPHA, Sun), to department and university
computers (Sun, HP/Apollo), to UNIX laboratories and to the
Internet. There are numerous computers at the University, which
are DEC products with a VMS operation system running on them,
and their preferred protocol is DECNET. There was an SNA-based
local network for years in the PS2 laboratory of our Department,
which is the preferred network architecture of the SNA.
Sztoczek gerinchálózat
Dial Up
Távközlési laborok
Stáb
II. em.
Multimédia Labor
PS2
Labor
Mérõhely felé
DSP Labor
Tanszéki gerinchálózat
16 Mbit/sec Token-Ring
I. em.
Egyetemi
hálózat felé
Alhálózati szegmensek
10 Mbit/sec Ethernet
Fszt.
UNIX Labor
Jelmagyarázat
Figure 1 Sematic draft of the network of the Department
We can track on the above figure, what kind of basic elements build
the department netwok. In the further part of our material we will
examine the role, the operation, and the test of the individual
elements in details, including the concept of the repeater, the
router, and the gateway.
5
Cabling
We can classify networks on the basis of the medium used for the
transmission. Here are some typical medium, transmission rate and
its connectors:
Copper cable
Unshielded-Twisted-Pair, UTP
Speed
10 Mbit/sec*
Tip. Z0 Conn
RJ11
120
RJ45
IBM tr
150
16 Mbit/sec
Shielded-Twisted-Pair, STP
Asymmetrical coaxial cable
10 Mbit/sec
BNC
50
Glass fiber
Multimodal cable pair
150 Mbit/sec
n/a
SMA
Multimodal cable pair
150 Mbit/sec
n/a
ST
Radio channel
Wireless LAN, transmission with spreaded
2 Mbit/sec
n/a
spectrum
*In the case of Fast-Ethernet the speed is 100 Mbit/sec! Nowadays the 100BaseT is
standardized.
Table 1. Some typical transmission medium
The figure below shows the cables mentioned in Table 1, with
their connectors:
IBM Token-Ring
RJ11
Krimpelt BNC
RJ45
Csavaros BNC
Figure 2 Cables with connectors
Hereafter we will present cable types of a network connecting tool
applied in our Department now, or earlier, with a simple error
searching process.
Our Department prefers the usage of the thin Ethernet cable for
connecting computers. Wave impedance of an RG58C/U typed
coaxal cable with an 5-mm diameter, and a plastic cover is 50 .
Individual parts are given by pieces with a BNC plug of their ends..
On Figure 1 elements marked as En2, En4, En6 were implemented
with this kind of cable type
The cable of ArcNet network used earlier was a coaxial RG62 type,
too, with a wave impedance of 95 . We do not already use this
type here at our Department.
Cable of the token ring realizing the main network of the
Department is an IBM Type 1, which has a pair of STP in a mutual
plastic wrap. We can see the identifier of the Tr5 in Figure 1.
Topology of cabling can be various, as we can seen on the
following figure:
Sín (Bus) topológia
Gyûrû (Ring) topológia
Csillag (Star) topológia
HUB
MAU
Csillag-Gyûrû (Star-Ring) topológia
Figure 3. Network topologies
Arrows on this figure intent from the transmitting unit of one
computer to the receiving unit of the other computer.
7
For the topology of the track the thin
Ethernet subnetwork segments of the
Department can provide a typical example
(En0, En4, En6 segments on Figure
1).Computers can connect to the segment
closed with a 50  of resistance on its two
ends with T forks on the bottom of the BNC
unit of the transceiver of the Ethernet
connecting card inside them. We can see a
on the right side of the figure a closure
implemented in a factory, while the figure
below shows a connecting point with the
raised connecting card. .
In case of a start topology the transmission-reception circuits in the
HUB unit will provide the transmission of the signal received on
one of the ports to the others. In case of the older Arcnet network
the active HUB can make a signal regeneration, too, while the
passive HUB is a simple circuit built up from resistances. The
modern Fast-Ethernet HUBs can make even intelligent traffic
filtering tasks.
Topology of Token ring realizing the main network of the
Department is the Star-Ring (it is the Tr5 ring in Figure 1). MAU
(Multi-station Access Unit, do not mix it with terminology named
Media Attachment Unit applied in IEEE 802.x standard series)
provides the sectioning of a wrong or a dead wire computer.
Simple ring is rarely applied because of its poor error-tolerant
ability, while the double ring is a typical topology of optical
connections with a large speed.
Examination of cables
Operation of local networks is largely influenced by the quality of
cabling. Data traffic can slow down, or can be entirely stopped
because of cable errors. It refers to that kind of error, if the number
of repetitions or the control text (CRC) errors grow very fast during
the examination with a protocol tester, or with the examination of
the inner counters of an intelligent network tool (e.g. SNMP based
monitoring).
With the help of the following simple measuring scheme the mosst
types of errors can be exposed easiliy besides locating the place ot
the error. Drawback of this measuring method, that it can be made
only on a section, which is free from traffic (free from energy
Principle of measurement:
Time domain reflection measurement (TDR)
Tools of measurement:
- LeCroy 9450A 300Mhz oscilloscope
- Justification generator of the oscilloscope, as an impulse
generator
- A computer connected to the oscilloscope with GPIB for
documentation purposes
Measurable object:
induction
- Klf.(?) cable sections with an error place
Draft of the measuring arrangement:
Oszcilloszkóp
Impulzusgenerátor
U0
Zg
Generátor impedancia
kiegészítése Z0-ra
U0/2
l
0
Kábelszakasz
az elsõ hibáig
Hibahely
0
t1 t2
t3
- Indítás felfutó élre - Trigger szint kb. U0/10
- Idõalap kb. 50 nsec/div - referencia az indításon
Lezárás
Z0
Figure 4. Arrangement of a simple TDR measurement
The task of the Zg complementary element shown on this figure is to
complement the inner impedance of the justification generator to the
nominal impedance of the tested RG58C/U cable section. We can
9
count the way from the reference point on the side of the generator to
the first error place (distance of the error place) from t1 time, which is
necessary to the wave front to run this distance from the first error
place and back (reflection).
In the case of the cable in the measuring place the speed of the
wave front is approximately 200000 km/sec (group speed), which is
smaller, than the speed of the light. In our case distance can be
estimated with the formula below:
l  t/10
ahol l méterben, t pedig nanoszekundumban van megadva.
Analysing the figure with the oscilloscope we can find several
cable errors. From t1 to t2 the stranger cable section with a larger
wave impedance, at t2 a capacitive endurance at the connection
point (waving!), from t3 it is a normal section, while the end of the
cable is closed with a tear (running up to U0). It is because of the
so many error places, that it cannot reach the U0 of the multiple
reflection
We can see some oscilloscope sheaths belonging to a simple
situation on the line of figures below:.
Tear at 10 m
(T cstal.slipped apart)
rough breakage)
Short circuit at 10 m
(a crucial BNC error, or a
Reactant endurance at 10m
(Breakage or a card error)
Normal closure at 10m
Figure 5. Some typical TDR situations
11
Examnation of line signals
Important characteristic of a given LAN architecture is the method
of a line coding (or perhaps modulation) applying during reception ,
and the electrical methods of the signal (levels, speed).
The two following tables summarize two processes applied in the
case of the LAN of the Department:
Name
Ethernet
Token-Ring
Standard
IEEE802.3
IEEE802.5
Speed
10Mbit/sec
16Mbit/sec
Coding
Manchester
Differential
Manchester
The following figure shows the beginning of an Ethernet package
on the screen of the oscilloscope. We can see on the lower ray the
beginning of the frame, as the transmitter switches the impulse
flow levelled 2.05V according to the standard to the cable free
fromm energy. (We will see only the -1.77 V signal, attenuated
by the cable section in the place of the examination.) We can see
on the upper ray the a part of the lower signal elongated to the 100
nsec of time base with the 10101011 bit series indicating the
beginning of the frame, at the end of the preamble. Manchester
coding seen on the figure is very simple,edge running up at the
middle of the bit time represents the binary one, while the running
down one represents the binary 0. Speed is 10Mbit/sec.
100nsec
1.77
V
1
0
1
0
1
0
1
1
Figure 6. Beginning of an Ethernet frame and its electrical
characteristics
13
On a fail-safe, but long cable section the signal suffers such a large
attenuation, that won’t be able to a fail-safe connection any more.
If, for example, we got at the measuring place packages, where the
signal level reduced under 1 V, we can surely expect to s low or
wrong operation in the case of a remote workstation.
In this case we must induct repeaters, that operates basically as a
signal generator, and in the case of a more developed tool, as a
traffic filter (which passes through only the traffic from one section
to the other). This kind of tool with four connection point can be
seen on Figure 1. with an MPR (MultiPort repeater) mark.
This table below summarizes the maximum length of the cable in
the csase of some Ehternet or token-ring cablings, and the number
of the accessible computers in the case of a passive segment.
Name
Identifier
Speed
Lenght
Thin Ethernet
Thickg Ethernet
UTP Ethernet
Fast Ethernet
Token ring
Token ring
10BASE2
10BASE5
10BASET
100BASET
Type 1 (STP)
Type 3 (UTP)
10 Mbit/sec
10 Mbit/sec
10 Mbit/sec
100Mbit/sec
4 Mbit/sec
4 Mbit/sec
185 m
500 m
100 m
N/A
750 m
N/A
---------------------------------------------------
Number
of
computer
30
100
2,(HUB)
2 (HUB)
260
72
IEEE802-es recommendation series
Examining the bottom of the data connection layer of OSI reference
model, we can group the various networks according to the method
of the medium access, too. The four main access methods are
shown in the following table:
Centred
Distributed
On-demand
Line connected
(PBX)
Random access
(CSMA/CD)
Controlled
Polling
Token
In order to a multiple usage of the given medium we can apply
time-shared, frequency-shared or code-shared (e.g. spreaded
spectrum) transmission technique.
In the case of LANs the IEEE recorded in its 802 recommendation
series some of this kind of methods, including the specifications of
the physical layer, too. They are summarized in the following table:
Standard
IEEE802.2
IEEE802.3
IEEE802.4
IEEE802.5
Subject
Logical connection control
CSMA/CD
Token tracks
Token ring
OSI layer
2LLC
2MAC/1
2MAC/1
2MAC/1
Illustration
Ethernet
ArcNet
IBM Token-ring
Hereinafter we will review only the Ethernet process in details,
which is a very preferred application at our Department.
IEEE802.3 (Ethernet means a product!) CSMA/CD (Carrier Sense
Multiple Access with Collision Detection) is a distributed, ondemand, random-access medium access method. This standard
recorded six basic functions for the MAC. These are the following: :
1.
Framing of the transmission data
Preamble,
frame, addressing, data embedding, CRC.
2.
Organization of medium access
transmitter, impact detection
3.
Data coding
4.
Receiver data decoding
Manchester decoding
beginning
of
Receiver perception, switching on
Manchester coding
Clock signal extraction, frame synch,
5.
Reception medium access
Detection, CRC control
6.
Unpacking of received data
Address control, data exposion
15
Here occurs first the typical basic action of the various protocols,
the repacking, which means the completion of data packages
arriving from higher protocol levels with incidental information
necessary for the operation of the given level. Figure 7.
demonstrates this activity.
Adat az LLC alrétegtõl
...
Keret start
Elõtag (preamble)
Célcím
Forráscím
Hossz
aa aa aa aa aa aa aa ab 00 00 C0 6f 42 b0 00 00 C0 6f 45 c3 05 0a
MAC
...
Adat az LLC alrétegtõl
CRC-32
11 5f 43 2d
Figure 7.
Framing process of MAC
Preamble:
aa
Hex
pattern
(10101010
bit series) with the length of 7 bytes to the synch o
n the side of the receiver
Frame start
1 byte ab Hex indicates the beginning of the frame
Task address: The 48-bit Ethernet address of the terminal. The
address, which consists of only numeric characters “1” is the so
called broadcast, which is a call to every station.
Resource address: Address of the transmitting station
Lenght:
Length of the frame
Data:
Embedded data from the LLC.
CRC-32
32-bit of controlling amount.
Since the appearance of the Ethernet, as a product anticipated the
standardization procedure, there were numerous types of frame
spreaded in practice. One of them is the "Ethernet II", where the
length information is absent, and instead of it the frame type occurs
derived from the higher protocol layers, that is not a really
matching information. .
What really unified is in this level, that is the distribution of the
first 3 maximum byte of the 48-bit Ethernet among the varoois
vendors.
Appendix 1 contains the prefixes assigned to the different vendors.
E.g. the addresses shown on Figure 7. according to the table refer to
the vendor named "Western Digital/SMC".
Standard of IEEE 802.2 specify the method of Logical Link Control
(LLC) of LANs. As the standard appeared a bit late, it was force to
give a start to other product, that have already got a strong place in
the market. This solution is really elegant. In the focus of the
standard a connection-oriented standard, the so called number 2
tries to fit in the OSI reference model, while the number 1
connection free protocol means the start, where there is no really
protocol in special cases, the layer is quasi transparent towards the
upper, not OSI layers.
In the case of the connection free protocol there is no frame
numbering and error protection – these are the tasks of the higher
protocol levels.
We will not review the connection-oriented case, in details, since
the LAN of the Department does not apply this one. Instead of it we
demonstrate the summary of frame types occurring at our
Department in practice, complemented with the LLC information
fields.
Byte
Ethernet II
Ethernet-SNAP
IEEE802.3
IEEE802.2
0-5
6-11
Task address
Resource
address
Type
Task address
Resource
address
Length
DSAP
SSAP
Control
Organization
Code
(3 byte)
Type
Task address
Resource
address
Length
Task address
Resource address
14
15
16
17
18
19
20-21
Length
DSAP
SSAP
Control-1
(Control-2)
The start giving mentioned above can manifest itself in the case of
the 802.2, and SNAP preferred by IBM, that the operation code of
the connection free LLC corresponds to the sending of a plain
information without any numbering (Control field, Unnumbered
Info, code: 03) at the transmission of Novell and TCP/IP protocols.
As an illustration, the table below shows some connection free
codes in the case of 802.2 and IBM framing..
Type 1.LLC operation
Unnumbered Info. (UI)
Change of identifier (XID)
TEST
802.2 Control
C0
F5
C7
IBM Control
03
AF
E3
Type identifiers (Type field) are current in practice, they identify
protocols of firms producting various LAN solutions, or “self -
17
employed” protocols of organizations – their list can be found in
Appendix 2
SAP (Service Access Point) provides theoretically virtual
connection points to the network layer for the access of the
individual network services, but in practice it serves for the
indentification of higher level or embedded protcols – as it is
shown in the table below.
00
02
03
04
06
0E
42
4E
5E
80
8E
AA
BC
E0
F0
F4
FC
FE
FF
Management
Individual LLC sublayer management
Group LLC sublayer management
SNA Path Control
Internet IP
Proway-LAN
Spanning tree
EIA-RS 511
ISI IP
3Com XNS
Proway-LAN
TCP/IP SNAP (Ethernet type in LLC)
Banyan VINES
Novell IPX
IBM NetBIOS
IBM LAN Management
RPL
ISO DIS 8473
Broadcast
In the case of the IPX/SPX protocol of the Novell Netware either
the resource (Source SAP, SSAP) or the task (Destination SAP,
DSAP) code is E0. In case of the Internet traffic of the Tr5 ring
seen on Figure 1 this code will be AA.
The SIEMENS K1102 typed LAN protocol tester
SIEMENS K1102 dual-port protocol analysator is suitable for the
examination of local (LAN), and large (WAN) netoworks, with
application of optionally changeable interface types - IEEE802.3
(Ethernet), IEEE802.4 Token-Bus, IEEE802.5 Token-Ring, FDDI,
and V11/V28 WAN.
The specimen in the laboratory has only IEEE802.3 and V28/V11
measuring interfaces.
The protocol tester has an independent transmission (traffic
generator) and receiver (analysator) function, separatedly for both
two ports, thus it is suitable for the examination of network routers
and gateways.
Its measuring interfaces are different from the normal network
connection tools in several points.
-
More developed clock signal extraction and sycnh
Filter functions with a transputer
Large, quick storage for longer registrated issues
A possibility for a direct data change between the two interfaces
Block diagram of the hardware protocol tester:
AT-bus
¦
+--AT-CPU----+
¦
¦
+-- billentyûzet
¦---¦ AT-alaplap ¦
¦
¦ processzor +-- printer
¦
¦
¦
¦
+------------+
+------------+ +------------+ ¦
+--DISPLAY---+
¦ 1.sz mérõ ¦ ¦ Transputer ¦ ¦
¦
EGA
¦
EL-EGA
LAN1-><--¦ interfész ¦--¦ + RAM
¦--+---¦ csatoló
+-- display
¦ és csatl. ¦ ¦ (+Filter) ¦ ¦
¦ kártya
¦
+------------+ +------------+ ¦
+------------+
¦
¦
+------------+ ¦
+------------+ +------+
¦
+---¦ Ütemezés, ¦ ¦
¦ Floppy disk¦ ¦Floppy¦
Adatcsere
¦ órajel
¦ ¦---¦ kontroller +-¦disk ¦
¦
+---¦ kinyerés
¦ ¦
¦
¦ ¦drive ¦
¦
¦
+------------+ ¦
+------------+ +------+
+------------+ +------------+ ¦
+------------+ +------+
¦ 2.sz mérő ¦ ¦ Transputer ¦ ¦
¦ Hard disk ¦ ¦Hard ¦
LAN2-><--¦ interfész ¦--¦ + RAM
¦--+---¦ kontroller +-¦disk ¦
¦ és csatl. ¦ ¦ (+Filter) ¦ ¦
¦
¦ ¦drive ¦
+------------+ +------------+ ¦
+------------+ +------+
¦
+------------+
¦
¦ szabad
¦
¦---¦ SLOT(ok)
¦
¦
¦
+------------+
The module of the protocol tester event and the data extractor
consist of the interface connector and the transputer card The
examined amount of data can be reduced by installing a hardware
levelled filtering function.
19
The protocol tester has a built-in tool ensuring the man-machine
connection (keyboard, display), a mass storage device (Floppy,
Hard disk, RAM), and recording tools (printer, disk). These
functions can operate with the help of a built-in IBM-PC/AT
compatible computer.
The basic operation system is the DOS 4.0, and the makers of this
tool prepared numerous applications for this. There are two
program packages in the computer, a one-port Ethernet analysator
package from 1992, and a dual-port from 1993, where one of the
supported interfaces is the Ethernet..
The one-port (SP) package (c:\k1102etn subdirectory) consists of
four elements:
* K1102I
frame program (shell)
* K1102AI standard tests
- Node detection
- Protocol detection
- Examination of the ISO transport layer
- Echo test
* K1102DI diagnostic
- Frame recording
- Traffic generation from stored frames
- Generate Network Load
- Programmed measures (Received event->frame sending)
* K1102SI preparation of statistics
- Load trend
- Collision trend
- Fault trend
- Length distribution
- Gap distribution
- Fault distribution
- Load distribution according to stations
- Display of connection matrix
The dual-port (DP) package (c:\k1102dp subdirectory k1102.exe)
makes possible the operation of the basic functions mentioned
above at the same time besides a multiple window display, where
the same or different results of one, or both ports can be displayed
in
two
windows.
The protocol tester at the measuring place has a special
configuration, because it was completed with a NE2000 compatible
Ethernet connecting card for documentation purposes, and with the
necessary softwares for the access to the Novell network.
The following figure shows the arrangement of the measuring place
in the LAN environment of the Department..
En2
Terminátor
MPR felé
K1102
10BASE2
Transceiver
BME-TEL felé
Dokumentációs célú
LAN kapcsolat
Mérõ interface
NE2000
LAN adapter
En4
AUI csatlakozó
Figure 8. Fitting of the measuring place to the LAN of the
Department
The measurable object in the case of monitoring will be the living
traffic of the thin Ehternet segment marked as En2 (logically it is
the main network of the Stoczek building), while in the case of
traffic generation we should use the En4 segment after the change
of the two connecting points.
After switching the tester on, students can enter automatically to
the Novell network of the Department, which makes possible the
storage of measurement results on the students’ workplaces (HOME
or PROJECT).
As a resident, there will be loaded a screen image storing program
named CAMERA, which makes possible the recording of the
graphic screen images of the tester in a file of LBM format. After
pressing the ALT+C keyboard combination SCREENnn.LBM files
are generated, where nn is the number of the picture. These can be
converted with the help of the CONVERT program to a PCX format
appropriate for the Word.
One of the services of the tester is to record some of the results to
files. We will review the files applied by the tester in the next
chapter in details.
21
Databases of the K1102
During the examination of the local networks the various data
structures have an important role, especially the set of the protocol
elements, the storage of the measuring results, and the li sts applied
during the operation of the network, which contain the data of
computers of LAN.
In the case of K1102 a separated menu can be found for handling of
the various database files, and for their selection (System
Management-File Management).
Figure 9. Databases of K1102
Perhaps there will be necessary for us to introduce filtering
conditions during the analysis of the traffic, if we wish to narrow
the range of our examinations e.g. for a grup of computers (filtering
according to the address), or for a kind of protocol, or for the
combination of these ones. The filtering conditions, which can be
set under the "Presetting-Harware filter" menu, can be stored in
files of *.FIL format.
Figure 10. Setting of filtering conditiions
On the previous we can see an example, where we narrow the
resource address to SMC/WD type of connection cards, and we
want to see only Novell packages with Ethernet II. (Novell old,
Type 8137 in the Area field).
We can set more of these kind of records, but we can activate only
six during one measurement. The tester contains more filters set in
advance (in USER or ROOT directories), some typical filters from
them:
DUR_IP.FIL
DUR_NOV.FIL
DUR_BANY.FIL
Internet IP packages
Novell IPX/SPX
Banyan Vines
During traffic generation or programmed measurement perhaps
there will be necessary to set the content of packages to be sent for
simulation purposes. Tester stores this kind of set of packages in
files of *.GEN format. Compilation of content of the chosen file
can be executed in the "Presetting - Transmit frames" menu, giving
the frame fields learnt at the filters, and the content of the package.
If later we would like to store one part of the traffic for processing
purposes (Evaluation menu), the tester will put the content of the
hardware filtered packages into *.DAT files.
Definition of the content of packages (Evaluation - Frame decoding
menü) can be made easier with *.NRM files given the names of the
individual protocol-dependent fields and their positions in the
frame. There is an appropriate file at the most frequent protocols
disposal. If we want to examine a special protocol (protocol
developint work), we can generate the NRM file with the help of
the enclosed SLD/PR translator.
NEWPROTO.SPZ
PSDL.EXE
NEWPROTO.NRM
We have also a SPZ specification belonging to the manufactured
NRMs.
Here is a detail from the TCP/IP specification:
Link
Link_addr
Type
::= PSDL_SEQUENCE {
destination
source
type
::= BYTE_HEX
::= BYTE_HEX
Link_addr,
Link_addr,
Type }
{LENGTH(6) STATION}
{LENGTH(2) COMMENT(
['0800'H] "internet",
['0806'H] "arp",
"not_internet")}
*.DBF (DBase III format) of the DP program package, and *.STA
database of the SP package serve for the registration of nodes of the
23
local network by name. It is very useful, if the individual nodes
appear according to their names at the maintenance activities of the
network, at error searching, and at preparation of statistics and
distributions, and we can thus refer to their names.
We can edit the list of stations in the "Sytem management - Node
list" menu.
Fortunately, the DBF format is quite frequent, so, for example even
the Microsoft-Excel can handle it directly. It is
worth to convert for the programs of the SP package
to the STA format with the help of the "File
management- Select file - transfer" menu.
During the monitoring of the network we can store
the results in *.MON files It can be evaluated later
according to various points of views (Evaluation menu), or it can
be converted for other table handling programs
(MON2DBF menu). E.g. distribution of a traffic
statistics related to computers can make in a circle
diagram format with a link of processes of
MON2DBF - Excel import - Excel chart.
Mandatory literature
BME-TTT, Segédlet a "Lokális számítógéphálózatok szolgáltatásai" c.
méréshez, 1995
N:\MERESEK\05\DOC\?????.DOC
BME-TTT, Segédlet az "Elektronikus Levelezés" c. méréshez, 19 94
N:\MERESEK\??\DOC\EMAIL.DOC
Recommended literature
James Martin, Kathleen K. Chapman: LOKÁLIS HÁLÓZATOK
NOVOTRADE Kiadó kft.-Prentice Hall, 1992
Andrew S. Tanenbaum: SZÁMÍTÓGÉP-HÁLÓZATOK
NOVOTRADE Kiadó kft.-Prentice Hall, 1992
Dr. Harangozó József: Számítógéphálózati laboratóriumi gyakorlatok
BME-Folyamatszabályozási Tanszék, 1994
SIEMENS Ag.: K1102 LAN Protocol Tester, User Manual,
Order No.: C73000-G6076-C200, 1991 április
25
Appendix 1.
00-00-02
00-00-0E
00-00-10
00-00-15
00-00-1A
00-00-1D
00-00-21
00-00-23
00-00-2A
00-00-3D
00-00-46
00-00-4B
00-00-51
00-00-55
00-00-5D
00-00-61
00-00-65
00-00-6B
00-00-77
00-00-7A
00-00-7D
00-00-80
00-00-84
00-00-89
00-00-93
00-00-95
00-00-98
00-00-A0
00-00-A3
00-00-A5
00-00-A7
00-00-A9
00-00-C0
00-08-2D
00-DD-00
02-07-01
08-00-02
08-00-06
08-00-09
08-00-0B
08-00-11
08-00-20
08-00-38
08-00-46
08-00-5A
08-00-6E
08-00-89
Ethernet Vendor codes
BBN
Fujitsu
Sytek/Hughes LAN Systems
Datapoint
AMD ?
Cabletron
SC&C
ABB
TRW
ATT
Bunker Ramo
APT
Hob Electronic
AT&T
RCE
Gateway
Network General
MIPS
MIPS/Interphase
Ardent
Cray Research/Harris
Dowty Network Services
Aquila ?
Cayman Systems
Proteon
Sony/Tektronics
CrossCom
Sanyo Electronics
NAT
Compatible Systems Corporation
NCD
Network Systems
Western Digital/SMC
Siemens Nixdorf: TACLAN
Ungermann-Bass
MICOM/Interlan
3Com-Bridge
Siemens Nixdorf
HP
Unisys
Tektronics
Sun
Bull
Sony
IBM
Excelan
Kinetics
00-00-0C
00-00-0F
00-00-11
00-00-18
00-00-1B
00-00-20
00-00-22
00-00-29
00-00-3C
00-00-44
00-00-49
00-00-4F
00-00-52
00-00-5A
00-00-5E
00-00-62
00-00-69
00-00-6E
00-00-78
00-00-7B
00-00-7F
00-00-81
00-00-86
00-00-8A
00-00-94
00-00-97
00-00-9F
00-00-A2
00-00-A4
00-00-A6
00-00-A8
00-00-AA
00-00-C9
00-AA-00
00-DD-01
02-60-8C
08-00-05
08-00-07
08-00-0A
08-00-10
08-00-14
08-00-2B
08-00-39
08-00-4E
08-00-69
08-00-7C
08-00-90
Cisco
NeXT
Tektronics
Webster
Novell/Eagle Technology
Data Industrier AB
Visual Technology
IMC
Auspex
Castelle
Apricot
Logicraft
ODS
SK/Xerox
IANA
Honeywell
Silicon Graphics
Artisoft
Labtam
Research Machines
Linotronic
Synoptics
Gateway
Datahouse Information Systems
Asante
Epoch
Ameristar Technology
Wellfleet
Acorn
Network General
Stratus
Xerox
Emulex
Intel
Ungermann-Bass
3Com
Symbolics
Apple
Nestar Systems
AT&T
Excelan
DEC
Spider
BICC
Silicon Graphics
Vitalink
Retix
Apppendix 2. Codes of the Ethernet Type field
0600
0800
0802
0804
0806
081C
0900
0A01
0BAF
10011600
3C004321
6000
6002
6004
6006
60107001
7003
7007
70207031
8003
8005
8008
8013
8015
8019
802F
8036
8038
803A
803C
803E
8040
8042
80468049
805C
8060
80658068
806A
806D
807A
807C
8080
8088809C80A380C6
80C880CF80D5
80DE80E480F3
80F7
81078130
8137
814C
817D
8582
8888
9001
9003
FF00
XNS
DOD IP
NBS internet
Chaosnet
ARP
Symbolics private
Ungermann-Bass net debug
Xerox PUP Address Translation
Banyan Echo
Berkeley trailer encapsulation
VALID system protocol
3Com NBP
THD - Diddle
DNA experimental
DNA Remote Console -MOPDEC: Local Area Transport
DEC: Customer Use
3Com
Ungermann-Bass NIUs
Ungermann-Bass
OS/9 Microware
Sintrom (was LRT)
Prime NTS
Cronus VLN
HP Probe
AT&T/Standford
Silicon Graphics diagnostic
Silicon Graphics
Apollo DOMAIN
Tigan
Aeonic Systems
DEC: bridge
DEC: (Argonaut console)
DEC: NMSV DNA Naming
DEC: distributed time service
DEC: NetBIOS Datagrams
DEC Unassigned
AT&T
ExperData
Stanford V Kernel
Little Machine
UMass. at Amherst
General Dynamics
Autophon
Compugraphic Corp.
Matra
Merit Internodal
Vitalink TransLAN III Mgmt
Xyplex
Datability
Siemens-Nixdorf
Pacer Software
Intergraph Corp.
Taylor Instrument
IBM SNA Service on Ethernet
TRFS (Integrated Solutions)
Datability
AppleTalk AARP
Apollo Computers
Symbolics
Waterloo Microsystems
Novell NetWare
SNMP over Ethernet
XTP
Kalpana
HP LanProb
3Com: XNS Mngmt
3Com: loopback detection
BBN VITAL-LanBridge
0601
0801
0803
0805
0807
08880A00
0BAD
1000
1234
1989
4242
5208
6001
6003
6005
6007
7000
7002
7005
7009
7030
7034
8004
8006
8010
8014
8016
802E
8035
8037
8039
803B
803D
803F
8041
8044
8048
805B
805D
8062
8067
8069
806C
806E807B
807D8081809B
809F
80C080C7
80CD80D380DD
80E080F2
80F4
80FF812B
8131
8139814F
81D6
XNS Address Translation
X.75 internet
ECMA internet
X.25 Level 3
XNS Compatibility
Xyplex
Xerox PUP
Banyan Systems
Berkeley trailer negotiation
DCA - Multicast
Artificial Horizons (dogfight sim.)
PCS Basic Block Protocol
BBN Simnet Private
DNA Dump/Load -MOPDNA IV Routing Layer
DEC: Diagnostics
DEC: LAVC
Ungermann-Bass download
Ungermann-Bass diagnostic/loopback
Ungermann-Bass Bridge
OS/9 Net ?
Racal-Interlan
Cabletron
Cronus Direct
Nestar
Excelan
Silicon Graphics network games
Silicon Graphics XNS Nameserver
Tymshare
Reverse ARP
IPX (Netware)
DEC: DSM/DDP
DEC: (VAXELN)
DEC: encryption
DEC: LAN Traffic Monitor
DEC: Local Area System Transport
Planning Research Corp.
DEC: DECamds
VMTP/RFC-1045
Evans & Sutherland
Counterpoint Computers
Veeco Integrated Automation
AT&T
ComDesign
Landmark Graphics Corp.
Dansk Data Elektronic
Vitalink Communications
Counterpoint Computers
AppleTalk (EtherTalk)
Spider Systems
DCA: Data Exchange Cluster
Appplitek Corp.
Harris Corporation
Rosemount Corp.
Varian Associates
Allen-Bradley
Retix
Kinetics
Wellfleet
Talaris
VG Laboratory Systems
KTI
Technically Elite Concepts
Lantastic
9000
9002
AAAA
Loopback
3Com: TCP/IP Mngmt
DECNET
27