Black Box NET-ADVISOR User Manual

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Net-Advisor
Data Clamp
I N T R O D U C T I O N
AC Adaptor
Carrying Case
User's Guide
Theory of Operation RS-232 Cable
Sotware Diskettes
AA Alkaline Batteries
Computer networks communicate by transmitting
and receiving information in the form of digital
signals. This information is electrically represented
by pulses of energy transmitted by a physical media
which is typically a metallic cable. Each pulse
travelling along a metallic cable creates an
electromagnetic field around the cable proportional
to the amplitude or strength of the pulse. These
radiated or "leaked" signals are sometimes referred
to as Electromagnetic Interference or EMI. Modern
cables use different techniques to reduce the amount
of leakage such as shielding or field cancellation by
tightly twisting the wires together. These techniques
dramatically reduce but can not eliminate the signal
leakage through the cable.
The Net-Advisor is an ultra-sensitive receiver tuned
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to the different network frequencies that is able to
detect and measure the leaked signals from the
The Net-Advisor operates on two AA size batteries. To remove
digital bits of data that are travelling through the
the battery cover located at the bottom of the unit, press down
cable. The Net-Advisor makes continuous
on the battery cover end with dimples with the right thumb. This
measurements of these network signals which are
displayed and updated once per second. The relieves the pressure on the battery cover latches. While pressing
measured data is displayed as a percentage of total
bandwidth. For example, on an Ethernet system
(10baseT, 2 or 5) the maximum bandwidth is 10
million bits per second (Mbps). If during a one
second measurement, the Net-Advisor detects one
million data bits the display will show a reading of
10% utilization. The various features provided by
the Net-Advisor are based on this continuous
detection, measurement and display of the leaked
data bits.
The Net-Advisor reads all of the traffic on a
segment or dedicated port. It does not filter for traffic
on a single node or address. Traffic can be monitored
from any point on a network that is not isolated from
the rest of the network.
OPERA OPERATING MODES OPERA OPERA OPERA TING MODES TING MODES TING MODES TING MODES
Basic RS Press ON to activate the Net-Advisor. When the unit is turned
1 1
on it presents a Net-Advisor start up screen for 2.5 seconds and
1 1
automatically transitions to the Traffic screen which is the master
1 1
screen that is returned to from all other functions.
1 1
1 TRAFFIC TRAFFIC TRAFFIC TRAFFIC TRAFFIC
2
2 2
the network to be tested is another configuration, go to the Setup
screen to select the appropriate parameters (see Control
Settings). To begin taking measurements push forward the Slide
Button on the right hand side of the instrument to open the
cableport, place the selected cable in the port and release the
slide button to close.
next to the elapsed time field. This shows that there is adequate
leaked signal to make the measurement. Note: The strength of
the leaked signals varies along the length of the cable. It is
down with the right thumb, slide
possible to find very small sections of a cable, typically 1 to 2
the cover horizontally (away
inches, where leakage is very low and "LOCK" appears
from your body). The cover will
intermittently or not at all. With the cable in the port, slide the
move approximately one
cable a few inches in either direction until "LOCK" appears
quarter of an inch and separate
consistently or you have confirmed that no signals are present.
from the unit.
Add or replace batteries as
shown. Check that the cover
orientation is correct by
ensuring that the AC adapter
hole in the cover is aligned with
the adapter jack pin inside the
second time stops the process, freezes the recorded data and
Net-Advisor.
presents the word "HOLD" in the display. Pressing Traffic again
resets the Net-Advisor to make another traffic reading. All other
buttons (except "ON") are active only when the Traffic Mode is
in this reset state.
Collision Index (CI ) - Is based on the calculated probability
of collisions occurring on the segment being tested. This
probability applies to Ethernet shared segments with "1"
indicating a very low probability and "5" indicating a very high
probability of collisions occurring. CI is calculated from Average
The Traffic Mode
Traffic and continuous readings of "4" or "5" indicate system
starts with the
upgrade should be considered. An arrowhead displayed in this
default conditions of
field means that a higher Max Range should be used.
10 Mbps Ethernet
running on UTP
T T T T T r r r r r af af af af aff f f f f ic bar g ic bar g ic bar gr r r r r a a a a a phs: ic bar g ic bar g phs: phs: phs: phs:
cable (10baseT). If
IN - Instantaneous display of the network traffic
for the previous one second.
AV - The average of all the one second traffic
measurements since Enter was pressed.
PK - The peak traffic level recorded in any one
second measurement period.
The Net-Advisor
immediately begins Note: When the Net-Advisor is first powered on, the full scale
to sense for signals default setting is 10%. The 10% setting gives a full scale dis-
and if any are play of 1 Mbps for Ethernet. The Net-Advisor is configured in
present it will display this manner because Ethernet network traffic levels are typi-
the word "LOCK" cally below 50% and this setting improves display resolution of
the bar graphs in the Traffic Screen. To set full scale to any
other value go to the Setup Screen and make the selection -
see Setup below.
A Digital display for-
mat for Traffic is se-
lected in Setup
through the Max
Range field by
choosing "DD%".
Once "LOCK"
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appears, press
Enter to start the
The Log Mode records network activity or bandwidth
measurement and
utilization over time.
display process. Log has seven
Pressing Traffic a settings from 12
minutes to 24 hours
(see Setup below)
LED LED LED LED LED
with the default Log time of 12 minutes (1 minute per division).
To begin the Log measurement, follow the procedure detailed
in the Traffic Mode section for attaching the instrument to the
cable, ensure that "LOCK" appears next to the elapsed time
display and press Enter. The Net-Advisor immediately begins
to build a histogram of the traffic levels.
The Log bar
graphs display the the LEDs can be viewed even when it is laid flat. LEDs display
average traffic the Instantaneous traffic ("IN" bar graph in the Traffic Mode)
("AV" bar graph in with each LED representing 10% of the full scale bandwidth.
the Traffic Mode)
A A A A A UDIO UDIO UDIO UDIO
UDIO
and are scaled to
the currently selected maximum range with a default value of
10%. The bar graphs are updated with every one second
measurement until time for the division is complete. When a
division is complete, the bar graph for the current division is
frozen and the instrument begins displaying the bar graph for
the next division. The Net-Advisor freezes the data by
automatically setting "HOLD" when all the divisions are complete.
The Audio tone is tied to the Instantaneous traffic ("IN" bar graph
Pressing Log will also create the "HOLD" condition. Pressing
in the Traffic Mode) and is generated once during each one
Log after "HOLD" appears will clear the display and reset the
second measurement if the threshold level has been exceeded.
Net-Advisor for another Log measurement. All other buttons
Audio has 11 threshold settings beginning with "On" and
(except "ON") are active only when the Log Mode is in this reset
increasing in 10% increments to 100%. The default setting is
state.
"On" which will cause the tone to be generated when traffic is
detected during the measurement period.
The Net-Advisor can be left running even after the Log time
has been completed without affecting the recorded data. For
SETUP SETUP SETUP SETUP SETUP
Log durations of three hours or more, it is recommended that
the AC Adapter is used.
CONTROL SETTINGS CONTROL SETTINGS CONTROL SETTINGS CONTROL SETTINGS CONTROL SETTINGS
Audio/LED Contr Audio/LED Contr Audio/LED Contr Audio/LED Contr Audio/LED Control ol ol ol ol
From the Traffic screen the center column of the screen.
(in initial or reset state),
Network Type. When entering the Setup screen, the first field
Audio or LED settings are
shows that the Net-Advisor is for use with Ethernet (10BaseT) .
entered by pressing the
corresponding button. Once
Cable Type. The default setting for Cable Type is Unshielded
in Audio or LED the settings
Twisted Pair (Category 3, 4 or 5) and is indicated by the reversed
change when the scroll
out "UTP". Press Scroll to advance to "STP" (Shielded Twisted
button is pressed. Press
Pair) and then "COAX" for coaxial/thinnet/10base2 cables.
Enter to exit the screen.
LEDs are used
when viewing the
instrument at a
distance. The
Net-Advisor is
designed so that
Audio is used
to alert the user
when network
utilization has
exceeded the
selected level.
Setup has six
selectable fields
with the active
field being
indicated by the
arrowhead in