Black Box NET-ADVISOR User manual

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
average traffic
(“AV” bar graph in
the Traffic Mode)
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.
Pressing Log will also create the “HOLD” condition. Pressing
Log after “HOLD” appears will clear the display and reset the
Net-Advisor for another Log measurement. All other buttons
(except “ON”) are active only when the Log Mode is in this reset
state.
The Net-Advisor can be left running even after the Log time
has been completed without affecting the recorded data. For
Log durations of three hours or more, it is recommended that
the AC Adapter is used.
CONTROL SETTINGSCONTROL SETTINGS
CONTROL SETTINGSCONTROL SETTINGS
CONTROL SETTINGS
Audio/LED ContrAudio/LED Contr
Audio/LED ContrAudio/LED Contr
Audio/LED Controlol
olol
ol
From the Traffic screen
(in initial or reset state),
Audio or LED settings are
entered by pressing the
corresponding button. Once
in Audio or LED the settings
change when the scroll
button is pressed. Press
Enter to exit the screen.
I N T R O D U C T I O N
Theory of Operation
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
to the different network frequencies that is able to
detect and measure the leaked signals from the
digital bits of data that are travelling through the
cable. The Net-Advisor makes continuous
measurements of these network signals which are
displayed and updated once per second. The
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.
OPERAOPERA
OPERAOPERA
OPERATING MODESTING MODES
TING MODESTING MODES
TING MODES
Press ON to activate the Net-Advisor. When the unit is turned
on it presents a Net-Advisor start up screen for 2.5 seconds and
automatically transitions to the Traffic screen which is the master
screen that is returned to from all other functions.
TRAFFICTRAFFIC
TRAFFICTRAFFIC
TRAFFIC
The Traffic Mode
starts with the
default conditions of
10 Mbps Ethernet
running on UTP
cable (10baseT). If
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.
The Net-Advisor
immediately begins
to sense for signals
and if any are
present it will display
the word “LOCK”
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
possible to find very small sections of a cable, typically 1 to 2
inches, where leakage is very low and “LOCK” appears
intermittently or not at all. With the cable in the port, slide the
cable a few inches in either direction until “LOCK” appears
consistently or you have confirmed that no signals are present.
Once “LOCK”
appears, press
Enter to start the
measurement and
display process.
Pressing Traffic a
second time stops the process, freezes the recorded data and
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
Traffic and continuous readings of "4" or "5" indicate system
upgrade should be considered. An arrowhead displayed in this
field means that a higher Max Range should be used.
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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.
Note: When the Net-Advisor is first powered on, the full scale
default setting is 10%. The 10% setting gives a full scale dis-
play of 1 Mbps for Ethernet. The Net-Advisor is configured in
this manner because Ethernet network traffic levels are typi-
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%".
LL
LL
LOGOG
OGOG
OG
The Log Mode records network activity or bandwidth
utilization over time.
Log has seven
settings from 12
minutes to 24 hours
(see Setup below)
LEDLED
LEDLED
LED
LEDs are used
when viewing the
instrument at a
distance. The
Net-Advisor is
designed so that
the LEDs can be viewed even when it is laid flat. LEDs display
the Instantaneous traffic (“IN” bar graph in the Traffic Mode)
with each LED representing 10% of the full scale bandwidth.
AA
AA
AUDIOUDIO
UDIOUDIO
UDIO
Audio is used
to alert the user
when network
utilization has
exceeded the
selected level.
The Audio tone is tied to the Instantaneous traffic (“IN” bar graph
in the Traffic Mode) and is generated once during each one
second measurement if the threshold level has been exceeded.
Audio has 11 threshold settings beginning with “On” and
increasing in 10% increments to 100%. The default setting is
“On” which will cause the tone to be generated when traffic is
detected during the measurement period.
SETUPSETUP
SETUPSETUP
SETUP
Setup has six
selectable fields
with the active
field being
indicated by the
arrowhead in
the center column of the screen.
Network Type. When entering the Setup screen, the first field
shows that the Net-Advisor is for use with Ethernet (10BaseT) .
Cable Type. The default setting for Cable Type is Unshielded
Twisted Pair (Category 3, 4 or 5) and is indicated by the reversed
out “UTP”. Press Scroll to advance to “STP” (Shielded Twisted
Pair) and then “COAX” for coaxial/thinnet/10base2 cables.
BB
BB
BAA
AA
ATTERTTER
TTERTTER
TTERYY
YY
Y
The Net-Advisor operates on two AAsize batteries. To remove
the battery cover located at the bottom of the unit, press down
on the battery cover end with dimples with the right thumb. This
relieves the pressure on the battery cover latches. While pressing
down with the right thumb, slide
the cover horizontally (away
from your body). The cover will
move approximately one
quarter of an inch and separate
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
Net-Advisor.
BOBO
BOBO
BOX CONTENTSX CONTENTS
X CONTENTSX CONTENTS
X CONTENTS
Net-Advisor Basic RS
Data Clamp 1 1
AC Adaptor 1 1
Carrying Case 1 1
User's Guide 1 1
RS-232 Cable 1
Sotware Diskettes 2
AA Alkaline Batteries 2 2

Press Enter to store the Cable Type setting and advance to the
next field.
Log Time. The duration of time that the network activity is
recorded in the Log Mode is set in this field. The default setting
is 12 minutes (1 minute per division) and has 7 selections up to
24 hours (2 hours per division). Press Scroll to change the Log
Time interval. Press Enter to store the Log Time setting and
advance to the next field.
Custom. The Custom field allows users to set the detection
level for cables that deviate from the standard settings. Many
factors affect the amount of signal leakage from a cable. The
settings used by the Net-Advisor in the Cable Type field are
based on extensive tests with different cables from different
manufacturers. The Net-Advisor should be initially checked on
a known good node or segment cable to verify that the settings
are appropriate for that cable type. The instrument has 19 levels
that are changed by pressing Scroll. The setting of 1 is the
most sensitive and the setting of 19 is the least sensitive.
Settings should not have to be changed in value by more than 1
or 2 from the default value for that cable type. Press Enter to
store the Custom setting and advance to the next field.
Maximum Range. Full scale range is set in this field. The
settings are 1%, 10% (default setting), 50%, 100% and DD%.
DD setting selects a Digital Display format for the Traffic mode
with a fixed full scale range of 100%. Press Scroll to change
the setting. The 1% setting is used when very low traffic levels
are expected. Press Enter to store the Maximum Range setting
and advance to the next field.
Alert Level. This field is used to set the threshold level for
generating the Audio alert. The default setting is “ON” which
will produce a tone if traffic is detected during each one second
measurement interval. The setting is changed in 10%
increments by pressing Scroll. Press Enter to store the Alert
Level setting and exit the Setup screen. The instrument is now
set to the new selections and automatically returns the user to
the Traffic or Log Screen.
Exit Setup. Press Enter 5 times (once for each field) to exit
Setup and return to the Traffic or Log Screen. Settings
automatically return to the default settings when the instrument
is powered on.
AC Adapter. An AC adapter is included with the Net-Advisor
for making long duration measurements or extending internal
battery life. The batteries can be left in or removed when the
adapter is used. Warning: Use only the AC adapter provided
with the unit or call the manufacturer for specifications for a
suitable replacement.
The Net-Advisor will operate for approximately 6 to 8 hours
of continuous use on two AA size alkaline batteries. Battery life
decreases when LED and Audio features are active.
RS-232 OperRS-232 Oper
RS-232 OperRS-232 Oper
RS-232 Operaa
aa
ation (Net-Adtion (Net-Ad
tion (Net-Adtion (Net-Ad
tion (Net-Advisor RS Only)visor RS Only)
visor RS Only)visor RS Only)
visor RS Only)
The Net-Advisor RS features an RS-232 interface for
downloading traffic measurements to a host computer in an
ASCII, comma separated variable format. The Net-Advisor
utility software graphically displays downloaded data (see
Readme file on diskette). Windows Terminal and Excel are
also compatible with this data format.
Single Download - After collecting data, press Log or
Traffic to “Hold” the data (“HOLD” is shown in the top center
of the display). Start the application software on the host
computer and connect the RS-232 cable from the Net-Advisor
to the selected COM port. Setup information and recorded
data is downloaded each time Enter is pressed.
Continuous Download - Connect the Net-Advisor to the
selected COM port with the provided RS-232 cable. Each
time the unit is powered On or Setup has been selected the
Net-Advisor configuration is downloaded. Press Enter from
either the Log or Traffic Modes to start data transfer with a
one second update rate. With Log or Traffic in “Hold”, press
Enter to download the last setup and recorded data.
Automatic Power Down
When the Net-Advisor is left in a mode other than Traffic/
Log measurement (time running) or Traffic/Log "Hold", the
unit automatically powers down after 10 minutes to extend
battery life.
Troubleshooting the Net-AdvisorTroubleshooting the Net-Advisor
Troubleshooting the Net-AdvisorTroubleshooting the Net-Advisor
Troubleshooting the Net-Advisor
If the screen is blank, freezes or shows only a partial
stripe across the top of the display, this means the batteries
are installed backwards or need to be changed. Remove
the battery cover, check for proper orientation of the batteries
and slide the cover back on. The unit will now reset on
power up clearing any invalid state. If the screen is still
frozen or only shows a partial stripe, install new batteries.
This product does not contain any user serviceable parts
internal to the case. Opening of the factory sealed case, other
than to replace the batteries, will invalidate the warranty. Contact
HARRIS CORPORATION Dracon Division or your dealer for
warranty and post warranty repairs.
SAFETYSAFETY
SAFETYSAFETY
SAFETY
The Net-Advisor is designed for use only with computer
network data cables. At no time should the unit be used on any
other type of cable including power cables.
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The Traffic Mode of the Net-Advisor quickly alerts the user if
there are any signals passing through the cable or if there are
too many signals passing through the cable. This mode provides
rapid isolation of network problems.
Bandwidth ManaBandwidth Mana
Bandwidth ManaBandwidth Mana
Bandwidth Managg
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gementement
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ement
The Log Mode is used to measure and record bandwidth
utilization. The histogram of utilization versus time provides the
basis for maintaining or reconfiguring the network. Traffic levels
consistently above 30% of the network rated bandwidth should
be considered for upgrading.
Improper Grounding for Coaxial CablingImproper Grounding for Coaxial Cabling
Improper Grounding for Coaxial CablingImproper Grounding for Coaxial Cabling
Improper Grounding for Coaxial Cabling
SystemsSystems
SystemsSystems
Systems
Coaxial cables that are not grounded in accordance with
the IEEE 802.3 standard may carry high levels of interfering
signals on the cable shield. This condition can allow coupling
of unwanted signals (noise) on to the network causing erratic
network operation and reduced system performance. Because
these noise signals are strong, the Net-Advisor reads and
displays this in-band noise as if it were traffic. Noise can be
identified on the Net-Advisor as all three of the Traffic bar graphs
will register 80% - 100% utilization.
Intermittent CaIntermittent Ca
Intermittent CaIntermittent Ca
Intermittent Cabb
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Intermittent conditions can be detected with a Net-Advisor by
attaching the instrument to the cable and using the Traffic Mode.
An intermittent connection can be seen by moving the cable to
different positions and watching for the “IN” bar to show no traffic
with the cable in some positions and regular traffic levels in other
positions.
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Isolating a node transmitting excessive traffic is accomplished
by using the Net-Advisor in the Traffic Mode. Attach the
instrument to a cable on the segment (preferably near the hub
or patch panel) and disconnect one node or connection at a
time until the “IN” bar or LEDs show a normal traffic level. The
Net-Advisor measures the total traffic on a segment and can be
attached on any cable that is not isolated from the rest of the
segment.
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Stations with a single network address that have multiple
adapters installed are difficult to monitor for individual adapter
loading. The Net-Advisor used in the Traffic or Log Mode
provides bandwidth utilization for each independent adapter that
is switched or on a separate segment. This measurement can
identify if additional or faster adapters are required.
Identifying Unused Cable RunsIdentifying Unused Cable Runs
Identifying Unused Cable RunsIdentifying Unused Cable Runs
Identifying Unused Cable Runs
As networks grow and change, cable runs may be
disconnected at the remote end but not removed from the
system. Many wiring closets and patch panels contain unused
cables which waste valuable connection points that could be
reconfigured to meet new requirements. The Net-Advisor used
in the Traffic Mode can quickly identify which cables are inactive
by looking for network activity with the IN bar, the LEDs or the
Audio Mode.
JUNE 1998
TS023A and TS024A
NET-ADVISOR and
NET-ADVISOR RS
DATA CLAMP
CUSTOMER
SUPPORT
INFORMATION
Call our Technical Support Specialists to
discuss your application.
For 24-hour technical support:
Call 724-746-5500 or fax [phone]
To order: Call 724-746-5500
7:00 AM to 8:00 PM EST
Mail Order: Black Box Corporation,
1000 Park Drive, Lawrence, PA 15055-1018
Copyright 1998. Black Box Corporation.
All rights reserved.
1000 Park Drive, Lawrence, PA 15055-1018
724-746-5500 Fax [phone]