PairGain HIGAIN HRU-412 User manual

HIGAIN REMOTE UNIT
Model List Number Part Number CLEI Code
HRU-412 9 150-1103-09 T1L2CCKAAA
PAIRGAIN TECHNOLOGIES, INC.
ENGINEERING SERVICES TECHNICAL PRACTICE
SECTION 150-412-109-01
Revision History of this practice.
July 9, 1997
A) Initial Release

Section 150-412-109 July 9, 1997 Revision 01
Page ii PairGain Engineering - Plant Series HiGain HRU-412
Copyright 1997 PairGain Technologies, Inc.
PairGain is a registered trademark, and HiGain is a trademark of PairGain Technologies, Inc.

Revision 01 July 9, 1997 Section 150-412-109
HiGain HRU-412 PairGain Engineering - Plant Series Page iii
TABLE OF CONTENTS
A. PRODUCT OVERVIEW................................................................................................................ 1
1. Description and Features................................................................................................... 1
2. Specifications.................................................................................................................... 6
3. Theory of Operation.......................................................................................................... 7
4. Applications...................................................................................................................... 8
5. Local and Line Powering .................................................................................................. 8
B. INSTALLATION............................................................................................................................ 9
6. Inspecting Your Shipment................................................................................................. 9
7. HRU-412 Card Edge Pin-Out Diagram ............................................................................ 10
8. User Options on the HRU-412 Backplane ........................................................................ 11
9. Installing the HRU-412.................................................................................................... 13
10. Connecting to a Dumb Terminal .................................................................................... 14
C. USING THE MAINTENANCE/REMOTE TERMINAL............................................................. 16
11. Using the Maintenance/Remote Terminal Menus........................................................... 16
12. Maintenance/Remote Terminal Main Menu ................................................................... 17
13. View Span Status...........................................................................................................19
14. Set Clock ....................................................................................................................... 24
15. System Settings.............................................................................................................. 25
16. View Performance Data ................................................................................................. 27
17. View Performance History............................................................................................. 30
18. View Alarm History....................................................................................................... 33
19. Remote Logoff............................................................................................................... 36
D. PERFORMANCE MONITORING............................................................................................... 37
20. Basic Features................................................................................................................ 37
21. Supplemental Test Indicators ......................................................................................... 37
22. Loopback Design Description ........................................................................................ 40
23. Loopback Test Procedures ............................................................................................. 42
E. PRODUCT SUPPORT .................................................................................................................. 44
24. Technical Support..........................................................................................................44
25. PairGain Warranty ......................................................................................................... 44
26. Certification................................................................................................................... 44
F. ABBREVIATIONS AND GLOSSARY ......................................................................................... 45
27. Abbreviations and Glossary............................................................................................ 45

Section 150-412-109 July 9, 1997 Revision 01
Page iv PairGain Engineering - Plant Series HiGain HRU-412
USING THIS TECHNICAL PRACTICE
Three types of messages, identified by icons, appear in the text:
A note informs you of special circumstances.
A caution indicates the possibility of equipment damage.
A warning indicates the possibility of personal injury.

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HiGain HRU–412 PairGain Engineering - Plant Series Page 1
A. PRODUCT OVERVIEW
1. Description and Features
1.1 This technical practice describes the PairGain
®
HiGain  HRU-412 List 9, a HiGain Remote Unit
(HRU) which functions as the remote end of a repeaterless T1 transmission system. When used with
HiGain Line Units (HLUs) and HiGain Doubler Units (HDUs), the HiGain system provides 1.544
Mbps on two unconditioned copper pairs over the full Carrier Service Area (CSA) range. This
practice describes using the HRU-412 with and without HiGain Doubler Units (HDUs).
1.2 Figure 1 shows a basic HiGain configuration for a T1 High-bit-rate Digital Subscriber Line (HDSL)
circuit. The HLU is installed at the Central Office (CO) shelf and the HRU is housed in a remote
enclosure at the Customer Premises Equipment (CPE) site. Optional HDUs provide the ability to
double or even triple the distance range for customer applications located outside the CSA.
Figure 1. Typical HiGain System
1.3 Section C describes using the Maintenance Terminal Main menu for non-doubler applications and
the Remote Terminal menus for doubler applications.
1.4 Standards compliance. The HiGain system uses HDSL transmission technology as
recommended by Bellcore TA-TSY-001210. HiGain complies with:
•ANSI T1E1.4, T1.403-1989 and 1995, and T1E1.4/92-00R2R technical standards and
recommendations
•TR-TSY-000063 Network Equipment Building System (NEBS) Generic Equipment
requirements
•TR-TSY-000499 Transport System Generic Requirements (TSGR) common requirements

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Page 2 PairGain Engineering - Plant Series HiGain HRU–412
1.5 HRU-412 List 9 features:
•Front panel:
– CPE current monitor test points
– Receive (RCV) and Transmit (XMT) access jacks for testing
– DS1 and HDSL status LEDs
– HDSL margin threshold indicator
– RS-232 console port for connection to a maintenance terminal
•Performs Super Frame (SF)/Extended Super Frame (ESF) conversion

ANSI T1.403 Performance Report Messages (PRMs)

Supplemental Performance Report Messages (SPRMs), Alarm Indication Signal-Customer
Interface (AIS-CI), and Remote Alarm Indicator-Customer Interface (RAI-CI) per
T1E1.4/92-00R2R
•ANSI T1.403 DS1 Customer Interface (CI)
•Generic and addressable repeater loopback activation codes
•Provisioning switches for Interface-Customer Premises Equipment (I-CPE) current, Super
Frame-Remote Alarm Indication (SF-RAI) signal, and Receive Level (RLEV) for the T1 output
signal
•Line or local power options
•Optional sealing current
•Lightning and power cross protection on HDSL and DS1 interfaces
•784 kbps full-duplex 2-Bits-1-Quaternary (2B1Q) HDSL Transmission on 2 pairs
•DS0 blocking
•Compatible with PairGain 1 x 1 Protection Switching System
The Transmit Loss of Signal Loopback (TLOS-LB) option in the HRU-412 List 8 has
been replaced by the SF-RAI option. This option controls the generation of an
SF-RAI signal in response to an ESF-RAI message.

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1.6 Front Panel. Figure 2 and Table 1 identify the HRU-412 front panel components. Table 2
describes the functions of the front panel components and Table 3 describes how to read the different
system status conditions indicated by the LEDs.
Figure 2. HRU-412 Front Panel
Table 1. HRU-412 Front Panel Components
Name Function
Test points Provides 60 mA MON (monitor) test points (see Table 2).
RCV and XMT Access Jacks Provides splitting and monitor access jacks to the CPE DS1 interface (see Table 2).
Alarm LEDs Shows alarm states (see Tables 2 and 3).
Loopback LEDs Shows loopback states (see Tables 2 and 3).
Loopback button Provides the ability to perform loopback test procedures (see Section 23).
Code LEDs Provides indications for line code options (see Tables 2 and 3).
Framing LEDs Provides indications for framing patterns (see Table 2 and 3).
RS-232 connector Confi
g
ured as Data Circuit-Terminatin
g
E
q
ui
p
ment (DCE) which allows
y
ou to control
the HRU-412 through a dumb terminal (or a PC with terminal emulation software).
HDSL LEDs Displays HDSL Loop 1 and Loop 2 Conditions (see Tables 2 and 3).
Card Handle Handle used to remove the HRU-412 from the remote enclosure.

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Page 4 PairGain Engineering - Plant Series HiGain HRU–412
Table 2. HRU-412 Front Panel Component Functions
Name Function
Test points 60 mA MON (monitor) test points which allow the 60 mA CPE current option, if selected, to be
measured. The current flowing is related to the voltage measured across the "+" and "-" test points by
the following relationship:
CPE current =1 mA / 1 mV. Typical readings range from 55 to 65 mV which equate to a 55 to 65 mA
current range.
RCV and
XMT Access
Jacks
Splitting and monitor access jacks to the CPE DS1 interface. See Figure 3 for circuit details. These
jacks are transformer-isolated from the CPE DS1 metallic interface:
CI: Customer Interface, LINE: Line Interface, MON: Monitor Interface
ALM LEDs Remote and Local Loss Of Signal (LOS).
REM LOS Displays remote (REM) LOS.
LOC LOS Displays local (LOC) LOS.
LB LEDs Loopback to/from the NET (Network) and to/from the Customer Interface (CI)
NET Displays NET loopback state.
CI Displays CI loopback state.
Loopback
(LB) button Activates the remote unit metallic loopback state by pressing the button for five (5) seconds. The unit can be unlooped by either pressing the button again for five seconds or via the standard loopdown coded
messages.
CODE LEDs Indications for code options.
B8ZS Indicates that the DS1 line code option is set to Bidirectional 8-Zero substitution (B8ZS).
AMI Indicates that the user DS1 line code option is set to Alternate Mark Inversion (AMI).
BPV Indicates that a Bipolar Violation (BPV) is received at the remote’s DS1 input.
FRM LEDs Indications for framing patterns.
ESF Displays ESF framing.
SF Displays SF framing.
ERR Framing error.
RS-232
connector Provides bi-directional communication between the unit and an external dumb terminal through an RS-232 interface to allow configuration and performance monitoring through the Maintenance Terminal
menus. See Section 10 for operating procedures.
HDSL LEDs Displays HDSL Loop 1 and Loop 2 Conditions
LP1 (Loop 1)
OK Displays synchronization state for HDSL Loop 1.
MAR Indicates that the Signal-to-Noise (S/N) margin has dropped below the margin threshold value.
ES Indicates at least one HDSL Cyclic Redundancy Check (CRC) error is detected from the upstream
module.
LP2 (Loop 2)
OK Displays synchronization state for HDSL Loop 2.
MAR Indicates that the S/N margin has dropped below the margin threshold value.
ES Indicates at least one HDSL CRC error is detected from the upstream module.

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Table 3. Reading the HRU-412 Front Panel LEDs
Name Mode Description
REM LOS Steady red LOS detected at the T1 input to the remote HLU unit. This condition causes the
HRU to transmit the AIS pattern towards the CPE.
Off Normal transmission of data.
LOC LOS Steady red LOS detected at the T1 input to the local HRU unit. This condition causes an
AIS-CI signal to be transmitted towards the customer and an AIS-CI signal to
be sent to the DSX-1 from the HLU. This state is not sent to the HLU and does
not register an LOS ALRM condition.
Off Normal transmission of data.
NET Steady green The HRU is in a loopback state in which the signal from the NET is being
looped back to the NET.
Off No NET loopbacks are active.
CI Steady yellow The HRU is in a loopback state in which the signal from the CI is being looped
back to the CI.
Off No CI loopbacks are active.
B8ZS Steady green DS1 line code option set to B8ZS. If however the user DS1 line code option is
set to Auto, LED indicates that the code of the DS1 signal being received at the
HRUs DS1 input is B8ZS.
AMI Steady yellow DS1 line code option set to AMI. If the user DS1 line code option is set to
Auto, LED indicates that the code of the DS1 signal being received at the HRUs
DS1 input is AMI.
BPV Blinking red Blinks every time a BPV, other than those associated with a B8ZS code, is
received at the HRUs DS1 input.
ESF Steady green Indicates that framing pattern of the signal being received at the HRUs DS1
input is ESF.
SF Steady yellow Indicates that framing pattern of the signal being received at the HRUs DS1
input is SF.
ERR Steady red Indicates a DS1 frame error has occurred.
LP1
OK Blinking green HDSL Loop 1 is synchronizing with the HLU.
Steady green HDSL Loop 1 is synchronized and ready to receive and transmit data.
MAR Blinking yellow Indicates a problem in Loop 1 (doubler applications only) of the HDSL cable
pairs that are non-adjacent to the HRU. Blinking once per second indicates a
Loss of Sync Word (LOSW) problem in Span 1’s Loop 1 HDSL pair between
the HLU and doubler. Blinking twice per second indicates a LOSW problem in
Span 2’s Loop 1 HDSL pair between the first and second doublers.
ES Blinking red Blinks every second in which at least one HDSL CRC error is detected on Loop
1 from the upstream module.
LP2
OK Blinking green HDSL Loop 2 is synchronizing with the HLU.
Steady green HDSL Loop 2 is synchronized and ready to receive and transmit data.
MAR Blinking yellow Indicates a problem in Loop 2 (doubler applications only) of the HDSL cable
pairs that are non-adjacent to the HRU. Blinking once per second indicates a
LOSW problem in Span 2’s Loop 2 HDSL pair between the HLU and doubler.
Blinking twice per second indicates a LOSW problem in Span 2’s Loop 2
HDSL pair between the first and second doublers.
ES Blinking red Blinks every second in which at least one HDSL CRC error is detected on Loop
2 from the upstream module.

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2. Specifications
Physical
Material...................................................... Steel
Finish..........................................................Zinc plated
Mounting.................................................... Any standard 400 mechanics shelf
Dimensions
Height......................................................... 5.6 in. (14.22 cm)
Width .........................................................1.4 in. (3.55 cm)
Depth..........................................................5.6 in. (14.22 cm)
Weight........................................................1 lb., 2 oz.
Power
Consumption ..............................................6 W (with I-CPE set to 0)
8 W (with I-CPE set to 60)
Maximum Provisioning Loss ...................... 35 dB at 196 kHz, 135 Ω
Electrical Protection ................................... Secondary surge and power cross protection on all DS1 and
HDSL ports
Environment
Operating Temperature............................... - 40 to + 65ºC
Operating Humidity.................................... 5 to 95% non-condensing
HDSL
Line Code...................................................784 kbps 2B1Q full duplex
Output ........................................................+13 dB ± 0.5 dB @ 135 Ω
Line Impedance..........................................135 Ω
Line DC resistive signature......................... 14 Ω
Startup Time............................................... 15 seconds (typical)
60 seconds (maximum)
DS1
Line Impedance..........................................100 Ω
Pulse Output............................................... 0 dB (RLEV = 0), -15 dB (RLEV = 15)
Input Level................................................. > 22.5 dB
Line Rate....................................................1.544 Mbps ± 200 bps
Output Wander (MTIE and TVAR) ............Compliant with Section 7.2.1 of the T1X1.3/90-026R7 SONET
Committee Report
Line Format................................................AMI, B8ZS, or ZBTSI
Frame Format............................................. ESF, SF or unframed
Line Clock Rate
Internal Stratum 4 clock

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3. Theory of Operation
3.1 HiGain utilizes 2B1Q HDSL transceiver systems to establish two full-duplex 784 kbps data channels
between the HLU and a remotely-mounted HRU-412. This provides a total capacity of 1.568 Mbps
between the two units. A block diagram of the HRU-412 is shown in Figure 3.
Figure 3. HRU-412 List 9 Block Diagram
3.2 The HRU-412 power supply converts the 90 to 130 Vdc power feed that is received on the simplex
pairs (or the -48V input when locally powered) to voltages and currents required by the HRU-412
circuitry. The power supply generates +5, -5 and 30 Vdc outputs. The 30 Vdc output is converted to
a 60 mA current feed used to simplex power the Network Interface Device (NID).
Caution should be used when the HRU is used to power Channel Service Units
(CSUs). Some CSUs require more output voltage than the 30 Vdc provided by
the HRU. The HRU cannot power both a NID and a CSU at the same time.
3.3 The HRU-412 typically dissipates 6 W of power with the I-CPE backplane switch set to 0, and 8 W
with the I-CPE backplane switch set to 60 (see section 8.1).

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4. Applications
4.1 The HiGain system provides a cost-effective, easy-to-deploy method for delivering T1 service over a
single metallic pair. Conventional in-line T1 repeaters are not required. Cable pair conditioning,
pair separation and bridged tap removal are not required.
4.2 General guidelines require that the loop has less than 35 dB of loss at 196 kHz, with 135 ohms
driving and terminating impedances. Table 4 provides a guide for the loss of various cable gauges at
196 kHz and 135 ohms. The table applies to the HDSL cable pairs between the HLU, HRU and
HDU modules. Without specific insertion loss measurement data, add 3 dB for each bridged tap and
1 dB for each cable gauge change.
Table 4. HDSL Loss Over Cables
Cable Gauge Loss at 196 kHz (dB/kft) Ohms per kft
26/0.4 mm 3.88 83
24/0.51 mm 2.84 52
22/0.61 mm 2.18 32
19/0.91 mm 1.54 16
4.3 HiGain systems:

Operate with any number of other T1, Plain Old Telephone Service (POTS), or other HiGain
systems sharing the same cable binder group.

Can be used with customers requiring T1 service on a temporary or permanent basis.

Provide a means of quickly deploying service in advance of fiber-optic transmission systems.

Are easily installed allowing service to be provided within hours. Fiber optic systems can be
installed at a leisurely pace and cut-over from the installed HiGain system when convenient to
do so. The installed HiGain system can then be easily removed and utilized elsewhere.
5. Local and Line Powering
5.1 The HRU-412 List 9 can be line or local powered. The unit always uses the local -48 V power
source if it is present, and defaults to line power in the absence of local power. List 6 and higher
versions of the HLU-231, all versions of the HLU-319 and HLU-388, and versions 6.4 and above of
the HLU-231 List 1, 2, 3, 3A and 4 units automatically turn off their line power supply when
connected to a locally powered HRU-412 List 9. The earlier versions of the HLU-231 (Lists 1, 2, 3,
3A and 4) must first have their PWRF user option set to Disable to work with a locally powered
HRU-412 List 9 unit.
The HRU-412 List 9 does not support three-span line powering.
5.2 When locally powered, the HRU-412 List 9 also provides from 20 mA (short loop) to 30 mA (long
loop) of simplex sealing current toward all versions of the HLU over the two HDSL pairs. Jumper
JP2 allows this sealing current to be enabled or disabled. See Section 8.1 for further information.

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5.3 The simplex sealing current is not compatible with the List 1, 2, or 3 HDU-451 doublers. These
doublers block the flow of simplexed sealing current. The HDU-451 List 4 must be used with the
HRU-412 List 9 to provide a path through which the simplexed sealing current can flow.
5.4 If local power is lost to the HRU in a non-doubler or a single doubler circuit, the system loses
synchronization. When the HLU or HDU attempts to re-acquire synchronization, it detects that the
HRU is not locally powered and applies line power to it. If local power is lost to the HRU in a two
doubler application, the circuit is permanently down since the HLU cannot provide line power to the
HRU in circuits with two doublers.
5.5 The -48V local power supply must have a 125 mA output current capacity (6 W) to power each
HRU-412 when the I-CPE option is set to 0. The -48 V local power supply must have a 175 mA
output current capacity (8 W) to power each HRU-412 whose I-CPE option is set to 60 mA.
5.6 A Teltrend WPS-2005 Wall-Mount Power Supply, or equivalent, is capable of powering two
HRU-412 units (with the I-CPE option switch set to 0 mA) or one unit (with the I-CPE option switch
set to 60 mA). Each unit provides spade lugs to access the -48 V output.
You can reach Teltrend at: 1 (800) TEL-TREN.
B. INSTALLATION
6. Inspecting Your Shipment
6.1 When you receive the equipment, inspect it for signs of damage. If the equipment has been damaged
in transit, immediately report the extent of damage to the transportation company and to PairGain.
6.2 Your shipment should consist of:
•One HRU-412 List 9
•This document

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7. HRU-412 Card Edge Pin-Out Diagram
7.1
The HRU-412 occupies one slot in a remote enclosure. The card edge pin-out diagram for the
HRU-412 is shown in Figure 4.
Figure 4. HRU-412 Card Edge Pin-outs

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8. User Options on the HRU-412 Backplane
8.1 The HRU-412 has four user options that must set before you install the unit into a shelf or enclosure.
Three of these options are set by using manual switches and the fourth (sealing current) is set using
jumper JP2. These options are located on the backplane of the unit as shown in Figure 5.
HiGain systems also have several special loopback (SPLB) options that are set
at the HLU. Refer to the specific technical practice for the HLU used in your
configuration for more details.
Figure 5. Backplane User Option Locations

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Page 12 PairGain Engineering - Plant Series HiGain HRU–412
8.2 Sealing Current (SCURR). The two-prong male JP2 jumper allows you to disable or enable the
sealing current. The default is disable. To set the sealing current, do one of the following:

To enable the sealing current, connect JP2 across both terminals using the supplied female
jumper block header.

To disable the sealing current, remove the jumper block header from both terminals and insert it
on the outer terminal for future use.
This simplexed sealing current is polarity sensitive and does not flow if the
two HDSL loops adjacent to the HRU are reversed. Reversed loops are
indicated by a Channel Reverse (CHREV) message in the Alarms line of the
Span Status Maintenance screen shown in Section 13.
8.3 I-CPE. The I-CPE switch allows you control the current settings for the interface at the customer
premises equipment. The default is 0. To set the I-CPE, do one of the following:

To set the CPE current to 0 mA, move the I-CPE switch to 0.

To set the CPE current to 60 mA, move the I-CPE switch to 60.
The CPE current control signals terminate on pins 32 and 34 of the card-edge
converter. These access pins are provided for factory test only and must never
be used. Older single slot HRE-421 remote enclosures and the HRE-427 seven-
slot enclosure use the pins to control the CPE options in older HRU units.
These enclosures must be optimized from 0-CPE current to prevent a conflict
between external connections to pins 32 and 34 and the settings of the I-CPE
switch.
8.4 SF-RAI. The SF-RAI switch allows you to enable or disable the generation of an SF-RAI signal in
response to an ESF-RAI message. The default is disable. To set the SF-RAI, do one of the
following:

To enable the SF-RAI signal activation, (which occurs in response to an ES-RAI message and
which in turn transmits an SF-RAI Yellow Alarm to the CI), move the switch to ENA. All three
of the following conditions must be met:
– The signal from the network must be ESF.
– The signal from the network must contain the RAI Yellow Alarm Bit-patterned message in the
facility data link.
– The signal being transmitted to the CI must be SF.
If one, two or all of the conditions listed above are not met, the SF-RAI signal activation cannot
be enabled.

To disable the SF-RAI signal activation, move the switch to DIS.
8.5 RLEV. The RLEV switch allows you to control the configuration of the T1 Receive Level (RLEV).
The default is 0. Setting RLEV to 0configures the T1 output signal level from the HRU towards the
Network Interface (NI) to 0 dB. This setting is recommended when the HRU does not function as
the NID but is connected to an external NID, and allows the external NID to set the appropriate NI
level. Setting RLEV to -15 configures the T1 RLEV to -15 dB, and sets the T1 output signal level
from the HRU towards the NI level to -15 dB. This setting is recommended when the HRU functions
as the NID. To set the RLEV do one of the following:

To set the T1 output signal level to O dB, move the RLEV switch to 0.

To set the T1 output signal level to -15 dB, move the RLEV switch to 15.

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9. Installing the HRU-412
9.1 The HRU-412 mounts in PairGain HiGain Remote Enclosures (HREs) and in any industry standard
400 mechanics shelves.
9.2 To install the HRU-412 (Figure 6):
1Set the user options as described in Section 8.
2Slide the HRU-412 into the card guides for the desired slot, then push the unit into the enclosure
until it touches the backplane card edge connector.
Figure 6. HRU-412 Installed in a Remote Enclosure
3Push the unit into the card edge connector until it is entirely within the card guide, indicating
that the unit is properly seated.

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Page 14 PairGain Engineering - Plant Series HiGain HRU–412
10. Connecting to a Dumb Terminal
10.1 The 9-pin RS-232 connector on the front of the HRU-412 allows you to connect your system to a
dumb terminal or PC running a terminal emulation program with a standard RS-232 cable. Once
connected to a dumb terminal, you can access the view-only Maintenance/Remote Terminal menus
(the Set Clock option is the only user-configurable option on the HRU-412). Figure 7 shows the
HRU-412 DB-9 RS-232 I/O.
Figure 7. DB-9 RS-232 I/O

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10.2 The dumb terminal is configured as DCE. To connect the HRU-412 to a dumb terminal, connect the
RS-232 COM port of the dumb terminal to the HRU-412 front-panel RS-232 connector using a serial
interface cable (Figure 8).
Figure 8. Connecting the HRU-412 to a Dumb Terminal

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Page 16 PairGain Engineering - Plant Series HiGain HRU–412
C. USING THE MAINTENANCE/REMOTE TERMINAL
11. Using the Maintenance/Remote Terminal Menus
11.1 This section covers both the Maintenance Terminal menus (for non-doubler applications) and the
Remote Terminal menus (for doubler applications). The screens for either application are identical,
except for the Set Clock option which is set from the Maintenance Terminal menu only. After you
have connected the HRU-412 to a dumb terminal, you must configure the dumb terminal to the
following communication settings.
•1200 to 9600 baud (9600 baud is recommended)
•Parity: None
•8 data bits
•1 stop bit
•Hardware Flow Control set to None
•VT Terminal Emulation
If using the Microsoft Windows terminal emulation program, from the Settings,
Terminal Preference menu, you must deselect
Show Scroll Bars
and
Use
Function, Arrow, and Ctrl Keys for Windows.
11.2 Navigating the Maintenance/Remote Terminal menus. Table 5 describes keys you can use
on the dumb terminal’s keyboard to navigate within the Maintenance/Remote Terminal menus.
Table 5. Dumb Terminal Navigational Keys
Key Function
<Enter> Logs into the Remote Terminal menus
<E> Exits the current menu
<U> Updates a report
<S> Selects the next Span Status screen
<P> Selects the previous page of a report
<N> Selects the next page of a report
11.3 Selecting an Option. The Maintenance/Remote Terminal menus use two different means of
selecting an option:

Press the key indicated to the left of the selection.

Press the letter in parenthesis of the parameter to be changed.