Cabletron Systems CSMIM-T1 User manual

CSMIM-T1
SN
1
2
3
4
5
6
7
8
CD TX RX
16
15
14
13
12
11
10
9
MODEM
PORT
STATUS
24
23
22
21
20
19
18
17
1-8 17-24
9-16
MODEM
CONFIG
STATUS
TEST LOS
SYNC
RED BLU
YEL
NETWORK
STATUS/
ALARMS
ON LINE
DROP/INSERT
INTERFACE
T1 NETWORK
INTERFACE
DI SYNC
ETHERNET
STAT S/U
ATTN TRAF
A B C
SET UP
CONSOLE
CSMIM-T1 HARDWARE
INSTALLATION GUIDE

iii
NOTICE
Cabletron Systems reserves the right to make changes in specifications and other
information contained in this document without prior notice. The reader should in all cases
consult Cabletron Systems to determine whether any such changes have been made.
The hardware, firmware, or software described in this manual is subject to change without
notice.
IN NO EVENT SHALL CABLETRON SYSTEMS BE LIABLE FOR ANY
INCIDENTAL, INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES
WHATSOEVER (INCLUDING BUT NOT LIMITED TO LOST PROFITS) ARISING
OUT OF OR RELATED TO THIS MANUAL OR THE INFORMATION CONTAINED
IN IT, EVEN IF CABLETRON SYSTEMS HAS BEENADVISED OF, KNOWN, OR
SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH DAMAGES.
© Copyright April 1997 by:
Cabletron Systems, Inc.
P.O. Box 5005
Rochester, NH 03866-5005
All Rights Reserved
Printed in the United States of America
Order number: 9032222 April 1997
MMAC and CSMIM-T1 are trademarks of Cabletron Systems, Inc.
Annex , Annex Three , Annex3, Remote Annex 6000 and Remote
Annex 6100
are trademarks of Xylogics, Inc.
Portions subject to copyright by Microcom Systems, Inc. 1993-1995.
Used by permission.
All other product names mentioned in this manual may be trademarks or
registered trademarks of their respective companies.

iv CSMIM-T1 Hardware Installation Guide
FCC NOTICE
This device complies with Part 15 of the FCC rules. Operation is subject to the following
two conditions: (1) this device may not cause harmful interference, and (2) this device
must accept any interference received, including interference that may cause undesired
operation.
NOTE : This equipment has been tested and found to comply with the limits for a ClassA
digital device, pursuant to Part 15 of the FCC rules. These limits are designed to provide
reasonable protection against harmful interference when the equipment is operated in a
commercial environment. This equipment uses, generates, and can radiate radio frequency
energy and if not installed in accordance with the operator’s manual, may cause harmful
interference to radio communications. Operation of this equipment in a residential area is
likely to cause interference in which case the user will be required to correct the
interference at his own expense.
WARNING : Changes or modifications made to this device which are not expressly
approved by the party responsible for compliance could void the user’s authority to
operate the equipment.
This equipment complies with FCC Rules Part 68. The FCC Registration Number is
located on the front of the CSMIM-T1.You must provide this information to the telephone
company if requested.
FCC Registration Number
3N9USA-22587-DD-N

CSMIM-T1 Hardware Installation Guide v
Notice to Users ofT1 Service
The following instructions are provided to ensure compliance with the Federal
Communications Commission (FCC) Rules, Part 68.
1.) All direct connections to T1 lines must be made using standard plugs and
jacks.
2.) Before connecting the unit, you must inform the local telephone company
of the following information:
3.) If the unit appears to be malfunctioning, it should be disconnected from the
telephone lines until you learn if your equipment or the telephone line is
the source of the trouble. If your equipment needs repair, it should not be
reconnected until it is repaired.
4.) The CSU/DSU has been designed to prevent harm to the T1 network. If the
telephone company finds that the equipment is exceeding tolerable
parameters, the telephone company can temporarily disconnect service,
although they will attempt to give you advance notice if possible.
5.) Under FCC Rules, no customer is authorized to repair this equipment. This
restriction applies no matter whether the equipment is in or out of warranty.
6.) If the telephone company alters their equipment in a manner that will affect
use of this device, they must give you advance warning so as to give your
company the opportunity for uninterrupted service.You will be advised of
your right to file a complaint with the FCC.
7.) In the event of equipment malfunction, all repairs should be performed by
our company or an authorized agent. It is the responsibility of users
requiring the service to report the need of service to our company or to one
of our authorized agents.
Port ID REN/SOC FIC USOC
CSMIM-T1
(Network Port)
CSMIM-T1 (Drop
and Insert Port)
6.0Y
6.0P(XD)
04DU9-BN
04DU9-DN
04DU9-1KN
04DU9-1ZN
04DU9-1SN
RJ48C
N/A

vi CSMIM-T1 Hardware Installation Guide
Equipment Attachment Limitations
NOTICE:
The Indusrty Canada label identifies certified equipment. This certification
means that the equipment meets certain telecommunications network protective
operational and safety requirements. The Industry Canada does not guarantee the
equipment will operate to the user’s satisfaction.
Before installing this equipment, users should ensure that it is permissible to be connected
to the facilities of the local telecommunications company. The equipment must also be
installed using an acceptable method of connection. In some cases the company’s inside
wiring associated with a single line individual service may be extended by means of a
certified connector assembly (telephone extension cord). The customer should be aware
that compliance with the above conditions may not prevent degradation of service in some
situations.
Repairs to certified equipment should be made by an authorized Canadian maintenance
facility designated by the supplier. Any repairs or alterations made by the user to this
equipment, or equipment malfunctions, may give the telecommunications company cause
to request the user to disconnect the equipment.
Users should ensure for their own protection that the electrical ground connections of the
power utility, telephone lines, and internal metallic water pipe system, if present, are
connected together. This precaution may be particularly important in rural areas.
CAUTION: Users should not attempt to make such connections themselves, but should
contact the appropriate electric inspection authority, or electrician, as appropriate.
The Load Number (LN) assigned to each terminal device denotes the percentage of the
load to be connected to a telephone loop which is used by the device, to prevent
overloading. The termination on a loop may consist of any combination of devices subject
only to the requirement that the total of the Load Numbers of all the devices does not
exceed 100.
Industry Canada Certification Number
2179 6790A
IC NOTICE
This Class A digital apparatus meets all requirements of the Canadian Interference-
Causing Equipment Regulations.
Cet appariel numerique de la classe A respecte toutes les exigences du Reglement sur le
materiel brouilleur du Canada.

CSMIM-T1 Hardware Installation Guide vii
EXCLUSION OFWARRANTY
AND DISCLAIMER OF LIABILITY
1. EXCLUSION OF WARRANTY. Except as may be specifically provided by
Cabletron in writing, Cabletron makes no warranty, expressed or implied, concerning
the Program (including Its documentation and media).
CABLETRON DISCLAIMS ALL WARRANTIES, OTHER THAN THOSE
SUPPLIED TOYOU BY CABLETRON IN WRITING, EITHER EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF
MERCHANTABLITY AND FITNESS FOR A PARTICULAR PURPOSE, WITH
RESPECT TO THE PROGRAM, THE ACCOMPANYING WRITTEN
MATERIALS, AND ANY ACCOMPANYING HARDWARE.
2. NO LIABILITY FOR CONSEQUENTIAL DAMAGES. IN NO EVENT SHALL
CABLETRON OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES
WHATSOEVER (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR
LOSS OF BUSINESS, PROFITS, BUSINESS INTERRUPTION, LOSS OF
BUSINESS INFORMATION, SPECIAL, INCIDENTAL, CONSEQUENTIAL, OR
RELIANCE DAMAGES, OR OTHER LOSS) ARISING OUT OF THE USE OR
INABILITY TO USE THIS CABLETRON PRODUCT, EVEN IF CABLETRON
HAS BEENADVISED OF THE POSSIBILITY OF SUCH DAMAGES. BECAUSE
SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF
LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES, OR ON
THE DURATION OR LIMITATION OF IMPLIED WARRANTEES IN SOME
INSTANCES THEABOVE LIMITATIONS AND EXCLUSIONS MAY NOT
APPLY TOYOU.

viii CSMIM-T1 Hardware Installation Guide

CSMIM-T1 Hardware Installation Guide ix
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION
1.1 General........................................................................................1-1
1.2 Organization of This Document...................................................1-1
1.3 Document Conventions...............................................................1-2
1.4 Getting Help.................................................................................1-3
1.5 CSMIM-T1 Overview...................................................................1-4
1.5.1 Software Information.......................................................1-5
1.6 CSMIM-T1 Front Panel................................................................1-5
1.6.1 Console Port...................................................................1-6
1.6.2 System LED Indicators ...................................................1-7
1.6.3 The SET UP Switch........................................................1-7
1.6.4 T-1 Network Access........................................................1-8
1.6.5 NETWORK STATUS / ALARMS ....................................1-8
1.6.6 Modem Configuration Status LEDs ................................1-9
1.6.7 Modem Port Status LEDs ...............................................1-9
1.6.8 EFS Key Number..........................................................1-10
1.7 Connectivity...............................................................................1-10
1.8 Telco Connection Information....................................................1-10
1.8.1 Connecting the CSMIM-T1 to a Full T-1 Line ...............1-10
1.8.2 Connecting the CSMIM-T1 to a Fractional T-1 Line .....1-11
1.9 Compatibility..............................................................................1-12
1.10 CSMIM-T1 Physical / Statistical Information .............................1-12
CHAPTER 2 INSTALLINGTHE CSMIM-T1
2.1 General........................................................................................2-1
2.2 Locating the Ethernet Jumpers....................................................2-2
2.2.1 Setting the Ethernet Jumpers .........................................2-3
2.2.2 Setting the Subnet Jumper .............................................2-3
2.3 Network Bypass Jumper..............................................................2-4
2.4 Installing the CSMIM-T1..............................................................2-5
2.5 Making Connections....................................................................2-7
2.5.1 Connecting a Console Terminal .....................................2-7
2.5.2 Connecting a T1 Network Interface ................................2-8
2.5.3 Connecting a Drop/Insert Interface.................................2-9
2.6 Power-up and Test......................................................................2-9
2.7 Auto-initializing the ROMs.........................................................2-11
2.7.1 BOOTP .........................................................................2-12
2.7.2 RARP............................................................................2-13
2.8 Software Installation Procedures...............................................2-13

Table of Contents
x CSMIM-T1 Hardware Installation Guide
2.8.1 Invoking the Console Monitor........................................2-15
2.8.2 Self-Booting the CSMIM-T1 ..........................................2-15
2.8.3 Reloading EFS Key Value.............................................2-16
CHAPTER 3 ROM MONITOR COMMANDS
3.1 General ........................................................................................3-1
3.2 Commands...................................................................................3-3
3.2.1 addr.................................................................................3-3
3.2.2 boot .................................................................................3-5
3.2.3 config.............................................................................3-11
3.2.4 console-baud.................................................................3-12
3.2.5 erase .............................................................................3-13
3.2.6 help................................................................................3-14
3.2.7 image.............................................................................3-14
3.2.8 ipx..................................................................................3-15
3.2.9 lat_key...........................................................................3-16
3.2.10 mop ...............................................................................3-17
3.2.11 net .................................................................................3-17
3.2.12 option_key.....................................................................3-18
3.2.13 ping................................................................................3-18
3.2.14 ports ..............................................................................3-19
3.2.15 sequence.......................................................................3-21
3.2.16 slip.................................................................................3-22
3.2.17 stats...............................................................................3-25
CHAPTER 4 CSMIM-T1 PARAMETERS
4.1 General ........................................................................................4-1
4.2 T-1 Commands ............................................................................4-1
4.3 T-1 Parameters............................................................................4-8
4.4 Parameter Descriptions ...............................................................4-9
4.5 Set T-1 Parameters Example.....................................................4-13
CHAPTER 5 TROUBLESHOOTING PROCEDURES
5.1 General ........................................................................................5-1
5.2 Power-Up and Boot Procedures ..................................................5-4
5.2.1 Normal Mode CSMIM-T1 Diagnostics.............................5-4
5.2.1.1 Normal Mode Error-Free Sequence................5-5
5.2.1.2 Normal Mode Error Sequence........................5-6
5.2.2 SET UP Mode .................................................................5-7
5.2.2.1 SETUP Mode Error-Free Sequence...............5-7
5.2.2.2 SETUP Mode Error States..............................5-8
5.3 BOOT Failures.............................................................................5-9

Table of Contents
CSMIM-T1 Hardware Installation Guide xi
5.3.1 Boot Error Report..........................................................5-10
5.3.2 Correcting CSMIM-T1 Parameters ...............................5-13
5.3.2.1 Load Server Host Not Responding...............5-14
5.3.2.2 UNIX Host on the LAN .................................5-14
5.3.2.3 Another CSMIM-T1 ......................................5-15
5.3.2.4 VAX VMS Load Host on the LAN.................5-16
5.4 CSMIM-T1 Dumps....................................................................5-17
CHAPTER 6 MODEM GUIDE
6.1 General........................................................................................6-1
6.2 Features ......................................................................................6-2
6.3 Using the AT Command Set........................................................6-3
6.3.1 Key AT Command Factory Defaults ...............................6-4
6.3.2 Establishing 11-Bit Data Connections ............................6-5
6.3.3 V.32bis Cellular Connections Using AT Commands ......6-6
6.3.3.1 Universal Cellular Setup.................................6-6
6.3.3.2 MNP 10 V.32bis Quick Connect Cellular Only
Setup6-6
6.4 Modulation Protocols...................................................................6-7
6.4.1 Protocol Configuration Command Settings...................6-10
6.4.2 Speed and Protocol Connection Matrices ....................6-11
6.5 Error Correction.........................................................................6-14
6.6 Diagnostics................................................................................6-16
6.6.1 Power-Up Diagnostics ..................................................6-16
6.6.2 Local Analog Loopback with Self-Test..........................6-16
6.6.3 Local Analog Loopback ................................................6-17
6.6.4 Remote Digital Loopback with Self-Test.......................6-17
6.6.5 Remote Digital Loopback..............................................6-18
6.6.6 Local Digital Loopback..................................................6-18
6.6.7 Respond to Remote Digital Loopback ..........................6-19
6.6.8 Automatically Terminating a Test: Register S18...........6-19
6.7 Result Codes.............................................................................6-20
6.7.1 Connection Result Code Tables...................................6-20
CHAPTER 7 AT COMMANDS AND REGISTERS
7.1 The Command Set ......................................................................7-1
7.1.1 Entering Commands.......................................................7-1
7.1.1.1 Issuing AT Commands at any Speed.............7-2
7.2 Commands..................................................................................7-2
7.2.1 Operating Mode Dial Modifiers .......................................7-9
7.3 Registers ...................................................................................7-41
7.3.1 Commands to Change or Read Registers....................7-41

Table of Contents
xii CSMIM-T1 Hardware Installation Guide
APPENDIX A PORT PIN/SIGNAL ALLOCATIONS
A.1 General ....................................................................................... A-1
A.2 Console Port ............................................................................... A-1
A.3 Interface Ports.............................................................................A-2
A.4 Additional Cabletron Cables and Connectors............................. A-3

CSMIM-T1 Hardware Installation Guide 1-1
CHAPTER 1
INTRODUCTION
1.1 GENERAL
Welcome to the Cabletron Systems’
CSMIM-T1 Hardware Installation
Guide
. This guide provides procedures for the installation of the
CSMIM-T1 into the Cabletron Systems Multi Media Access Center
(MMAC), as well as information on configuring your communications
server to load its operational software. Please read through this manual to
familiarize yourself with the content and to gain an understanding of the
features of the product.
This manual assumes that you have some understanding of networking,
remote access, T1, and telephony technology.
Please note that this manual covers installation and initial configuration
instructions only. Software instructions are provided in the
document set
provided with the software package.
This guide provides instructions for installation and testing of the
CSMIM-T1. ROM monitor commands, troubleshooting and diagnostic
procedures are also provided.
1.2 ORGANIZATION OFTHIS DOCUMENT
•Chapter 1, Introduction, describes the hardware features and
firmware functions.
•Chapter 2, Installing the CSMIM-T1, provides installation, power
up, and booting procedures.
•Chapter 3, ROM Monitor Commands, describes the ROM Monitor
commands that modify specific configuration parameters, perform
diagnostic tests, and load the operational code.
•Chapter 4, CSMIM-T1 Parameters, providesT1-specific commands
and parameters.

Chapter 1: INTRODUCTION
1-2 CSMIM-T1 Hardware Installation Guide
•Chapter 5, Troubleshooting Procedures, provides Troubleshooting
and diagnostic information.
•Chapter 6, Modem Guide, describes modem features and setup.
•Chapter 7, AT Commands and Registers, provides a listing of
modem commands and parameters.
•AppendixA ,Port/PinSignalAllocations, detailstheCSMIM-T1 port
pinouts, and cabling information.
1.3 DOCUMENT CONVENTIONS
The following conventions are used throughout this document:
NOTE
Note symbol. Calls the reader’s attention to any item of
information that may be of special importance.
!
CAUTION
Caution symbol. Contains information essential to avoid
damage to the equipment.
Electrical Hazard Warning symbol.Warns against an action
that could result in personal injury or death due to an electrical
hazard.

Getting Help
CSMIM-T1 Hardware Installation Guide 1-3
1.4 GETTING HELP
If you need additional support related to this device, or if you have any
questions, comments, or suggestions concerning this manual, contact
Cabletron Systems Technical Support:
Before calling Cabletron Systems Technical Support, have the following
information ready:
• A description of the failure
• A description of any action(s) already taken to resolve the problem
(e.g., changing mode switches, rebooting the unit, etc.)
• A description of your network environment (layout, cable type, etc.)
• Network load and frame size at the time of trouble (if known)
• The serial and revision numbers of all Cabletron Systems products in
the network
• The device history (i.e., have you returned the device before, is this a
recurring problem, etc.)
• Any previous Return Material Authorization (RMA) numbers
Phone [phone]
Monday – Friday; 8
A . M . – 8 P . M . Eastern Time
CompuServe GO CTRON from any ! prompt
Internet mail [email protected]
FTP ctron.com (134.141.197.25)
Login
anonymous
Password your email address
BBS [phone]
Modem setting 8N1: 8 data bits, 1 stop bit, No parity
For additional information about Cabletron Systems products, visit our
World Wide Web site: http://www.cabletron.com/

Chapter 1: INTRODUCTION
1-4 CSMIM-T1 Hardware Installation Guide
1.5 CSMIM-T1 OVERVIEW
The CSMIM-T1 is a dual-slot, Annex Software compatible system
designed to reside in the MMAC series of hubs. The module takes the
existing CSMIM2 core and adds enhanced processing power in the form
of dual 486SXLC2-40 clock doubled processors. Both the main and
secondary processors have been upgraded, which allows the main
processor to control the MMAC network interfaces, while the second
controls the serial ports. These processors have access to a minimum of
4 MB DRAM (standard), but may be upgraded to 8 MB through the
installation of SIMM modules. This memory is shared between the
processors, and arbitrated on a cycle by cycle basis.
Extensive power up diagnostics are provided to confidence check the
system prior to the loading of application software. A Console Port is
used for system setup, booting, and diagnostic purposes. After booting,
the Console Port is idle. System boot is accomplished either from a UNIX
host, a VAX VMS host, or an optional Flash PROM. If you are operating
from Flash only, be aware that host based services such as security are
not
supported. If you have any questions, contact Cabletron Technical
Support.
It should be mentioned that although the CSMIM-T1 is capable of
running in a Novell environment, it will not boot from a Novell server. In
a Novell environment, the module must be booted either from a UNIX
server, or from Flash.
There are 24V.34 modems in the CSMIM-T1.Access for the T-1 network
is provided by a single RJ48C connector on the front panel. Data received
from the T-1 network is either moved through the CSMIM-T1 module and
onto the Ethernet backplane, or fed back out through the Drop and Insert
Interface on the front panel. An example of this would be connecting the
Drop and Insert Interface to a PBX for voice applications.

CSMIM-T1 Front Panel
CSMIM-T1 Hardware Installation Guide 1-5
1.5.1 Software Information
The CSMIM-T1 is shipped to our customers with software that provides
network access to the following networks:
• Novell Netware (IPX)
• UNIX (TCP/IP)
• Macintosh (AppleTalk)
Refer to the software document set for a description of the supported
software features.
In addition to the standard software package, the CSMIM-T1 software
distribution includes a number of T-1 specific commands and parameters
that are used for configuration and administration. Refer to Chapter 4,
CSMIM-T1 Parameters for a description.
1.6 CSMIM-T1 FRONT PANEL
The CSMIM-T1 LED indicators provide the user with feedback on
system activity. Each port connector has an associated LED to indicate
activity on the receive data line. Several other LEDs indicate network
activity, port and connection status, modem status, and diagnostic
information. Refer to Figure 1-1.

Chapter 1: INTRODUCTION
1-6 CSMIM-T1 Hardware Installation Guide
Figure 1-1 CSMIM-T1 Front Panel
1.6.1 Console Port
The Console Port is used for system setup and diagnostic purposes only.
A single RJ45 connector is used to connect a VT terminal and access the
command set. After booting, the console port is inactive.
CSMIM-T1
SN
1
2
3
4
5
6
7
8
CD TX RX
16
15
14
13
12
11
10
9
MODEM
PORT
STATUS
24
23
22
21
20
19
18
17
1-8 17-24
9-16
MODEM
CONFIG
STATUS
TEST LOS
SYNC
RED BLU
YEL
NETWORK
STATUS/
ALARMS
ON LINE
DROP/INSERT
INTERFACE
T1 NETWORK
INTERFACE
DI SYNC
ETHERNET
STAT S/U
ATTN TRAF
A B C
SET UP
CONSOLE

CSMIM-T1 Front Panel
CSMIM-T1 Hardware Installation Guide 1-7
1.6.2 System LED Indicators
There are 7 indicators to show system activity and status.
ATTN
The amber Attention LED is on when the module requires operator
attention, and flashes when a problem is detected.
STAT
The green Status LED is ON after the module passes the core power-up
diagnostics. This LED also flashes while the module is in a reset state.
TRAF
The green Traffic LED flashes when the module successfully transmits or
receives data over the MMAC Ethernet backplane channel.
S/U
When the green SET UP LED is ON steady, the module is in the SET UP
mode and the user can input configuration data via the console port prior
to booting the operational software.
When the module is in the RESET mode (press and hold the SET UP
button for 3 seconds) the green LED will flash while the CSMIM-T1
executes power up diagnostics.
Ethernet Channel Indicators
There are three green LEDs that indicate the Ethernet channel
(A, B, or C) that is selected by either the software or by jumper
configuration.
1.6.3 The SET UP Switch
The SET UP Switch allows the user to change the operational mode of the
module from normal to set up. When the module powers up, it
automatically enters the normal mode. To enter the SET UP mode, the
SET UP switch must be depressed within 30 seconds of power-up. When
the S/U LED lights, the unit is in the SET UP mode.
Depressing the SET UP Switch at any time for approximately three
seconds causes the module to enter a RESET state. This is the equivalent
of a reboot. The green S/U LED will flash while the unit executes power
up diagnostics, and the SET UP mode can be entered.

Chapter 1: INTRODUCTION
1-8 CSMIM-T1 Hardware Installation Guide
1.6.4 T-1 Network Access
There are two ports on the front panel that allow access to the T-1
network. The T-1 Network Interface Port is an 8-pin, RJ48C port that
provides access for the digital T-1 line. The Drop/Insert Interface is also
an 8-pin, RJ48C port, and provides connection to a local Private Branch
Exchange (PBX), or other equipment, such as an ETWMIM equipped
with a T-1 interface.
In addition to these ports, there are 8 Status LEDs that provide the user
with valuable information regarding the T-1 network.
DI SYNC
The green DI SYNC LED is ON when the T-1 engine is detecting frame
synchronization on the Drop and Insert Interface. The LED is off when
there is a Loss of Frame (LOF) synchronization.
An LOF condition causes the T-1 engine to transmit all unframed ones
(keep alive signal) to the device attached to the Drop and Insert Interface.
ON LINE LED
The green ON LINE LED is ON when the T-1 engine is connected to the
network interface.
1.6.5 NETWORK STATUS / ALARMS
TEST - NetworkTest
This red indicator is ON when the T-1 engine network interface is placed
into a test loopback condition. Loopback tests are activated either locally
by the user, or by the telco provider.
SYNC - Synchronized
This green indicator is ON when the T-1 engine is properly synchronized
with the network signal and is receiving proper framing information.
LOS - Loss of Signal
This red indicator is ON when the T-1 engine is detecting no signal
(pulses) on the network interface receiver. When a LOS condition exists
the T-1 engine transmits unframed all ones (Alarm Indication Signal) to
the network.