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Current issue : #52 | Release date : 1998-01-26 | Editor : route
| Introduction | Phrack Staff |
| Phrack Loopback | Phrack Staff |
| Line Noise | various |
| Phrack Prophile on o0 | Phrack Staff |
| Everything a hacker needs to know about getting busted | Agent Steal |
| Hardening the Linux Kernel | daemon9 |
| The Linux pingd | daemon9 |
| Steganography Thumbprinting | unknown |
| On the Morality of Phreaking | Phrack Staff |
| A Quick NT Interrogation Probe | twitch |
| Subscriber Loop Carrier | voyager |
| Voice Response Systems | voyager |
| Pay Per View (you don't have to) | cavalier |
| The International Crime Syndicate Association | D. Demming |
| Digital Certificates | Yggdrasil |
| Piercing Firewalls | bishnu |
| Protected mode programming and O/S development | mythrandir |
| Weakening the Linux Kernel | plaguez |
| Phrack World News | disorder |
| extract.c | Phrack Staff |
Title : Subscriber Loop Carrier
Author : voyager
---[ Phrack Magazine Volume 8, Issue 52 January 26, 1998, article 11 of 20
-------------------------[ The Subscriber Loop Carrier (slick)
--------[ Voyager[TNO]
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
I............................................... Overview
II.............................................. The Central Office Terminal
III............................................. The Remote Terminal
IV.............................................. SLC-2000 Shelves
V............................................... Where might you find an RT?
VI.............................................. SLC Interface Software
VII............................................. SLC Glossary
VIII............................................ SLC Vendors
+----------+
| Overview |
+----------+
A Subscriber Loop Carrier (SLC) (often pronounced "slick") is a
multiplexer which allows a large number of analog lines to be provided
over a very small number of digital lines. A good example is the AT&T
SLC 5, which allows 192 subscriber loops to be provided through two or
four digital lines. SLCs are also referred to as Digital Loop Carriers
(DLCs).
The first SLC was installed in 1971. As of 1995, between 5 and 10% of
all lines are served by SLCs, as are roughly 50% of all new lines built
each year. SLCs are available from quite a few vendors. This article
focuses on the extremely popular SLC-2000 from AT&T.
A SLC usually consists of two separate subsystems, the Central Office
Terminal (COT) and the Remote Terminal (RT). The COT is connected to
the RT via a DS1 circuit. The DS1 circuit may be carried over actual T1
lines, or it may be carried over another medium such as lightwave or
digital radio. The RT is then connected to the subscribers using a
Voice Frequency (VF) circuit. The VF circuit is what you and I would
recognize as our normal phone line.
This diagram illustrates a subscriber loop constructed using an SLC:
+---------+
| | /---------\
| Central | +----+ /-----------\
| Office | | |
| | --- DS1 circuit --- | RT | --- VF circuit -- | Residence |
| (COT) | | | | |
| | +----+ +-----------+
+---------+
+-----------------------------+
| The Central Office Terminal |
+-----------------------------+
The SLC-2000 COT is a modular design usually consisting of the following
components:
. Access Resource Manager (ARM) shelf
. Metallic Distribution Assembly (MDS) shelves
. Heat Baffles
. Alarm and Test Unit (ATU)
+--------------------------+
| | | | | | | | | | <------- Alarm and Test Unit
|--------------------------|
| | | <------- Heat baffle
|--------------------------|
||||||||||||||||||||||||||||
|:::::::::::::::::::;::;:::| <--\
|--------------------------| \___ Access Resource Manager (ARM) shelf
|:;;;;;;::;::::::::||||||||| /
|.##||||.|,,,,,,,,,........| <--/
|.##||||' '''''''''|||||||||
|--------------------------|
| | | <------- Heat baffle
|--------------------------|
|!!!!!!!!!!^^||^^!!!!!!!!!!| <------- Metallic Distribution Shelf (MDS)
|!!!!!!!!!!^^||^^!!!!!!!!!!|
|--------------------------|
|!!!!!!!!!!^^||^^!!!!!!!!!!| <------- Metallic Distribution Shelf (MDS)
|!!!!!!!!!!^^||^^!!!!!!!!!!|
|--------------------------|
| | | <------- Heat baffle
|--------------------------|
|!!!!!!!!!!^^||^^!!!!!!!!!!| <------- Metallic Distribution Shelf (MDS)
|!!!!!!!!!!^^||^^!!!!!!!!!!|
|--------------------------|
|!!!!!!!!!!^^||^^!!!!!!!!!!| <------- Metallic Distribution Shelf (MDS)
|!!!!!!!!!!^^||^^!!!!!!!!!!|
+--------------------------+
+---------------------+
| The Remote Terminal |
+---------------------+
The SLC-2000 RT is a modular design usually consisting of the following
components:
. Access Resource Manager (ARM) shelf
. Metallic Distribution Assembly (MDS) shelves
. High Density Fiber Optics Shelf (HDOS) shelves (FITL only)
. Cooling fans
An SLC-2000 RT configured for a Metallic Application
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+--------------------------+
| | | <------- Fan unit
|--------------------------|
||||||||||||||||||||||||||||
|:::::::::::::::::::;::;:::| <--\
|--------------------------| \___ Access Resource Manager (ARM) shelf
|:;;;;;;::;::::::::||||||||| /
|.##||||.|,,,,,,,,,........| <--/
|.##||||' '''''''''|||||||||
|--------------------------|
|!!!!!!!!!!^^||^^!!!!!!!!!!| <------- Metallic Distribution Shelf (MDS)
|!!!!!!!!!!^^||^^!!!!!!!!!!|
|--------------------------|
|!!!!!!!!!!^^||^^!!!!!!!!!!| <------- Metallic Distribution Shelf (MDS)
|!!!!!!!!!!^^||^^!!!!!!!!!!|
|--------------------------|
|!!!!!!!!!!^^||^^!!!!!!!!!!| <------- Metallic Distribution Shelf (MDS)
|!!!!!!!!!!^^||^^!!!!!!!!!!|
|--------------------------|
|!!!!!!!!!!^^||^^!!!!!!!!!!| <------- Metallic Distribution Shelf (MDS)
|!!!!!!!!!!^^||^^!!!!!!!!!!|
+--------------------------+
An SLC-2000 RT configured for a Fiber In The Loop (FITL) Application
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+--------------------------+
| | | <------- Fan unit
|--------------------------|
||^||^||^||^||^||^||^||^||^| <------- High Density Optics Shelf (HDOS) #2
||^||^||^||^||^||^||^||^||^|
|--------------------------|
||^||^||^||^||^||^||^||^||^| <------- High Density Optics Shelf (HDOS) #1
||^||^||^||^||^||^||^||^||^|
|--------------------------|
| | | <------- Fan unit
|--------------------------|
||||||||||||||||||||||||||||
|:::::::::::::::::::;::;:::| <--\
|--------------------------| \___ Access Resource Manager (ARM) shelf
|:;;;;;;::;::::::::||||||||| /
|.##||||.|,,,,,,,,,........| <--/
|.##||||' '''''''''|||||||||
|--------------------------|
| | | | ||||| | | | | | <-------- Metallic Distribution Shelf (MDS) #4
| | | | ||||| | | | | |
|--------------------------|
| | | | ||||| | | | | | <-------- Metallic Distribution Shelf (MDS) #3
| | | | ||||| | | | | |
|--------------------------|
| | | | ||||| | | | | | <-------- Metallic Distribution Shelf (MDS) #2
| | | | ||||| | | | | |
|--------------------------|
| | | | ||||| | | | | | <-------- Metallic Distribution Shelf (MDS) #1
| | | | ||||| | | | | |
+--------------------------+
+------------------+
| SLC-2000 Shelves |
+------------------+
The SLC-2000 is divided into a number of shelves, each of which hold
circuit cards that are responsible for specific functions within the
SLC. Some shelves are found only in COTs, others are found only in
RTs, while most shelves are used in both COTs and RTs.
Access Resource Manager (ARM) Shelf
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The ARM shelf provides feeder interface, bandwidth management and
circuit maintenance features.
The ARM shelf consists of the following functional component groups:
. User Interface Panel (UIP)
. Integrated Test Head (ITH)
. Provisioning Display Controller (PDC)
. Bandwidth Management Complex
. DS1 distribution
. DS1/VT feeder interfaces
. SONET feeder
The following diagram illustrates the functional components of an ARM shelf:
/<-- ESD ground jack
|/<-- Power Converter Unit
|| /<-- Transmission Signaling Unit
|| | /<-- Analog Measurement Unit
|| | | /<-- Power Amplifier Unit
|| | | | /<-- Craft Access Unit
|| | | | | /<-- System Memory Unit
|| | | | | | /<-- Provisioning and Display Controller
|| | | | | | | /<-- Link to Alarm and Networks
|| | | | | | | | /<-- DS1 interfaces
|| | | | | | | | |
+----------------------------------------------------+
|^ |
|----------------------------------------------------|
||P|T| |A|P|C|S|P| |L|D|D|D|D|D|D|D|D|.|.|.|.|.|.|.|.|
||C|S| |M|A|A|M|D| |A|S|S|S|S|S|S|S|S|---------------|
||U|U| |U|U|U|U|C| |N|1|1|1|1|1|1|1|1| | | | | | | | |
||.|.|.|.|.| |.|.|.|.|.|.|.|.|.|.|.|.| | | | | | | | |
|------------------------------------+ | | | | | | | |
|| | | | | | | | | | | | | | | | | | | | | | | | | | | <-\
/-> || | | | | | | | | | | | | | | | | | | | | | | | | | | |
| ||.|:|:|:|:|:|:|.|.|:|.|.|.|.|.|.|.|.|:|:|:|:|:|:|:|:| |
| ||.|.|.|.|.|.|.|.|.|.|.|.|.|.|.|.|.|.| | | | | | | | | |-\
/-| |------------------------------------+ | | | | | | | | | |
| | || |o|o| | | | | ||| | | | | | | | | |---------------| | |
| | ||.|o|o| | | | | |:|:|:|:|:|:|:|:|:|:|.|.|.|.|.|.|.|.| | |
| \-> ||.| | | | | | | | |:|:|:|:|:|:|:|:|:| | | | | | | | | >-/ |
| ||.| | | | | | | | | | | | | | | | | | | | | | | | | | |
| +----------------------------------------------------- |
| | | | | | | | | | |
| \ / \ \ / / | | \-- Test Head Controller (THC) |
| | \ / | \-- System Controller (SYSCTL) |
| | | \-- Overhead Controller (OHCTL) |
| | \-- STS-1 Multiplexer (MXRVO) |
| \--- Optical Line Interface Unit (OLIU) |
\-- Synchronous Timing Generator (TGS) |
Bandwidth Management Complex --/
The User Interface Panel (UIP) represents the highest level of
interaction possible with the SLC-2000 without plugging some other
piece of equipment into it. Here is a close-up of the User Interface
Panel:
Abnormal -->\
AMD (Alphanumeric Message Display) -->\ NE Activity >--\ |
Attention -->\ | Major -->\ | |
Panel Fault -->\ | | Critical -->\ | | |
/<-- ESD ground jack | | | | | | |
| | | | | | | |
+------------------------------------------------------------------------+
| | ~=~ ~~~ ~~ ~~ ~~~~~~ | __ ____________________ __ __ __ __ |
| O |________/----------------| |/ |* User Int. Panel | |/ |/ |/ |/ |
| | | __ ~~~~~~~~~~~~~~~~~~~~ __ __ __ __ |
| | = = ooo #### ## :::::: | |/ ^v # # # o# # |/ |/ |/ |/ |
+------------------------------------------------------------------------+
||| ||| | | |||||| | | | | | | | | | | |
||| \|/ | | |||||| | | | | | | | | | | |
\|/ | | | |||||| | | | | | | | | | | |
| | | | |||||| | | | | | | | | | | |
Fuses-->/ | | | |||||| | | | | | | | | | | |
Power test | | | |||||| | | | | | | | | | | |
points -->/ | | |||||| | | | | | | | | | | |
CIT connector -->/ | |||||| | | | | | | | | | | |
DDS clock conn. -->/ |||||| | | | | | | | | | | |
DDS Maintenance Jack -->/||||| | | | | | | | | | | |
DS0 Maintenance Jack -->/|||| | | | | | | | | | | |
DS1 Maintenance Jack -->/||| | | | | | | | | | | |
T-R Maintenance Jack -->/|| | | | | | | | | | | |
T1-R1 Maintenance Jack -->/| | | | | | | | | | | |
E&M Maintenance Jack -->/ | | | | | | | | | | |
Power -->/ | | | | | | | | | |
Scroll Buttons ->/ | | | | | | | | |
Enter -->/ | | | | | | | |
Escape -->/ | | | | | | |
LED Test -->/ | | | | | |
ACO -->/ | | | | |
Update -->/ | | | |
Minor -->/ | | |
Power Minor ->/ | |
FE Activity -->/ |
Session -->/
There are many connections on the UIP. The Electrostatic Discharge
(ESD) ground jack is for a static control wrist strap. The Craft
Interface Terminal (CIT) connector is a DB-25 for plugging in a CIT or a
PC running terminal emulation software. The DDS clock connector
provides a clock source for test sets. The Power Test Points allow you
to monitor the -48v power to the unit.
There are many LED's on the UIP. The Attention LED is yellow when the
there is something new on the Alphanumeric Message Display (AMD). The
Panel Fault LED is red when the UIP is in need of repair. The Power LED
is green when -48v power is present. The Power Minor LED is yellow when
the system is operating on battery power. The Alarm Cut Off (ACO) LED is
green when the ACO button has been pressed during an alarm. The
Critical LED is red when a failure has caused a loss of service for 128
or more customers. The Major LED is red when a failure has caused a
loss of service for 24 or more customers. The Minor LED is yellow when
an error exists, but is not causing a loss of service to any customers.
The Near End (NE) Activity LED is yellow when the local terminal has
some alarm condition. The Far End (FE) Activity LED is yellow when the
remote terminal has some alarm condition. The Abnormal LED is yellow
when the SLC-2000 is not in a mode that provides service, such as a test
mode. The Session LED is yellow when a technician has a CIT connected to
the remote terminal.
The most interesting part of the UIP is the Alphanumeric Message Display
(AMD) and the buttons associated with its use. The AMD displays a
single 24 character line of text. The scroll buttons may be pushed to
move forward and backward through various menu choices. The <Enter> and
<Escape> keys work just as you might imagine.
Three types of messages appear on the User Interface Panel (UIP):
. Automatic Messages
. Fault Messages
. Alarm Messages
Automatic Messages are triggered by pressing certain buttons,
UIP or PDC unavailability, and SYSCTL installation.
Fault Messages are displayed when the RETRIEVE-FAULTS command is
selected on the UIP.
Alarm Messages are displayed when the RETRIEVE-ALARMS command is
selected on the UIP.
The Automatic Messages are:
. PANEL FAULT
. MN:NE:pdc unavail
. UPDATE: In-Progress
. UPDATE: done
. SONET SUBSYS UPDATE done
. SYSCTL INITIALIZATION
. SYSCTL EXTENDED INITZN
. SYSCTL EXTND INITZN done
. STATUS -LOCAL SONET
. STATUS -LOCAL SONET SITE
. STATUS -REMOTE SITE 1
. STATUS -REMOTE SITE 2
. STATUS -REMOTE SITE 3
. STATUS -REMOTE SITE 4
. STATUS -REMOTE SITE 5
. STATUS -REMOTE SITE 6
. STATUS -REMOTE SITE 7
. STATUS -REMOTE SITE 8
"PANEL FAULT" indicates that the User Interface Panel (UIP) has
failed and is unable to communicate with the Provisioning
Display Controller (PDC).
"MN:NE:pdc unavail" indicates that the Provisioning Display
Controller (PDC) is unable to communicate with the User
Interface Panel (UIP) because it has failed, or because software
installation on the PDC is in progress.
"UPDATE: In-Progress" indicates that the UPDATE button has been
pressed and that an update is in progress. (See "Update button"
below.)
"UPDATE: done" indicates that an Update has been completed in
response to the use of the UPDATE button.
"SONET SUBSYS UPDATE done" indicates that an Update has been
completed in the SONET subsystem in response to the use of the
UPD/INIT button on the SYSCTL.
"SYSCTL INITIALIZATION" appears for 10 seconds after a SYSCTL
with working software has been inserted. If the UPD/INIT button
on the SYSCTL is pressed while this message is displayed, the
SYSCTL will reset all SONET parameters to their factory
defaults.
"SYSCTL EXTENDED INITZN" appears after SYSCTL INITIALIZATION has
been completed.
"SYSCTL EXTND INITZN done" appears after SYSCTL EXTND INITZN has
been completed.
"STATUS -LOCAL SONET" indicates the User Interface Panel (UIP)
indicators reflect the alarm status of the local system only.
The letter "L" is displayed in the SYSCTL 7-segment display.
This occurs when the user toggles the Far-End Select (FE SEL)
button on the SYSCTL.
"STATUS -LOCAL SONET SITE" indicates the User Interface Panel
(UIP) indicators reflect the combined alarm status of all the
SONET network elements at the local site. The SITE ID and a '.'
is displayed in the SYSCTL 7-segment display. This occurs when
the user toggles the Far-End Select (FE SEL) button on the
SYSCTL.
"STATUS -REMOTE SITE x" indicates the User Interface Panel (UIP)
indicators reflect the alarm status of REMOTE SITE x. The
number "x" is displayed in the SYSCTL 7-segment display. This
occurs when the user toggles the Far-End Select (FE SEL) button
on the SYSCTL.
There are several other miscellaneous buttons on the UIP. The LED Test
button lights up all of the LED's to allow quick identification of burnt
out LED's. The Alarm Cut Off (ACO) button shuts off the current alarm
condition. The Update button operates much like the "Detect New
Hardware" icon in Windows95, except that on the SLC-2000 it never locks
up your system.
Metallic Distribution Shelf (MDS)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The MDS provides control and distribution for Data Service 0 (DS0) and
Fiber In The Loop (FITL) interfaces.
The following diagram roughly illustrates an MDS shelf assembly in a
metallic configuration:
+-----------------------------------------------------------------------+
|* AT&T ##== ##== ##== ##== ##== ##== Metallic Distribution Shelf |
|-----------------------------------------------------------------------|
|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|
| :| :| :| :| :| :| :| :| :| *| *| *| *| *| *| :| :| :| :| :| :| :| :| :|
| :| :| :| :| :| :| :| :| :| *| *| | | *| *| :| :| :| :| :| :| :| :| :|
|=:|=:|=:|=:|=:|=:|=:|=:|=:| | | | | | |=:|=:|=:|=:|=:|=:|=:|=:|=:|
|=:|=:|=:|=:|=:|=:|=:|=:|=:| *| | | | | *|=:|=:|=:|=:|=:|=:|=:|=:|=:|
| || || || || || || || || || || || || || || || || || || || || || || || ||
|!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||
|-----------------------------------------------------------------------|
|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|~~|
| :| :| :| :| :| :| :| :| :| *| *| *| *| *| *| :| :| :| :| :| :| :| :| :|
| :| :| :| :| :| :| :| :| :| *| *| | | *| *| :| :| :| :| :| :| :| :| :|
|=:|=:|=:|=:|=:|=:|=:|=:|=:| | | | | | |=:|=:|=:|=:|=:|=:|=:|=:|=:|
|=:|=:|=:|=:|=:|=:|=:|=:|=:| *| | | | | *|=:|=:|=:|=:|=:|=:|=:|=:|=:|
| || || || || || || || || || || || || || || || || || || || || || || || ||
|!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||!||
+-----------------------------------------------------------------------+
MDS upper and lower shelves are numbered from bottom to top. On the
left and right side of each shelf half are 12 channel units (only 9 are
pictured in the ASCII diagram). In the middle of each shelf half are
the common units.
The following diagram roughly illustrates an MDS shelf assembly in a
Fiber In The Loop (FITL) configuration:
+-----------------------------------------------------------------------+
|* AT&T ##== ##== ##== ##== ##== ##== Metallic Distribution Shelf |
|-----------------------------------------------------------------------|
|AT&T|AT&T|AT&T|AT&T| |~~|~~|~~|~~|~~|~~|AT&T|AT&T|AT&T|AT&T| |
|* |* |* |* | | *| *| *| *| *| *|* |* |* |* | |
|* |* |* |* | | *| *| | | *| *|* |* |* |* | |
|* |* |* |* | | | | | | | |* |* |* |* | |
|* |* |* |* | | *| | | | | *|* |* |* |* | |
| || | || | || | || | | || || || || || || || | || | || | || | |
| || | || | || | || | |!||!||!||!||!||!|| || | || | || | || | |
|-----------------------------------------------------------------------|
|AT&T|AT&T|AT&T|AT&T| |~~|~~|~~|~~|~~|~~|AT&T|AT&T|AT&T|AT&T| |
|* |* |* |* | | *| *| *| *| *| *|* |* |* |* | |
|* |* |* |* | | *| *| | | *| *|* |* |* |* | |
|* |* |* |* | | | | | | | |* |* |* |* | |
|* |* |* |* | | *| | | | | *|* |* |* |* | |
| || | || | || | || | | || || || || || || || | || | || | || | |
| || | || | || | || | |!||!||!||!||!||!|| || | || | || | || | |
+-----------------------------------------------------------------------+
High Density Fiber Optics Shelf (HDOS)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The HDOS interfaces between the electrical signals on the MDSs and
optical signals on the Multi-Services Distant Terminals (MSDTs).
The following diagram roughly illustrates an HDOS assembly:
+-------------------------------------------------------------------+
|~~|~~|~~|~~|AT&T|~~|~~|~~|~~|AT&T|~~|~~|~~|~~|AT&T|~~|~~|~~|~~|AT&T|
|~~|~~|~~|~~| |~~|~~|~~|~~| |~~|~~|~~|~~| |~~|~~|~~|~~| |
| | | | | .| | | | | .| | | | | .| | | | | .|
| | | | | | | | | | | | | | | | | | | | |
| | | | | | | | | | | | | | | | | | | | |
|OU|OU|OU|OU| |OU|OU|OU|OU| |OU|OU|OU|OU| |OU|OU|OU|OU| |
| || || || || || || || || || || || || || || || || || || || ||
| || || || ||PCU|| || || || ||PCU|| || || || ||PCU|| || || || ||PCU||
|-------------------------------------------------------------------+
| ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ |
|-------------------------------------------------------------------+
|1 AMP FUSES -------> == == == == == == == == |
+-------------------------------------------------------------------+
Note: An HDOS contains 8 Optical Unit (OU) / Power Conversion Unit (PCU)
packs, not 4 as shown in the ASCII diagram.
Alarm and Test Unit (ATU)
~~~~~~~~~~~~~~~~~~~~~~~~~
The ATU panel reports alarms and trouble indicators using audible
alarms, visual indicators, and telemetry. In addition, the ATU provides
interfaces to the Pair Gain Test Controller (PGTC) and DC bypass pair
connections.
An ATU panel looks roughly like this:
+---------------------------------------------------------------------+
| | | | | | | | | | * * |
| | | | | | | | | | * * |
| | | | | | | | | | * * |
+---------------------------------------------------------------------+
Here is a close-up of the indicator lights on the far right end of the
ATU:
+--------------+
| __ __ |
Fault ---> | |/ |/ | <-- Critical
| |
| __ __ |
Busy ---> | |/ |/ | <-- Major
| |
| __ __ |
Power Minor ---> | |/ |/ | <- Minor
| |
+--------------+
Fan Units and Heat Baffles
~~~~~~~~~~~~~~~~~~~~~~~~~~
Fan units are used in RTs to provide cooling, while COTs use heat
baffles for the same purpose.
The fan unit looks in an RT looks something like this:
+-----------------------------------------------------------------------+
|*AT&T .| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
| ~* ~~| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
|~~ o ~~| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
| o ~~| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
|~ o ~~| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
| .| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
|~o | ============= |
+-----------------------------------------------------------------------+
A close-up of the far left end of the fan unit looks like this:
+------------------------+
| *AT&T o |
| +----------+ |
| FAULT * | CHANGE | |
| | FAN | |
|+--------+ SPEED | |
||LED O (10 MIN. | |
||TEST TIMEOUT)| |
|+-------------------+ |
| 10 - - 212 |
| + O 8 - - 176 |
| 6 - - 140 |
| TEMP 4 - - 104 |
| 2 - - 68 |
| - O 0 - - 32 |
| V F |
| C=10 * V |
| ESD o |
| ORD O |
+------------------------+
+-----------------------------+
| Where might you find an RT? |
+-----------------------------+
RTs are found in quite an interesting variety of enclosures, including
metal and cast concrete. Some are only large enough to hold the RT,
while others are environmentally controlled and large enough to hold the
equipment and several working technicians.
. 44A + 44B Cabinets
. WP-91071 Cabinet
. 51A cabinet
. 80D Cabinet (Community Service Vault)
. 80E Cabinet (Community Service Vault)
. Mini hut
. Maxi hut
. Concrete hut
. Controlled Environment Vault (CEV)
The 44A Cabinet is a wall mounted cabinet that requires a 44B Cabinet
to house the powering equipment.
WP-91071 Cabinet is a stand alone cabinet.
The 51A cabinet is 48" high by 29" wide by 20.5" deep. The 51A cabinet
consists of three sections: the front door, the electronics section,
and the battery section. The front door is hinged on the left and
opens to reveal the electronics section. The electronics section is
also hinged on the left, and opens to reveal the battery section.
The 80D Cabinet (Community Service Vault).
The 80E Cabinet (Community Service Vault).
The Mini hut is a prefabricated 6' by 10' by 8' high enclosure.
The Maxi hut, also known as the Electronic Equipment Enclosure (EEE) is
a prefabricated 10' by 20' by 8' high environmentally controlled
enclosure.
The Concrete Hut is 13' 2" by 7' 7 and 8' 8.5" high. The walls of the
Concrete Hut are made of precast concrete and are 4" thick. The inside
of the Concrete Hut is ventilated, heated and air conditioned. The
Concrete Hut is protected by intrusion alarms, smoke alarms, and high
temperature alarms.
The Controlled Environment Vault (CEV) is a precast concrete enclosure
designed for installation below ground. The CEV is cast in three parts:
the bottom half, the top half, and the entrance hatch. The entrance to
a CEV shows a ladder leading down into the enclosure. The CEV is the
ultimate in environmental control. In addition to ventilation, heating
and optional air conditioning, the CEV also features a gas monitor that
senses explosive and toxic gasses, a dehumidifier, and a sump pump. The
CEV is lit by four fluorescent lamps backed up by an emergency lamp. The
CEV is protected by a gas alarm, a high temperature alarm, a
high-humidity alarm, a power-loss alarm, a high-water alarm and an
intrusion alarm.
+--------------------------------------------------------------+
| Enclosure | Systems | Dual Channel Banks | Lines |
|------------------+---------+--------------------+------------+
| 44A+44B Cabinets | 2 | 1 | 192 |
| WP-91071 Cabinet | 4 | 2 | 394 |
| 51A Cabinet | 2 | 1 | 192 |
| 80D Cabinet | 4 | 2 | 384 |
| 80E Cabinet | 8 | 4 | 768 |
| Concrete Hut | 32(36) | 16(18) | 3072(3456) |
| CEV (16') | 40(44) | 20(22) | 3840(4224) |
| CEV (24') | 60(78) | 30(39) | 5760(7488) |
| EEE | 72(78) | 36(29) | 6912(7488) |
+--------------------------------------------------------------+
Note: Number in parenthesis are applicable only to systems using bulk power.
+------------------------+
| SLC Interface Software |
+------------------------+
+--------------+
| SLC Glossary |
+--------------+
A&M Addition and Maintenance
ACO Alarm Cut Off
ACU Alarm Control Unit
ACXT Apparatus Case Crosstalk
ADPCM Adaptive Differential Pulse Code Modulation
ADU Alarm Display Unit
AIU Alarm Interface Unit
ALBO Automatic Line Build Out
ALC Automatic Loss Compensation
ALIT Automatic Line Insulation Test
AMD Alphanumeric Message Display
ANI Automatic Number Identification
ASN Abstract Syntax Notation
ASU Alarm Suppressor Unit
ATU Alarm and Test Unit
AWC Average Worst Case
B-E Both-Ends
B8ZS Bipolar with 8 Zero Substitution
BCU Bank Controller Unit
BFU Bank Fuse Unit
BIU Backplane Interface Unit, Bank Interface Unit
BMP Bandwidth Management Processor
CAU Craft Access Unit, Channel Access Unit
CCITT International Telephone and Telegraph Consultative Committee
CCS Hundred Call Seconds
CDO Community Dial Office
CDS Circuit Design System
CENTREX Central Office Exchange Service
CEV Controlled Environment Vault
CFU Channel Fuse Unit
CIMAP Circuit Installation and Maintenance Package
CIR Customer Information Release
CIT Craft Interface Terminal
CIU Craft Interface Unit
CLC Common Language Coordinator
CLEI Common Language Equipment Identification
CLF Carrier Line Failure
CLLI Common Language Location Identification
CLRC Circuit Layout Record Card
CMC Construction Management Center
CMIS Common Management Information System
CND Calling Number Delivery
CO Central Office
COACH Customized On-line Aid for Customer Help
CODEC Coder/Decoder
COE Central Office Engineer
COT Central Office Terminal
CP Circuit Pack
CPC Circuit Provisioning Center
CPI Circuit Party Identification
CRC Cyclic Redundancy Check, Circuit Redundancy Code
CSA Carrier Serving Area
CSC Community Service Cabinet
CSDC Circuit Switched Digital Capability
CSPEC Common Systems Planning and Engineering Center
CSS Controlled Slip Second
CTB Cut Through Board
CTU Channel Test Unit
CU Channel Unit
CUE Channel Unit Emulator
CV Coding Violation
CWG Construction Work Group
CZ Carrier Zone
DA Distribution Area
DACS Digital Access Cross-connect System
DCC Data Communications Channel
DCLU Digital Carrier Line Unit
DCU Digital Connectivity Units
DDF Digital Digroup Formatter
DDS Digital Data Service
DF Distributing Frame
DFI Digital Facilities Interface
DID Direct Inward Dial
DILEP Digital Line Engineering Program
DLC Digital Loop Carrier
DLI Data Link Interface
DLP Detailed Level Procedure
DLR Design Layout Record
DLS Digital Line Schematic
DLU Data Link Unit
DM Degraded Minute
DPO Dial Pulse Originating
DPT Dial Pulse Terminating
DPX DATAPATH Extension
DR Demand Repeater
DS0 Digital Signal 0, Data Service 0
DS0DP Digital Signal 0 Dataport
DS1 Digital Signal 1 (1.544 MB/s)
DSDC Distribution Services Design Center
DSL Digital Subscriber Line
DSNE Directory Services Network Element
DSPC Distribution Services Planning Center
DST Digital Signal Translator
DSU Data Service Unit
DSX Digital Service Cross-connect
DT Distant Terminal
DTU Digital Test Unit
E Ear
EASOP Economic Alternative Selection for Outside Plant
ECCR Exchange Customer Cable Record
EEC Electronic Equipment Enclosure
EEC Equipment Engineering Center
EFPA Enhanced Feature Package A
EFPB Enhanced Feature Package B
EFPC Enhanced Feature Package C
EFPD Enhanced Feature Package D
EFRAP Exchange Feeder Route Analysis Program
EJO Engineering Job Order
ELIU Electrical Line Interface Unit
EMO Expected Measured Loss
EOC Embedded Operations Channel
ES Errored Seconds
ESD ElectroStatic Discharge
ESF Extended Super Frame
ESPORTS Extended Super POTS
EWC Extreme Worst Case
EWO Engineering Work Order
FA Feeder Administration
FAC Facility Assignment and Control Center
FACS Facility Assignment and Control System
FAP Facility Analysis Plan
FCS Frame Checking Sequence
FCU Fan Control Unit
FDI Feeder Distribution Interface
FDL Facility Data Link
FE Far End
FELP Far End LooP
FEMF Foreign Potential
FEXT Far End Crosstalk
FITL Fiber In The Loop
FL Fault Locating
FLTA Fault Locate Test Adapter
FPA Feature Package A
FPB Feature Package B
FPC Feature Package C
FPD Feature Package D
FPS Framing Pattern Sequence
FSM Fiber Service Module
FSR Frequency Selective Ringing
FSS Fiber Service Shelf
FTTH Fiber To The Home
FX Foreign Exchange
FXO Foreign Exchange Office
FXS Foreign Exchange Station
GNE Gateway Network Element
GS Ground Start
HDIC High Density Interconnect
HDOS High Density Optics Shelf
HDT Host Digital Terminal
HTR Heater
IBN Integrated Business Network
IDCU Integrated Digital Carrier Unit
IDF Intermediate Distributing Frame
INA Integrated Network Access
IOP Input/Output Processor
ISD Isolation Diagram
ISDN Integrated Services Digital Network
ISLU Integrated Services Line Unit
ITH Integral Test Head
LAC Loop Assignment Center
LAN Link to Alarm and Networks
LBO Line Build Out
LBRV Low Bit Rate Voice
LCRIS Loop Cable Record Inventory System
LDS Local Digital Switch
LDU Load Distribution Unit
LEC Loop Electronic Coordinator
LED Light Emitting Diode
LFACS Loop Facility Assignment and Control System
LFC Line Feeder Converter
LFU Line Fuse Unit
LIC Lightguide Interconnect Cable
LIT Line Insulation Test
LIU Line Interface Unit
LM Loop Multiplexer
LMOS Loop Maintenance Operating System
LOF Loss Of Frame
LOS Loss Of Second
LP Low Power
LRAP Long Route Analysis Program
LRD Long Route Design
LROPP Long Range Outside Plant Plan
LRT Local Remote Terminal
LS Loop Start
LSI Line Side In
LSO Line Side Out
LSS Loop Switching System
LSU Line Switching Unit
LT Line Terminal
LTC Local Test Cabinet
LTD Local Test Desk
M Mouth
MC Maintenance Center
MCC Master Control Center
MD Manufacture Discontinued
MDF Main Distributing Frame
MDS Metallic Distribution Shelf
MH Man Hole
MIU Metallic Interface Unit, Maintenance Interface Unit
MJ Major
MLT Mechanized Loop Testing
MM Material Management
MN Minor
MPP Miscellaneous Pair Panel
MR Meter Reading
MSDT Multi-Services Distant Terminal
MTS Message Telephone Service
MVEC Majority Vote Error Correction
MWC Maintenance Work Center
MWG Maintenance Work Group
MWI Message Waiting Indication
MXU Multiplexer Unit
NAB Network Alarm Bus
NAIU Network Access Interface Unit
NCTE Network Channel Terminating Equipment
NE Near End
NEXT Near End Crosstalk
NIDB Network Interface Data Bus
NIU Network Interface Unit
NM New Manhole
NMA Network Monitoring and Analysis
NPA Numbering Plan Area
NT Network Termination
NTEC Network Terminal Equipment Center
NTP Non Trouble-Clearing Procedure
OCU Office Channel Unit
OCUDP Office Channel Unit Dataport
OHCTL Overhead Controller
OHT On-hook Transmission
OIC Optical Interconnect
OIU Office Interface Unit
OLIU Optical Line Interface Unit
ONI Operator Number Identification
ONU Optical Network Unit
OOS Out Of Service
OPE Outside Plant Engineer
OPS Off Premise Station
OPS/INE Operations System/Intelligent Network Element
ORB Office Repeater Bay
OSP Outside Plant
OSPE Outside Plant Engineer
OTU Office Timing Unit
OU Optical Units
OW Order Wire
PAM Pulse Amplitude Modulation
PAU Power Amplifier Unit
PBX Private Branch Exchange
PCM Pulse Code Modulation
PCU Power Converter Unit
PDC Provisioning Display Controller
PG Pair Gain
PGD Pair Group Display
PGP Pair Group Planning
PGS Pair Gain System
PGTC Pair Gain Test Controller
PIC Polyethylene Insulated Conductor
PICS Plug-in Inventory Control System
PMN Power Minor
PMO Present Mode of Operation
POTS Plain Old Telephone Service
PRU Positive Ringing Unit
PTAB Port Test Alarm Bus
PU Power Unit
PWB Printed Wiring Board
R&R Remove and Reinstall
RCU Ring Control Unit
RCVG Receiving
RDES Remote Data Entry System
REN Ringer Equivalency Number
RLS Repeater Location Schematic
RMU Remote Measurement Unit, Remote Maintenance Unit
ROS Remote Operations Service
RPFT Remote Power Feed Terminal
RSB Repair Service Bureau
RSM Remote Switching Module
RT Remote Terminal
RTS Remote Test System
RTU Remote Test Unit
RZ Resistance Zone
S&E Service and Equipment
S-E Signal-End
S/I Signal to Interference
S/N Signal to Noise
S1DN Stage One Distributing Network
S1DP Stage One Distributing Panel
SAI Serving Area Interface
SARTS Switched Access Remote Testing System
SB Signal Battery
SCC Switching Control Center
SCCS Switching Control Center System
SCEC Secondary Channel Error Correction
SDDF Subscriber Digital Distributing Frame
SDFI Subscriber Digital Facility Interface
SDH Synchronous Digital Hierarchy
SDX Subscriber Digital Crossconnect
SEFS Severely Errored Framing Second
SES Severely Errored Seconds
SF Super Frame
SFIU Switching Facility Interface Unit
SG Signal Ground
SID System IDentification
SLC Subscriber Loop Carrier
SLIM Subscriber Line Interface Module
SM Switching Module
SMAS Switched Maintenance Access System
SMU System Memory Unit
SO Service Order
SONET Synchronous Optical Network
SP Standard Power, Special Protection
SPGM Suburban Pair Gain Planning
SPGPM Suburban Pair Gain Planning Method
SPOTS Special Plain Old Telephone Service
SPR Superimposed Ringing
SPTS Signaling Path Test Set
SSC Special Service Center
SSP Special Service Protection
SSU Special Service Unit
STIU Switching Transmission Interface Unit
STM Span Terminating Module
STS Synchronous Transport Signal
SXS Step-by-Step
SYSCTL System Controller
T-BRITE T-Basic Rate Interface Transmission Extension
TAD Trouble Analysis Data
TAP Trouble Analysis Procedure
TASC Telecommunications Alarm Surveillance Control System
TASX Telecommunications Alarm Surveillance and Control System
TAU Time Assignment Unit
TBCU Test Bus Control Unit
TBOS Telemetry Byte-Oriented Serial
TCU TransCoder Unit
TD Toll Diversion
TDM Tandem
TFD Trunk Distributing Frame
TFIU Transmission Facility Interface Unit
TGS Synchronous Timing Generator
THC Test Head Controller
TIRKS Trunk Inventory and Record Keeping System
TLWS Trunk Line Work Station
TMC Time slot Management Channel
TMT Transmission Maintenance Terminal
TNO The New Order
TNOP Total Network Operating Plan
TO Transmission Only
TOC Task Oriented Costing
TOP Task Oriented Procedure
TPI Tip Party Identification
TRMTG Transmitting
TRU Transmit/Receive Unit
TSI Time Slot Interchange
TSU Transmission Signaling Unit
UAS UnAvailable Second
UIP User Interface Panel
UL Underwriters Laboratory
UNICCAP Universal Cable Circuit Analysis Program
USDL U-interface Digital Subscriber Line
VF Voice Frequency
VRT Virtual Remote Terminal
VT Virtual Tributary
VTU Virtual Tributary Unit
WATS Wide Area Telephone Service
WC Wire Center
WCPC Wire Center Planning Center
WES Warranty Eligibility System
WORD Work Order Record Details
XADU eXtended Alarm Display Unit
XTC eXtended Test Controller
ZCS Zero Code Suppression
+-------------+
| SLC Vendors |
+-------------+
AT&T
12450 Fair Lakes Cir
Ste 302
Fairfax, VA 22033
Phone: (703) 802-3853
Fax: (703) 802-3853
+----------------------------------------------------------+
| | SLC-5 | SLC-2000 |
+----------------------------------------------------------+
| Maximum No. Subscriber Ports | 192 | 768 |
| Remote Terminal (qty. per 7-ft. size) | 3 | 1 |
| Remote Inventory and Diagnostics | Y | Y |
| Identical Plug-ins for RT and COT | Y | Y |
| Max. DS1 Span Lines Supported | 24 | 28 |
| Max. DS1 Span Lines Powered/Protected | 24 | 28 |
| Integrated DS-3 Interface | N | N |
| Integrated Sonet Interface | | OC-3 |
| TR-008 Compatible Mode | Y | Y |
| TR-303 Compatible Mode | Y | Y |
+----------------------------------------------------------+
Fujitsu Network Communications Inc
2801 Telecom Parkway
Richardson, TX 75082
Phone: (800) 777-3278
Fax: (214) 479-6990
+------------------------------------------------------+
| | FDLC | FACTR |
+------------------------------------------------------+
| Maximum No. Subscriber Ports | 192 | 1920 |
| Remote Terminal (qty. per 7-ft. size) | 4 | 5 |
| Remote Inventory and Diagnostics | Y | Y |
| Identical Plug-ins for RT and COT | Y | Y |
| Max. DS1 Span Lines Supported | 8 | 28 |
| Max. DS1 Span Lines Powered/Protected | 0 | 0 |
| Integrated DS-3 Interface | N | N |
| Integrated Sonet Interface | N | Y |
| TR-008 Compatible Mode | Y | Y |
| TR-303 Compatible Mode | N | Y |
+------------------------------------------------------+
NEC America Inc
14040 Park Center Rd
Herndon, VA 22071
Phone: (703) 834-4000
Fax: (703) 834-4306
+-------------------------------------------------+
| | ISC-303 |
+-------------------------------------------------+
| Maximum No. Subscriber Ports | 192 |
| Remote Terminal (qty. per 7-ft. size) | 10 |
| Remote Inventory and Diagnostics | Y |
| Identical Plug-ins for RT and COT | Y |
| Max. DS1 Span Lines Supported | 5 |
| Max. DS1 Span Lines Powered/Protected | 0 |
| Integrated DS-3 Interface | N |
| Integrated Sonet Interface | |
| TR-008 Compatible Mode | Y |
| TR-303 Compatible Mode | Y |
+-------------------------------------------------+
Northern Telecom, Inc.
Northern Telecom Limited
8220 Dixie Road
Suite 100
Brampton, Ontario
L6T 5P6 Canada
Phone: (905)863-0000
Phone: (800)4-NORTEL
+-------------------------------------------------------------------+
| | DMS-1 Urban | Access Node |
+-------------------------------------------------------------------+
| Maximum No. Subscriber Ports | 544 | 672 |
| Remote Terminal (qty. per 7-ft. size) | 0 | 1 |
| Remote Inventory and Diagnostics | Y | Y |
| Identical Plug-ins for RT and COT | Y | Y |
| Max. DS1 Span Lines Supported | 8 | 28 |
| Max. DS1 Span Lines Powered/Protected | 8 | 0 |
| Integrated DS-3 Interface | N | Y |
| Integrated Sonet Interface | N | Y |
| TR-008 Compatible Mode | Y | Y |
| TR-303 Compatible Mode | N | Y |
+-------------------------------------------------------------------+
RELTEC Corp
5875 Landerbrook Dr
Cleveland, OH 44124
Phone: (216)460-3600
Fax: (216)460-3690
+----------------------------------------------------------------------------+
| | DISCS 1 | Sonet DISCS | DISCS FITL |
+----------------------------------------------------------------------------+
| Maximum No. Subscriber Ports | 672 | 2016 | 0 |
| Remote Terminal (qty. per 7-ft. size) | 672 | 672 | 672 |
| Remote Inventory and Diagnostics | Y | Y | Y |
| Identical Plug-ins for RT and COT | Y | Y | Y |
| Max. DS1 Span Lines Supported | 28 | 84 | 84 |
| Max. DS1 Span Lines Powered/Protected | 0 | 0 | 0 |
| Integrated DS-3 Interface | N | N | N |
| Integrated Sonet Interface | N | Y | Y |
| TR-008 Compatible Mode | Y | Y | Y |
| TR-303 Compatible Mode | Y | Y | Y |
+----------------------------------------------------------------------------+
Siescor Technologies, Inc. (A division of Raytheon)
Box 470580
Tulsa, OK 74147-0580
Phone: (918)252-1578
Fax: (918)252-2757
E-Mail: [email protected]
+-----------------------------------------------------------------------+
| | FiberTraq | S-24DU | RLC-1920 |
+-----------------------------------------------------------------------+
| Maximum No. Subscriber Ports | | | 1920 |
| Remote Terminal (qty. per 7-ft. size) | | | |
| Remote Inventory and Diagnostics | | | |
| Identical Plug-ins for RT and COT | | | |
| Max. DS1 Span Lines Supported | | | |
| Max. DS1 Span Lines Powered/Protected | | | |
| Integrated DS-3 Interface | | | |
| Integrated Sonet Interface | | | |
| TR-008 Compatible Mode | | | |
| TR-303 Compatible Mode | | | |
+-----------------------------------------------------------------------+
----[ EOF
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