Lucent Technologies FT-2000 OC-48 User Manual

Circuit Pack Descriptions
Issue 8.0 July 2002
7-23
Memory 7
Start-Up Memory. 7The start-up memory consists of 64 kilobytes of read-only
memory. The start-up memory contains the program that allows the processor to
load the executable code and data from the SYSCTL circuit pack into the
operating memory. This allows the processor to start up operation during a
power-up or a reset condition, or when initializing new software.
Operating Memory. 7The main operating memory consists of 4 megabytes of
DRAM. Direct memory access (DMA) allows the board controller to load the
executable code and data received from the SYSCTL circuit pack (via the
overhead access local area network) into the operating memory during a
power-up or reset condition, or when initializing new software.
Nonvolatile Memory. 7The nonvolatile memory consists of 128 bytes of
electrically-erasable programmable read-only memory (EEPROM). The
nonvolatile memory is used to store information about the history of the OHCTL
(TERM) circuit pack such as the
CLEI code and type/version information.
Interface Circuitry 7
Overhead Access Local Area Network Interface. 7The overhead access local area
network (OALAN) interface allows the OHCTL (TERM) circuit pack to
communicate with the SYSCTL circuit pack. In Release 6 and later releases, the
OALAN allows the OHCTL (TERM) circuit pack to communicate with the
Overhead Controller - Tributary (TOHCTL) circuit pack.
Overhead Byte Interface. 7The overhead byte interface interacts with the overhead
channel. The overhead byte interface accepts the data communications channel
(DCC) bytes from the System Controller circuit pack (via the OALAN) and the
following overhead bytes from the interconnection panel of the Enhanced High
Speed Shelf (or High Speed Shelf):
■ Line orderwire
■ Section orderwire
■ User
■ Growth.
The overhead byte interface multiplexes this information and sends it via the
overhead channel to the transmit byte processor (TBP) on the OC48 Transmitter
(OC48 TRMTR) circuit pack for transmission over the OC-48 high speed line. This
information provides end-to-end communications and maintenance. In the LAA22
OHCTL (TERM) circuit pack, the protection overhead channel from the overhead
byte interface to the TBP on the OC48 TRMTR circuit pack is not used and cannot
be switched into service. One LAA22 and one LAA21 OHCTL (TERM) circuit pack
are required for FT-2000 OC-48 Add/Drop-Rings Terminals equipped with the
High Speed Shelf.

Lucent Technologies FT-2000 OC-48 Specifications

General

Brand	Lucent Technologies
Model	FT-2000 OC-48
Category	Network Hardware
Language	English