363-206-295
Glossary
Issue 1 December 1997 GL-7
Dual 0x1 Cross-Connection
In a single-homed application, the DDM-2000 OC-3/OC-12 Multiplexer uses a dual 0x1
cross-connection to map the VT1.5 channels between the DDM-2000 FiberReach OC-1
and the DDM-2000 OC-3/OC-12 rings. This dual 0x1 architecture means that the VT1.5
path switching is only in the DDM-2000 FiberReach and not in the host DDM-2000.
Individual DS1 signals within an STS-1 can therefore be dropped to DDM-2000 OC-3
shelves at several nodes around the ring. See Single 0x1.
Dual Homing
In DDM-2000 FiberReach, a network topology in which two OC-3 shelves serve as
DDM-2000 FiberReach Multiplexer hosts supporting up to twelve OC-1 rings. Each
DDM-2000 FiberReach Multiplexer ring is interconnected between the two separate
hosts. Two
SLC
-2000 Access Systems serving as DDM-2000 FiberReach hosts can
support up to four OC-1 rings. See Single Homing."
E
EC-1, EC-n
Electrical Carrier — The basic logical building block signal with a rate of 51.840 Mb/s for
an EC-1 signal and a rate of n times 51.840 Mb/s for an EC-n signal. An EC-1 signal can
be built in two ways: A DS1 can be mapped into a VT1.5 signal and 28 VT1.5 signals
multiplexed into an EC-1 (VT1.5 based EC-1), or a DS3 can be mapped directly into an
EC-1 (DS3 based EC-1).
ECI
Equipment Catalog Item — The bar code number on the faceplate of each circuit pack
used by some inventory systems.
EEPROM
Electrically Erasable Programmable Read-Only Memory
EIA
Electronic Industries Association
EMC
Electromagnetic Compatibility
EMI
Electromagnetic Interference
EOOF
Excessive Out of Frame
EPROM
Erasable Programmable Read-Only Memory
EQ
Equipped (memory administrative state)