Lucent Technologies DDM-2000 OC-3, User & Service Manual

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363-206-285
Applications
Issue 3 June 2001 2-21
OC-1 Ring Transport on OC-3 Ring 2
OC-1 ring transport on OC-3 rings can be used in both single-homed and dual-
homed configurations. Figure 2-13 shows how single-homed OC-1 extensions
can satisfy a growing access network. Single-homing applications connect both
rotations of the OC-1 extension to a single DDM-2000 OC-3 or
SLC -2000 Access
System host. The DDM-2000 FiberReach is located at the customer's location,
such as in a telecommunications equipment closet on each floor of a high-rise
office complex, and delivers up to 16 fully protected DS1 channels per system.
The OC-1 ring capability allows multiple DDM-2000 FiberReach systems to be
connected to the backbone network via a single facility. Compared to other optical
extension products that are limited to a single remote node per extension, the
ring-based DDM-2000 FiberReach solution uses far less fiber and host optics for
typical serving areas with multiple business locations. Network growth is as easy
as adding another DDM-2000 FiberReach node on the ring; no additional fiber or
host circuit packs need to be added.
With the dual OC-1 capability of the 27-type OLIU, a DDM-2000 OC-3 ring node
supports up to six single-homed OC-1 extensions; a
SLC -2000 Access System
ARM shelf can supply up to two single-homed OC-1 extensions. Thus, competing
businesses in the same serving area can receive a dedicated access facility into
the backbone ring, alleviating any privacy concerns.
The single OC-1 26G2-U OLIU further expands the options by allowing the
dropping of DS1s without the need for the MXRVO or BBF5 Jumper circuit packs
(a Group 4 shelf is required).
The DDM-2000 FiberReach remote systems employ standard path protection
switching for a highly reliable network that guarantees 60 millisecond recovery
from any single facility or equipment failure. Path protection switching occurs at
the nodes where a channel is dropped from the ring to a low-speed interface.
Channels pass between the OC-1 and OC-3 rings at the host DDM-2000 OC-3
and
SLC -2000 systems with a 0x1 low-speed cross-connection. This arrangement
supports full TSI assignment between low-speed and high-speed time slots while
preserving independent service and protection paths between the host and
extension rings.