Total Access 3000 DSLAM DS3 Primary Switch Module Installation and Maintenance Practice
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61181041L3-5A
MDE
The Metallic Data Extension (MDE) bus is an ADTRAN proprietary, metallic, short range, high-
speed interconnection bus between an ADTRAN Primary Total Access 3000 Shelf and up to
five Expansion shelves. All shelves in the system must have the same number of slots. The
DS3-PSM is connected to the ESM in expansion shelves via standard CAT-5e twisted pair
cable. The bus capacity is approximately 655 Mb/s of user and management data. The total
length of the bus is limited to 20 meters (65.6 feet).
shows an MDE Link overview.
Figure 2. MDE Link Overview
Primary Shelf
The Primary Shelf acts as the gatekeeper for both management and user data. It terminates
the network feed and routes the data to the appropriate Expansion shelves over the MDE bus.
It also terminates the management interface(s) whether local Ethernet, in-band, craft, X.25 (if
required), and Asynchronous RS-232 for PPP (if required). The PCU and the DS3-PSM(s) reside
in the Primary Shelf.
Total Access HDX
Primary Shelf
MDE CAT 5
DS3
PCU
ECU
ECU
ECU
ECU
DS3
PSM
ESM
ESM
ESM
ESM
ADSL
DS3
PSM
ESM
ESM
ESM
ESM
Expansion Shelf 1
Expansion Shelf 2
Expansion Shelf 3
Expansion Shelf 4
ECU ESM ESM
Expansion Shelf 5
