Specifications

Introducing the MGX 8220 Shelf 1-3
MGX 8220 System Overview
Aggregation of Traffic into ATM Networks
Each MGX 8220 shelf connects to the BPX switch across:
• A T3 or E3 ATM to a BNI or T3/E3 BXM module on the BPX switch
or
• A SMF SONET ATM link to a BXM-155-8 port or BXM-155-4 port on the BPX switch
Thus, the MGX 8220 shelf supports aggregation of traffic up to 80 T1 or E1 access ports or up to
1240 64-Kbps subscribers, onto a single T3, E3, or OC-3c trunk, using only a single port on the
BPX switch.
The MGX 8220 shelf should normally be collocated with the BPX switch. Figure1-2 shows how the
MGX 8220 shelf usage is envisioned in Release 4.1.
Figure1-2 MGX 8220/BPX Switch Relationship
For remote locations with limited bandwidth needs, the MGX 8220 shelf can be remotely located
from the BPX switch using IMA trunk machines as shown in Figure1-3.
Figure1-3 Remote MGX 8220 Configuration
The following subsections provide an overview of the MGX 8220 shelf, the Release 4.1 cards, and
management capabilities. In-depth details are provided in subsequent chapters.
MGX 8220 Shelf
Physically, the MGX 8220 shelf consists of cards in a 19 inch rack mountable shelf.
The shelf can be powered either from a -48V DC source or from a 220-240V AC source. The DC
version includes DC power entry modules that can be mounted in the shelf. The AC version requires
an external rack mounted, AC Power Module. Both versions require a rack mounted cooling
assembly. Multiple MGX 8220 shelves can be mounted in the same rack sharing power and cooling
assemblies.
The MGX 8220 shelf contains 16 slots where each slot can accommodate a front card and a back
card. The front row is used for function modules, cards that perform more complex functions within
the unit (for example, frame relay to ATM conversion). The back row is used for line modules, cards
that provide interfaces to one or more transmission lines connected to the MGX 8220 shelf
(for example, the trunk line to the BPX switch or an RS-232 line to a control terminal).