Introduction 1-3
MGX 8220 Shelf
Aggregation of Traffic into ATM Networks
Each MGX 8220 shelf connects to the BPX switch across a T3 or E3 ATM STI (Cisco Trunk
Interface) to a BNI module on the BPX switch. Thus, the MGX 8220 shelf Release 3.0 supports
aggregation of traffic up to 40 T1 or E1 access ports or up to 1240 64-Kbps subscribers, onto a single
T3 or E3 trunk, using only a single port on the BPX switch.
In this release, the MGX 8220 shelf should normally be collocated with the BPX switch. Figure 1-2
shows how the MGX 8220 shelf usage is envisioned in Release 3.0.
Figure 1-2
MGX 8220/BPX Switch Relationship
For remote locations with limited bandwidth needs, the MGX 8220 shelf can be remoted from the
BPX switch using IMA trunk machines. (See Figure 1-3.)
Figure 1-3
Remote Cisco MGX 8220 Configuration
The following sections provide an overview of the MGX 8220 shelf, the Release 3.0 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 -48VDC source or from a 220V 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).
40 T1 or E1
service interface
lines
MGX 8220
BPX 8620
Broadband
ATM
service
T3 ATM STI
connection
H8239
40 T1 or E1
service interface
lines
MGX 8220
BPX 8620
Broadand
ATM service
IMATM
Long distance
IMA trunk
T1 or E1 service
interface lines
H8240
