Cisco Systems 8240 User Manual 2

Description

Physical Description

The MGX 8240 shelf is a multi-slot chassis, supporting multiple PSM cards and their associated
interface I/O assemblies. The shelf is designed as an integrated unit containing the following:

• 16-slot card cage (15 slots usable for PSMs; 1 divided slot for IMC or common equipment card).

• Single 16-slot mid-plane.

• Three independent, hot-swappable fan trays (any two of which can adequately cool the fullyloaded

chassis).

• Removable air filter.

• -48 VDC Power Input Module with dual redundant power entries.

• Individual face plates on each PSM Module for Airflow and Electro-Magnetic Interference (EMI)

Sealing, as well as Alarm and Connector Identification.

• Removable Cable Management System.

The shelf is designed for center mounting only. It is NEBS compliant with the GR-63-CORE and
GR-1089-CORE requirements.

CHAPTER

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Figure 2-1 MGX 8240 Front View

Chapter 2 Description

Physical Interfaces & Specifications

This section describes the types of physical interfaces supported by the MGX 8240.
Table 2-1 lists the switch physical interfaces under different conditions.

Table 2-1 Switch Physical Interfaces Supported

Number of Ports Supported

Physical Interface

DS3 Access Port 45 36 3
DS1 ports under DS3 1,260 1,008 84
DS0 ports under DS3 30,240 24,192 2,016
SONET ATM Trunk Ports 15 (30 with APS) 12 (24 with APS) 1 (2 with APS)

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No Redundancy

1 for 4 Redundancy
Support Each PSM Blade

Release 3.0, Part Number 78-10728-01, July 2000

Chapter 2 Description

Table 2-1 Switch Physical Interfaces Supported

Number of Ports Supported

1 for 4 Redundancy

Physical Interface

RS232 Serial Ports for

No Redundancy

Support Each PSM Blade

16 16 1

CLI.
10/100BaseT Ethernet

Ports for network
management

Table 2-2 shows the dimensions of an unmounted MGX 8240 unit.

Table 2-2 Unmounted MGX 8240 Dimensions

Dimension Value

Depth (without cable management) 18.5 in.
Depth (withcable management)

22.5 in.
Width (without mounting brackets) 21.25 in.
Height 33.25 in.(19 RU)
Weight (empty) 100 lbs.
Weight (fully loaded) 220 lbs.
Shelf wattage (fully loaded) 1500 Watts

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Figure 2-2 MGX 8240 Physical Dimensions

Chapter 2 Description

The shelf is designed to be center-mountedin a standard telecom 23-inch relay rack. Two chassis can be
mounted in a standard 7-foot configuration. There should be at least 5” betweenthe two chassis.

Module Cage and Slot Designation

The MGX 8240 shelf has a 16-slot card cage. There are 15 full-size slots and 2 half-size slots. The two
half-sized slots are for IMCs.

An MGX 8240 with IMC redundancy uses two IMCs, one primary and one backup. An IMC fits into
each of the two half-size slots. At installation, usually the top IMC is primary, and the bottom IMC is
backup. Figure 2-3 shows the slot designation for the cards.

Note If only one IMC is to be used, it should be placed in Slot 1A.

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Release 3.0, Part Number 78-10728-01, July 2000

Chapter 2 Description

Figure 2-3 Slot Designation (Front View)

The PSM slots are numbered 1 through 16 (from left to right) on the bottom of the card cage.
Slot 1:

• Reserved for common equipment purposes (the IMC card).

• Divided into two slots (A and B) for the IMC card. These slots are wired in parallel.

• Provides:

–

Ethernet connectivity for remaining 15 slots.

–

BITS A and B connections for the user.

–

Alarm relay connections for the user.

Slots 2 through 16:

• Are identical with respect to the PSM cards and Interface I/O Mid-plane.

• Are wired for Ethernet connections and have point-to-point connection to slot 1.

• Are coupled to both BITS A and B.

• Contain alarms relay control signals for four contact closures.

The Mid-plane design:

• Eliminates most of the discrete wiring within the shelf.

• Provides connection between the front and back cards.

• Provides the interconnection for the cards, interface I/O panels, fan tray, and -48 VDC Power Input.

• Supports hot swapping of cards, Interface I/Os, and fan tray.

• Has no active circuitry.

I/O Panels are installed in the rear of the chassis. Two types of I/O cards exist:

1. The PSM I/O, with two OC3 transceivers, three DS3 ports, and an RJ45 CRAFT port.

2. The IMC I/O card, with 1 Ethernet port, 1 RJ45 console port, and BITS A and BITS B ports, and a

D connector for alarms.

A blank I/O panel is supplied to cover slots that do not contain one of the above cards.

Release 3.0, Part Number 78-10728-01, July 2000

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