BPX Switch Common Core Components

Note

The BCC-4 is required for the Virtual Switch Interface (VSI) and Multiprotocol Label Switching (MPLS) features operation

The BCC-4V provides a 16 x 32 crosspoint switch architecture to extend the BPX peak switching capability from 9.6 up to 19.2 Gbps peak. The BCC-4V also provides 4 MBytes of BRAM and 128 MBytes of DRAM.

The following are the functions of the common core components shown in Figure 3-1:

Broadband Controller Card

The Broadband Controller Card (BCC) is a microprocessor-based system controller, which is used to control the overall operation of the BPX switch. The controller card is a front card that is usually equipped as a redundant pair.

Slots number 7 and number 8 are reserved for the primary and secondary (standby) broadband controller cards. Each broadband controller front card requires a corresponding back card.

For nonredundant nodes, a single BCC is used in front slot number 7 with its appropriate back card.

For redundant nodes, a pair of BCCs of matching type, are used in front slot numbers 7 and 8.

Note The three types of BCCs with their proper back cards may be operated together temporarily for maintenance purposes, for example, replacing a failed controller card. Throughout a network, individual BPX switches may have either a single BCC-4V controller card or a pair of the identical type of BCC.

The term BCC refers to the functional operation of the Broadband Controller Card. When a difference in operation does occur, the specific type of BCC is specified.

The BCC-4V provides a 16 x 32 cross-point architecture that increases the peak switching capacity of the BPX switch to 19.2 Gbps, with a sustained nonblocking throughput of 9.6 Gbps.

Features

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Runs the system software for controlling, configuring, diagnosing, and monitoring the BPX switch.

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Contains the crosspoint switch matrix operating at 800 Mbps per serial link or up to 1600 Mbps (BCC-4V).

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Contains the arbiter which controls the polling each high-speed data port and grants the access to the switch matrix for each port with data to transfer.

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Generates Stratum-3 system clocking and can synchronize it to either a selected trunk or an external clock input.

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Communicates configuration and control information to all other cards in the same node over the backplane communication bus.

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Provides a communications processor for an Ethernet LAN port plus two low-speed data ports. The BCC15-BC provides the physical interface for the BCC-32.
The BCC-3-BC provides the physical interface for the BCC-3-32M, BCC-3-64M, and BCC-4V.

Functional Description

The BPX switch is a space switch, which employs a crosspoint switch for individual data lines to and from each port. The switching fabric in each BPX switch consists of three elements for the BCCs (see Figure 3-2):

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16 X 32 Crosspoint Switching Matrix on each BCC (2 X [12 X 12]) used for BCC-4V.

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Serial Interface and LAN Interface Modules on each BCC and on each Function Module.

The arbiter polls each card to see if it has data to transmit. It then configures the crosspoint switching matrix to make the connection between the two cards. Each connection is unidirectional and has a capacity of 800 Mbps (616.7 Mbps for cell traffic plus the frame overhead).

Each card contains a Switch Interface Module (SIM), which provides a standardized interface between the card and the data lines and polling buses. The SIM responds to queries from the BCC indicating whether it has data ready to transmit.

With the BPX switch equipped with two BCCs, the cell switching is completely redundant in that there are always two arbiters, two crosspoint switches, two completely independent data buses, and two independent polling buses.

The BCC incorporates nonvolatile flash EEPROM, which permits new software releases to be downloaded over the network and battery-backup RAM (BRAM) for storing user system configuration data. The memory features maintain system software and configuration data even during power failures, eliminating the need to download software or reconfigure after the power returns.

The BPX switch cell switching is not synchronized to any external clocks; it runs at its own rate. No switch fabric clocks are used to derive synchronization nor are these signals synchronized to any external sources.

Node clocking is generated by the BCC. Because the BPX switch resides as an element in a telecommunications network, it is capable of synchronizing to higher-stratum clocking devices in the network and providing synchronization to lower stratum devices. The BCC can be synchronized to any one of three different sources under software control:

The BCC clock circuits provide clocking signals to every other card slot. If a function card needs to synchronize its physical interface to the BPX switch clock, it can use this timing signal to derive the proper reference frequency. These reference frequencies include DS1, E1, DS3, and E3.

Front Panel Description

The BCC front panel has four Led, three card status LEDs, and a LAN LED (see Figure 3-3 and Table 3-1).

Table 3-1 BCC Front Panel Indicators
Number	Indicator	Function
1	LAN	Indicates there is data activity over the Ethernet LAN port.
2	card - act	Card active LED indicates this BCC is online and actively controlling the node.
3	card - stby	Card standby LED indicates this BCC is offline but is ready to take over control of the node at a moments notice.
4	card - fail	Card fail LED indicates this BCC has failed the internal self-test routine and needs to be reset or replaced.

The BCC runs self-tests continuously on internal functions in the background and if a failure is detected, the fail LED is lighted. If the BCC is configured as a redundant pair, the off-line BCC is indicated by the lighted stby LED. The stby LED also flashes when a software download or standby update is in progress. The LAN LED indicates activity on the Ethernet port.

Back Cards for the BCC-4V

The back cards for the BCC serve as an interface between the BPX switch and the BPX switch network management system.

For the BCC-4V, the back card is the BCC-3-BC. (These back cards are also known as the BCC back cards).

The BCC-4V provides important features such as support for up to 19.2 Mbps peak operation with BXM cards. Both BCCs in a node should be of the same type.

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A serial RS-232 Control Port for connecting to a VT100-compatible terminal or modem.

The face plate connectors are described in Table 3-2, Table 3-3, and shown in Figure 3-4. The BCC15-BC is shown on the left and the BCC-3-BCC is shown on the right.

Table 3-2 BCC15-BC Back Card for BCC-32, Connectors
Connector	Function
CONTROL	A DB25 connector for a VT100 or equivalent terminal for a basic terminal connection enabling you to use the command line interface commands. You can also connect to a dial-in modem for remote service support or other network management dial-up access. This is a bidirectional RS232 communications port. It is not used for CWM Network Management; the LAN connector is used for CWM Network Management.
AUXILIARY	A DB25 connector for a system printer. This is a one-way, RS232 outgoing port.
XFER TMG	DB15 connector that supplies an 8-kHz timing signal (RS422 type output that is synchronized to the BPX switch system clock.)
EXT TMG	A 75-ohm BNC connection for clock input. An E1 source with 75 ohm impedance typically uses this connector. If the shield on the cable needs grounding, slide the BCC back card out and jumped connector JP1 across its two pins.
EXT TMG	DB15 connector for a primary and optional redundant external source of system clock. A T1 source with 100 ohm impedance or an E1 source with 100/120 ohm impedance typically use this connector.
LAN	A DB15 Ethernet LAN connection for connecting to a CWM NMS. You can also connect a terminal (or NMS other than CWM) to the BPX switch LAN port via Ethernet. However, only the CWM NMS provides full management configuration and statistics capabilities via SNMP and TFTP.

Table 3-3 BCC-3-BC Back Card for BCC-4V
Connector	Function
CONTROL	A DB25 connector for a VT100 or equivalent terminal for a basic terminal connection using command line interface commands. You can also connect to a dial-in modem for remote service support or other network management dial-up access. This is a bidirectional RS232 communications port. This is not used for CWM Network Management; the LAN connector is used for CWM Network Management.
AUXILIARY	A DB25 connector for a system printer. This is a one-way, RS232 outgoing port.
LAN	A DB15 Ethernet LAN connection for connecting to a CWM NMS. A terminal or NMS other than CWM can also be connected to the BPX switch LAN port via Ethernet. However, only the CWM NMS provides full management configuration and statistics capabilities through SNMP and TFTP.
EXT TMG	A 75-ohm BNC connection for clock input. An E1 source with 75 ohm impedance typically uses this connector. If the shield on the cable needs grounding, slide the BCC back card out and jumper connector JP1 across its two pins.
EXT 1 TMG	DB15 connector for a primary and optional redundant external source of system clock. A T1 source with 100 ohm impedance or an E1 source with 100/120 ohm impedance typically use this connector.
EXT 2 TMG	Provides for an external clock source redundant to the EXT 1 TMG source.

Another function of the line module back card is to provide the following two low-speed, serial communications ports as described in Table 3-3:

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Control port—Specifies a bidirectional port for connecting the BPX switch to a local terminal or to a modem for a remote terminal dial-in connection.

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Auxiliary port—Specifies an output only port that is typically used to connect to a printer dedicated to printing logs.

The Cisco WAN Manager NMS is connected to the LAN port on the BCC back cards. When control is provided through an Ethernet interface, you configure the node IP address by using the cnflan command for the BPX switch. For redundancy, also configure the LAN ports on both BCC back cards, each connected to an AUI adapter.

The LAN port of the primary BCC is active. If the secondary BCC becomes primary (active), then its LAN port becomes active. The Cisco WAN Manager workstation will automatically try to restore communications over the LAN and interfaces with the newly active BCC.

For small networks, one Cisco WAN Manager workstation is adequate to collect statistics and provide network management. For larger networks, additional Cisco WAN Manager workstations is required. For more information, refer to the Cisco WAN Manager User's Guide.

Alarm/Status Monitor Card

The Alarm/Status Monitor (ASM) card is a front card. Only one is required per node and it is installed in slot 15 of the BPX switch. It is used in conjunction with an associated back card, the Line Module for the ASM (LM-ASM) card.

The ASM and LM-ASM cards are noncritical cards used for monitoring the operation of the node and not directly involved in system operation. Therefore, there is no provision or requirement for card redundancy.

Features

The ASM card provides a number of the following support functions for the BPX switch:

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Node power monitoring (including provision for optional external power supplies).

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Sensing for the presence of other cards that are installed in the BPX switch.

Functional Description

BPX switch system software commands the ASM card to activate the major and minor alarm indicators and relays.

The following are the four significant circuits controlled by the ASM processor:

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Alarm—Controls the operation of the front panel alarm LEDs and ACO and history push buttons as well as the alarm relays that provide dry contact closures for alarm outputs to customer connections.

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Power supply monitor—Monitors the circuit monitors for the status of the -48V input to the shelf on each of the two power buses, A and B. The status of both the A bus and B power bus is displayed on the ASM front panel.

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Fan and temperature monitor—Specifies each of the three cooling fans that is monitored by the fan monitor circuit, which forwards a warning to the BPX switch system software if any fan falls below a preset RPM. Cabinet internal temperature is also monitored by the ASM, which sends the temperature to the system software to be displayed on the NMS terminal. The range that is displayed is 0 degrees to 60 degrees Centigrade.

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Card detection—Specifies that the ASM card performs a card monitoring function that polls for either card insertion or removal on all BPX slots every 100 ms.

Front Panel Description

The front panel displays the status of the node and any major or minor alarms that might be present. Figure 3-5 illustrates the front panel of the ASM card. Each front panel feature is described in Table 3-4.

Table 3-4 ASM Front Panel Controls and Indicators
Number	Controls/Indicator	Function
1	alarms LEDs	A red major alarm and a yellow minor alarm indicator to display the status of the local node. In general, a major alarm is affects service whereas a minor alarm is a failure that does not affect service.
2	dc LEDs	Two green LEDs display the status of the two DC power busses on the Stratabus backplane. ON indicates voltage within tolerance. OFF indicates an out-of-tolerance voltage.
3	ACO/hist LEDs	ACO LED (yellow) lights when you press the front panel ACO push button. History LED (green) indicates an alarm has been detected by the ASM at some time in the past but might not be clear at present time.
4	ACO switch	When operated, releases the audible alarm relay.
5	history clear switch	Extinguishes the history LED if the alarm condition has cleared. If the alarm is still present when the history clear switch is thrown, the history LED will stay lit.
6	card status LEDs	Active (green) indicates the card is online and clear of alarms. Standby (yellow) indicates the card is offline. Fault (red) indicates a card failure is detected by the card self-test diagnostics.

Line Module for the Alarm/Status Monitor Card

The Line Module for the Alarm/Status Monitor Card (LM-ASM) is a back card to the ASM card. It provides a simple connector panel for interfacing to your alarm system. It is not required for system and ASM operation.

Figure 3-6 illustrates the face plate of the LM-ASM which contains a single subminiature connector
(see Table 3-5). The Alarm Relay connector provides dry-closure (no voltage) relay contact outputs.

BPX Switch StrataBus 9.6 and 19.2 Gbps Backplanes

The BPX switch is equipped with a backplane that supports either a 9.6 or up to 19.2 Gbps operation. The 19.2 Gbps backplane can physically be identified by the card slot fuses on the bottom rear of the backplane. All BPX switch modules are interconnected by the BPX switch StrataBus backplane physically located between the front card slots and the back card slots.

Although the ATM data paths between the switching fabric and the interface modules are individual data connections, there are also a number of system bus paths for controlling the operation of the BPX switch. The StrataBus backplane, in addition to the 15 card connectors, contains the following signal paths:

Table 3-5 LM-ASM Face Plate Connectors
Number	Connector/Indicator	Function
1	ALARM RELAYS	A DB15 connector for alarm relay outputs. For more information about the pinouts, see "BPX Switch Cabling Summary."

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ATM crosspoint wiring—Specifies the individual paths to carry ATM trunk data between both the network interface and service interface modules and the crosspoint switching fabric.

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Polling bus—Enables the signals between the BCC and all network interface modules.

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Communications bus—Specifies the internal communications between the BCC and all other cards in the node.

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Clock bus—Carries the timing signals between the BCC and all other system cards.

All StrataBus wiring is completely duplicated and the two sets of bus wiring operate independently to provide complete redundancy. Either the A-side wiring or B-side wiring is enabled at any particular time by signals on the Control bus.

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