Table of Contents

BPX Switch Common Core

BPX Switch Common Core

This chapter contains a description of the common core group, comprising the Broadband Controller Cards (BCCs), the Alarm/Status Monitor (ASM) card, associated backcards, and the StrataBus backplane.

This chapter contains the following:

• BPX Switch Common Core Group
  
  
• Broadband Controller Card (BCC-32, BCC-3, BCC-4)
  
  
• Alarm/Status Monitor Card
  
  
• BPX Switch StrataBus 9.6 and 19.2 Gbps Backplanes
  
  

BPX Switch Common Core Group

The BPX switch Common Core group includes the Broadband Controller Card (BCC-3 and associated BCC-3-bc backcard, or BCC-32 and associated BCC-b backcard), or BCC-4 and associated BCC-3-c backcard, the Alarm/Status Monitor (ASM), a Line Module for the ASM card (LM-ASM), and the StrataBus backplane (see Figure 3-1). The BCC-3 and BCC-32 are functionally equivalent and support 9.6 Gbps operation, but use different backcards. The BCC-4 supports the 19.2 Gbps operation of the BXM cards and provides 32M or 64M.

• ATM cell switching.
  
• Internal node communication.
  
  
• Remote node communication.
  
  
• Node synchronization.
  
  
• Network management communications (Ethernet), local management (RS-232).
  
  
• Alarm and status monitoring functions.
  
  

Broadband Controller Card (BCC-32, BCC-3, BCC-4)

The Broadband Controller Card is a microprocessor-based system controller and 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 non-redundant nodes, a single BCC is used in front slot number 7 with its appropriate backcard.
  
  
• For redundant nodes, a pair of BCCs of matching type, are used in front slot numbers 7 and 8.
  
  

Figure 3-1: Common Core Group Block Diagram

The BCC-3 and BCC-32 are functionally equivalent and the BCC-4 is similar except for some additional features such as support of 19.6 Gbps operation. The term BCC is used in this manual to refer to the functional operation of the Broadband Controller Card. When a difference in operation does occur, the specific type of BCC is specified. This card group (see Figure 3-1) provides the following functions:

Features

The Broadband Controller Card performs the following major system functions:

• Runs the system software for controlling, configuring, diagnosing, and monitoring the BPX switch.
  
  
• Contains the crosspoint switch matrix operating at 800 Mbps per serial link (BCC-32 or BCC-3) or up to 1600 Mbps (BCC-4).
  
• 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.
  
• Generates Stratum 3 system clocking and can synchronize it to either a selected trunk or an external clock input.
  
• Communicates configuration and control information to all other cards in the same node over the backplane communication bus.
  
  
• Communicates with all other nodes in the network.
  
  
• Provides a communications processor for an Ethernet LAN port plus two low-speed data ports. The BCC-bc provides the physical interface for the BCC-32, and the BCC-3-bc provides the physical interface for the BCC-3 and BCC-4.
  

Each Broadband Controller Card includes the following:

• 68EC040 processor operating at 33 MHz.
  
  
• 32 Mb of DRAM for running system software (BCC-32 and BCC-3), 32 Mb or 64 MB option for BCC-4.
  
  
• 4 Mb of Flash EEPROM for downloading system software.
  
  
• 512 Kbps of BRAM for storing configuration data.
  
  
• EPROM for firmware routines.
  
  
• 68302 Utility processor.
  
  
• SAR engine processor operating at 33 MHz.
  
  
• Communication bus interface.
  
  
• HDLC processor for the LAN connection interface.
  
  
• Two RS-232 serial port interfaces.
  
  

Functional Description

The BPX switch is a space switch. It 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 BCC-32, BCC-3 and for the BCC-4 (see Figure 3-2 and Figure 3-3):

• Central Arbiter on each BCC.
  
  
• Crosspoint Switch.
  
  
  • 16 X 16 Crosspoint Switching Matrix on each BCC (12 X 12 used) for BCC-32 and BCC-3.
    
    
  • 16 X 32 Crosspoint Switching Matrix on each BCC (2 X [12 X 12]) used for BCC-4.
    
    
• 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).

Since there are 16 X 16 (BCC-32 or BCC-3) or 16 X 32 (BCC-4) independent crosspoints and only 15 cards, the switch fabric is non-blocking. However, only one connection at a time is allowed to an individual card. 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.

Each card contains a Switch Interface Module (SIM) which merely 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 non-volatile flash EEPROM which permits new software releases to be downloaded over the network and battery-backup RAM (BRAM) for storing user system configuration data. These memory features maintain system software and configuration data even during power failures, eliminating the need to download software or reconfigure after the power returns.

Node clocking is generated by the BCC. Since 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:

• An internal, high-stability oscillator
  
  
• Derived clock from a BNI module (no IPX clock sources allowed)
  
  
• An external clock source connected directly to the BPX
  
  

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.

Figure 3-3: BCC-4 Block Diagram

Front Panel Description

The BCC front panel has four Led, three card status LEDs, and a LAN LED. (See Figure 3-4 and Table 3-1.)

Figure 3-4: BCC Front Panel

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.

19.2 Gbps Operation with the BCC-4

In order to operate the BPX switch at 19.2 Gbps the following is required:

• A 19.2 Gbps backplane
  
  
• BCC-4 or later controller cards
  
  
• One or more BXM cards
  
  
• Release 8.4.00 or later switch software
  
  
• A backplane NOVRAM that is programmed to identify the backplane as a 19.2 Gbps backplane.
  
  

  Switch software will not allow node operation at 19.2 Gpbs unless it can read the backplane NOVRAM to verify that the backplane is a 19.2 Gbps backplane.

The 19.2 backplane can be visually identified by the small white card slot fuses at the bottom rear of the backplane. These fuses are approximately 1/4 inch high and 1/8 inch wide. The 9.6 Gbps backplane does not have these fuses. If the BPX switch is a late model, then a 19.2 Gbps backplane is installed. This can be verified by running the despond command which will display "Word #2 =0001" if the backplane NOVRAM has been programmed. If anything else is displayed, visually check the backplane for the fuses.

If the backplane is a 19.2 Gbps backplane, but the backplane NOVRAM has not been set to display Word #2 =0001, then the cnfbpnv command may be used to program the NOVRAM as follows:

Are you sure this is a new backplane (y/n).
 

Step 2   Enter y

Step 3   Confirm that the change has been made by entering dspbpnv to confirm the response:

Word #2 =0001

Step 4   Enter switchcc in order for the change to be recognized by the switch software.

If the backplane is not a 19.2 Gbps backplane, then it will be necessary to install a 19.2 Gbps backplane to obtain 19.2 Gbps operation. Contact Customer Service.

Back Cards for the BCC-3 and BCC-32

The backcards for the Broadband Controller Card serve as an interface between the BPX switch and the BPX switch network management system. For the BCC-32, the backcard is the BCC-bc. For the BCC-3 and BCC-4, the backcard is the BCC-3-bc. (These cards are also known as the BCC backcards). The BCC-3 and the BCC-32 are functionally interchangeable, while the BCC-4 provides additional features such as support for 19.2 Mbps operation by the BXM cards. Both BCCs in a node should be of the same type. The backcard provides the following interfaces:

• An 802.3 AIU (Ethernet) interface for connecting the node to a StrataView Plus NMS.
  
  
• A serial RS-232 Control Port for connecting to a VT100-compatible terminal or modem.
  
  
• A serial RS-232 Auxiliary Port for connecting to an external printer.
  
  
• External clock inputs at T1 or E1 rates, output at 8 kHz.
  
  

The face plate connectors are described in Table 3-2 and Table 3-3 and shown in Figure 3-5. For information on cabling, refer to Appendix B, BPX Switch Cabling Summary.

Figure 3-5: BCC-3-bc or BCC-c Face Plate Connectors

Another function of the line module back card is to provide two low-speed, serial communications ports. (Refer to Table 3-3.) The first port (CONTROL) is a bidirectional port used for connecting the BPX switch to a local terminal or to a modem for a remote terminal "dial-in" connection. The second port (AUXILIARY) is an output only and is typically used to connect to a log printer.

The SV+ NMS is connected to the LAN port on the BCC backcards. When control is provided via an Ethernet interface, the node IP address is configured with the cnflan command for the BPX switch, and the back cards are Y-cable connected to an AUI adapter (individual cables and AUIs may also be used for each LAN port). The LAN port of the primary Broadband Control Card is active. If the secondary Broadband Control Card becomes primary (active), then its LAN port becomes active. The SV+ workstation will automatically try to restore communications over the LAN and will interface with the newly active Broadband Controller Card.

For small networks, one SV+ workstation is adequate to collect statistics and provide network management. For larger networks additional SV+ workstations may be required. Refer to the Cisco StrataView Plus Operations Guide for more information.

Alarm/Status Monitor Card

The Alarm/Status Monitor (ASM) card is a front card and a member of the BPX switch Common Core group. 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 non-critical 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 support functions for the BPX switch including:

• Telco compatible alarm indicators, controls, and relay outputs.
  
  
• Node power monitoring (including provision for optional external power supplies).
  
• Monitoring of shelf cooling fans.
  
  
• Monitoring of shelf ambient temperature.
  
• Sensing for the presence of other cards that are installed in the BPX switch.
  
  

Functional Description

There are four significant circuits controlled by the ASM processor: alarm, power supply monitor, fan and temperature monitor, and card detection. The alarm monitor controls the operation of the front panel alarm LEDs and ACO and history pushbuttons as well as the alarm relays which provide dry contact closures for alarm outputs to customer connections. BPX switch system software commands the ASM card to activate the major and minor alarm indicators and relays.

The power supply monitor circuit monitors 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.

Each of the three cooling fans 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 so it may be displayed on the NMS terminal. The range that can be displayed is 0 degrees to 60 degrees Centigrade.

Front Panel Description

The front panel displays the status of the node and any major or minor alarms that may be present. Figure 3-6 illustrates the front panel of the ASM card. Each front panel feature is described in
Table 3-4.

Figure 3-6: ASM Front Panel Controls and Indicators

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 the customer alarm system. It is not required for system and ASM operation and must be installed in back slot number 15.

Figure 3-7 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.

Figure 3-7: LMI-ASM Face Plate

BPX Switch StrataBus 9.6 and 19.2 Gbps Backplanes

The BPX switch may be equipped with a backplane that supports either a 9.6 or 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. Further information is provided in the Cisco BPX 8600 Series Reference.

All BPX switch modules are interconnected by the BPX switch StrataBus backplane physically located between the front card slots and the back card slots. Even though the ATM data paths to/from the switching fabric and the interface modules are individual data connections, there are also a number of system bus paths used for controlling the operation of the BPX switch. The StrataBus backplane, in addition to the 15 card connectors, contains the following signal paths:

• ATM crosspoint wiring—individual paths used to carry ATM trunk data between both the network interface and service interface module(s) and the crosspoint switching fabric.
  
  
• Polling bus—used to carry enable signals between the BCC and all network interface modules.
  
  
• Communications bus—used for internal communications between the BCC and all other cards in the node.
  
  
• Clock bus—used to carry timing signals between the BCC and all other system cards.
  
  
• Control bus—enables either the A bus wiring or B bus wiring.
  
  

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.