Cisco Systems 8600 Series manual Cbr Vbr

Broadband Network Interface Cards, BNI-155

Functional Description

In the egress direction, the BNI-155 has 2 Queue Service Engine (QSEs) which provide each of the ports with 12 programmable queues with selectable parameters such as minimum bandwidth, priority, and maximum bandwidth. The BNI queues are based on a class of service algorithm. The BNI supports the following trunk queues:

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Voice

Non-Time Stamped

Time Stamped

Bursty Data A

Bursty Data B

High Priority (Network Management Traffic)

CBR

VBR

In the ingress direction, the BNI-155 has 2 Cell Input Engines (CIEs) that convert the incoming cell headers to the appropriate connection ID based on input from a Network Address Table.

The Serial Interface Unit (SIU) provides the BNI with an 800 Mbps cell interface to the StrataBus. It provides serial-to-parallel conversion of data, along with loopback and test signal generation capabilities.

The Line Interface Unit (LIU) performs the following ingress functions:

•Provides framing detection and synchronization.

•Provides the ability to extract timing from the incoming signal, and use it as a receive clock for incoming data, while providing transmit clock in the other direction. Alternatively, loop timing can be used to turn the receive clock back around to be used as a transmit clock. The receive clock may also be used to synchronize the node.

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Detects alarms, frame errors, and parity errors.

Detects far end errors, including framing errors, and yellow alarm indications.

Provides optional cell descrambling, header error check (HEC), and idle cell filtering.

Provides a small FIFO buffer for incoming cells.

Provides optical to electrical conversion.

4-12Cisco BPX 8600 Series Reference