1.TN81EX2 Front Panel and Functions

The TN81EX2 supports two 10G optical interfaces, and uses the LC optical fiber connector. It forwards data packets. For the data packets, the TN81EX2 supports QoS functions such as traffic management, congestion control, and queue scheduling.

2.Appearance

Figure 1 shows the appearance of the front panel of the TN81EX2.

Figure 1 Appearance of the front panel of the TN81EX2

3.Indicators

The following indicators are present on the front panel of the TN81EX2.

STAT indicator, red, green, or orange, which indicates the working status

ACT indicator, green, which indicates the service activation status

PROG indicator, red or green, which indicates the running status of the program

SRV indicator, red, green, or orange, which indicates the service status

L/A1 and L/A2 indicators, green or orange, which indicate the receiving, transmitting, and connection states of the data.

For details on indications of indicators, see Board Indicators.

4.Interfaces

Two XFP interfaces, which slope downwards 35 degrees, are present on the TN81EX2. Table 1 lists the types and usage of the interfaces. For fiber corresponding to the interfaces, see Types of Fiber.

Table 1 Types and usage of the interfaces on the TN81EX2

Functions and Features:

Table 2 lists the functions and features of the TN81EX2.

Table 2 Functions and features of the TN81EX2

1.Working Principle and Signal Flow

The TN81EX2 mainly consists of the network management module, transmission management module, switching buffer module, management module, power supply module, and clock module.

Figure 1 shows the block diagram for the working principle of the TN81EX2.

Figure 1 Block diagram for the working principle of the TN81EX2

2.In the Transmit Direction

The cross-connect buffer module processes the cells sent by the cross-connect unit and then sends the cells to the transmission management module. The transmission management module rearranges the cells to recover packets, for which the buffer and QoS management are performed. The packets are then sent to the network processing module. The network processing module performs the coding/decoding and the serial/parallel conversion for the data, and then sends the data to the 10 GE optical interface.

3.In the Receive Direction

The network processing module performs the O/E conversion for the Ethernet optical signals from the port of the Ethernet equipment, and performs the coding/decoding and the serial/parallel conversion for the data. The network processing module also performs route searching and address matching for the data packets, and transmits the corresponding packets to the transmission management module. After the transmission management module buffers and schedules the packets, the transmission management module slices the packets into cells required by the switching network. After the switching buffer module buffers the cells, the cells are then sent to the cross-connect unit.

4.Network Processing Module

The functions supported by this module are listed as follows:

In the receive direction, performs the O/E conversion for the 10GE Ethernet optical signals from the port of the Ethernet equipment (switch or router), and performs the coding/decoding.In the transmit direction, perform the coding and parallel/serial conversion on the signals from the transmission management module, and then perform the O/E conversion and transmit the signals.

5.Performs route searching and address matching for the data packet.

Extracts the synchronous Ethernet clock signals.

Extracts the IEEE 1588 V2 packets.

Transmission Management Module

This module slices packets into cells, and performs the QoS, line rate forwarding, and large volume buffer functions. The functions supported by this module are listed as follows:

QoS: This module provides functions of scheduling services and restricting the bandwidth, which include the flow queues and port queues. In addition, this module provides the statistics information accordingly.

Line rate forwarding: This module can bi-directionally transmit and receive packets at the full line rate, that is, 20 Gbit/s.

Large volume buffer: This module supports 50-ms buffer in the case of 20 Gbit/s traffic.

6.Switching Buffer Module

This module mainly performs buffer, queue management, and scheduling for cells. This module and the cross-connect unit form a three-level switching fabric to switch cells.

Management Module

This module provides buses, such as the parallel management bus and Ethernet communication bus, to manage other modules on the board. This module also monitors and reports alarms and performance events to the system control unit.

7.Clock Module

The functions supported by this module are listed as follows:

Provides clock signals for each module of the board.

Supports the synchronous Ethernet.

Supports the IEEE 1588 V2 protocol.

Supports the 1588 ACR clock.

8.Power Supply Module

This module converts the input DC voltage into various DC voltages required by each module on the board.

Valid Slots

Two slots house one TN81EX2. On the U2000, the two slots are displayed as the one with the smaller number. For example, slots 3 and 4 house the TN81EX2. On the U2000, only slot 3 is displayed.

Table 1 lists the valid slots for the TN81EX2.

Table 1 Valid slots for the TN81EX2