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M120 Craft Interface Description

 

The craft interface allows you to view status and troubleshooting information at a glance and to perform many system control functions. It is hot-insertable and hot-removable. The craft interface is located on the front of the router above the upper fan tray and contains the following:

Craft Interface Front Panel

The craft interface allows you to view status and troubleshooting information at a glance and to perform many system control functions. It is hot-insertable and hot-removable. The craft interface is located on the front of the router above the upper fan tray and contains the following:

Figure 1: Front Panel of the M120 Craft Interface
Front Panel of the M120 Craft
Interface

The front panel of the craft interface contains:

  • Yellow Minor Alarm LED, red Major Critical Alarm LED.

  • Alarm cutoff/lamp test ACO/LT button.

  • Chassis Status Master and Standby LEDs.

  • OK, FAIL, and ACT LEDs for each TXP-F13 SIB.

  • OK and FAIL LEDs for the front and rear fan trays.

  • OK and FAIL LEDs for each power supply.

M120 Alarm Relay Contacts on the Craft Interface

The host interface has two alarm relay contacts for connecting the router to external alarm devices (see Figure 1). Whenever a system condition triggers either the red or yellow alarm on the craft interface, the alarm relay contacts are also activated. The alarm relay contacts are located below the Routing Engine ports.

M120 External Clock Interface Ports on the Craft Interface

Two external clock ports EXT CLOCK to the right of the craft interface alarm LEDs enable you to connect the router’s internal Stratum 3 clock to an external reference clock source with an RJ-45 cable. Using the router’s software, you can configure the internal Stratum 3 clock to synchronize with an external Building Integrated Timing System (BITS) or SDH Equipment Timing Source (SETS) timing source by including a clock synchronization statement at the [edit chassis] hierarchy level.

Note

Refer to the, Junos OS Administration Library for configuration information.

The EXT CLOCK ports are labeled A and B. They accept two RJ-45 connectors for external clock inputs with T1 or E1 reference clocks.

M120 Routing Engine Interface Ports and Status Indicators

To the right of the alarm relay contact on the craft interface are two sets of ports that connect the Routing Engines to one or more external devices on which system administrators can issue Junos OS command-line interface (CLI) commands to manage the router (see Front Panel of the Craft Interface). The set of ports in the left connects to the Routing Engine in the left Routing Engine slot (REO) and the set on the right connects to the Routing Engine (RE1) in the right Routing Engine slot.

The ports with the indicated label in each set function as follows:

  • AUX—Connects the Routing Engine to a laptop, modem, or other auxiliary device through a cable with an RJ-45 connector.

  • CONSOLE—Connects the Routing Engine to a system console through a cable with an RJ-45 connector.

  • ETHERNET—Connects the Routing Engine through an Ethernet connection to a management LAN (or any other device that plugs into an Ethernet connection) for out-of-band management. The port uses an autosensing RJ-45 connector to support both 10- and 100-Mbps connections. Two small LEDs on the bottom of the port indicate the connection in use: the LED lights yellow or green for a 10-Mbps or 100-Mbps connection, and the LED lights green when traffic is passing through the port.