E1/T1 Media Module

The E1/T1 Media Module has a total of four LEDs. The E1/T1 Media Module has three LEDs on its faceplate, which are under software control. Table 107 shows their color and faceplate positions.

The E1/T1 Media Module has a fourth GREEN SIG LED that indicates whether the link to the Central Office (CO) is up (equivalent to the TN464F circuit pack Status 3 GREEN LED). See Figure 18.

Note: Power-up and alarm states are the only conditions where hardware sets the state of the LEDs independent of ANGEL firmware control.

Figure 18. E1/T1 Media Module LEDs

The supported portion of the LED Control message allows software to change the status of the three standard LEDs on the E1/T1 Media Module faceplate. The exceptions to letting software turn off the LEDs are:

• The board is in reset (Red LED remains on)
• A call is up (Yellow LED remains on while the E1 line is in-frame and at least one voice/data call is up)
• During board reset initialization testing (Green LED remains on until initialization testing is complete).

Note: For ISDN operation, the Yellow LED will be turned on if ANY port has an active TDM connection (including the D-channel).

Synchronization

Clock synchronization is set via the Media Gateway Processor (MGP) command line interface (CLI). The command (in 'configure' mode) set sync interface {primary | secondary} {<mmID> | [<portID>]} defines a potential stratum clock source (E1/T1 Media Module, ISDN-BRI).,

where <mmID> is the Media Module ID of a MM stratum clock source of the form "vn", where "n is the MM slot number, and
For the MM720 BRI Media Module, <portID> is formed by combining the mmID of the MM to the 2-digit port number of the BRI port.

By setting the clock source to primary, normal failover will occur. Setting the source to secondary overrides normal failover, generates a trap, and asserts a fault. The identity of the current sync source in use is not stored in peristent storage. Persistent storage is used to preserve the parameters set by this command.
Control of which reference source is the "Active" source is accomplished by issuing the command set sync interface {primary | secondary}. If 'secondary' is chosen, then the secondary source becomes "Active", and the primary becomes "standby", and, in addition, fallback to the primary source will not occur if or when it becomes available.
If neither primary nor secondary sources are identified, then the local clock becomes "Active".

When a MM710 Media Module is driving a clock sync source line to the G700 main clock, the Yellow LED does not indicate port activity, but instead indicates that the MM710 is the sync source as follows:

• If the incoming signal is good, the YELLOW LED is driven on for three seconds and off for 200 milliseconds.
• If the incoming signal is lost and the sync line cannot be driven, the YELLOW LED is alternately off for three seconds and on for 200 milliseconds.
• If the YELLOW LED is on for 2.7 seconds and off for.3 seconds, the toneclock synchronizer is in "active" mode and an external synchronization source is being used as a synchronization reference.
• If the YELLOW LED is on 0.3 seconds and off 2.7 seconds, the toneclock synchronizer is in "active" mode and the internal (onboard) high accuracy clock is being used as a synchronization reference.
• If the UDS1 receives a downlink CCMS message to stop driving the clock sync lines, the YELLOW LED reverts back to indicating port activity.

Note: Unless otherwise indicated, the following commands issue from the G700 MGP CLI.

To test for slippage, from the SAT issue the command:

test mo logical 4255 physical 1v4 test 144

The results from the above command are given in Table 111:

If a secondary is similarly provisioned:

To activate the secondary, the following is similarly done:

To activate local the following is done:

To reactivate the primary, the following is done:

If the T1 physical connection were removed, then the secondary becomes active and the primary reports a failure.

Initialization

The E1/T1 Media Module LEDs behave in the following manner during initialization:

• The Angel provides a visual indication of the board's status through the three board LEDs.
• During initialization the YELLOW LED is held off, while the RED and GREEN LEDs are on during the entire initialization sequence.
• Upon power up or reset, if only the RED LED comes on, the Angel processor is dead or the board is being held permanently in reset.
• Upon completion of the diagnostics and initialization, the GREEN LED turns off.
• If the initialization tests fail, the RED LED remains on.
• If the tests all pass, then all LEDs are extinguished until switch software starts using the board.

After a successful initialization sequence, the LEDs are controlled as follows:

• The Angel lights the YELLOW LED when there is at least one non-idle trunk. If switch software sent a message to drive the clock sync signals, the YELLOW LED indicates this instead of the port busy/idle status.
• The SPE may independently light and extinguish the three LEDs through downlink LED Control messages, subject to the constraint that it may not turn off a YELLOW LED turned on by the Angel as a result of port activity.
• If the NCE+ resets the board for any reason and does not release the board from reset, the RED LED lights and the YELLOW and GREEN LEDs are held off.