Table of Contents

Network Adaptation Module

This chapter describes the Network Adaptation module (NAM).

5.1   Functional Description

This section provides a description of the NAM which is illustrated in Figure 5-1.

The function of the NAM is to extract the output signal from the dense wavelength division multiplexing (DWDM) laser on the Client Layer Interface Port (CLIP) module to the A side, the B side, or both sides. In optically protected systems, the NAM splits the output signal from the DWDM laser on the CLIP module to the A and the B directions. The signal can be split symmetrically (50/50) or asymmetrically (10/90 or 90/10). This splitting depends on the distance (attenuation) to the receiving collector node on the A side and B side, respectively. In optically unprotected systems, the NAM transfers the optical signal to the A or B side (100/0 or 0/100). The output splitting ratio is controlled by a fixed optical coupler.

The NAM is also used to transfer the optical signal from another node to the receiver(s) of the CLIP module. Furthermore, the NAM is also used to display the status of the CLIP module that is mounted directly above it; that is, the LEDs on the front panel of the NAM indicate the status of the CLIP module, not the NAM itself.

5.1.1   Alarm and Supervisory Subunit

The NAM is active, but does not include alarm or supervisory subunit functions.

5.1.2   Front-Panel Indicators, Connections, and Adjustments

The NAM front-panel LEDs are used to monitor CLIP operating parameters. Monitored items include the alarms, power, and status. Table 5-1 lists the conditions indicated by LEDs on the NAM front panel.

5.1.3   NAM Configuration

A CLIP module is mounted directly above the NAM. Two (unprotected) or three (protected) fibers come from the NAM to the CLIP module front panel. The receiver fibers are labeled A and B.

The four DWDM-side fibers from a protected NAM (two DWDM-side fibers from a unprotected NAM) are separated into two groups, labeled A and B, respectively. Each of these groups consists of one optical fiber connector (type MU) from the transmitter and one from a receiver.

Two fibers are mounted together in a duplex MU connector and are labeled A or B, respectively. The transmitting fibers are also labeled with the coupling ratio (10, 50, or 90) to ensure that the fibers are connected correctly to each Hub Filter module (HFM).

In the unprotected case, the NAM optical coupler is removed and only two patch cords are mounted on the NAM, one for the receiver and one for the transmitter. Note that only receiver A on the CLIP module is intended for the received optical signal for unprotected CLIP modules. Figure 5-2 illustrates a block diagram of the NAM used in protected configurations. Figure 5-3 illustrates a block diagram of the NAM used in unprotected configurations.

Located on lower right hand corner of the NAM module are 4-bit configuration header (jumpers) that the CLIP uses to identify the splitting ratio. The jumpers are numbered 1 through 4. Table 5-2 lists the jumper setting for each splitting ratio.

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5.2   Technical Specifications

This section covers environmental and mechanical specifications for the NAM. Although the NAM is an active device, electrical specifications do not apply.

5.2.1   Environmental Specifications

Environmental specifications for the NAM during operating conditions are listed in Table 5-3.

5.2.2   Mechanical Specifications

All NAMs consist of the following parts:

Protected NAMs consist of the following additional parts:

Unprotected NAMs consist of the following additional parts:

5.3   Removal and Replacement

This section explains how to remove and replace a NAM. The replacement module and any supplies, such as tagging materials, should be present on site before beginning the removal and replacement procedures.

The ONS 15252 Release 1.01 includes an updated Network Adaptation Module (NAM). The Release 1.01 NAM is designated with a "N3"label on the faceplate, whereas the previous version of the NAM does not have a faceplate label. The Release 1.01 shelf requires the Release 1.01 NAM. You can also use Release 1.01 NAMs in the Release 1.0 shelf. For more information about the shelf versions, refer to the Cisco ONS 15200 Product Description.

Caution   Placing NAMs without the N3 label into an Release 1.01 shelf may result in equipment damage.

Warning The ONS 15200 is energized with -48 VDC power.

Caution   Static electricity can damage electro-optical modules. While handling electro-optical modules, wear a grounding wrist strap to discharge the static buildup. Wrist straps are designed to prevent static electricity damage to equipment.

Procedure: Remove a Network Adaptation Module from the ONS 15252 MCU

Warning Follow proper safety procedures when removing modules without switching off the relevant subrack.

Warning Do not look directly at the optical connector output beams during connector removal. The beams can cause permanent eye damage.

If the NAM (channel) is protected, repeat Step 1 on the other side of the passive optical shelf.

Step 2   Remove the MU duplex connector from one HFM at a time.

Step 3   Put caps on the ends of the disconnected optical fiber jumper cables.

Step 4   Put dust plugs in the MU adapters in the HFM.

If the NAM is protected, repeat Steps 2, 3, and 4 on the other side of the passive optical shelf.

Step 5   One at a time, disconnect the three (or two unprotected) MU connectors at the CLIP module:

Step 6   Using a slot or Phillips screwdriver, loosen the NAM retaining screw.

Step 7   Carefully remove the NAM from the slot.

Step 8   If you are not going to replace a NAM, insert a Dummy NAM in the slot.

Procedure: Replace a Network Adaptation Module in the ONS 15252 MCU

Caution   Before replacing a NAM, verify that the NAM is the appropriate release for the shelf assembly or equipment damage could result. For an ONS 15200 Release 1.01 shelf assembly (800-12162-03) the NAM label should display N3. For an ONS 15200 Release 1 shelf assembly (800-12162-02) the NAM will not be labeled.

Note   If you are replacing a NAM, remove the currently installed NAM. If you are replacing a Dummy NAM, remove the Dummy NAM from the relevant NAM position.

Note   Before replacing the NAM, verify that the NAM jumpers are set to reflect the planned protection scheme and match the label on the NAM module. See Table 5-2 for the NAM jumper settings.

Warning Follow proper safety procedures when removing modules without switching off the relevant subrack.

Warning Do not look directly at the optical connector output beams during connector removal. The beams can cause permanent eye damage.

Note   Make sure that the NAM is properly inserted in the ONS 15252 MCU guide rails (in particular, the lower guiding rail).

Step 2   Carefully seat the NAM into the slot, making sure the backplane connector and the NAM connector are correctly mated.

Caution   Be sure not to harm the optical fibers and connectors emerging from the NAM.

Step 3   Using a slot or Phillips screwdriver, tighten the NAM retaining screw.

Step 4   Remove the dust cap from the relevant MU connector.

Step 5   Clean and inspect the relevant MU connector.

Step 6   Remove the dust plugs from the relevant MU adapter.

Step 7   Connect the three (or two unprotected) MU connectors from the NAM to the three (or two unprotected) MU adapters in the corresponding CLIP module. Begin with the inner connectors, labeled A and B, and connect the outer transmitter connector last. Figure 5-5 shows a connected NAM and CLIP module.

Step 8   One at a time, remove dust plugs from the HFM and remove fiber caps from NAM duplex MU connectors.

Step 9   Clean and inspect the optical fiber connectors.

Step 10   Connect one (unprotected) or two (protected) duplex MU connectors from the NAM to the HFM (unprotected) or HFMs (protected). Use the labeling on the fiber to ensure that the A-side and the B-side of the node are not interchanged. Figure 5-6 shows a NAM connected to an HFM.

Step 11   After connecting the NAM to the HFM, press the button at the HFM bottom and push the HFM slightly upward (about 10 mm [0.5 in.]) to expose two grooves on the HFM top.

Step 12   Verify that the fiber is firmly fixed in the two lateral grooves on top of the HFM.

Step 13   Snap the HFM back into place by pushing the button and gently pressing downwards.

Step 14   In the case of a protected channel, repeat Steps 11, 12, and 13 for the other HFM.

Step 15   Store excessive fiber in the space between the NAM and the ONS 15252 MCU passive optical shelf.

Step 16   Close the cover over the passive optical shelf.