Cisco ONS 15200 Module Handbook, Release 1.0.1
Chapter 5, Network Adaptation Module
Table of ContentsNetwork Adaptation Module
5.1 Functional Description
5.1.1 Alarm and Supervisory Subunit5.2 Technical Specifications
5.1.2 Front-Panel Indicators, Connections, and Adjustments
5.1.3 NAM Configuration
5.3 Removal and Replacement
Procedure: Remove a Network Adaptation Module from the ONS 15252 MCU
Procedure: Replace a Network Adaptation Module in the ONS 15252 MCU
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.
Figure 5-1 NAM50/50 split
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.
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.
Figure 5-2 Protected NAM block diagram
Figure 5-3 Unprotected NAM block diagram
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.
Environmental specifications for the NAM during operating conditions are listed in Table 5-3.
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.
Step 1 At the associated Hub Filter module (HFM), press the button at the bottom and push the HFM slightly upward (about 10 mm [0.5 in.]) to expose two grooves on the HFM top. Remove the fiber from the two lateral grooves on top.
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.
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.
Figure 5-4 NAM placement
Step 1 Align the NAM with the module slot in the ONS 15252 MCU immediately below the already-installed CLIP module.
Step 2 Carefully seat the NAM into the slot, making sure the backplane connector and the NAM connector are correctly mated.
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.
Figure 5-5 Connecting the NAM to the 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.
Figure 5-6 Connecting the NAM to the HFM A side
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.