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This chapter explains how to set up the Cisco ONS 15454 SDH in different SDH topologies. Table 5-1 lists network setup topics.
To avoid errors during network configuration, Cisco recommends that you draw the complete ONS 15454 SDH topology on paper (or electronically) before you begin the physical implementation. A sketch ensures that you have adequate slots, cards, and fibers to complete the topology.
The ONS 15454 SDH node offers numerous types of protection. Table 5-2 shows the three main categories of protection types found in a network topology.
Table 5-2 Network Protection Types
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Table 5-3 shows the number of DCCs used by each SDH ring type.
Table 5-4 is a quick reference indicating when to perform a lockout on the ONS 15454 SDH node.
Table 5-4 ONS 15454 SDH Lockout Matrix
The ONS 15454 SDH is a Class 1 (CDRH) and Class 1M (IEC) laser system. Some procedures require the installation or removal of optical cards and fibers. Take appropriate safety precautions while performing these procedures.
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Caution Hazardous voltage may be present on the backplane when the system is operating. Use caution when removing or installing cards. |
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Subnetwork Connection Protection Rings (SNCP) provide duplicate fiber paths around the ring. Working traffic flows in one direction and protection traffic flows in the opposite direction. If a problem occurs in the working traffic path, the receiving node switches to the path coming from the opposite direction. With SNCP rings, switching occurs at the end of the path and is triggered by defects or alarms along the path.
The network can be divided into a number of interconnected subnetworks. Within each subnetwork, protection is provided at the path level and the automatic protection switching between two paths is provided at the subnetwork boundaries. The node at the end of the path and the intermediate nodes in the path select the best traffic signal. The virtual container is not terminated at the intermediate node, instead it compares the quality of the signal on the two incoming ports and selects the better signal.
CTC automates ring configuration. SNCP ring traffic is defined within the ONS 15454 SDH on a circuit-by-circuit basis. If an extended SNCP mesh network circuit is not defined within a 1+1 or MS-SPRing line protection scheme and path protection is available and specified, CTC uses an SNCP ring as the default protection mechanism.
Figure 5-1 shows a basic SNCP ring configuration. If Node A sends a signal to Node C, the working signal travels on the working traffic path through Node B. The same signal is also sent on the protect traffic path through Node D. If a fiber break occurs (Figure 5-2), Node C switches its active receiver to the protect signal coming through Node D.
Because each traffic path is transported around the entire ring, SNCPs are best suited for networks where traffic concentrates at one or two locations and is not widely distributed. SNCP ring capacity is equal to its bit rate. Services can originate and terminate on the same SNCP ring, or they can be passed to an adjacent access or interoffice ring for transport to the service-terminating node.
Figure 5-3 shows a common SNCP ring application. STM-1 path circuits provide remote switch connectivity to a host V5.x switch. In the example, each remote switch requires eight E-1s to return to the host switch. Figure 5-4 and Figure 5-5 show the shelf layout for each node in the example.
Node A has four E1-14 cards to provide 56 active E-1 ports. The other sites only require two E1-14 cards to carry the eight E-1s to and from the remote switch. You can use the other half of each ONS 15454 SDH shelf assembly to provide support for a second or third ring to other existing or planned remote sites.
In this sample STM-1 SNCP ring, Node A contains four E1-14 cards and two STM-1 cards. Six free slots are available, which you can provision with cards or leave empty.
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Note Fill unused card slots with a blank faceplate (Cisco P/N 15454E-BLANK). The blank faceplate ensures proper airflow when operating the ONS 15454 SDH. |
Figure 5-4 shows the shelf setup for these cards.
In the Figure 5-3 example, Nodes B - D each contain two E1-14 cards and two STM-1 cards. Eight free slots are available which you can provision with other cards or leave empty. Figure 5-5 shows the shelf assembly setup for this configuration sample.
To set up an SNCP ring, you perform five basic procedures:
Step 2 Complete the "Configure the SNCP Ring DCC Terminations" procedure.
Step 3 Configure the timing. See the "Set up External, Line, or Mixed Timing for the ONS 15454 SDH" procedure or the "Set Up Internal Timing for the ONS 15454 SDH" procedure.
Step 4 Complete the "Set Card Ports In Service" procedure.
Step 5 After enabling the ports, set up the SNCP circuits. SNCP signal thresholds—the levels that determine when the SNCP path is switched—are set at the circuit level. To create SNCP circuits, see the "Introduction" section.
Step 6 You configured an SNCP ring for one node. Use the same procedures to configure the additional nodes. To create an extended SNCP mesh network, see the "Extended SNCP Mesh Networks" section. To create circuits, see the "Creating VC High-Order Path Circuits" section.
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Caution Always wear an authorized electrostatic discharge wrist band when removing or installing ONS 15454 SDH cards. |
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Step 2 Allow the cards to boot. For more information about installing cards, see the "Card Installation" section.
Step 3 Attach the fiber to the west and east STM-N card ports at each node:
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Note The SDH and SONET versions of the Cisco ONS 15454 do not interoperate via DCC. DCC interoperability is not available for ONS 15454 SDH Software R3.3. |
Step 2 From the node view, click the Provisioning > SDH DCC tabs.
Step 3 In the SDCC Terminations section, click Create.
Step 4 On the Create SDCC Terminations dialog box, press the Control key and click the two slots/ports that will serve as the SNCP ports at the node. For example, Slot 5 (STM-16)/Port 1 and Slot 14 (STM-16)/Port 1.
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Note The ONS 15454 SDH uses the SDH Section layer DCC (SDCC) for data communications. It does not use the Line DCCs. Line DCCs can be used to tunnel DCCs from third-party equipment across ONS 15454 SDH networks. |
Step 5 Deselect the "Set Port In Service" checkbox. Place the ports in service after the timing is configured.
The slots/ports display in the SDCC Terminations section.
Step 7 Complete Step 2—Step 6 at each node that will be in the SNCP ring.
Step 8 After configuring the SDH DCC, set the timing for the node. See the "Setting Up ONS 15454 SDH Timing" section.
Step 9 After configuring the timing, set the card ports in service. See the "Set Card Ports In Service" procedure.
This section explains how to add and remove nodes in an ONS 15454 SDH SNCP ring configuration. To add or remove a node in an SNCP ring, you perform two basic procedures:
Step 2 Add an SNCP node. See the "Add an SNCP Node" procedure.
Remove an SNCP node. See the "Remove an SNCP Node" procedure.
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Step 2 Right-click the span that will be cut to add or delete a node and choose Circuits from the shortcut menu (Figure 5-8).
Step 3 On the Circuits on Span dialog box (Figure 5-9), choose the protection from the Perform SNCP span switching menu:
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Caution FORCE and LOCKOUT commands override normal protective switching mechanisms. Applying these commands incorrectly can cause traffic outages. |
Step 4 Click Apply.
Step 5 When the confirmation dialog box appears, click Yes to confirm the protection switching. The column under Switch State changes to your chosen level of protection.
Step 6 Click Close after Switch State changes.
Step 2 Clear any alarms or conditions on the ring nodes. See the "Check for Alarms" procedure.
Step 3 At the node that you will add to the SNCP:
Step 4 Start CTC for a node that will physically connect to the new node.
Step 5 See the "Switch SNCP Ring Traffic" procedure to initiate a FORCE switch to move traffic away from the span that will connect to the new node.
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Caution Traffic is not protected during a protection switch. |
Step 6 Two nodes will connect directly to the new node; remove their fiber connections:
a. Remove the east fiber connection from the node that will connect to the west port of the new node.
b. Remove the west fiber connection from the node that will connect to the east port of the new node.
Step 7 Replace the removed fiber connections with connections from the new node.
Step 8 Log out of CTC and then log back into the new node in the ring.
Step 9 Display the network view. The new node should appear in the network view. Wait for a few minutes to allow all the nodes to appear.
Step 10 Click the Circuits tab and wait for all the circuits to appear, including spans. Circuits that will pass through the new node display as "incomplete."
Step 11 In the network view, right-click the new node and choose Update Circuits With New Node from the list of options. Wait for the confirmation dialog box to appear. Verify that the number of updated circuits displayed in the dialog box is correct.
Step 12 Click the Circuits tab and verify that no incomplete circuits are displayed. If incomplete circuits are displayed, repeat Step 10.
Step 13 Use the "Switch SNCP Ring Traffic" procedure to clear the protection switch.
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Caution The following procedure is designed to minimize traffic outages while nodes are removed, but traffic will be lost when you delete and recreate circuits that passed through the removed node. |
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Step 2 Complete the "Switch SNCP Ring Traffic" procedure to initiate a FORCE switch to move traffic away from the node you will remove. Initiate a FORCE switch on all spans connected to the node you are removing.
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Caution Traffic is not protected during a forced protection switch. |
Step 3 Log into the node that you will remove if you are already logged in, display the node view.
Step 4 Delete circuits that originate or terminate in that node. (If a circuit has multiple drops, delete only the drops that terminate on the node you are deleting.)
Step 5 From the node that will be deleted, remove the east and west span fibers. At this point, the node is no longer a part of the ring.
Step 6 Reconnect the span fibers of the nodes remaining in the ring.
Step 7 Log out of CTC and then log back into a node in the ring.
Step 8 Click the Alarms tab of each newly-connected node and verify that the span cards are free of alarms. Resolve any alarms before proceeding.
Step 9 If the removed node was the BITS timing source, select a new node as the BITS source or select another node as the master timing node.
Step 10 See the "Switch SNCP Ring Traffic" procedure to clear the protection switch.
Multiplex Section Shared Protection Rings (MS-SPRings) share the ring bandwidth equally between working and protection traffic. Half the payload bandwidth is reserved for protection in each direction, making the communication pipe half-full under normal operation.
There are two types of MS-SPRings, two-fiber and four-fiber. Two-fiber MS-SPRings share service and protection equally, but only two physical fibers are required. For more information, see the "Two-Fiber Multiplex Section Shared Protection Ring" section. With four-fiber MS-SPRings, the nodes on either side of the failed span perform a span switch and use the second pair of fiber as the new working route. For more information, see the "Four-Fiber MS-SPRings" section.
MS-SPRing nodes can terminate traffic that it receives from either side of the ring. Therefore, MS-SPRings are suited for distributed node-to-node traffic applications such as interoffice networks and access networks.
MS-SPRings allow bandwidth to be reused around the ring and can carry more traffic than a network with traffic flowing through one central hub. MS-SPRings can also carry more traffic than an SNCP operating at the same STM-N rate. Table 5-5 shows the bidirectional bandwidth capacities of two-fiber MS-SPRings. The capacity is the STM-N rate divided by two, multiplied by the number of nodes in the ring and minus the number of pass-through VC4 circuits.
Table 5-5 Two-Fiber MS-SPRing Capacity
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1 N equals the number of ONS 15454 SDH nodes configured as MS-SPRing nodes. 2 PT equals the number of VC4 circuits passed through ONS 15454 SDH nodes in the ring (capacity can vary depending on the traffic pattern). |
Table 5-6 shows the bidirectional bandwidth capacities of four-fiber MS-SPRings.
Table 5-6 Four-Fiber MS-SPRing Capacity
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Figure 5-10 shows an example of MS-SPRing bandwidth reuse. The same VC4 carries three different traffic sets simultaneously on different spans on the ring: one set from Node 3 to Node 1, one set from Node 1 to Node 2, and another set from Node 2 to Node 3.
The ONS 15454 SDH can support a number of ring combinations if the total DCC usage is equal to or less than 10 DCCs. Each MS-SPRing can have up to 16 ONS 15454 SDHs. Because the working and protect bandwidths must be equal, you can create only STM-4 (two-fiber only), STM-16, or STM-64 MS-SPRings.
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Note MS-SPRings with 16 or fewer nodes will meet the ITU G.841 switch time requirement. |
In two-fiber MS-SPRings, each fiber is divided into working and protect bandwidths. For example, in an STM-16 MS-SPRing (Figure 5-11), VC4s 1 - 8 carry the working traffic, and VC4s 9 - 16 are reserved for protection. Working traffic (VC4s 1 - 8) travels in one direction on one fiber and in the opposite direction on the second fiber. The Cisco Transport Controller (CTC) circuit routing routines calculate the "shortest path" for circuits based on requirements set by the circuit provisioner, traffic patterns, and distance. For example, in Figure 5-11, circuits going from Node 0 to Node 1 typically travel on Fiber 1, unless that fiber is full, in which case circuits are routed on Fiber 2 through Node 3 and Node 2. Traffic from Node 0 to Node 2 (or Node 1 to Node 3), can be routed on either fiber, depending on circuit provisioning requirements and traffic loads.
The SDH K1 and K2 bytes carry the information that governs MS-SPRing protection switches. Each MS-SPRing node monitors the K bytes to determine when to switch the SDH signal to an alternate physical path. The K bytes communicate failure conditions and actions taken between nodes in the ring.
If a break occurs on one fiber, working traffic targeted for a node beyond the break switches to the protect bandwidth on the second fiber. The traffic travels in the reverse direction on the protect bandwidth until it reaches its destination node. At that point, traffic is switched back to the working bandwidth.
Figure 5-12 shows a sample traffic pattern on a four-node, two-fiber MS-SPRing.
Figure 5-13 shows how traffic is rerouted after a line break between Node 0 and Node 3.
Figure 5-14 shows a sample two-fiber MS-SPRing implementation. A regional long-distance network connects to other carriers at Node 0. Traffic is delivered to the service provider's major hubs.
Figure 5-15 shows the shelf assembly layout for Node 0, which has one free slot. Figure 5-16 shows the shelf assembly layout for the remaining sites in the ring. In this MS-SPRing configuration, an additional eight E-3s at Node IDs 1 and 3 can be activated. An additional four E-3s can be added at Node ID 4, and ten E-3s can be added at Node ID 2. Each site has free slots for future traffic needs.
The ONS 15454 SDH can support many ring combinations if the total DCC usage is equal to or less than 10 DCCs. Each MS-SPRing can have up to 16 ONS 15454 SDHs. Because the working and protect bandwidths must be equal, you can create only STM-16 or STM-64 MS-SPRings.
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Note MS-SPRings with 16 or fewer nodes will meet the ITU G.841 switch time requirement. |
Four-fiber MS-SPRings double the bandwidth of two-fiber MS-SPRings. Four-fiber MS-SPRings increase the reliability and flexibility of traffic protection because they allow span switching as well as ring switching. Two fibers are allocated for working traffic and two fibers for protection, as shown in Figure 5-17. To implement a four-fiber MS-SPRing, you must install four STM-16 cards or four STM-64 cards at each MS-SPRing node.
Four-fiber MS-SPRings provide span and ring switching:
The ONS 15454 SDH uses the K3 overhead byte for MS-SPRing automatic protection switching (APS) to allow an ONS 15454 SDH MS-SPRing to have more than 16 nodes. If an MS-SPRing is routed through third-party equipment that cannot transparently transport the K3 byte, you can remap the ring to either the Z2, E2, or F1 bytes on STM-16 cards. (K3 byte remapping is not available on other STM-N cards other than STM-16.) If you remap the K3 byte, you must remap it to the same byte on each MS-SPRing trunk card that connects to the third-party equipment. All other MS-SPRing trunk cards should remain mapped to the K3.
For example, in Figure 5-20, an MS-SPRing span between Node 2 and Node 4 passes through third-party equipment. Because this equipment cannot transparently transport the K3 byte, the STM-16 card at Node 2/Slot 12 and the STM-16 card at Node 4/Slot 5 are provisioned to use an alternate byte. Other MS-SPRing trunk cards are not changed.
Do not perform K3 byte remapping unless a remap is required to provision an MS-SPRing that uses third-party equipment. See the "Remap the K3 Byte" procedure as needed.
To set up an MS-SPRing on the ONS 15454 SDH, you perform six basic procedures:
Step 2 Complete the "Create the MS-SPRing DCC Terminations" procedure.
Step 3 Set up MS-SPRing timing. See the "Set up External, Line, or Mixed Timing for the ONS 15454 SDH" procedure or the "Set Up Internal Timing for the ONS 15454 SDH" procedure.
Step 4 Complete the "Set Card Ports In Service" procedure.
Step 5 If an MS-SPRing span passes through equipment that cannot transparently transport the K3 byte, remap the MS-SPRing extension byte on the trunk cards on each end of the span. See the "Remap the K3 Byte" procedure.
Step 6 Complete the "Provision the MS-SPRing" procedure.
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Caution Always wear an authorized electrostatic discharge wrist band when removing or installing ONS 15454 SDH cards. |
Step 2 Allow the cards to boot. For more information about installing cards, see "Card Installation" section.
Step 3 Attach the fiber to the east and west MS-SPRing ports at each node.
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Note The SDH and SONET versions of the Cisco ONS 15454 do not interoperate via DCC. DCC interoperability is not available for ONS 15454 SDH Software R3.3. |
Step 2 Click the Provisioning > SDH DCC tabs.
Step 3 In the SDCC Terminations section, click Create.
Step 4 On the Create SDCC Terminations dialog box, press Ctrl and click the two slots/ports that will serve as the MS-SPRing ports at the node. For example, Slot 5 (STM-16)/Port 1 and Slot 12 (STM-16)/ Port 1. For four-fiber MS-SPRings, provision the working cards, but not the protect cards, as DCC terminations.
Step 5 Deselect the "Set Port In Service" checkbox. Ports should be placed in service after the timing is configured.
Step 7 The slots/ports appear in the SDCC Terminations list.
Step 8 Complete Step 3—6 at each node that will be in the MS-SPRing.
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Note The ONS 15454 SDH uses the SDH Section layer DCC (SDCC) for data communications. It does not use the Line DCCs; therefore, the Line DCCs are available to tunnel DCCs from third-party equipment across ONS 15454 SDH networks. For more detail, see the "Provision a DCC Tunnel" procedure. |
Step 9 After configuring the SDH DCC, set the timing for the node. For procedures, see the "Setting Up ONS 15454 SDH Timing" section.
Step 10 After configuring the timing, set the card ports in service. See the "Set Card Ports In Service" procedure.
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Step 2 Double-click the STM-16 card that connects to the third-party equipment. The card view displays.
Step 3 Click the Provisioning > Line tabs.
Step 4 Click MS-SPRing Ext Byte and choose the alternate byte: Z2, E2, or F1.
Step 6 (Four-fiber MS-SPRing only) Repeat Steps 2—5 for each protect card.
Step 7 (Two-fiber MS-SPRing only) Repeat Steps 2—5 at the node and card on the other end of the MS-SPRing span.
Step 2 Choose the Provisioning > Ring tabs.
Step 3 Click Create.
Step 4 On the Create MS-SPRing dialog box (Figure 5-24), set the MS-SPRing properties:
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Note The east and west ports must match the fiber connections and DCC terminations set up in the "Install the MS-SPRing Trunk Cards" procedure and the "Create the MS-SPRing DCC Terminations" procedure. |
For four-fiber MS-SPRings, complete the following:
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Note To avoid reversion time mismatches, Cisco recommends that you use the same span reversion time throughout the ring. |
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Note Some or all of the following alarms display during MS-SPRing setup: E-W MISMATCH, RING MISMATCH, APSCIMP, APSDFLTK, MSSP-OOSYNC. The alarms will clear after you configure all the nodes in the MS-SPRing. |
Step 6 Complete Step 1—5 at each node that you are adding to the MS-SPRing.
Step 7 After you configure the last MS-SPRing node, wait for the MS-SPRing Ring Map Change dialog box to display (this can take 10 - 30 seconds).
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Note The dialog will not display if SDCC Termination alarms (e.g., EOC) or MS-SPRing alarms (such as E-W MISMATCH and RING MISMATCH) are present. If an SDCC alarm is present, review the DCC provisioning at each node; see the "Create the MS-SPRing DCC Terminations" procedure. If MS-SPRing alarms have not cleared, repeat Step 1—5 at each node, making sure each node is provisioned correctly. You can also follow alarm troubleshooting procedures provided in the Cisco ONS 15454 SDH Troubleshooting and Maintenance Guide. |
Step 8 On the MS-SPRing Ring Map Change dialog, click Yes.
Step 9 On the MS-SPRing Ring Map dialog box, verify that the ring map contains all the nodes you provisioned in the expected order. If so, click Accept. If the nodes do not appear, or are not in the expected order, repeat Step 1—8, making sure no errors are made.
Step 10 Display the network view and verify the following:
Step 11 Test the MS-SPRing using testing procedures normal for your site; here is a common test procedure:
a. Run test traffic through the ring.
b. Log into a node on the ring, click the Maintenance > Ring tabs, and choose MANUAL RING from the East Switch list. Click Apply.
c. In network view, click the Conditions tab and click Retrieve. You should see a Ring Switch West event, and the far-end node that responded to this request will report a Ring Switch East event.
d. Verify that traffic switches normally.
e. Choose Clear from the East Switch list and click Apply.
f. Repeat Steps a—d for the West Switch.
g. Disconnect the fibers at any node on the ring and verify that traffic switches normally.
This section explains how to add nodes in an ONS 15454 SDH MS-SPRing configuration. You can only add one node at a time to an MS-SPRing.
To add a node to an MS-SPRing, you perform five procedures:
Step 2 Install cards and configure the new node. See the "Install Cards and Configure the New MS-SPRing Node" procedure.
Step 3 Before connecting the fiber, route traffic away from the area of the ring where service will be performed. See the "Switch MS-SPRing Traffic Before Connecting a New Node" procedure.
Step 4 After switching ring traffic, connect the fiber. See the "Connect Fiber to the New Node" procedure.
Step 5 Add an MS-SPRing node. See the "Provision the Ring for the New Node" procedure.
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Step 2 Allow the cards to boot. For more information about installing cards, see the "Card Installation" section. Run test traffic through the node to ensure the cards are functioning properly.
Step 3 Log into the new node. Complete the "Add the Node Name, Contact, Location, Date, and Time" procedure.
Step 4 Provision the SDH DCC. Complete the "Create the MS-SPRing DCC Terminations" procedure.
Step 5 Configure the MS-SPRing timing. See the "Set up External, Line, or Mixed Timing for the ONS 15454 SDH" procedure or the "Set Up Internal Timing for the ONS 15454 SDH" procedure.
Step 6 Complete the "Set Card Ports In Service" procedure for the new node's cards.
Step 7 If the new node will connect to third-party equipment that cannot transport the K3 byte, see the "Remap the K3 Byte" procedure to remap STM-16 cards trunk card that connects to the third-party equipment. Make sure the trunk card at the other end of the span is mapped to the same byte set on the new node.
Step 8 Complete the "Provision the MS-SPRing" procedure.
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Caution Traffic is unprotected during a protection switch. |
Step 2 Switch protection on its east port:
Performing a FORCE switch generates a manual switch request on an equipment (MANUAL-REQ) alarm. This is normal.
Step 3 Log into the existing node that will connect to the new node through its west port (Node 1 in the Figure 5-27 example).
Step 4 Switch protection on its west port:
a. Remove the east fiber from the node that will connect to the west port of the new node. In the Figure 5-27 example, this is Node 4/Slot 12.
b. Remove the west fiber from the node that will connect to the east port of the new node. In the Figure 5-27 example, this is Node 1/Slot 5.
Step 2 Replace the removed fibers with fibers connected from the new node. Connect the west port to the east port and the east port to the west port. Figure 5-28 shows the MS-SPRing example after the node is connected.
Step 3 Exit CTC.
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Note The new node will not appear in the ring until you exit CTC, restart, and provision the ring to accept the new node. |
Step 2 In node (default) view, choose the Provisioning > Ring tabs.
Step 3 Click a ring and then click Ring Map.
Step 4 On the MS-SPRing Map Ring Change dialog box, click Yes.
Step 5 On the MS-SPRing Ring Map dialog box, verify that the new node is added. If it is, click Accept. If it does not appear, Start CTC for the new node. Verify that the MS-SPRing is provisioned correctly according to the "Provision the MS-SPRing" procedure, then repeat Step 1—Step 4 in this procedure. If the node still does not appear, repeat all procedures for adding a node making sure that no errors were made.
Step 6 Display the network view and click the Circuits tab. Wait until all the circuits are discovered. The circuits that pass through the new node will be shown as incomplete.
Step 7 Right-click the new node and choose Update Circuits With New Node from the shortcut menu. Verify that the number of updated circuits displayed in the dialog box is correct.
Step 8 Choose the Circuits tab and verify that no incomplete circuits are present.
Step 9 Clear the protection switch on the existing node using its east port to connect to the new node. Then clear the protection switch on the existing node using its west port to connect to the new node. The protection switches were first performed in the "Switch MS-SPRing Traffic Before Connecting a New Node" procedure.
a. To clear the protection switch from the east port, display the node view and display the Maintenance > Ring tabs. From the East Switch list choose CLEAR. Click Apply.
b. To clear the protection switch from the west port, display the node view and display the Maintenance > Ring tabs. From the West Switch list choose CLEAR. Click Apply.
This section explains how to remove nodes in an ONS 15454 SDH MS-SPRing configuration.
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Note Do not Start CTC for the node that you will remove. |
Step 2 Start CTC for the node that you will remove.
Step 3 Use the following substeps to delete all the circuits that originate or terminate in that node.
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Note If a circuit has multiple drops, delete only the drops that terminate on the node you want to delete. |
a. Click the Circuits tab. The circuits that use this node are displayed.
b. Choose circuits that originate or terminate on the node. Click Delete.
d. If a multidrop circuit has drops at the node that will be removed, choose the circuit, click Edit, and remove the drops.
Step 4 Switch traffic away from the ports of neighboring nodes that will be disconnected when the node is removed.
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Note Refer to the list you created. See the prerequisite list at the beginning of this procedure for more information. |
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Caution Traffic is unprotected during the protection switch. |
a. Start CTC for the neighboring node that is connected through its east port to the removed node.
b. Click the Maintenance > Ring tabs.
c. From the East Switch list, choose FORCE RING. Click Apply.
d. Start CTC for the node that is connected through its west port to the removed node.
e. Click the Maintenance > Ring tabs.
f. From the West Switch list, choose FORCE RING. Click Apply.
Step 5 Remove all fiber connections between the node being removed and the two neighboring nodes.
Step 6 Reconnect the two neighboring nodes directly, west port to east port.
Step 7 If the removed node contained trunk STM-16 cards with K3 bytes mapped to an alternate byte, use the "Remap the K3 Byte" procedure to verify and remap, if needed, the MS-SPRing extended bytes on the newly-connected neighboring nodes.
Step 8 Exit CTC, then Start CTC for a node on the reduced ring.
Step 9 Wait for the MS-SPRing Map Ring Change dialog box to display. When the dialog box displays, click Yes.
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Note If the dialog box does not display after 10 - 15 seconds, choose the Provisioning > Ring tabs and click Ring Map. |
Step 10 On the MS-SPRing Ring Map dialog box, click Accept.
Step 11 Display the network view, then choose the Circuits tab.
Step 12 Delete, then recreate any incomplete circuits. Any circuits that you recorded in Step 6 will be shown as incomplete. See the "Creating VC High-Order Path Circuits" section. Recreate the incomplete circuits one at a time.
Step 13 Clear the protection switches on the neighboring nodes:
a. Display the node with the protection switch on its east port.
b. Click the Maintenance > Ring tabs and choose CLEAR from the East Switch list. Click Apply.
c. Start CTC for the node with the protection switch on its west port.
d. Click the Maintenance > Ring tabs and choose CLEAR from the West Switch list. Click Apply.
Step 14 If a BITS clock is not used at each node, check that the synchronization is set to one of the eastbound or westbound MS-SPRing spans on the adjacent nodes. If the removed node was the BITS timing source, use a new node as the BITS source or select internal synchronization at one node where all other nodes will derive their timing. (For information about ONS 15454 SDH timing, see the "Setting Up ONS 15454 SDH Timing" section.)
Two-fiber STM-16 or STM-64 MS-SPRings can be upgraded to four-fiber MS-SPRings. To upgrade, you install two STM-16 or STM-64 cards at each two-fiber MS-SPRing node, then start CTC and upgrade each node from two-fiber to four-fiber. The fibers that were divided into working and protect bandwidths for the two-fiber MS-SPRing are now fully allocated for working MS-SPRing traffic.
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Step 2 Install two STM-16 or STM-64 cards at each MS-SPRing node. You must install the same STM-N card rate as the two-fiber ring. See the "Card Installation" section.
Step 3 Set the card ports in service for each new STM-N card. See the "Set Card Ports In Service" procedure.
Step 4 Connect the fiber to the new cards. Use the same east/west connection scheme that connected the two-fiber connections. Figure 5-22 shows an example of how to connect fiber.
Step 5 Test the new fiber connections using procedures standard for your site. For example, pull a Tx fiber for a protect card and verify that an LOS alarm displays for the appropriate Rx card. Do this fiber test for every span in the MS-SPRing protect ring.
Step 6 Perform a span lockout at each MS-SPRing node (Figure 5-31):
a. At one of the MS-SPRing nodes, display the node view. Click the Maintenance > Ring tabs.
b. Under West Switch for the two-fiber MS-SPRing you will convert, choose LOCKOUT SPAN. Click Apply.
c. Under East Switch, choose LOCKOUT SPAN. Click Apply.
d. Repeat Steps a - c at each node in the two-fiber MS-SPRing.
Step 7 Upgrade each node from two-fiber to four-fiber MS-SPRing:
a. At one of the MS-SPRing nodes, display the node view. Click the Provisioning > Ring tabs.
b. Choose the two-fiber MS-SPRing. Click Upgrade.
c. On the Upgrade MS-SPRing dialog box, complete the following:
Step 8 Clear the span lockout:
a. Display an MS-SPRing node in node view. Click the Maintenance > Ring tabs.
b. Under West Switch, choose CLEAR. Click Apply.
c. Under East Switch, choose CLEAR. Click Apply.
d. Repeat Steps a - c at each node in the new four-fiber MS-SPRing.
e. Display the network view. Verify that no critical or major alarms are present, nor any facility alarms, such as LOS or LOF. If an alarm is present, resolve the problem using the Cisco ONS 15454 SDH Troubleshooting and Maintenance Guide.
Step 9 Test the four-fiber MS-SPRing using the "Provision the MS-SPRing" procedure.
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Caution To ensure that circuit and provisioning data is preserved, call the Technical Assistance Center before performing this procedure. For a complete list of TAC phone numbers, refer to the section called "About this Guide" in the Product Overview. |
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Caution To change MS-SPRing trunk cards, you will drop one node at a time from the current MS-SPRing. This procedure is service affecting during the time needed to complete the steps below. Service disruption applies to all MS-SPRing nodes where cards will change slots. Review all the steps before you proceed. |
Figure 5-33 shows a four node STM-16 MS-SPRing using trunk cards in Slots 6 and 12 at all four nodes. In this example, the user moves trunk cards at Node 4 in Slots 6 and 12 to Slots 5 and 6. Node 4 must be temporarily removed from the active MS-SPRing while the trunk cards are moved.
Figure 5-34 shows the MS-SPRing after the cards are moved.
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Caution Always wear an authorized electrostatic discharge wrist band when removing or installing ONS 15454 SDH cards. |
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Step 2 Switch traffic away from the node where the trunk card will be moved:
a. Start CTC for the node that is connected through its east port to the target node. (In the Figure 5-33 example, this is Node 1.) Click the Maintenance > Ring tabs.
b. From the East Switch list, choose FORCE RING. Click Apply.
When you perform a manual switch, a manual switch request equipment alarm (MANUAL-REQ) is generated. This is normal.
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Caution Traffic is unprotected during a protection switch. |
c. Start CTC for the node that is connected through its west port to the target node. (In the Figure 5-33 example, this is Node 3.) Click the Maintenance > Ring tabs.
d. From the West Switch list, choose FORCE RING. Click Apply.
Step 3 Start CTC on the target node.
Step 4 Click the Circuits tab. Write down the circuit information or, from the File menu, choose Print or Export to print or export the information; you will need it to restore the circuits later. See the "Printing CTC Data" section and the "Exporting CTC Data into Other Applications" section for more information.
Step 5 Delete the circuits on the card you are removing:
Step 6 Delete the SDH DCC termination on the card you are removing:
a. Click the Provisioning > SDH DCC tabs.
b. From the SDCC Terminations list, click the SDH DCC you need to delete and click Delete.
Step 7 Disable the ring on the target node:
a. Click the Provisioning > Ring tabs.
b. Highlight the ring and click Delete.
c. On the confirmation message, confirm that this is the ring you want to delete. If so, click Yes.
Step 8 If an STM-N card is a timing source, choose the Provisioning > Timing tabs and set timing to Internal.
Step 9 Place the ports on the card out of service:
Step 10 Physically remove the card.
Step 11 Insert the card into its new slot and wait for the card to boot.
Step 12 To delete the card in CTC from its former slot, right-click the card in node view and choose Delete Card from the list of options.
Step 13 Place the port(s) back in service. See the "Set Card Ports In Service" procedure.
Step 14 Follow the steps described in the "Setting Up MS-SPRings" section to reenable the ring using the same cards (in their new slots) and ports for east and west. Use the same MS-SPRing Ring ID and Node ID that was used before the trunk card was moved.
Step 15 Recreate the circuits that were deleted. See "Creating VC High-Order Path Circuits" section.
Step 16 If you use line timing and the card you are moving is a timing reference, reenable the timing parameters on the card. See the "Setting Up ONS 15454 SDH Timing" section for instructions.
The ONS 15454 SDH supports up to ten SDH DCCs. Therefore, one ONS 15454 SDH node can terminate and groom any ring combination if the total DCC usage is equal to or less than 10 DCCs.
Figure 5-35 shows an ONS 15454 SDH with multiple subtending rings.
Figure 5-36 shows an SNCP ring subtending from an MS-SPRing. In this example, Node 3 is the only node serving both the MS-SPRing and SNCP ring. STM-N cards in Slots 5 and 12 serve the MS-SPRing, and STM-N cards in Slots 6 and 13 serve the SNCP ring.
Figure 5-37 shows two MS-SPRings shared by one ONS 15454 SDH. The ONS 15454 SDH can support two MS-SPRings on the same node. This capability allows you to deploy an ONS 15454 SDH in applications requiring SDH DCSs (digital cross connect systems) or multiple SDH ADMs (add/drop multiplexers).
Ring 1 runs on Nodes 1, 2, 3, and 4. Ring 2 runs on Nodes 4, 5, 6, and 7. Two MS-SPRing rings, Ring 1 and Ring 2, are provisioned on Node 4. Ring 1 uses cards in Slots 5 and 12, and Ring 2 uses cards in Slots 6 and 13.
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Note Although different node IDs are used for the two MS-SPRings shown in Figure 5-37, nodes in different MS-SPRings can use the same node ID. |
After subtending two MS-SPRings, you can route circuits from nodes in one ring to nodes in the second ring. For example in Figure 5-37, you can route a circuit from Node 1 to Node 7. The circuit would normally travel from Node 1 to Node 4 to Node 7. If fiber breaks occur, for example between Nodes 1 and 4 and Nodes 4 and 7, traffic is rerouted around each ring: in our example, Nodes 2 and 3 in Ring 1 and Nodes 5 and 6 in Ring 2.
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Step 2 Attach fibers from these cards to the SNCP trunk cards on the SNCP nodes. In Figure 5-36, Node 3/Slot 6 connects to Node 5/Slot 13, and Slot 13 connects to Node 6/Slot 6.
Step 3 From the node view, click the Provisioning > SDH DCC tabs.
Step 4 Click Create.
Step 5 In the Create SDCC Terminations dialog box, click the slot and port that will carry the SNCP ring.
Step 6 Set the ports in service by making sure the "Set Port In Service" checkbox is checked.
The selected slots/ports are displayed in the SDCC Terminations section.
Step 8 Follow Steps 1 - 7 for the other nodes you will use for the SNCP ring.
Step 9 Display the network view to view the subtending ring.
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Step 2 Attach fibers from these cards to the MS-SPRing trunk cards on the MS-SPRing nodes. In Figure 5-36, Node 3/Slot 6 connects to Node 5/Slot 13, and Slot 13 connects to Node 6/Slot 6.
Step 3 From the node view, click the Provisioning > SDH DCC tabs.
Step 4 Click Create.
Step 5 In the Create SDCC Terminations dialog box, click the slot and port that will carry the MS-SPRing.
Step 6 Set the ports in service by making sure the "Set Port In Service" checkbox is checked.
Step 7 Click OK.
Step 8 The selected slots/ports are displayed under SDCC Terminations.
Step 9 Configure the MS-SPRing. See the "Provision the MS-SPRing" procedure.
Step 10 Follow Steps 1 - 9 for the other nodes that will be in the MS-SPRing.
Step 11 Display the network view to see the subtending ring.
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Step 2 Attach fibers from these cards to the MS-SPRing trunk cards on the MS-SPRing nodes. In Figure 5-37, Node 4/Slot 6 connects to Node 7/Slot 13, and Slot 13 connects to Node 5/Slot 6.
Step 3 From the node view, click the Provisioning > SDH DCC tabs.
Step 4 Click Create.
Step 5 In the Create SDCC Terminations dialog box, click the slot and port that will carry the MS-SPRing.
Step 6 Set the ports in service by making sure the "Set Port In Service" checkbox is checked.
Step 7 Click OK.
Step 8 The selected slots/ports are displayed in the SDCC Terminations section.
Step 9 To configure the MS-SPRing, use the "Provision the MS-SPRing" procedure. The subtending MS-SPRing must have a ring ID that differs from the ring ID of the first MS-SPRing.
Step 10 Follow Steps 1 - 9 for the other nodes that will be in the subtending MS-SPRing.
Step 11 Display the network view to see the subtending ring.
Figure 5-38 shows an example of two subtending MS-SPRings.
You can configure ONS 15454 SDHs as a line of add/drop multiplexers (ADMs) by configuring one set of STM-N cards as the working path and a second set as the protect path. Unlike rings, linear (point-to-point) ADMs require that the STM-N cards at each node have a 1+1 protection scheme to ensure that a break to the working line is automatically routed to the protect line.
Figure 5-39 shows three ONS 15454 SDHs in a linear ADM configuration. Working traffic flows from Node 1/Slot 6 to Node 2/Slot 6, and from Node 2/Slot 12 to Node 3/Slot 12. You create the protect path by placing Slot 6 in 1+1 protection with Slot 5 at Nodes 1 and 2, and placing Slot 12 in 1+1 protection with Slot 13 at Nodes 2 and 3.
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Step 2 Set up the network information for the node. For procedures, see the "Setting Up Network Information" section.
Step 3 Set up 1+1 protection for the STM-N cards in the ADM. In Figure 5-39, Slots 6 and 12 are the working ports and Slots 5 and 13 are the protect ports. In this example, you would set up one protection group for Node 1 (Slots 5 and 6), two for Node 2 (Slots 5 and 6, and 12 and 13) and one for Node 3 (Slots 12 and 13). To create protection groups, see the "Creating Card Protection Groups" section.
Step 4 For STM-N ports connecting ONS 15454 SDHs, set the SDH DCC terminations:
a. Start CTC for a linear ADM node and choose the Provisioning > SDH DCC tabs.
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Note The terminating nodes (Nodes 1 and 3 in Figure 5-39) will have one SDCC, and the intermediate nodes (Node 2 in Figure 5-39) will have two SDCCs. |
Step 5 Set up the node timing. If a node is using line timing, set the working STM-N card as the timing source. See the "Setting Up ONS 15454 SDH Timing" section.
Step 6 Place the STM-N ports in service. See the "Set Card Ports In Service" procedure.
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Caution This procedure is service affecting. |
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Caution Always wear an authorized electrostatic discharge wrist band when removing or installing ONS 15454 SDH cards. |
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Step 2 Click the Maintenance > Protection tabs.
Step 3 Under Protection Groups, choose the 1+1 protection group (that is, the group supporting the 1+1 span cards).
Step 4 Under Selected Group, verify that the working slot/port is shown as "Working/Active." If it is, proceed to Step 5. If the working slot says "Working/Standby" and the protect slot says "Protect/Active," switch traffic to the working slot:
a. Under Selected Group, choose the Protect/Active slot.
a. From the Switch Commands, choose Manual.
b. Click Yes on the confirmation dialog box.
c. Under Selected Group, verify that the working slot/port is Working/Active. If so, continue to Step d. If not, clear the conditions that prevent the card from carrying working traffic before proceeding.
d. From the Switch Commands, choose Clear. A Confirm Clear Operation dialog is displayed.
Step 5 Repeat Step 4 for each group in the 1+1 Protection Groups list at all nodes that will be converted.
Step 6 For each node, delete the 1+1 STM-N protection group that supports the linear ADM span:
a. Click the Provisioning > Protection tabs.
b. From the Protection Groups list, choose the 1+1 group you want to delete. Click Delete.
c. Click Yes on the confirmation dialog box.
d. Verify that no traffic disruptions are indicated on the test set. If disruptions occur, do not proceed. Recreate the protection group and isolate the cause of the disruption.
e. Continue deleting 1+1 protection groups while monitoring the existing traffic with the test set.
Step 7 Physically remove one of the protect fibers running between the middle and end nodes. For example, in Figure 5-40, the fiber from Node 2/Slot 13 to Node 3/Slot 13 is removed. The corresponding STM-16 card will cause an LOS condition for that fiber and port.
Step 8 Physically reroute the other protect fiber to connect the two end nodes. In the Figure 5-40 example, the fiber between Node 1/Slot 5 and Node 2/Slot 5 is rerouted to connect Node 1/Slot 5 to Node 3/Slot 13.
If you are leaving the STM-N cards in place, proceed to Step 13. If you are removing the cards, complete Steps 9 - 12. (In this example, cards in Node 2/Slots 5 and 13 are removed.)
Step 9 In the middle node, place the cards in Slots 5 and 13 out of service:
a. Display the first card in card view and choose the Provisioning > Line tabs.
Step 10 Delete the equipment records for the cards:
b. Right-click the card you just took out of service (e.g. Slot 5) and choose Delete Card.
Step 11 Save all circuit information.
a. In node view, choose the Provisioning > Circuits tab.
b. Record the circuit information using one of the following methods:
See the "Printing CTC Data" section and the "Exporting CTC Data into Other Applications" section for more information.
Step 12 Remove the STM-N cards that are no longer connected to the end nodes (Slots 5 and 13, in the example).
Step 13 In CTC display one of the end nodes (Node 1 or Node 3 in the example).
Step 14 Click the Provisioning > SDH DCC tabs.
Step 15 In the SDCC Terminations section, click Create.
Step 16 In the Create SDCC Terminations dialog box, choose the slot/port that was the protect slot in the linear ADM, for example, in Node 1, the previous protect slot is Slot 5/Port 1 (STM-16).
An EOC SDCC alarm will occur until you create an SDCC termination on the adjacent node.
Step 18 Display the node on the opposite end (Node 3 in the Figure 5-40 example) and repeat Steps 14 - 17.
Step 19 Delete and reenter the circuits one at a time. (See the "Creating VC High-Order Path Circuits" section.)
You can create the circuits automatically or manually. However, circuits must be protected. When they were built in the linear ADM, they were protected by the protect path on Node 1/Slot 5 to Node 2/Slot 5 to Node 3/Slot 13. With the new SNCP create circuits with protection.
Deleting the first circuit and recreating it to the same card/port should restore the circuit immediately.
Step 20 Monitor your SDH test set to verify that the circuit was deleted and restored.
Step 21 You should also verify that the new circuit path for the clockwise (CW) fiber from Node 1 to Node 3 is working. To do this, display the network view and move your cursor to the green span between Node 1 and 3.
Although the cursor only shows the first circuit created, do not become alarmed that the other circuits are not present. Verify with the SDH test set that the original circuits and the new circuits are operational. The original circuits were created on the counter clockwise linear path.
Step 22 Display the network view to view the newly-created ring.
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Caution This procedure is service affecting. |
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Caution Always wear an authorized electrostatic discharge wrist band when removing or installing ONS 15454 SDH cards. |
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Step 2 Click the Maintenance > Protection tabs.
Step 3 Under Protection Groups, choose the 1+1 protection group (that is, the group supporting the 1+1 span cards).
Step 4 Under Selected Group, verify that the working slot/port is shown as "Working/Active." If it is, proceed to Step 5. If the working slot says "Working/Standby" and the protect slot says "Protect/Active," switch traffic to the working slot:
a. Under Selected Group, choose the Protect/Active slot.
a. From the Switch Commands pull-down menu, choose Manual.
b. Click Yes on the confirmation dialog box.
c. Verify that the working slot is carrying traffic. If it is, continue to Step d. If not, clear the conditions that prevent the card from carrying working traffic before proceeding to Step d.
d. From the Switch Commands, choose Clear. A Confirm Clear Operation dialog is displayed.
Step 5 Repeat Step 4 for each group in the 1+1 Protection Groups list at all nodes that will be converted.
Step 6 For each node, delete the 1+1 STM-N protection group that supports the linear ADM span:
a. Click the Provisioning > Protection tabs.
b. From the Protection Groups list, choose the group you want to delete. Click Delete.
c. Click Yes on the confirmation dialog box.
d. Verify that no traffic disruptions are indicated on the SDH test set. If disruptions occur, do not proceed. Add the protection group and begin troubleshooting procedures to find out the cause of the disruption.
Step 7 Physically remove one of the protect fibers running between the middle and end nodes. In the Figure 5-41 example, the fiber running from Node 2/Slot 13 to Node 3/Slot 13 is removed. The corresponding end-node trunk card will display an LOS alarm.
Step 8 Physically reroute the other protect fiber so it connects the two end nodes. In the Figure 5-41 example, the fiber between Node 1/Slot 5 and Node 2/Slot 5 is rerouted to connect Node 1/Slot 5 to Node 3/Slot/13.
If you are leaving the STM-N cards in place, proceed to Step 13. If you are removing the cards, complete Steps 9 - 12. (In this example, cards in Node 2/Slots 5 and 13 are removed.)
Step 9 In the middle node, place the cards in Slots 5 and 13 out of service:
a. Display the first card in card view, then choose the Provisioning > Line tabs.
Step 10 Delete the cards from CTC:
a. From the View menu, choose Node View.
b. Right-click the card you just took out of service (e.g. Slot 5) and choose Delete Card.
c. Click Yes on the confirmation dialog box.
d. Repeat (a) through (c) for the second card (e.g. Slot 13).
Step 11 Save all circuit information:
a. In node view, choose the Provisioning > Circuits tab.
b. Record the circuit information using one of the following procedures:
See the "Printing CTC Data" section and the "Exporting CTC Data into Other Applications" section for more information.
Step 12 Remove the STM-N cards that are no longer connected to the end nodes (Slots 5 and 13, in the example).
Step 13 Start CTC for an end node. In node view, click the Provisioning > SDH DCC tabs.
Step 14 In the SDCC Terminations section, click Create.
Step 15 Highlight the slot that is not already in the SDCC Terminations list (in this example, Port 1 of Slot 5 (STM-16) on Node 1.
Step 16 Click OK. (An EOC SDCC alarm will occur until the DCC is created on the other node; in the example, Node 3/Slot 13.
Step 17 Start CTC for the node on the opposite end (Node 3 in Figure 5-41) and repeat Steps 13 - 16.
Step 18 For circuits running on an MS-SPRing protect VC4 (VC4 3 - 4 for an STM-4 MS-SPRing, VC4s 9 - 16 for an STM-16 MS-SPRing, and VC4s 33-64 for an STM-64), delete and recreate the circuit:
a. Delete the first circuit by clicking the Circuits tab, choose the circuit, click Delete, and click Yes when prompted.
b. Recreate the circuit on VC4s 3 - 4 (for an STM-4 MS-SPRing), VC4s 9 - 16 (for an STM-16 MS-SPRing), or VC4s 33-64 (for an STM-64 MS-SPRing) on the fiber that served as the protect fiber in the linear ADM. During circuit creation, deselect "Route Automatically" and "Fully Protected Path" on the Circuit Creation dialog box so you can manually route the circuit on the appropriate VC4s. See "Creating Multiple Drops for Unidirectional Circuits" section for more information.
c. Repeat Steps (a) and (b) for each circuit residing on an MS-SPRing protect VC4.
Step 19 Follow all procedures in the "Setting Up MS-SPRings" section to configure the MS-SPRing. The ring should have an East/West logical connection. While it may not physically be possible to connect the STM-N cards in an East/West pattern, it is strongly recommended. If the network ring that is already passing traffic does not provide the opportunity to connect fiber in this manner, logical provisioning can be performed to satisfy this requirement.
Be sure to assign the same Ring ID and different node IDs to all nodes in the MS-SPRing. Do not accept the MS-SPRing ring map until all nodes are provisioned.
Step 20 Display the network view to verify the newly-created ring.
In addition to single MS-SPRings, SNCP rings, and ADMs, you can extend ONS 15454 SDH traffic protection by creating extended SNCP mesh networks. Extended SNCPs include multiple ONS 15454 SDH topologies and extend the protection provided by a single SNCP ring to the meshed architecture of several interconnecting rings.
In an extended SNCP, circuits travel diverse paths through a network of single or multiple meshed rings. When you create circuits, you can provision CTC to automatically route circuits across the extended SNCP, or you can manually route them. You can also choose levels of circuit protection. For example, if you choose full protection, CTC creates an alternate route for the circuit in addition to the main route. The second route follows a unique path through the network between the source and destination and sets up a second set of cross-connections.
For example, in Figure 5-42, a circuit is created from Node 3 to Node 9. CTC determines that the shortest route between the two nodes passes through Node 8 and Node 7, shown by the dotted line; CTC then automatically creates cross-connections at Nodes 3, 8, 7, and 9 to provide the primary circuit path.
If full protection is selected, CTC creates a second unique route between Nodes 3 and 9 which, in this example, passes through Nodes 2, 1, and 11. Cross-connections are automatically created at Nodes, 3, 2, 1, 11, and 9, shown by the dashed line. If a failure occurs on the primary path, traffic switches to the second circuit path. In this example, Node 9 switches from the traffic coming in from Node 7 to the traffic coming in from Node 11 and service resumes. The switch occurs within 50 ms.
Extended SNCPs also allow spans of different SDH line rates to be mixed together in "virtual rings." Figure 5-43 shows Nodes 1, 2, 3, and 4 in a standard STM-16 ring. Nodes 5, 6, 7, and 8 link to the backbone ring through STM-4 fiber. The "virtual ring" is formed by Nodes 5, 6, 7, and 8 uses both STM-16 and STM-4 speeds.
You enable card ports to service and check for alarms during all topology-provisioning procedures. Use the following procedures when required.
Step 2 Click the Provisioning > Line tabs.
Step 3 Under the Status column, choose In Service.
Step 4 Click Apply.
Step 2 Verify the following:
If trouble is indicated, for example, a major alarm exists, resolve the problem before proceeding. Refer to the Cisco ONS 15454 SDH Troubleshooting and Maintenance Guide for alarm troubleshooting procedures.
Posted: Thu Jul 24 11:34:22 PDT 2003
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