Chapter 11, Optical Channel Circuits and Virtual Patchcords Reference

This chapter explains the Cisco ONS 15454 dense wavelength division multiplexing (DWDM) optical channel (OCH) circuit types and virtual patchcords that can be provisioned on the ONS 15454. Circuit types include the OCH client connection (OCHCC), the OCH trail, and the OCH network connection (OCHNC). Virtual patchcords include internal patchcords and provisionable (external) patchcords (PPCs).

Note Unless otherwise specified, "ONS 15454" refers to both ANSI and ETSI shelf assemblies.

11.1 Optical Channel Circuits

The ONS 15454 DWDM optical circuits provide end-to-end connectivity through three OCH circuit types: OCHNCs, OCHCCs, and OCH trails.

OCHNCs establish connectivity between two optical nodes upon a specified C-band or L-band wavelength through the ports residing on wavelength selective switches, multiplexers, demultiplexer, and add/drop cards, as shown in Table 11-1.

Table 11-1 OCHNC Ports
Card	Source Ports	Destination Ports
32WSS 32WSS-L 40-WSS-C	ADD-RX	—
32MUX-O 40-MUX-C	CHAN-RX	—
32DMX-O 32DMX 32DMX-L 40-DMX-C	—	CHAN-TX
4MD AD-1B-xx.x AD-4B-xx.x AD-1C-xx.x AD-4C-xx.x	CHAN-RX	CHAN-TX

OCHCC circuits extend the OCHNC to create an end-to-end optical connection from client card to client card. OCHCCs are transported by OCH trails. OCH trail circuits create an optical connection from the source client card trunk port to the destination client card trunk port. Each OCH trail is associated to one or more OCHNCs. Figure 11-1 shows the relationships and optical flow between the OCHCC, the OCH trail, and the OCHNC.

Each OCHCC circuit is associated to a pair of client or trunk ports on the transponder (TXP), muxponder (MXP), GE_XP, 10GE_XP, or ITU-T line card. Each OCH trail is associated to a pair of trunk ports on the TXP, MXP, GE_XP, 10GE_XP, or ITU-T line card. The OCH trail ports are automatically associated to the OCHCC. If the OCHCC is created between two TXP, MXP, GE_XP, or 10GE_XP cards, two ports belong to the OCHCC at each circuit end:

If the OCHCC is created between two TXPP or two MXPP cards, three ports belong to the OCHCC at each end:

If the OCHCC is created between two ITU-T line cards, only one trunk port belongs to the OCHCC at each end. Table 11-2 lists the ports that can be OCHCC and OCH trail endpoints.

Table 11-2 OCHCC and OCH Trail Ports
Card	OCHCC	OCH Trail
TXPs MXPs GE_XP 10GE_XP ADM-10G	Any client port	Any trunk port
ITU-T line cards: •OC48/STM64 EH •OC192 SR/STM64 •MRC-12 •MRC-2.5-12 •MRC-2.5G-4	Any trunk port	Any trunk port

11.1.1 Administrative and Service States

OCHCCs, OCH trails, and OCHNCs occupy three different optical layers. Each OCH circuit has its own administrative and service states. The OCHCCs impose additional restrictions on changes that can be made to client card port administrative state.

The OCHCC service state is the sum of the OCHCC service state and the OCH trail service state. When creating an OCHCC circuit, you can specify an initial state for both the OCHCC and the OCH trail layers, including the source and destination port states. The ANSI/ETSI administrative states for the OCHCC circuits and connections are:

OCHCC service states and source and destination port states can be changed independently. You can manually modify client card port states in all traffic conditions. Setting an OCHCC circuit to OOS,DSBLD/Locked,disabled state has no effect on OCHCC client card ports.

An OCH trail is created automatically when you create an OCHCC. OCH trails can be created independently between OCH-10G cards and GE_XP and 10GE_XP when they are provisioned in Layer 2 Over DWDM mode. The OCH trail ANSI/ETSI administrative states include:

You can modify OCH trail circuit states from the Edit Circuit window. Placing an OCH trail OOS,DSBLD/Locked,disabled causes the following state changes:

Changing the OCH trail state to IS,AINS/Unlocked,automaticInService causes the following state changes:

The OCH trail service state is the sum of the OCHCC trunk port state and the OCHNC (if applicable) state. Changing the client card trunk ports to OOS,DSBLD/Locked,disabled when the OCH trail state IS/Unlocked will cause the OCH trail state to change to OOS,DSBLD/Locked,disabled and its status to change to Partial.

The OCHNC circuit states are not linked to the OCHCC circuit states. The administrative states for the OCHNC circuit layer are:

When you create an OCHNC, you can set the target OCHNC circuit state to IS/Unlocked or OOS,DSBLD/Locked,disabled. You can create an OCHNC even if OCHNC source and destination ports are OOS,MT/Locked,maintenance. The OCHNC circuit state will remain OOS-AU,AINS/Unlocked-disabled,automaticInService until the port maintenance state is removed. During maintenance or laser shutdown, the following behavior occurs:

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If OCHNCs or their end ports move into an AINS/AutomaticInService state because of user maintenance activity on an OCHCC circuit (for example, you change an optical transport section (OTS) port to OOS,DSBLD/Locked,disabled), Cisco Transport Controller (CTC) suppresses the loss of service (LOS) alarms on the TXP, MXP, GE_XP, 10GE_XP, or ITU-T line card trunk ports and raises a Trail Signal Fail condition. Line card trunk port alarms are not changed, however.

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If TXP client or trunk port are set to OOS,DSBLD/Locked,disabled state (for example, a laser is turned off) and the OCH trunk and OCH filter ports are located in the same node, the OCH filter LOS alarm is demoted by a Trail Signal Fail condition.

OCHCCs are associated with the client card end ports. Therefore, the following port parameters cannot be changed when they carry an OCHCC:

Certain OCHCC parameters, such as service type, service size, and OCHNC wavelength can only be modified by deleting and recreating the OCHCC. If the OCHCC has MXP end ports, you can modify services and parameters on client ports that are not allocated to the OCHCC. Some client port parameters, such as Ethernet frame size and distance extension, are not part of an OCHCC so they can be modified if not restricted by the port state. For addition information about administrative and service states, see "Administrative and Service States."

11.1.2 Creating and Deleting OCHCCs

To create an OCHCC, you must know the client port states and their parameters. If the client port state is IS/Unlocked, OCHCC creation will fail if the OTN line parameters (ITU-T G.709, FEC, signal fail bit error rate (SF BER), and signal degrade bit error rate (SD BER) on the OCHCC differ from what is provisioned on the trunk port. The port state must be changed to OOS-DSLB/Locked,disabled in order to complete the OCHCC.

If you delete an OCHCC, you can specify the administrative state to apply to the client card ports. For example, you can have the ports placed in OOS,DSBLD/Locked,disabled state after an OCHCC is deleted. If you delete an OCHCC that originates and terminates on MXP cards, the MXP trunk port states can only be changed if the trunk ports do not carry other OCHCCs.

11.1.3 OCHCCs and Service and Communications Channels

Although optical service channels (OSCs), generic communications channels (GCCs), and data communications channels (DCCs) are not managed by OCHCCs, the following restrictions must be considered when creating or deleting OCHCCs on ports with service or communication channels:

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Creating an OCHCC when the port has a service or a communications channel is present—OCHCC creation will fail if the OCHCC parameters are incompatible with the GCC/DCC/GCC. For example, you cannot disable ITU-T G.709 on the OCHCC if a GCC carried by the port requires the parameter to be enabled.

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Creating a service or communications channel on ports with OCHCCs—OCHCC creation will fail if the GCC/DCC/GCC parameters are incompatible with the OCHCC.

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Deleting an OCHCC on ports with service or communications channels—If an OSC/GCC/DCC is present on a TXP, MXP, GE_XP, 20GE_XP, or ITU-T line card client or trunk port, you cannot set these ports to the OOS,DSBLD/Locked,disabled state after the OCHCC circuit is deleted.

11.2 Virtual Patchcords

TXP, MXP, TXPP, MXPP, GE_XP, 10GE_XP, and ADM-10G client ports and DWDM filter ports can be located in different nodes or in the same single-shelf or multishelf node. ITU-T line card trunk ports and the corresponding DWDM filter ports are usually located in different nodes.

OCHCC provisioning requires a virtual patchcord between the client card trunk ports and the DWDM filter ports. Depending on the physical layout, this can be an internal patchcord or a provisionable (external) patchcord (PPC). Both patchcord types are bidirectional. However, each direction is managed as a separate patchcord.

Internal patchcords provide virtual links between the two sides of a DWDM shelf, either in single-shelf or multishelf mode. They are viewed and managed on the Provisioning > WDM-ANS > Internal Patchcords tab ( Figure 11-2).

CTC calculates internal patchcords automatically after you click the Default Patchcords button on the Internal Patchcords tab. However, some internal patchcords cannot be calculated because of the card types that are installed and/or the card positions within a shelf. These internal patchcords must be created manually. For example, internal patchcords related to optical bypass circuits must be manually provisioned. When you create an internal patchcord manually, the Internal Patchcord Creation wizard asks you to choose one of the following internal patchcord types:

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OCH-Trunk to OCH-Filter—Creates an internal patchcord between the trunk port of a TXP, MXP, GE_XP, 10GE_XP, or ITU-T line card, and an OCH filter card (wavelength selective switch, multiplexer, or demultiplexer).

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OTS/OCH to OTS/OCH—Creates an internal patchcord between two OTS OCH ports.

Note If an OTS-to-OTS PPC is created between nodes, it will no longer function if the node Security Mode mode is enabled (see "DLP-G264 Enable Node Security Mode" section on page 3-20). The reason for this is that if the Secure mode is enabled, it is no longer possible for the DCN extension feature to use the LAN interface to extend the internal network (due to the network isolation in this configuration mode). The result is that the topology discovery on the OTS-to-OTS PPC no longer operates.

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If the GCC, DCC, or OSC link between two nodes is disconnected that is also connected by a PPC link, the PPC link disappears from the CTC network view. The PPC link re-appears in the CTC network view after 15 secs (the time that OSPF takes to re-converge) if the nodes are connected to a LAN.

Table 11-3 shows the internal patchcord OCH trunk, OCH filter, and OTS/OCH ports.

Table 11-3 Internal Patchcord Ports
Card	OCH Trunk Ports	OCH Filter Ports	OTS/OCH Ports
TXPs MXPs GE_XP 10GE_XP ADM-10G ITU-T line cards	Any trunk port	—	—
OPT-BST OPT-BST-E OPT-BST-L	—	—	COM-TX COM-RX OSC-TX OSC-RX
OPT-AMP-17-C OPT-AMP-L	—	—	COM-TX COM-RX OSC-TX1 OSC-RX¹ DC-TX1 DC-RX1
OPT-PRE	—	—	COM-TX COM-RX DC-TX DC-RX
OSCM OSC-CSM	—	—	COM-TX COM-RX OSC-TX OSC-RX
32MUX 32MUX-O 40-MUX-C	—	Any CHAN RX port	COM-TX
32DMX 32DMX-L 32DMX-O 40-DMX-C	—	Any CHAN TX port	COM-RX
32WSS 32WSS-L 40-WSS-C	—	Any ADD port	COM-TX COM-RX EXP-TX EXP-RX DROP-TX
40-WXC-C	—	—	ADD-RX DROP-TX COM TX COM RX
MMU	—	—	EXP A TX EXP A RX

¹When provisioned in OPT-PRE mode.

PPCs are created and managed from the network view Provisioning > Provisionable Patchcord (PPC) tab ( Figure 11-3), or from the node view (single-shelf mode) or multiself view (multishelf mode) Provisioning > Comm Channel > PPC tab.

PPCs are required when the TXP, MXP, GE_XP, 10GE_XP, ADM-10G, or ITU-T line card is installed in a different node than the OCH filter ports. They can also be used to create OTS-to-OTS links between shelves that do not have OSC connectivity. PPCs are routable and can be used for network topology discovery by Open Shortest Path First (OSPF). GCCs and DCCs are not required for PPC creation. When you create a PPC, the PPC Creation wizard asks you to choose one of the following PPC types:

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OCH-Trunk to OCH-Trunk—Creates a PPC between two OCH trunk ports on TXP, MXP, GE_XP, 10GE_XP, ADM_10G, or ITU-T line cards.

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OTS to OTS—Creates a PPC between two OTS ports. This option establishes data communications network (DCN) connectivity between nodes that do not have OSCM or OSC-CSM cards installed and therefore do not have OSC connectivity. CTC selects the OTS ports after you choose the origination and termination sides.

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OCH-Trunk to OCH-Filter—Creates a PPC between a OCH trunk port on a TXP, MXP, GE_XP, 10GE_XP, ADM-10G, or ITU-T line card and an OCH filter port on a multiplexer, demultiplexer, or wavelength selective switch card.

Table 11-4 Provisionable Patchcord Ports
Card	OCH Trunk Port	OTS Port	OCH Filter Port
TXPs MXPs GE_XP 10GE_XP ADM-10G ITU-T line cards	Any trunk port	—	—
OPT-BST OPT-BST-E OPT-BST-L	—	COM RX¹ LINE RX LINE TX	—
OPT-AMP-17-C OPT-AMP-L	—	COM RX² COM TX³ LINE RX3 LINE TX3	—
OPT-PRE	—	COM RX4 COM TX⁴	—
OSC-CSM	—	COM RX1 LINE RX LINE TX	—
32MUX 32MUX-O 40-MUX-C	—	—	Any CHAN RX port
32DMX 32DMX-L 32DMX-O 40-DMX-C	—	—	Any CHAN TX port
32WSS 32WSS-L 40-WSS-C	—	—	Any ADD port
40-WXC-C	—	COM RX COM TX	—
MMU	—	EXP A RX EXP A TX	—

¹Line nodes only.

²When Card Mode is OPT-PRE.

³When Card Mode is OPT-LINE.

⁴Line nodes with two OPT-PRE cards and no BST cards installed.

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The OCH trunk and OCH filter ports must be on the same wavelength. CTC checks the ports for wavelength compatibility automatically during PPC provisioning.

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For OC-48/STM-16 and OC-192/STM-64 ITU-T line cards, the wavelength compatibility check is performed only when the cards are installed. The check is not performed for preprovisioned cards.

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For all other preprovisioned cards, a wavelength compatibility check is not performed if card is set to First Tunable Wavelength. The wavelength is automatically provisioned on the port, according to the add/drop port that you chose when you created the PPC.

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Trunk-to-trunk connections require compatible wavelengths if the port is equipped. A check is automatically performed during patchcord provisioning to ensure wavelength compatibility of ports.

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For connections involving one or more preprovisioned ports, no compatibility check is performed.

Table Of Contents

Optical Channel Circuits and Virtual Patchcords Reference

11.1 Optical Channel Circuits

11.1.1 Administrative and Service States

11.1.2 Creating and Deleting OCHCCs

11.1.3 OCHCCs and Service and Communications Channels

11.2 Virtual Patchcords