Understanding Optical Supervisory Channel Communication in the Amplifier Chain
Starting with Junos OS release 17.1, you can control and manage optical inline amplifiers (ILA) over the optical supervisory channel (OSC) of the PTX3000 integrated photonic line system. This topic provides an overview of the OSC communication across the PTX3000 integrated photonic line system when you are using Juniper Networks optical inline amplifiers (ILA)s in the amplifier chain. It also describes the control and manage capabilities of the optical ILA through the Junos OS CLI. The following sections are included:
Understanding the Functional Components of the Optical Inline Amplifier
To understand OSC communications, it is helpful to understand the functional components of the optical ILA. Understanding these components also helps when you are configuring the optical ILA or interpreting status output through the Junos OS CLI.
The optical ILA is a bidirectional amplifier that provides optical gain for the dense wavelength division multiplexing (DWDM) signal traversing the amplifier in each direction. You can use the optical ILA in packet optical multispan linear networks, as well as multispan ring networks.
As illustrated in Figure 1, the optical ILA is functionally two separate amplifiers; the E_AB amplifier provides optical gain for the DWDM signals traversing the unit east to west and the E_BA amplifier provides optical gain for the DWDM signals traversing the unit west to east.
There are two independent optical paths on the optical ILA:
Line A Input to Line A Output
Line B Input and Line B Output
Channels, shown as green arrows in Figure 1, received at Line A Input are amplified by E_AB, a variable gain erbium-doped fiber amplifier (EDFA), attenuated by VOA_B, a variable optical amplifier (VOA), and transmitted out Line B Output. Channels received at Line B Input are amplified by a second variable gain EDFA (E_BA), attenuated by VOA_A, and transmitted out Line A Output.
Understanding How the Optical ILA is Managed and Controlled
For OSC communications, the optical ILA uses two OSC channels: OSC_A and OSC_B. The OSC channel (shown in red arrows in Figure 1, is bidirectional in a given direction; OSC_A uses Line A Input and Line A Output, whereas OSC_B uses Line B Input and Line B Output. When an OSC message is received from a downstream node on Line A Input, the amplifier responds to the message over Line A Output. For upstream OSC communications, Line B Input receives an OSC message and responds to it over Line B Output. OSC communications are sent over an inband optical channel. Nodes can be either an optical ILA or an IPLC module in the PTX3000 integrated photonic line system.
Figure 2 illustrates the management, control, and communication of the optical ILA in the amplifier chain. You can manage the optical ILA using an SNMP network management system (NMS), Juniper Networks Connectivity Services Director over the DMI interface, the user interface of the optical ILA, or through the Junos OS CLI.
For OSC communications across the amplifier chain, the PTX3000 integrated photonic line system uses an anchor IPLC module, which communicates directly with each optical ILA. Because IPLC modules are standalone appliances in the chassis, they have no host path connectivity to the routing engine or switch fabric and thus have no connectivity to other FPC interfaces, as such, all OSC communications go through the anchor IPLC. You can designate only one IPLC in the line system as the anchor of the amplifier chain.
For OSC communications and identification purposes, you assign each IPLC module and each optical ILA a unique, private IP address. OSC communications use an internal private LAN and IPLC modules and optical ILAs must be on the same, private IP subnet. OSC management IP addresses are not advertised by the PTX3000 Series router and are not auto-discoverable. You can further identify optical ILAs by specifying a unique identification number. IPLC modules are also identified by their MAC address.
You can configure only one IPLC module as the anchor IPLC of the PTX3000 integrated photonic line system and you must specify that the remote PTX3000 router as not an anchor IPLC.
For OSC communications, all optical ILAs and IPLC modules must be on the same, private IP subnet as the anchor IPLC.
SNMP Management Overview and Configuration
If you are using an SNMP network management system (NMS) to manage the optical ILAs in the amplifier chain, there is no direct communication between the optical ILAs in the amplifier chain and the SNMP NMS. All communication to and from the SNMP NMS and optical ILAs in the chain is handled by the anchor IPLC module. The IPLC modules relays the command to the specified optical ILA. Each command from the NMS must include a community string indicating the unique identification number of the optical ILA in the amplifier chain. SNMP traps are propagated from each optical ILA to the anchor IPLC and out to the SNMP NMS.
The following various get/set commands are supported from the SNMP NMS:
Commands: Save a configuration, restore a configuration, upgrade firmware
Set the optical ILA: power threshold crossing alerts (TCA)s for the optical ILA performance monitors
Get the specified optical ILA: part number, serial number, uptime, temperature, fan speed, firmware upgrade status, SNMP user information, EDFA (module type, part number, working status, gain, temperature), optical power, VOA attenuation, and OSC (index).
View active alarms and historical alarms
Optical ILA Control and Management Features Available in the Junos OS CLI
The OSC enables you to control and manage certain capabilities on the optical ILA through the Junos OS CLI. Table 1 describes the Junos OS CLI capabilities for the optical ILA.
To configure all other optical ILA parameters not supported in the Junos OS CLI, see PTX3000 Packet Transport Router with Integrated Photonic Line Card.
Table 1: Summary of Optical ILA Configuration Capabilities in Junos OS CLI
Optical ILA Configuration Capability in Junos OS CLI
What it is and Where to Find it in the Guide
Unique identification number
Configure a unique ID for the optical ILA for OSC communication, see Configuring the Optical ILA Identification Number
Configure the optical ILA IP address for OSC communication, see Configuring the IP Address of an Optical Inline Amplifier
Security, software upgrades, and resets
Configure user authentication, perform software upgrades and soft and hard reset, see Configuring Optical ILA Authentication Through the Junos OS CLI and Upgrading the Optical Inline Amplifier from the Junos OS CLI
View statistics for the following components on the optical ILA:
Configure and view threshold crossing alerts (TCA)s for the optical ILA performance monitors. Performance monitors monitor the health of the optical ILA at various points on the optical ILA hardware based on threshold levels. TCAs can give the management system an early indication as to the state of the associated entity when it crosses a certain threshold. You can use the CLI to configure and manage the these items on the optical ILA performance monitors:
Understanding How to Configure the OSC Using the Junos OS CLI
To configure the OSC in the PTX3000 integrated photonic line system and amplifier chain:
Configure one of the IPLC modules in the line system as the anchor IPLC, see Configuring the Anchor IPLC of the Amplifier Chain.
Configure a unique IP address on the anchor IPLC module, see Configuring the IP Address of the Anchor IPLC.
Configure the MAC address of the anchor IPLC, see Configuring the MAC Address of the Anchor IPLC.
Configure a unique identification number for each optical ILA in the amplifier chain, see Configuring the Optical ILA Identification Number.
Configure a unique IP address for each optical ILA in the amplifier chain, see Configuring the IP Address of an Optical Inline Amplifier.
For the complete procedure, see Configuring the Optical Supervisory Channel Across the Amplifier Chain of the PTX3000 Integrated Photonic Line System.