Understanding IPLC Base and Expansion Modules

Overview

The IPLC supports wavelengths up to 100 Gbps and enables ad-hoc allocation of network bandwidth for high-demand, real-time applications, and network services that are delivered over an optical fiber infrastructure. The IPLC base module provides the combined functionality of a 32-port reconfigurable optical add-drop multiplexer (ROADM), optical amplification, optical equalization, and optical channel monitoring on a single card. The IPLC base module also interfaces with the optional IPLC expansion module, which increases the port capacity to 64 add-drop ports.

Figure 1: IPLC Point-to-Point Configuration

Figure 1 shows a typical IPLC point-to-point configuration. In this configuration, the Line IN and Line OUT ports on the front of the IPLC base modules are connected to Juniper Networks’ optical inline amplifier (ILA) in the optical fiber network. Optical ILA nodes are typically placed into the network where the fiber length is greater than 80—100 km.

For ring configurations or for other east-west or north-south two-line deployment scenarios, you can connect two IPLC base modules together to form a single-node that consists of two 32-port ROADMs, each with its own line-side fiber span.

Configuring, Managing, and Monitoring the IPLC

You configure, manage, and monitor IPLC modules in a similar fashion to a standard PTX3000 Series interface, by entering a minimum set of CLI commands and making the proper connections between the ports on the IPLC front panel and the PTX Series interfaces.

SNMP

You can also use SNMP to configure the IPLC performance monitor thresholds, and monitor and manage the IPLC modules

Connectivity Services Director

Optionally, you can use the Junos Space Connectivity Services Director to configure, manage, and monitor the IPLC and the optical ILA.

Optical Supervisory Channel

The IPLC uses an in-band optical supervisory channel to communicate with the IPLC expansion module, as well as with remote IPLC modules and optical ILA nodes.

High Availability, Resiliency, and Integrity

Because the IPLC modules do not connect to the PTX Series high-speed backplane, upgrades to the system software and resets do not affect traffic running on the IPLC modules. From an optical perspective, the IPLC modules tolerate both fast and slow changes in physical conditions. For example, if a large number of optical channels disappear due to a fiber cut, the IPLC has sophisticated control circuitry that prevents any errors on the remaining channels. Similarly, slow degradation of the fiber plant is also accommodated to ensure optimal performance across the lifespan of the system.

To ensure error-free transmission across both long fiber runs and large numbers of wavelengths on spans, the IPLC base module automatically controls the power of each channel.

Usability, Serviceability, Security and Troubleshooting

Traditionally, wavelength-division multiplexing (WDM) systems and subsystems have relied on a high degree of manual configuration and fine-tuning from expert users to enable signals to be transmitted error free across the inherently analog medium of optical fiber. The IPLC automates these activities to the point that adding a wavelength is as simple as configuring a port on the router. No optical expertise is required because the IPLC automates the introduction, removal, and balancing of optical channels and you simply need to enable the traffic-carrying port by setting some basic Junos CLI commands.

Unlike traditional WDM systems, the IPLC and optical ILA can accommodate fiber spans between 0 dB and 30 dB with a single hardware variant, simplifying network designs and reducing spare inventory requirements.

WDM networks typically contain many elements and identifying underlying failure points is often complex. With the IPLC, if at any point traffic is interrupted, the system raises a number of alarms to notify the management and control layers of the system and also, to help quickly and easily identify the root cause of the failure.

Performance Monitors

Alarms and analog performance monitors are available to allow expert or non-expert users easily identify and localize faults. Performance monitors monitor analog data and alarms enabling you to quickly view the the health of the IPLC. You can quickly and easily configure and enable alarm thresholds at the various monitoring points on the IPLC module.

Usage Scenarios

Optical Bypass Node Configuration

Two IPLCs can be installed in the same shelf to form an Optical Bypass. In addition, should need arise, two Optical Passive Expansion Cards (OPECs) can be added (one connected to each IPLC card). In the latter case, the expansion cards expand the number of channels supported beyond the initial 32 channels.

You can also connect two IPLC modules to form an Optical Bypass node. In this case, the EXPRESS IN and EXPRESS OUT of one card connected to the EXPRESS OUT and EXPRESS IN of the other card respectively.

Optical bypasses are software configurable and controlled through the IPLC’s wavelength selective switch (WSS) so there is no need for manual intervention. The IPLCs software optical bypass enables wavelengths that do not terminate on the given node to be passed through to the remote node without optical-electrical-optical (OEO) conversion.