Nortel NTHW15AG 4POC3SMIR 4-Port OC-3c/STM-1 ATM FP Card

The Nortel Networks NTHW15AG (commonly referred to as 4POC3SMIR) is a 4-Port OC-3c/STM-1 ATM Functional Processor (FP) Card designed for the Nortel Passport MSS 15000 multiservice switching platform. It provides four independent OC-3c/STM-1 (155.52 Mbps) ATM ports with single-mode intermediate-reach (SMIR) optical interfaces.This line interface module supports full ATM cell switching, traffic management, VP/VC cross-connection, and Quality of Service (QoS) features required for carrier-grade multiservice networks. Each port operates at the standard 155.52 Mbps STM-1/OC-3c line rate and is optimized for ATM Adaptation Layers (AAL1, AAL2, AAL5) and interworking with other Passport line cards and fabric modules.

The NTHW15AG features four single-mode fiber ports with SC duplex connectors and supports transmission distances up to 15 km over ITU-T G.652 single-mode fiber (SMF). The intermediate-reach (IR) optics make it suitable for metro and intra-city ATM backbone or aggregation applications. The card integrates directly with the high-speed Passport 15000 backplane, working in conjunction with fabric modules (such as NTHR16GA) for non-blocking cell forwarding and system-wide traffic engineering.

For installation and maintenance, the module occupies a dedicated line card slot in the Passport MSS 15000 chassis. It is a field-replaceable unit with robust backplane connectors. The card operates on standard -48 VDC telecom power and includes front-panel LEDs for per-port link status, activity, alarms, and module health. Proper fiber cleaning and inspection practices are essential to maintain optimal optical performance.

The card is engineered for carrier-class reliability in central office environments, complying with NEBS-level requirements for electromagnetic compatibility, thermal performance, and high availability. It supports redundant configurations and facilitates fault isolation through built-in diagnostics, loopback testing, and comprehensive system-level monitoring.

During operation, the NTHW15AG continuously monitors port status, ATM cell statistics, link quality, and error conditions on all four ports, reporting alarms and performance data to the central control processor. Configuration, traffic engineering, and firmware updates are managed through the Passport Element Management System or CLI.

The Nortel Networks NTHW15AG 4POC3SMIR is intended for high-density ATM deployments in the Passport 15000 platform, enabling cost-effective OC-3/STM-1 connectivity for voice, video, and data services over single-mode fiber infrastructure in metro and regional networks.