Nortel NTHR17DA 4POC3MM 4-Port OC-3c/STM-1 ATM FP Card

The Nortel Networks NTHR17DA (often referred to as 4POC3MM) 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 high-density ATM connectivity with four independent OC-3c/STM-1 (155.52 Mbps) ports using multi-mode fiber (MMF) interfaces.This line interface module supports ATM cell switching, traffic management, and Quality of Service (QoS) features required for multiservice networks. Each port operates at 155.52 Mbps and is optimized for ATM Adaptation Layer (AAL) processing, virtual path/virtual channel (VP/VC) switching, and interworking with other Passport line cards. The card is particularly suited for ATM backbone, aggregation, or access applications in carrier and large enterprise environments.

The NTHR17DA features four multi-mode fiber ports with SC duplex connectors, supporting transmission distances typically up to 2 km over 62.5/125 µm or 50/125 µm multi-mode fiber. It integrates directly with the Passport 15000 backplane, working in conjunction with fabric modules (such as NTHR16GA) for non-blocking cell forwarding and system-wide traffic management.

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 are essential for maintaining 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 system-level monitoring.

During operation, the NTHR17DA continuously monitors port status, ATM cell statistics, and link quality 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 NTHR17DA 4POC3MM is intended for ATM-based multiservice deployments in the Passport 15000 platform, enabling cost-effective high-density OC-3/STM-1 connectivity for voice, video, and data services over multi-mode fiber infrastructure.