ABSTRACT: An Optical Network Unit (ONU) transforms incoming optical signals into electronics at a customer's premises. An ONU closure is a
mechanical compartment that houses the ONU equipment..
An ONU system consists of a closure that is a metallic or non-metallic enclosure that provides physical and environmental protection
for the active electronic, optoelectronics, and passive optical components it houses.
GR-950-CORE Issue 4, Telcordia Generic Requirements for Optical Network Unit (ONU) Closures and ONU Systems, provides
criteria for analyzing ONU closures and systems used in a variety of Outside Plant (OSP) environments and applications, including those
used in building entrance facilities. It includes functional design criteria, generic mechanical and environmental requirements,
desired features, and the performance tests used for comparing ONU closures and systems with the stated requirements.
The performance tests for analyzing ONU closures and systems are intended to reflect a composite picture of standard installation
and operating conditions.
Issue 4 was revised to harmonize with the most recent editions of Telcordia GR-63, GR-487, GR-1089, GR-3171,
GR-3178 and other related generic requirements. The intent of Issue 4 is to add clarity to the test procedures and requirements. It
can be assumed that products that meet the requirements of Issue 3 would also meet the requirements of Issue 4 without requiring any
Changes to Issue 4 include, but are not limited to, the following:
"GR-3108-CORE Class References" was updated to match the latest found in GR-3108-CORE, Telcordia Generic Requirements for
Network Equipment in the Outside Plant (OSP).
Inclusion of the use of UL62368-1, Audio/Video, Information and Communication Technology Equipment Part 1: Safety Requirements, as
acceptable for NRTL Listing.
"Bonding and Grounding" test procedures were updated for clarification as well as use of updated ground symbol.
"Closure Surface Criteria (Surface Coating/Paint Tests)" was updated to include the criteria and testing used in GR-487-CORE,
Telcordia Generic Requirements for Electronic Equipment Cabinets.
"Temperature and Humidity" was updated to discuss humidity conditions.
"Power Cross Ignition" was updated with additional test procedure information.