In the USA, the ex-BellSouth network deploys some ONTs with a ‘ALT Optics’ label that use a different wave length, 1310 nm for upstream and 1550 nm for downstream (instead of 1490 nm). This was done to be able to quickly convert a network with low fibre capacity while allowing the same fibre to be reused for multiple services contemporarily: both FTTH and FTTC/IFITL2,3,4.
This is one of the few ONTs that has a variant that works with this wavelength.
The last model letter in a Nokia/Alcatel ONT indicates the variant: A-M ALu ONT Manufacturer, P-Z external Manufacturer https://hack-gpon.org/assets/img/ont-nokia-naming.jpg ↩
Alt optic box. https://forums.att.com/conversations/att-internet-equipment/alt-optic-box/5defe95abad5f2f606973d3f ↩
Alt Optic Network Modem Question. https://forums.att.com/conversations/att-fiber-installation/alt-optic-network-modem-question/61134eaa7f0d0c5065624aea ↩
[AT&T Fiber] Bye bye 802.1x, you will not be missed. https://www.dslreports.com/forum/r33456904-, https://www.dslreports.com/forum/r33458733- ↩