LOF is not supported by V5.2 protocol. LOS is used instead. If LOF or LOS is received, LOS is assumed in the L1 state machine. If both LOF and LOS ceased, no LOS is assumed in the L1 state machine.
osmo-v5 - Osmocom implementation of ETSI/ITU V5 interface
This is a repository containing code implementing the ETSI/ITU V5 interface as specified in ITU-T G.964 + G.965.
V5 is an interface spoken between digital telephone exchange and its [remote] access network (multiplexers + concentrators of subscriber access lines).
For some general intro into V5, you might find the following OsmoDevCall recording interesting: https://media.ccc.de/v/osmodevcall-20211228-laforge-retro-isdn-v5
Initial development was done just using the spec as reference; from 09/2022 onwards a Nokia EKSOS N20 became the primary target. The code has been uses successfully against Nokia EKSOS N20 and Siemens Fastlink.
The project homepage is at https://osmocom.org/projects/retronetworking/wiki/Osmo-v5.
You can clone from the official osmo-v5.git repository using
git clone https://gitea.osmocom.org/retronetworking/osmo-v5
There is a web interface at https://gitea.osmocom.org/retronetworking/osmo-v5
Discussions related to osmo-v5 are happening on the email@example.com mailing list, please see https://lists.retronetworking.org/postorius/lists/discussion.lists.retronetworking.org/ for subscription options and the list archive.
Please observe the Osmocom Mailing List Rules when posting.