Amendment 1 to Recommendation ITU-T Y.1731 provides the following modifications:

A new OAM, "ETH-CSF", is introduced in clauses 7 and 9.

The consideration of interoperability between ETH-LT (2006) and ETH-LT (2008) is added in clause 7 and Annex B.

The clarification of ETH-LCK transmission is added in clause 7.

Some definitions in clause 5 are moved to clause 3.

Revision of the Introduction, clauses 2, 6, 8, Annex A and Appendix I.