A dying gasp is a message (or signal) sent by the customer premises equipment (CPE) to equipment managed by an internet service provider (ISP) to indicate that the CPE has lost power.
A DSL device will send a dying gasp signal to the digital subscriber line access multiplexer (DSLAM) when a power outage occurs.
[3] The dying gasp message will end the session and a new session will be able to be made as soon as power returns and the modem retrains.
[citation needed] Dying gasp is referenced in section 7.1.2.5.3 of ITU-T Recommendation G.991.2 (12/2003) as the Power Status bit.
[citation needed] When an optical network terminal loses power it will send a dying gasp signal to the optical line terminal which will end the session.