A dying gasp is a message (or signal) sent by the
customer premises equipment
In telecommunications, a customer-premises equipment or customer-provided equipment (CPE) is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication circuit at the demarcation po ...
(CPE) to equipment managed by an
internet service provider
An Internet service provider (ISP) is an organization that provides a myriad of services related to accessing, using, managing, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, no ...
(ISP) to indicate that the CPE has lost power. Also known as last gasp.
DSL
A DSL device will send a dying gasp signal to the
digital subscriber line access multiplexer
A digital subscriber line access multiplexer (DSLAM, often pronounced ''DEE-slam'') is a network device, often located in telephone exchanges, that connects multiple customer digital subscriber line (DSL) interfaces to a high-speed digital co ...
(DSLAM) when a power outage occurs. A DSL interface with dying gasp must derive power for a brief period from another source so that the message can be sent without external power. 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.
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.
Fiber
When an
optical network terminal
upTwo simple NIDs, carrying six lines each, on the outside of a building
upA German copper phone line termination box called '':de:Abschlusspunkt Linientechnik, Abschlusspunkt LinienTechnik'' (APL, "Demarcation point")
In telecommunications, a ...
loses power it will send a dying gasp signal to the
optical line terminal
An optical line termination (OLT), also called an optical line terminal, is a device which serves as the service provider endpoint of a passive optical network. It provides two main functions:
# to perform conversion between the electrical sign ...
which will end the session.
See also
*
Passive optical network
A passive optical network (PON) is a fiber-optic telecommunications network that uses only ''unpowered'' devices to carry signals, as opposed to electronic equipment. In practice, PONs are typically used for the '' last mile'' between Internet ...
References
External links
ITU-T Recommendation G.991.2: Single-pair high-speed digital subscriber line (SHDSL) transceivers
Digital subscriber line
{{telecomm-stub