G.992.5 (also referred to as ADSL2+, G.dmt.bis+, and G.adslplus) is an

ITU-T The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Commu ...

standard for

asymmetric digital subscriber line Asymmetric digital subscriber line (ADSL) is a type of digital subscriber line (DSL) technology, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide ...

(ADSL)

broadband In telecommunications, broadband is wide bandwidth data transmission which transports multiple signals at a wide range of frequencies and Internet traffic types, that enables messages to be sent simultaneously, used in fast internet connections. ...

Internet access Internet access is the ability of individuals and organizations to connect to the Internet using computer terminals, computers, and other devices; and to access services such as email and the World Wide Web. Internet access is sold by Internet ...

. The standard has a maximum theoretical downstream sync speed of 24 megabits per second (Mbit/s). Utilizing G.992.5 Annex M upstream sync speeds of 3.3 Mbit/s can be achieved.

Technical information

ADSL2+ extends the capability of basic

ADSL Asymmetric digital subscriber line (ADSL) is a type of digital subscriber line (DSL) technology, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. ...

by doubling the number of downstream channels. The data rates can be as high as 24 Mbit/s downstream and up to 1.4 Mbit/s upstream depending on the distance from the

DSLAM 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 ...

to the customer's premises. ADSL2 frequencies

ADSL2+ is capable of doubling the frequency band of typical ADSL connections from 1.1 MHz to 2.2 MHz. This doubles the downstream data rates of the previous

ADSL2 ITU G.992.3 is an ITU (International Telecommunication Union) standard, also referred to as ADSL2 or G.dmt.bis. It optionally extends the capability of basic ADSL in data rates to 12 Mbit/s downstream and, depending on Annex version, up to 3 ...

standard (which was up to 12 Mbit/s), and like the previous standards will degrade from its peak bitrate after a certain distance. ADSL2+ also allows

port bonding A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Ha ...

. This is where multiple ports are physically provisioned to the end user and the total bandwidth is equal to the sum of all provisioned ports. So if 2 lines capable of 24 Mbit/s were bonded the result would be a connection capable of 48 Mbit/s download and twice the original upload speed. Not all DSLAM vendors have implemented this functionality. ADSL2+ port bonding is also known as ''G.998.x'' or ''G.Bond''.

References

External links

ITU-T Recommendation G.992.5: Asymmetric Digital SubscriberLine (ADSL) transceivers – Extended bandwidth ADSL2 (ADSL2+)
* http://homehelphub.com/Tutorials/ADSL {{DEFAULTSORT:Itu G.992.5 Digital subscriber line ITU-T recommendations ITU-T G Series Recommendations Telecommunications-related introductions in 2009 Telecommunication protocols

Technical information

See also

References

External links