In
computer networking
A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or b ...
, upstream refers to the direction in which data can be transferred from the
client to the
server (
uploading). This differs greatly from
downstream not only in theory and usage, but also in that upstream speeds are usually at a premium.
Whereas downstream speed is important to the average home user for purposes of
downloading content, uploads are used mainly for
web server
A web server is computer software and underlying Computer hardware, hardware that accepts requests via Hypertext Transfer Protocol, HTTP (the network protocol created to distribute web content) or its secure variant HTTPS. A user agent, co ...
applications and similar processes where the ''sending'' of data is critical. Upstream speeds are also important to users of
peer-to-peer software.
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 wire, copper telephone lines than a conventional voiceband modem ...
and
cable modems are
asymmetric, with the upstream data rate much lower than that of its downstream. Symmetric connections such as
Symmetric Digital Subscriber Line (SDSL) and
T1, however, offer identical upstream and downstream rates.
If a node A on the Internet is closer (fewer hops away) to the
Internet backbone than a node B, then A is said to be upstream of B or conversely, B is downstream of A. Related to this is the idea of upstream providers. An upstream provider is usually a large
ISP that provides Internet access to a local ISP. Hence, the word upstream also refers to the data connection between two ISPs.
See also
*
Upstream server
*
Return channel
References
*
Data transmission
Orientation (geometry)
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