Upstream (networking)
Encyclopedia
In computer networking, 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
applications and similar processes where the sending of data is critical. Upstream speeds are also important to users of peer-to-peer software
.
ADSL
and cable modem
s 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.
Client (computing)
A client is an application or system that accesses a service made available by a server. The server is often on another computer system, in which case the client accesses the service by way of a network....
to the server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
(uploading
Uploading and downloading
In computer networks, to download means to receive data to a local system from a remote system, or to initiate such a data transfer. Examples of a remote system from which a download might be performed include a webserver, FTP server, email server, or other similar systems...
). This differs greatly from downstream
Downstream (computer science)
In a telecommunications network or computer network, downstream refers to data sent from a network service provider to a customer.Although the best voiceband modems are called 56 kbit/s modems, downstream speeds can be limited to a few tens of kilobits per second with even lower upstream speeds...
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
Uploading and downloading
In computer networks, to download means to receive data to a local system from a remote system, or to initiate such a data transfer. Examples of a remote system from which a download might be performed include a webserver, FTP server, email server, or other similar systems...
content, uploads are used mainly for web server
Web server
Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
applications and similar processes where the sending of data is critical. Upstream speeds are also important to users of peer-to-peer software
Peer-to-peer
Peer-to-peer computing or networking is a distributed application architecture that partitions tasks or workloads among peers. Peers are equally privileged, equipotent participants in the application...
.
ADSL
Asymmetric Digital Subscriber Line
Asymmetric digital subscriber line is a type of digital subscriber line technology, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. It does this by utilizing frequencies that are not used by a voice...
and cable modem
Cable modem
A cable modem is a type of network bridge and modem that provides bi-directional data communication via radio frequency channels on a HFC and RFoG infrastructure. Cable modems are primarily used to deliver broadband Internet access in the form of cable Internet, taking advantage of the high...
s are asymmetric
Symmetry
Symmetry generally conveys two primary meanings. The first is an imprecise sense of harmonious or aesthetically pleasing proportionality and balance; such that it reflects beauty or perfection...
, with the upstream data rate much lower than that of its downstream. Symmetric connections such as Symmetric Digital Subscriber Line
Symmetric Digital Subscriber Line
Symmetric digital subscriber line can have two meanings:* In the wider sense it is a collection of Internet access technologies based on DSL that offer symmetric bandwidth upstream and downstream...
(SDSL) and T1
T-carrier
In telecommunications, T-carrier, sometimes abbreviated as T-CXR, is the generic designator for any of several digitally multiplexed telecommunications carrier systems originally developed by Bell Labs and used in North America, Japan, and South Korea....
, however, offer identical upstream and downstream rates.
If a node A on the Internet is closer (fewer hops away) to the Internet backbone
Internet backbone
The Internet backbone refers to the principal data routes between large, strategically interconnected networks and core routers in the Internet...
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
Internet service provider
An Internet service provider is a company that provides access to the Internet. Access ISPs directly connect customers to the Internet using copper wires, wireless or fiber-optic connections. Hosting ISPs lease server space for smaller businesses and host other people servers...
that provides Internet access to a local ISP. Hence, the word upstream also refers to the data connection between two ISPs.