Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Point-to-Point Protocol
open-in-new
<p>In <a href="/facts/Computer_network/3w5RM99p">computer networking</a>, Point-to-Point Protocol (PPP) is a <a href="/facts/Data_link_layer/K9yPufbt">data link layer</a> (layer 2) <a href="/facts/Communication_protocol/5uady7cB">communication protocol</a> between two routers directly without any host or any other networking in between. It can provide loop detection, <a href="/facts/Authentication/64y4S69b">authentication</a>, transmission <a href="/facts/Encryption/16q29Fdv">encryption</a>, and <a href="/facts/Data_compression/gMFuY4FT">data compression</a>. </p><p>PPP is used over many types of physical networks, including <a href="/facts/Serial_cable/SSI6eMoY">serial cable</a>, <a href="/facts/Phone_line/YdKUAka9">phone line</a>, <a href="/facts/Trunking/YazQ6Stv">trunk line</a>, <a href="/facts/Cellular_telephone/H3EcqD9h">cellular telephone</a>, specialized radio links, <a href="/facts/ISDN/zcV99rUb">ISDN</a>, and <a href="/facts/Fiber-optic_communication/dc6S0Hg5">fiber optic links</a> such as <a href="/facts/SONET/G3LgtGS6">SONET</a>. Since IP packets cannot be transmitted over a <a href="/facts/Modem/9H0Xwtq0">modem</a> line on their own without some data link protocol that can identify where the transmitted frame starts and where it ends, <a href="/facts/Internet_service_provider/dUacAxef">Internet service providers</a> (ISPs) have used PPP for customer <a href="/facts/Dial-up_access/gfhNU9s3">dial-up access</a> to the <a href="/facts/Internet/Xw1rVvJU">Internet</a>. </p><p>PPP is used on former <a href="/facts/Dial-up_networking/gfhNU9s3">dial-up networking</a> lines. Two derivatives of PPP, <a href="/facts/Point-to-Point_Protocol_over_Ethernet/dSfSRACH">Point-to-Point Protocol over Ethernet</a> (PPPoE) and <a href="/facts/Point-to-Point_Protocol_over_ATM/IVy5A2RW">Point-to-Point Protocol over ATM</a> (PPPoA), are used most commonly by ISPs to establish a <a href="/facts/Digital_subscriber_line/3pY5osov">digital subscriber line</a> (DSL) Internet service LP connection with customers. </p>