437 KB0 KB200620252024Jakus, Gregaštevilka:5letnik:91str. 290-295ISSN:0013-5852COBISSID_HOST:217871619URN:URN:NBN:SI:doc-M5FBOV12slElektrotehniška zveza SlovenijeElektrotehniški vestnikdelayokostenelostossificationQUICTCPtransport mechanismstransportni mehanizmizakasnitveKaj prinaša transportni protokol QUIC?|For a secure transfer of the web content, we generally use a combination of the HyperText Transfer Protocol (HTTP) for communication with a web server, Transport Layer Security (TLS) for the encryption of the content and Transmission Control Protocol (TCP) for a reliable transfer. Using a combination of the protocols results in a poorer performance than using a single protocol, as each protocol has its own overhead, which is mainly reflected in an increased latency of the transfer. Moreover, the development of the World Wide Web and other Internet applications has created a need for more efficient transport mechanisms, which are difficult to implement in practice due to the ossification of the transport layer. Improvements to transport mechanisms have therefore been implemented as part of application protocols, in particular HTTP. The Quick UDP Internet Connections (QUIC) protocol combines the transport mechanisms implemented in HTTP, TLS and TCP under one roof and thus improves the efficiency of the web content transfer. QUIC is not a completely independent transport protocol, as it uses the User Datagram Protocol (UDP) to transport its messages and thus ensures that it is not rejected by the network devices. The main advantages of QUIC over the combination of the TCP, TLS and HTTP protocols are the faster connection establishment, the solution to the head-of-line blocking problem and its implementation in the user space of operating systems, which enables faster upgradesZa varen prenos spletnih vsebin najpogosteje uporabljamo kombinacijo protokolov HTTP (HyperText Transfer Protocol) za komunikacijo s spletnim strežnikom, TLS (Transport Layer Security) za šifriranje uporabniške vsebine in TCP (Transmission Control Protocol) za zanesljiv prenos sporočil. Posledica uporabe kombinacije protokolov je slabša učinkovitost, kot če bi uporabili en sam poseben protokol, saj vsak protokol vsebuje lastno režijo, kar se odraža predvsem v povečanih zakasnitvah pri prenosu. Z razvojem svetovnega spleta in drugih internetnih aplikacij so se poleg tega pojavile potrebe po učinkovitejših transportnih mehanizmih, ki pa jih je v praksi težko uvesti zaradi okostenelosti transportnega sloja. Nadgradnje transportnih mehanizmov so bile zato udejanjene v okviru aplikacijskih protokolov, še posebej protokola HTTP. Protokol QUIC (Quick UDP Internet Connections) prevzame pod svoje okrilje transportne mehanizme, udejanjene v protokolih HTTP, TLS in TCP, in s tem izboljša učinkovitost prenosa spletnih vsebin. QUIC ni popolnoma samostojen transportni protokol, saj za prenos svojih sporočil uporablja protokol UDP (User Datagram Protocol), s čimer zagotovi, da ga omrežne naprave ne zavračajo. Glavne prednosti protokola QUIC v primerjavi s kombinacijo protokolov HTTP, TLS in TCP so hitrejša vzpostavitev povezave, odprava problema blokade vodilnega sporočila in izvedba v okviru uporabniškega prostora operacijskih sistemov, kar omogoča hitrejše nadgradnjeTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaElektrotehniška zveza Slovenije