Electronic Mail: SMTP, POP3, IMAP push protocol: a client who wants push(send) data initiate a connection pull protocol: a client who wants to pull (receives) data initiate a connection SMTP 👉 push protocol / POP3, IMAP 👉 pull protocol Electronic mail Three Major Components Mail User Agents (MUA) creating email msg and transfer it to MTA & retrieving emails Mail Servers or Mail Transfer Agent (M..
CS/컴퓨터네트워크
Network Apps Loss-sensitive application (= data integrity = reliable) email, web, text messaging, remote login, P2P file sharing Delay-sensitive application multi-user network games, voice over IP (e.g. Skype) Bandwidth-sensitive application streaming stored video (YouTube, Netflix), real-time video conferencing Creating a network app no need to write software for network-core devices -> network..
Delay, Loss, Throughput in Networks Delay in networks Packets queue in router buffers When packet arrival rate to link (temporarily) > output link capacity -> packets queue, wait for turn d = $d_{proc}$ + $d_{queue}$ + $d_{trans}$ + $d_{prop}$ -> 한 라우터를 거쳐갈 때마다 $d_{proc}$: processing delay, determine output link by forwarding table lookup, 무시해도 되는 정도 $d_{queue}$: queueing delay, tme waiting at o..
인터넷 개요 What's the Internet? Nuts and bolts View Internet: network of networks host = end system = end node = termial = station protocols control sending, receiving of messages Internet standards: RFC, IETF Service View infrastructure that provides services to applicaations provide programming interface to application What's a protocol? Protocols define format, order of messages sent and received..
