TCP Segmentation at layer 4 v.s. IP Fragmentation at layer 3 TCP Segmentation at layer 4: TCP breaks a message down into MSS sizes to perform reliable data delivery without being affected by IP fragmentation. (MSS  IP Fragmentation at layer 3 is necessary in order to deliver a (relatively large) message through a link with (relatively small) MTU.MSS (Maximum Segment Size) : 4계층 TCP 용어MTU (Maximu..

Application architecture) Client-Sever(C-S) vs. Peer-to-Peer(P2P)C-S 구조에서는 클라이언트가 증가할 수록 서버의 용량 (computing power and access network uplink capacity)이 전체 서비스에 미치는 영향이 큼.P2P's self-scalability : as the number of clients (peers) grows, P2P shows less file distribution delay than Client and Server architecture. (연습문제 p9 풀어보기) VoD (Video On Demand) Streaming serviceStreaming service means that (audio..

Mapping between hostname (URL or FQDN: Fully Qualified Domain Name) and IP address   "AAAA"(IPv6)Forwarding DNS : hostname --> IP addressReverse DNS : IP address --> hostname (receiving mail server가 sending mail server를 인증하기 위해 사용됨)Host aliasing (mapping btw alias and canonical) 다중 서비스를 하나의 서버에서 운영하는 경우 서로 다른 서버들이 모두 동일한 IP address로 동일한 machine에서 운영됨.[예1: multiple service on a single server] (ww..

Push protocol A client who initiates a TCP connection to a server wants to send(push) data to the server (ex: SMTP, etc)SMTP (push protocol) : used for sending(pushing)/delivering (NOT retrieving) emails Pull protocol A client who initiates a TCP connection to a server wants to receive(pull) data to the server (ex: HTTP, DNS, IMAP, etc)IMAP (pull protocol) : used for accessing emailsSMTP : Push ..

*** Web cookieHTTP is a stateless protocol which does not keep status of a HTTP client at a server.However, using cookie a server can maintain information about its clients.How to set up and use cookie ID? What are its benefits?What is the third-party cookie (타사쿠키)? 내가 접속한 웹서버(A)가 아닌 다른 회사(B)에서 발행한 쿠키를 이용함. 회사 B는 이를 이용하여 나의 cross-site 이력을 "추적(tracking)" 하여 필요한 광고를 노출시켜 이득을 취하는 방식이며 A를 이를 허용하고 B ..