networking

Introduction Two key functions forwarding: move packets from router’s input to appropriate router output routing: determine route taken by packets from source to destination. Forwarding Table header value Output Link 0100 3 0101 2 0111 2 1001 1 Network Service Model Example services for individual datagrams guaranteed delivery guaranteed delivery with less than 40 msec delay Example services for a flow of datagrams in-order datagram delivery guaranteed minimum bandwidth to flow restrictions on changes in inter-packet spacing Virtual Circuit and Datagram Networks Connection, Connect-less Service Datagram network provides network-layer connectionless service. [Read More]

Principles of Network Applications 1. Network Application Architectures An application architecture is designed by application developer and dictates how the application is structured over the various end system. There are two predominant architectural paradigms used in modern network applications: the client-server architecture or the peer-to-peer (P2P) architecture. Client-server architecture (Web, FTP, e-mail) Server has a permanent IP address. clients do not directly communicate with each other, but with server. P2P architecture: application exploits direct communication between pairs of intermittently connected hosts. [Read More]

What is the internet? 1. Nuts-and-Bolts Description. connected computing devices are called hosts = end systems running network apps End systems are connected by a network of communication links and packet switches Different links can transmit data at different transmission rate: bandwidth Packet switches: takes a packet arriving on one of its incoming communication links and forwards that packet on one of its outgoing communication links types of packet switches: routers and link-layer switches route / path:the sequence of communication links and packet switches traversed by a packet from the sending end system to the receiving end system Internet service Providers (ISPs): end system access the internet through ISPs. [Read More]