Week8 final
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Transcript of Week8 final
Media (wired and wireless);
Topology (bus, star, mesh, ring, tree);
Protocol (HTTP, TCP/IP, MAC);
Addressing (IP, MAC);
Naming (domain, hostnames);
Layered Communication (TCP/IP model);
Networking devices (hubs, switches, routers);
Routing and Internetworking;
Recap of Network lectures
1. (Inter)networking application: how email works?
2. Network classification: According to scope (campus, metropolitan, home); According to paradigm (server-based, peer-to-peer) ; According to hierarchy (core, access); According to type (intranet, internet, extranet, VPN).
3. Network technologies: Core network: MPLS (packet switching), ATM (cell switching) Access network: narrowband (dial-up), broadband (DSL,
Cable, WiMax)
Today’s lecture outline
User sends email
SMTP data
Source MAC address | Destination MAC address 23:34:aa:bb:cc:dd | 12:34:aa:bb:cc:dd
FCSPayload
Payload
Source Port | Destination Port> 1024 | 25
Payload
Payload
Source IP | Destination IP 202.125.157.150 | 115.186.131.69
Payload
Application layer
Transport layer
Link layer
Internet layer
This is a mail client software (e.g., Outlook Express (shown); Mozilla Thunderbird)
Compare with browser software:(Internet explorer; Mozilla Firefox)
Webmail.niit.edu.pk
Webmail.niit.edu.pk
User receives email
POP request
Source MAC address | Destination MAC address 23:34:aa:bb:cc:dd | 12:34:aa:bb:cc:dd
FCSPayload
Payload
Source Port | Destination Port> 1024 | 110 (POP)
Payload
Payload
Source IP | Destination IP 202.125.157.150 | 115.186.131.69
Payload
Application layer
Transport layer
Link layer
Internet layer
or IMAP requestor HTTP request
Source Port | Destination Port> 1024 | 143 ( if IMAP) Source Port | Destination Port> 1024 | 80 ( if HTTP)
or IMAP requestor HTTP request
(Geographical Scope)Classification
• Wide Area Networks
• Metropolitan Area Networks
• Campus Area Networks
• Home Area Networks
• Personal Area Networks
Decreasing Scope
(Network Paradigm)Classification
Client-server networks:
Examples: DNS, HTTP, DBMS servers and client
(Network Paradigm)Classification
Peer-to-peer (P2P) networks:
Examples: Workgroup computing; P2P networks such as BitTorrent, Gnutella, Morpheus, etc.
(Type)Classification
VPN
Image source: http://www.flexsys-group.com
Intranet
Extranet
Internet
Multi-protocol label switching (MPLS)• Packet based• Unified data-carrying service for both
circuit-based and packet-based clients
Asynchronous Transfer Mode (ATM)• Cell (small fixed sized packets) based
•Both ATM and MPLS allow traffic engineering
Core network technologies
• Uses analog telephone lines
• Utilizes a modulator/ demodulator (Modem)
• Modems perform error correction/ compression
• V.34 (28.8, 33.6 kbps); V.90 and V.92 (56 kbps)
• Telephone networks limit a single narrowband channel to 56 kbps
(Narrowband)Access technology
• Leased Circuits: E1 (2M), E2 (8M), E3 (34M)
• DSL: Utilizes telephone lines but performs efficient digital codingTypes: ADSL, HDSL, SDSL, VDSL
• Cable: Utilizes co-axial cables and provides similar access speeds to DSL
• WiMax: Wireless broadband technology
(Broadband)Access technology
Lecture’s
Summary
a) We described
how email works.
b) We classified networks
according to their
scope, paradigm
, hierarchy, and
type.
c) We discussed
narrowband
and broadband
data communications
.
???Questions/
Confusions?
Credits/ Acknowledgement can be found
at the course website:
http://tinyurl.com/5hb8pp