Year CPU Bit Bus MHz Frequency MHz 1979

Year CPU Bit Bus MHz Frequency MHz 1979 8088 8 1978 8086 8 1982 80286 16 16 20 134, 000 1985 80386 32 33 33 275, 000 1989 80486 32 50 120 1, 185, 000 8 KB 1993 Pentium 32 66 200 3. 1 million 16 KB Ext 2 1997 Pentium MMX 32 66 233 4. 5 million 32 KB Ext 2 MMX 1995 Pentium Pro 32 66 200 5. 5 million 16 KB 1 MB 3 RISC 1997 Pentium II Klamath 32 66 300 7. 5 million 32 KB 512 KB half freq. 3 Pipeline 1998 Pentium II Deschutes 32 100 450 7. 5 million 32 KB 512 KB half freq. 3 1997 Celeron 32 66 500 19 million 32 KB 128 KB full freq. 3 1999 Pentium III Katmai 32 133 600 9. 5 million 32 KB 512 KB half freq. 3 SSE 2000 Pentium III Coppermine 32 133 1, 200 28 million 32 KB 256 KB full freq. 3 0. 18 micron 2001 Pentium IV Willamette 32 133 2, 000 42 million 8 + 12 KB 256 KB full freq. 3 2002 Pentium IV Northwood 32 800 3, 200 55 million 8 KB 512 KB 3 2003 Itanium 64 400 1, 500 120 million 32 KB 256 KB Level 3 cache 6 MB 2004 Pentium IV E Prescott 32 1, 066 3, 800 125 million 16 KB 1 MB 0. 9 micron >100 W, EE 2005 Pentium D Smithfield 64 800 3, 200 230 million 2 x 16 KB 2 x 1 MB 130 W 2006 Pentium D Presler 64 1, 066 3, 730 380 million 2 x 16 KB 2 x 1 MB 150 W 2007 Pentium Core 2 Allendale 64 800 2, 400 291 million 2 x 64 2 MB 65 W, 0. 65 micron 2008 Pentium Core 2 Wolfdale 64 1, 333 3, 333 410 million 2 x 64 6 MB 0. 45 micron Transistors Cache 1 level Cache 2 level ALU Notes 29, 000 FPU 0. 13 micron 2 FPU

Hard disk Capacity: Cylinders x Heads x Sectors

Hard disk

Hard disk 1957 1995 - 2005 1975 1984 now

Hard disk Two main types of data loss: 1) System crashes: - everything is lost, need to recover from scratch - usually, as soon as possible 2) Accidental mistakes: - some files have been deleted or overwritten, need to restore latest good version Strategy against 1) is hardware redundancy Strategy against 2) is periodical automated backup (better if on redundant hardware) Combine 1) and 2) and sleep well…

0 96 192 255 4 x 4 = 16 bytes x 3 layers = 48 bytes

The Internet protocol stack Application Transport Software Network Data link Hardware Physical

Packet switching

Coaxial cable (BNC)

Twisted pair (RJ 45)

LANs & WANs • LAN (Local Area Network) – – Ethernet Token Ring Optic Fiber WIFI • WAN (Wide Area Network) – – – – Optic Fiber Analog telephone modem ISDN ADSL, XDSL, etc. ATM, X. 25, Frame Relay Satellite etc.

The Internet protocol stack Application Transport Software Network Data link Hardware Physical

Ethernet LAN • CSMA/CD – Carrier Sense Multiple Access, Collision Detect • Frame – Header (source, destination), payload • MAC address – Medium Access Control – Six bytes, worldwide unique, factory assigned ex: 00 -a 0 -d 2 -1 a-25 -5 a • ARP – Address Resolution Protocol

ARP: W must contact Y

The Internet protocol stack Application Transport Software Network Data link Hardware Physical

IP Protocol: addressing

IP Protocol: addressing • Netmask + computer address – ex. 192. 168. 1. 60 / 24 means: • the first 24 bits identify the network • the remaining 8 bits identify the computer • Old style: class A, B and C • Class A: 8 bits • Class B: 16 bits • Class C: 24 bits

IP Protocol: addressing

IP Protocol: addressing • In a network, the first address is the network itself, the last is the broadcast – ex. with 192. 168. 1. 0 / 24 we have: • 192. 168. 1. 0 • 192. 168. 1. 255 • 1 to 254 the network broadcast available computer addresses

Routing • If the destination is on the same network, deliver directly, using ARP • If the destination is on a different network, send the message to a gateway computer • A gateway (or router) is a computer with at least two network interfaces, on two different networks

Important: DNS • Domain Name System – Internet distributed Phone Book – hyerarchy of DNS server – root servers (13) – top level domain: . com, . org, . net, . edu, . etc – country level domain: . it, . uk, . fr, etc. – new tl domains: . biz, . info, . name etc. • The first (closest) DNS server must be identified by its IP address

The Internet protocol stack Application Transport Software Network Data link Hardware Physical

May I? Welcome OK, here are the data send e ledg w kno ac I’ve finished OK, bye Bye TCP/IP

The TCP/IP abstraction A TCP/IP connection looks like a point-to-point link. Transport Network Data Link Physical Router PC 1 PC 2

The Internet protocol stack Application Transport Software Network Data link Hardware Physical

TCP/IP application protocols • • Http Smtp Ftp Ping Ssh IRC Bootp Obsolete – Telnet – Finger – Gopher – etc. browsing: Explorer, Firefox, etc. e-mail File Transfer Protocol diagnostics Secure Shell chat remote bootstrap • Get a full list from windowssystem 32driversetcservices

<HTML> <HEAD> <TITLE>An HTML Page</TITLE> </HEAD> <BODY> <H 1>Hallo, World!</H 1> </BODY> </HTML> tags

URL (Uniform Resource Locator) directory path protocol http: //www. iao. florence. it/coop/dgcsprojects/projectpage. php? key=3&lang=it domain name computer name filename program variables

Internet Governance • IETF – Internet Engineering Task Force – Technical aspects – Open, democratic – Lobbying pressure low, but increasing • ICANN - Internet Corporation for Assigned Names and Numbers – DNS and IP address – Former US, now “open” – Controversies, political lobbying • W 3 C – World Wide Web Consortium – HTML and much more – Membership fee; dictatorship of Tim Berners-Lee – Commercial lobbying

W 3 C staff in 2013 http: //www. w 3. org/2013/11/team-photo. jpg