Internet & Home networking. Prof. J. Won-Ki Hong [email protected] Dept. of Computer Science & Engineering POSTECH. Contents. Data Communication Network Internet & World Wide Web Home Networking. Data Communication Network. Brief History of Computer Networks.
1 communication services to support high-performance computing and multimedia applications across the globe?”
Input data g
Output data g’
Destination SystemA Communication Model
POSTECH LAN (1998.6) communication services to support high-performance computing and multimedia applications across the globe?”
POSTECH LAN (1999. 3) communication services to support high-performance computing and multimedia applications across the globe?”
Internet in Korea (1995.5) communication services to support high-performance computing and multimedia applications across the globe?”
Internet in Korea (1999.6) communication services to support high-performance computing and multimedia applications across the globe?”
Syntax: data format and signal levels
Semantics: control information for coordination and error handling
Timing: speed matching and sequencing
OSI Stack are
1. Physical layer – responsible for the electro-mechanical interface to the communications media
2. Data link layer – responsible for transmission, framing and error control over a single communications link.
3. Network layer – responsible for data transfer across the network, independent of both the media comprising the underlying subnetworks and the topology of those subnetworks.
4 are. Transport layer – responsible for reliability and multiplexing of data transfer across the network (over and above that provided by the network layer) to the level required by the application.
5. Session layer – responsible for establishing,, and managing sessions between cooperating applications.
6. Presentation layer – responsible for providing independence to the application process from differences in data representation (syntax).
7. Application layer – ultimately responsible for managing the communications between applications.
Layer N + 1
Layer N entities
in their layer N Protocol
SAP = Service Access Point
IDU = Interface Data Unit
SDU = Service Data Unit
PDU = Protocol Data Unit
ICI = Interface Control Information
The Anarchistic are
The OSI Model
The TCP/IP Model
Golden age of networking
The Web and TCP/IP
MegaTrend: From one Internet
device per home to MANY
Public networks are
Phone line network
End to end
New media supportHome Network Architecture
Leveraging Web technologies
Internet exists and it works
20 ~ 80K bytes code
30 ~ 90K gates on silicon
30 ~ 90K bytes code
30 ~ 80K gates on silicon
Ethernet, 1394 or
Device specific sizeWeb for “Devices”
Application specific size
Internet Router from POSTECH