| Layer |
Design Issues |
Duties |
Protocols |
| Application |
sending large information. eg: 5gb, caching:how long fetched data is valid and when to query back?, security, slow client or server |
User services(eg: Emails, video share etc) |
DNS,DHCP,HTTP,LDAP |
| Presentation(Handles any conversions between data formats required by users such as different character sets, encodings, compression, encryption, etc) |
|
Presentation of data(ie syntax, semantics of data received) |
|
| Session |
|
Establish sessions(eg: token management etc) b/w hosts on different machines |
|
| Transport(App to App) |
Services provided to upper layer |
Process to process delivery, Congestion & flow Control, Error detection |
TCP,UDP |
| Network(Host to Host) |
Store/Forward pkt, Implementation of connectionless/connection-oriented |
Handling congestion |
IP,ICMP,IGMP |
| Between L3,L2 |
|
|
ARP |
| Data Link(Hop to Hop) |
Framing, Error control, Flow control |
Detect/correct PHY layer errors. Used to deliver data frame within same network |
L2TP |
| Physical(Electrical or Optical Cabling) |
Making sure sender sends 1 and recr receives 1 not 0 |
Send 0,1s on network |
|
