11-03-2014, 04:59 PM
Internet working
Fragmentation
Transparent fragmentation : in this method
when an oversized packet arrives at a gateway , the gateway breaks it up into fragments . Each fragments is addressed to the same exit gateway where the pieces are recombined . In this way passage through the small packet network has been made transparent .subsequent networks are not even aware that fragmentation has occurred
Nontransparent fragmentation :once the packet has been fragmented each fragment is treated as original packet
all the fragments are passed through the same exit gateway but recombining occurs only at the destination host
Design Principles for Internet
Make sure it works.
Keep it simple.
Make clear choices.
Exploit modularity.
Expect heterogeneity.
Avoid static options and parameters.
Look for a good design; it need not be perfect.
Be strict when sending and tolerant when receiving.
Think about scalability.
Consider performance and cost.
IP Protocol
IP Datagram consist of Header part and text part
The header has a 20 bytes fixed part and a variable length optional part
It transmit in bigendian format
Autonomous System (AS)
An internet is collection of subnet works or Autonomous System (AS) that are connected together
Autonomous System is independent of other network which uses own protocol to transmit data
Internet working Routing protocols are divided into two categories
Interior gateway protocol : routing with in each network (AS) use interior gateway protocol
Exterior gateway protocol : routing between network (AS) use exterior gateway protocol