6.1.2 Characteristics of the IP Protocol

Best Effort

- IP is inherently unreliable because packet delivery is not guaranteed - IP does not have the capability to manage and recover from undelivered or corrupt packets - Packets may arrive at the destination corrupted, out of sequence, or not at all.

Media Independent

- IP operation is independent of the medium carrying the data - IP only considers the MTU

Characterists of IP

- connectionless - best effort - media independent

Connectionless

- no connection with the destination is established before sending data packets - no initial exchange of control information is required to establish an end-to-end connection before the packets are forwarded - does not require additional fields in the header to maintain an established connection

IP

- provides only functions necessary to deliver a packet from source to destination over an interconnected system of networks - not designed to track and manage the flow of packets

Maximum Transmission Unit (MTU)

- the only characteristic of media that the network layer considers - the maximum size of PDU that each medium can transport - communicated between the data link and network layers

Cons of connectionless

- the sender does not know if the receiver is present, if the packet arrived, or if the receiver can read the packet - the receiver doesn;t know the packet is coming

IP header

- used to deliver a packet to the destination host - remains the same from source to destination

IP does not have the capability to manage and recover from undelivered or corrupt packets because ___________________________________.

IP packets contain no information that can be processed to inform the sender whether delivery was successful

Fragmenting the packet or fragmentation

When an intermediate device, usually a router, must split up a packet when forwarding it from one medium to another medium with a smaller MTU

IP encapsulates a transport layer segment or other data by _______________.

adding an IP header

Benefit of best effort/unreliability

allows IP to function very efficiently

IP was designed to be ________________.

as efficient as possible (low overhead)

Pro of connectionless

greatly reduced overhead of IP

IP provides no capability for packet _________________ if errors occur.

retransmission