Foreword
This issue is a network layer
1 Overview
Network layer can be divided into two interacting portions, i.e., the data plane and control plane.
The function of the data plane, i.e. the network layer functions for each router.
The data plane function determines the datagram reaches the input link to one of the router (i.e. network layer packet) how to forward to one of the output link of the router.
2. Forwarding and Routing: data plane and control plane
(1) Forward:
When a packet arrives at an output link of a router, the router must move the packet to the appropriate output link.
(2) routing:
When the flow of packets received from the sender side, the network layer routing or path must decide the packets used. These algorithms calculate the path routing algorithm is called.
3. Network Service Model
End network service model defines the characteristics of the transport packet between the receiving end from the transmitting end system. These services may include:
- Ensure delivery. The service ensures that packet will eventually reach their destination.
- With a time delay on the sector to ensure that service. The service not only ensures packet delivery and latency into the host community in the particular host delivery
- Ordered packet delivery. The service ensures that packet sent in the order of their arrival.
- Ensure minimum width. This network layer service between transmission and reception mimicked host a particular transmission link bit rate behavior. As long as the sending host transmission bit rate lower than a specific bit rate, then all packets will eventually be delivered to the destination host.
- safety. Network layer can encrypt all data packets in the source and destination decrypt these packets, thereby providing confidentiality for all transport layer segments.
4. The router works
Four router components: routing port, the switch fabric output ports, routing processor
5. Packet Scheduler
- First In First Out (FIFO)
- Priority Queuing
- Cycle and weighted fair queuing
IPv4 addressing
Host and link boundary is called before the physical interface. Each host and router interfaces have their own IP address.
Each IP address length is 32 bits (4 bytes), a total of 32 power 2 ip address. Dotted decimal notation: 193.32.216.9.
Dynamic Host Configuration Protocol (DHCP): allows a host to automatically obtain an ip address.
ipv6: ipv4 protocol address space is exhausted, a new ip protocol development.