Network Improvement

Network Improvement is a large subject that encompasses all actions that can be taken to improve computer or digital networks.

Network Traffic Control

A network traffic controller is a mechanism to control the flow of traffic on the network. The controller may be used to reduce overall packet loss and congestion. A network controller implements this by setting up restrictions and\or prioritising traffic for certain protocols, applications, ports on a network or by modifying the behaviour of traffic.

The main elements of traffic control are classification, scheduling and queuing. Classification looks at packet content or at other information related to packets and attribute them to a distinct class. Packets are then put into queues and eventually scheduled for transmission. The class of a packet determines in which queue the packet goes and how it is scheduled.

TCP Tuning

TCP tuning is a method of increasing the buffer space for TCP packets, the TCP maximum window size is around 64kb/s. For high performance networks an improvement will be noticed in increasing the maximum window size for TCP packets. To get maximal throughput it is critical to use optimal TCP send and receive socket buffer sizes. But if the buffers are too small, the TCP congestion window will never fully open up. However if the receiver buffers are too large, TCP flow control breaks and the sender can overrun the receiver, which will cause the TCP window to shut down. This is likely to happen if the sending host is faster than the receiving host. Overly large windows on the sending side is not a big problem as long as the memory is available.

In deciding the optimal size for the TCP buffer the following formula is used:

bandwidth * RTT

As the higher the BDP the higher the traffic is on the network, an increase in buffer size wil reduce the amount of packet loss and as a result improve efficiency.

VLAN

A VLAN, also known as a virtual LAN, is a method for dividing up a network regardless of physical infrastructure. A VLAN would be used when devices need to be separated as they have different requirements. As an example a VLAN can be created for devices within a firewall. However the ease of physically moving a device while still keeping the same logical connection on the network is the most beneficial addition of a VLAN.