We have discussed the different techniques of building an IP-based network in the previous chapters. The enterprise network is fundamentally a packet-based network with the IP packets flowing from the source to the destination. The IP packets would be routed and forwarded from the source to the destination along the best path available from among the various paths available based upon the routing topology.

The network would also carry traffic from multiple users, and the traffic would be of different types. The traffic would consist of business-critical traffic like the one used for business applications such as SAP or other ERP systems, voice traffic for communication between different users on the network, video traffic from video calls between users using dedicated video end points or even soft clients on desktops/laptops, internet traffic for web browsing...