routeprotocol

Packet marking in quality of service colours a packet by modifying a field within the packet or frame header with a traffic descriptor. By adding the traffic descriptor it allows other mechanisms within quality of service to identify and apply an action to that packet. (Shaping or queuing for example) Packets are marked as they…

NBAR2, Next Generation Network-Based Application Recognition, is a packet inspection engine that can classify and identify a variety of protocols and applications using the packets layer 3 to 7 data. NBAR2 can recognise more than one thousand applications, with new update packs being released for recognition of new and emerging applications. A protocol pack update…

Classification of packets is part of a Quality of Service mechanism that distinguishes between different traffic streams. Traffic descriptors categorise an IP packet to a specific class. Classifying packets should take place at the network edge as close to the source of the traffic as possible. Once the packet has been classified, it can be…

Quality of Service has three different implementation models. Best Effort Quality of Service is not enabled for traffic in a best effort set-up. Traffic is not given any special or priority treatment. Integrated Services Integrated services leave the responsibility to the application sending the data to signal that special Quality of Service treatment is required.…

Latency is the time it takes for packets to travel across a network from a source to a destination. ITU recommendation G114 recommends that network latency of 400ms should not be exceeded, and real-time traffic latency should be no longer than 150ms. Network latency can be broken down into four categories: Fixed propagation delay Fixed…

Between two destinations, the available bandwidth on a path is equal to the hop with the lowest bandwidth link. If the maximum capacity of this lowest bandwidth link is reached, congestion will take place resulting in traffic drops. The obvious solution is to increase the link bandwidth capacity, but may not always be possible due…

Quality of Service, or more commonly known as QoS, is a technology that relies on assigning different levels of priority to different types of IP traffic flows. Higher prioritised IP traffic flows are given preference on the network, reducing packet loss on congested links and help control latency plus jitter. Lower prioritised IP traffic are…