Basically, it is Quality of Service
Quality of Service (QoS) for networks is an industry-wide set of standards and mechanisms for ensuring high-quality performance for critical applications. By using QoS mechanisms, network administrators can use existing resources efficiently and ensure the required level of service without reactively expanding or over-provisioning their networks.
Traditionally, the concept of quality in networks meant that all network traffic was treated equally. The result was that all network traffic received the network’s best effort, with no guarantees for reliability, delay, variation in delay, or other performance characteristics. With best-effort delivery service, however, a single bandwidth-intensive application can result in poor or unacceptable performance for all applications. The QoS concept of quality is one in which the requirements of some applications and users are more critical than others, which means that some traffic needs preferential treatment.
QoS Concepts
The goal of QoS is to provide preferred delivery service for the applications that need it by ensuring sufficient bandwidth, controlling latency and jitter, and reducing data loss.
Network Characteristics Managed by QoS
| Network Characteristic | Description |
| Bandwidth | The ratre at which traffic is carried by the network. |
| Latency | The delay in data transmission from source to destination. |
| Jitter | The variation in latency. |
| Reliability | The percentage of packets discarded by a routher. |
