Class of Service (CoS)
Definition - What does Class of Service (CoS) mean?
Class of Service (CoS) is a term that describes the process of managing different kinds of data traffic in the network in different ways. Professionals may talk about giving each type of data it's own "service priority" or "bandwidth" within the system.
Techopedia explains Class of Service (CoS)
In order to achieve this kind of prioritization, systems may use specific tools such as 802.1 layer 2 tagging, type of service (TOS) indicators, or differentiated services resources. One example is that by using layer 2 of the OSI model, systems can evaluate packets and assign them a class of service that determines how that data is treated in the network. For example, a network might treat voice data differently than informational data, in order to preserve crystal-clear voice connections. Or, with data transmission, formats like image and video may be treated differently than text or alphanumerical data. It is all part of sophisticated network administration, and allocating resources for different types of data transmissions.