Class of Service (CoS) or Quality of Service (QoS) is a way to manage multiple traffic profiles over a network by giving certain types of traffic priority over others. For example you can give Voice traffic priority over email or http traffic. CoS is offered by service providers normally within an MPLS (Multi Protocol Label Switching) offering. Unlike QoS (Quality of Service) CoS does not offer guarantees with bandwidth or delivery time its based on a best effort basis. Currently stream Networks offer between 2 to 6 levels of service depending on the solution and access technology used.
Typically the 6 current level of service traffic types are defined below.
CoS 1. Voice - (e.g. VoIP and PSTN breakout)
CoS 2. Assured Data – ERP applications or Real-time Multimedia - (e.g. Video conference and other interactive service)
CoS 3. Assured Data - ERP applications
CoS 4. Assured Data - ERP applications
CoS 5. Assured Data - ERP applications
CoS 6. Standard – Email, Intranet, FTP and Internet Breakout Telnet and other network management.