Class of Service
The term Class of Service (CoS) corresponds to the German term service class and has different meanings depending on the application (context):
- IT, network, LAN
- According to IEEE 802.1p , various services in the Local Area Network (LAN) can be classified via CoS.
- IT, network, WAN
- In ATM or Frame Relay based Wide Area Networks (WAN), four service classes (isochronous or burst-like traffic, constant or variable bit rates) are distinguished.
- TK, permissions
- In telecommunications, CoS is understood to mean the authorization class assigned to the user (e.g. not authorized to act, fully authorized to act, with foreign authorization ...).
Class of Service in the LAN
With CoS a method for labeling and subsequent refers prioritization in IP -based networks , according to the IEEE 802.1p are standardized.
CoS enables targeted prioritization, while Quality of Service (QoS) sets up explicit bandwidth guarantees or restrictions.
According to the classification that is still widespread today, three specific class-of-service categories can be distinguished:
- Application class 1: language;
- Application class 2: business-critical data transfer such as SAP , ERP or video conferences ;
- Application Class 3: geschäftsunkritische applications such as e-mail and Web -Browsing.
Class of Service in the WAN
Many Multi-Protocol Label Switching (MPLS) providers also offer a more differentiated classification according to the Differentiated Services Code Point (DSCP) method.
Class of service in telecommunications
The old term trunk authorization is rarely used in today's telecommunications networks. Today TK networks are used for a variety of services: voice, video, presence, instant messaging, chat.
CoS is a more generic term for different authorization classes.
See also
- Multi-Protocol Label Switching (MPLS)
- Community of Interest Networks (COIN)
Web links
- Application-Driven Networking: Class of Service in IP, Ethernet and ATM Networks (IBM Redbook; PDF file; 1.9 MB; English)
- Description (Engl.)