IEEE P802.1p

IEEE 802.1p was a working group of the IEEE, which should govern, among other things, the transport of data with different priorities in computer networks new. The resulting therefrom IEEE 802.1Q standard works on the 2nd level of the OSI reference model. The transmitted frames are divided into priority classes 0-7. The 0 is used for frames that are not assigned to a specific priority. The standard only specifies that the priority is coded with a number from 0 to 7, but does not make further statements about how the frames are to be addressed in detail. The priorities of the Tag Control Information ( TCI) field encoded by the Priority Code Point (PCP ) field in an additional VLAN tag ( see IEEE 802.3 MAC Tagged frame).

The prioritization of the frames is necessary in order to guarantee low latency and high data security heavily loaded networks. Applications such as Voice over IP given a high priority to keep latency and jitter low, while other applications with less stringent requirements to receive lower priorities.

Under the name IEEE 802.1p never was a document published by the IEEE. The contents of the Working Group are discussed in IEEE 802.1Q.

Prioritization level

The prioritization levels are divided by the 3- bit PCP field as follows in 8 Level:

The above recommendations have been revised in IEEE 802.1Q -2005 and differ from the original recommendations in IEEE 802.1D - 2004.