Strict Priority; Tagging - Hirschmann MS30, Power MICE, MACH 4000, OCTOPUS User Manual

Traffic control

8.4.2 Strict Priority

With Strict priority, the Switch sends all data packets with a higher priority
level before it sends a data packet with the next lower priority level. Thus the
Switch does not send a data packet with the next lower priority until there are
no other data packets waiting in the queue.

8.4.3 Tagging

The VLAN tag is integrated into the MAC data frame for the VLAN and prio-
ritization functions in accordance with the IEEE 802.1 Q standard. The VLAN
tag consists of 4 Bytes. It is inserted between the source address field and
the type field.
With data packets with VLAN tag, the Switch evaluates
D
the priority information at all times, and
D
the VLAN information, if VLANs have been set up.
Data packets whose VLAN tags contain priority information but no VLAN
information (VLAN ID = 0) are known as "Priority Tagged Frames".
Layer 2 Enhanced with Layer 2 Professional
Release 1.0 10/05
8.4 Prioritization
115