Vlan Tagging - Hirschmann RS20 User Manual

Network load control

7.4.2 VLAN tagging

The VLAN tag is integrated into the MAC data frame for the VLAN and Prior-
itization 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.
For data packets with a VLAN tag, the device evaluates
the priority information at all times, and
the VLAN information if VLANs have been set up.
Data packets with VLAN tags containing priority information but no VLAN in-
formation (VLAN ID = 0), are known as Priority Tagged Frames.
Priority en- Traffic class for
tered RS20/RS30/
RS40,
MACH 1000,
MS20/MS30,
OCTOPUS
(default)
0 1
1 0
2 0
3 1
4 2
5 2
6 3
7 3
Table 4: Assignment of the priority entered in the tag to the traffic classes
Note: Network protocols and redundancy mechanisms use the highest traffic
classes 3 (RS20/30/40, MS20/30, MACH 1000, OCTOPUS) and 7 (Power
MICE, MACH 4000). Therefore, you select other traffic classes for applica-
tion data.
Basic Configuration L2P
Release 4.2 07/08
Traffic class for IEEE 802.1D traffic type
MACH 4000 and
Power MICE
(default setting)
2 Best effort (default)
0 Background
1 Standard
3 Excellent effort (business critical)
4 Controlled load
(streaming multimedia)
5 Video, less than 100 milliseconds of
latency and jitter
6 Voice, less than 10 milliseconds of
latency and jitter
7 Network control reserved traffic
7.4 QoS/Priority
111