Vlan Tagging - Hirschmann MACH 4000 User Manual

Network load control
VLAN priority based on IEEE 802.1Q/ 802.1D (Layer 2)
Type of Service (ToS) or DiffServ (DSCP) for IP packets (Layer 3)

8.4.2 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 Switch 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(de-
tered fault setting)
0 2
1 0
2 1
3 3
4 4
5 5
6 6
7 7
Table 10: Assignment of the priority entered in the tag to the traffic classes
18
IEEE 802.1D traffic type
Best effort (default)
Background
Standard
Excellent effort (business critical)
Controlled load
(streaming multimedia)
Video, less than 100 milliseconds of latency and jitter
Voice, less than 10 milliseconds of latency and jitter
Network control reserved traffic
8.4 QoS/Priority
Basic - L3P
Release 4.0 11/07