GP-L200M User Manual
23
Appendix C
About QoS
PLC 200AV allows 4 levels of Channel Access Priority (CAP (0 – 3)). The 8 levels of
VLAN Ethernet tags must be mapped to the 4 levels of CAP priority, where CAP 3 is
the highest priority and CAP 0 is the lowest. CAP 3 priority is used for voice and
network management frames. CAP 2 is used for streaming video and music while
CAP 1 and CAP 0 are used for data.
Default CAP
The Default CAP group allows default priority mapping of packets that do not have a
VLAN tag. Settings are available for unicast (directed to a host).
z
IGMP - (default CAP 3) - set the channel access priority for IGMP frames -
these are the group management frames, not the stream data.
z
Unicast - (default CAP 1) - set the default channel access priority for unicast
frames not matching any other classification or mapping.
z
IGMP managed Multicast Stream (Fixed to CAP 2) - set the default channel
access priority for stream data belonging to a snooped IGMP multicast group.
z
Multicast/Broadcast - set the default CAP for multicast frames not in a snooped
group and for broadcast frames.
The following are the factory default settings for VLAN Tags and TOS Bits:
VLAN Tag
User priority
Default CAP
Priority
TOS Bit User
Priority
Default CAP
Priority
0 CAP1 0
CAP1
1 CAP0 1
CAP0
2 CAP0 2
CAP0
3 CAP1 3
CAP1
4 CAP2 4
CAP2
5 CAP2 5
CAP2
6 CAP3 6
CAP3
7 CAP3 7
CAP3
