Pilz PSSnet SHL 8T MRP - Manual (Page 124)

Network load control
PSSnet SHL - Basic Configuration
Pilz GmbH & Co. KG, Felix- Wankel Str. 2, 73760 Ostfildern
8.4 QoS/Priority
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8.4.4 Management prioritizing
In order for you to have full access to the management of the device, even
when there is a high network load, the device enables you to prioritize man-
agement packets.
In prioritizing management packets (SNMP, Telnet, etc.), the device sends
the management packets with priority information.
X On Layer 2 the device modifies the VLAN priority in the VLAN tag.
For this function to be useful, the configuration of the corresponding ports
must permit the sending of packets with a VLAN tag.
X On Layer 3 the device modifies the IP-DSCP value.
8.4.5 Handling of received priority information
The device provides three options, which can be chosen globally for all ports,
for selecting how it handles received data packets that contain priority infor-
mation.
X trust dot1p
The device assigns VLAN-tagged packets to the different traffic classes
according to their VLAN priorities. The assignment is based on the pre-
defined table
(see on page 119 „VLAN tagging“) . You can modify this as-
signment. The device assigns the port priority to packets that it receives
without a tag.
X untrusted
The device ignores the priority information in the packet and always as-
signs the packets the port priority of the receiving port.
X trust ip-dscp
The device assigns the IP packets to the different traffic classes according
to the DSCP value in the IP header, even if the packet was also VLAN-
tagged. The assignment is based on the pre-defined values
(see
table 11) . You can modify this assignment.
The device prioritizes non-IP packets according to the port priority.