Quantum and Evolution Series Installation and Operating Handbook
7-119
the layer 2 IEEE 802.1q VLAN header. The packets must already be
tagged at the point of entry to the modem. Priority 7 is typically used for
network-critical traffic such as dynamic routing protocol packets; priorities 5
and 6 for video and voice, etc. The modem uses the priority tag to decide
how to process each packet. The options are:
•
Strict priority queuing
: packets are queued for transmission
based solely on their priority – highest will always be sent first.
•
Fair-weighting queuing
: higher priority transmitted first but
lower priority packets are given a percentage of the bandwidth
to stop total starvation.
The implementation of IEEE 802.1p is as follows:
•
The 8 QoS priority levels are mapped to three TCP/IP queues
in the modem.
•
Packets with highest QoS priority (level 7) are sent to high
priority TCP/IP queue.
•
Delay-sensitive packets (QoS levels 6 and 5) are sent to the
medium priority queue.
•
The remainder (QoS levels 4 to 0) are sent to the low priority
TCP/IP queue.
•
For strict priority queuing, all packets in high priority queue are
processed before any in medium priority queue which in turn
are processed before any in the low priority queue.
For fair-weighting queuing, for every 4 packets sent from high priority
queue, 2 are sent from medium queue and 1 from low priority queue.
Factory
default:
Off
Description:
Enables IEEE 802.1p IP packet prioritisation.
Edit-Unit-Interface-IP-
Traffic Port IP Address Screen
Factory default:
0.0.0.0
Description:
Sets the IP address for the base modem IP traffic port or the IP Traffic
card if this is fitted. Both of the Ethernet ports on the IP Traffic card use
this same address and can be used interchangeably. Unlike the base
modem Remote M&C port, DHCP is not supported and therefore an
Traffic port IP address:
[0.0.0.0]
New: [010.000.070.002]
