User guide

QOS QoS implementation for DIFFSERV
iMG/RG Software Reference Manual (Quality of Service)
7-8
FIGURE 7-2 Metering for Traffic Control
Note that the Meter uses the TRUE size of the IP packet for metering. For example, if the Meter receives an
Ethernet packet with the following structure:
• 14 bytes Ethernet header.
• 100 bytes of IP packet (20 bytes IP header + 80 bytes payload).
• 4 bytes of Ethernet padding & FCS.
For these types of packets, the Meter will uses 100 bytes for metering calculations. Therefore, don't be sur-
prised if the Meter is configured at 100kbps and you send an Ethernet packet stream of 118 kbps (Ethernet
packet size 118bytes) which is unaffected by the Meter process.
Incoming Packet
Meter Packet
Check Action
Discard Packet
Set Drop Priority
Set DSCP Value
Action == Drop
Set DSCP?