Edge-Core ES3510MA-DC Management Manual page 252

| Quality of Service
C 12
HAPTER
Creating QoS Policies
respectively. The maximum size of the token bucket P is BP and the
maximum size of the token bucket C is BC.
The token buckets P and C are initially (at time 0) full, that is, the token
count Tp(0) = BP and the token count Tc(0) = BC. Thereafter, the token
count Tp is incremented by one PIR times per second up to BP and the
token count Tc is incremented by one CIR times per second up to BC.
When a packet of size B bytes arrives at time t, the following happens if
trTCM is configured to operate in Color-Blind mode:
If Tp(t)-B < 0, the packet is red, else
■
if Tc(t)-B < 0, the packet is yellow and Tp is decremented by B, else
■
the packet is green and both Tp and Tc are decremented by B.
■
When a packet of size B bytes arrives at time t, the following happens if
trTCM is configured to operate in Color-Aware mode:
If the packet has been precolored as red or if Tp(t)-B < 0, the
■
packet is red, else
if the packet has been precolored as yellow or if Tc(t)-B < 0, the
■
packet is yellow and Tp is decremented by B, else
the packet is green and both Tp and Tc are decremented by B.
■
The trTCM can be used to mark a IP packet stream in a service, where
◆
different, decreasing levels of assurances (either absolute or relative)
are given to packets which are green, yellow, or red. Refer to RFC 2698
for more information on other aspects of trTCM.
Random Early Detection – RED starts dropping yellow and red packets
when the buffer fills up to 0x60 packets, and then starts dropping any
packets regardless of color when the buffer fills up to 0x80 packets.
CLI R
EFERENCES
"Quality of Service Commands" on page 877
◆
C U
OMMAND SAGE
A policy map can contain 512 class statements that can be applied to
◆
the same interface (page
for ingress ports.
After using the policy map to define packet classification, service
◆
tagging, and bandwidth policing, it must be assigned to a specific
interface by a service policy
– 252 –
259). Up to 32 policy maps can be configured
(page 259) to take effect.