
Chapter 1 Introduction Installation and Operation Manual
1-18 Functional Description Egate-100 Ver. 4.0
• VLAN + 802.1p + IP Precedence
• VLAN + 802.1p + DSCP
Policing and Bandwidth Profiles
Egate-100 supports 256 policer profiles and instances.
Policers can be applied per flow. The policers operate according to the dual token
bucket mechanism with the following configurable parameters:
• CIR
• CBS
• EIR
• EBS
Egate-100 does not support policer for Network to User flows.
Queue Management
The following sections explain how queues are managed.
Priority Queues
Egate-100 supports four queues at the egress E1/T1 ports.
The scheduling method can be configured by the user, per queue, to be strict or
WFQ, according to the scheduling method. This allows a combination of strict and
WFQ queue management scheme.
Strict. The data flow set to the highest priority is transmitted first. If this data
flow stops, all tasks at lower priorities move up by one priority level. For example,
the data flow set to the second-highest priority is then transmitted at the
highest priority.
WFQ. Allows different scheduling priorities to statistically multiplex data flows
with different shares on the service. Each data flow has a separate FIFO queue. A
link transmitting at a data rate
R
,
N
non-empty data flows are served
simultaneously according to the assigned share
w
, each at an average rate of
R/(w
1
+ w
2
+ w
3
+ … +w
N
)
. If one data flow stops, the remaining data flows each
receive a larger share w.
Congestion Control
Each queue employs an early discard mechanism for yellow packets to ensure CIR
traffic (green packets). Early discard of yellow packets (EIR), upon crossing a
predefined fill level threshold ensures CIR traffic over EIR traffic. Green packets
are dropped in the tail drop mechanism.
Quality of Service
Egate-100 supports QoS mapping with up to four strict or WFQ priority queues at
the logical port egress according to one of the following:
• VLAN priority (available in VLAN-aware bridge mode only)
• IP precedence (ToS byte)
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