Alcatel-Lucent OmniAccess 700, Руководство по настройке CLI

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QoS Overview
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Alcatel-Lucent
Beta Beta
CLI Configuration Guide
P
OLICING
Dropping or marking packets in order to make traffic stay below a configured
bandwidth. Thus defined, a traffic policing do not remove traffic burst, but controls
the size of the peak.
S
HAPING
The process of delaying packets before they go out, to make the traffic confirm to
a configured maximum rate. The main intention of shaping the traffic is to define
the traffic to flow within an envelop.
S
CHEDULING
The process of identifying which packet is to be selected for further action.
Q
UEUING
An algorithm that manage the queue of an interface/sub-interface. Queue
algorithm could be a passive (drop tail, drop-head, etc.) or active (RED, WRED
etc.)
D
IFF
-
SERV
Diff-serv is a class-based mechanism for specifying and controlling network traffic.
It differentiates IP traffic so that the traffic's relative priority could be determined on
a per-hop basis. It helps certain types of traffic (like voice) get precedence over
others.
D
IFFERENTIATED
S
ERVICES
F
IELD
(DS F
IELD
)
Defines the packets class (or type) in a Diff-serve domain. The classical TOS field
in the IP header is renamed as DS field. Six bits of the DS field are used as a code
point (DSCP) to select the Per-Hop Behavior (PHB) a packet experiences at each
node.
PHB (P
ER
H
OP
B
EHAVIOR
)
In a diff-serv approach of providing QoS for IP flow, each packet is treated in a
specific manner in each node. This treatment of packet at each hop is defined as
Per Hop Behavior.
A
SSURED
F
ORWARDING
(AF)
Is a type of Per-Hop Behavior (PHB) group that provides delivery of IP packets in
four independently forwarded AF classes. Within each AF class, an IP packet can
be assigned one of three different levels of drop precedence.
E
XPEDITED
F
ORWARDING
(EF)
The intent of the EF Per-Hop Behavior (PHB) is to provide a building block for low
loss, low delay and low jitter services.