Alcatel-Lucent 7750 SR - Figure 2: Unicast Service Queuing with Shared Queuing Enabled

Services
7750 SR OS Services Guide Page 35
queue for the destination forwarding plane. The shared queues are used by all services configured
for shared queuing.
When the first SAP or SLA profile instance is configured for shared queuing on an ingress
forwarding plane, the system allocates eight hardware queues per available destination forwarding
plane, one queue per forwarding class. (Twenty four hardware queues are also allocated for
multipoint shared traffic, but that is discussed in the following section.) The shared queue
parameters that define the relative operation of the forwarding class queues are derived from the
Shared Queue policy defined in the QoS CLI node. Figure 2 demonstrates shared unicast queuing.
SAP or SLA profile instance multipoint queuing is not affected by enabling shared queuing.
Multipoint queues are still created as defined in the ingress SAP QoS policy and ingress
multipoint packets only traverse the ingress forwarding plane a single time.
Enabling shared queuing may affect ingress performance due to double packet processing through
the service and shared queues.
Figure 2: Unicast Service Queuing With Shared Queuing Enabled
OSSG226
Service
Queue
Ingress Policer
for RT Traffic
PiR set to minimize jitter,
Second Pass discards
Out-of-Contract.
Ingress
Forwarding Plane
First Pass
Ingress
Forwarding Plane
Second Pass
Queue Decision
Based on QoS
Policy Service
Queue Mapping
of FC and
Forwarding Type
Queue Decision
Based on FC and
SF Destination
Dest A
Queue
Dest B
Queue
Dest C
Queue
Dest D
Queue
Dest E
Queue
Dest n
Queue
Service
Queue
Service
Queue