4A0-107 Sample Questions Answers

The IOM3 adds more memory to both forwarding complexes which increases the total number of queues available.

The IOM3 only contains a single forwarding complex which reduces the number of queues used.

The IOM3 allows multiple forwarding classes to be assigned to a single queue.

The IOM3 allows queues to be dynamically allocated between ingress and egress.

The IOM3 has a larger CPU capable of tracking active hardware queue utilization and adjusting memory allocation accordingly.

The available bandwidth of the port is divided in a strict priority over its children.

Expedited queues must be serviced before best-effort queues.

Orphaned queues are serviced on the 8th scheduling priority.

The configured CIR dictates the maximum port bandwidth that can be allocated during the within-CIR pass for that level.

1

2

3

4

5

8

The weight specifies the priority of the queue during scheduling up to its CIR.

The weight specifies the priority of the queue during scheduling above-CIR, up to its PIR.

The weight is used to determine how this queue and other queues or schedulers at the same CIR-level share available CIR bandwidth at that level.

The weight is used to determine how this queue and other queues or schedulers at the same level share available above CIR bandwidth at that level.

H-QoS capabilities must be enabled globally on the router

A scheduler-policy must be configured.

The queues in the SAP-ingress and SAP-egress policies do not require additional configuration attributes to make use of the hierarchical schedulers.

The network queue policy must be configured to make use of the scheduler-policy.

The scheduler-policy must be referenced in the SAP-ingress and SAP-egress policies.

The scheduler-policy must be applied on the service SAP.

Closest

Average

Min

Max

Change the CIR-level value for the best-effort queue to 8.

Do not change anything; it is already guaranteed to receive its CIR

Change the CIR-level value for the best-effort queue to 1.

Change the CIR-weight value of the AF queue to 0.

It determines the packet’s forwarding class based on classification criteria

It modifies the current packet’s forwarding class to indicate promotion or demotion

It sets the TOS, DSCP, EXP, or Dot1p field based on classification criteria

It modifies the current TOS, DSCP, EXP, or Dot1p marking to indicate promotion or demotion

On the network egress port.

On the SDP.

On the access ingress port.

On the egress MDA.

On the SAP.

On the ingress MDA.

ToS

DSCP

PREC

EXP

Packets corresponding to a layer-2 service can be pre-marked on SAP-ingress.

Packets corresponding to a layer-2 service can be pre-marked on network-ingress.

Packets corresponding to a layer-3 service can be pre-marked on SAP-ingress.

Packets corresponding to a layer-3 service can be pre-marked on network-ingress.

The DSCP value will be set to af21.

The DSCP value will be set to be.

TheDSCPvaluewillbesettoaf23.

The DSCP value will be set to af 12.

Thedot1pvaluewillbesetto5.

Thedot1pvaluewillbesetto2.

The dot1p value will be set to 3.

TRUE

FALSE

QoS is not configured on the router.

Packets in forwarding classes "be" and "12" are being queued.

Traffic belonging to forwarding class "ef" is not experiencing queuing delays.

Traffic belonging to forwarding class "11 "will never make use of the shared buffer pool.

Out-of-profile traffic in the shared buffer pool is being dropped.

SAP-ingress only

SAP-egress only

SAP-ingress and SAP-egress

Network ingress

Network egress

8

16

6

4

3

When using profile-mode queues, traffic that is marked as in-profile on ingress and scheduled in the above-CIR loop will still be considered as in-profile at egress.

When an HQoS strategy using an egress port-scheduler has been deployed, Tier 1 receives its scheduling rates based on the amount of egress bandwidth available for each forwarding class.

The greater the difference between PIR and CIR rates in a queue, the less likely a CIR will be provided.

Packets scheduled out of high-priority queues in the default scheduler will have a lower chance of packet loss at the expense of incurring a higher probability of delay.

When using priority-mode queues, traffic that is marked as in-profile on ingress and scheduled in the above-CIR loop will be considered as in-profile at egress.

8, 6, 3

8, 8, 6

16, 8, 4

8, 6, 4

24, 16, 8

Microflow reservations using RSVP

DSCP to EXP translation

Traffic classification

Automatic profiling and policy configuration

Buffer memory management

Traffic scheduling

Interfaces, ports, SAPs

Ports, ports, MDAs

MDAs, MDAs, ports

Interfaces, interfaces. MDAs

MDAs, ports, interfaces

16

8

32

48

56

The administrative PIR values are ignored and both operational rates are set to the minimum residual rate allowed by the hardware.

The administrative PIR value is ignored and both operational rates are set to the administrative CIR value.

They are chosen as the largest multiple of the hardware rate step that is less than or equal to the corresponding CIR/PIR administrative value.

They are chosen as the smallest multiple of the hardware rate step that is greater than or equal to the corresponding CIR/PIR administrative value.

SAP-ingress only

SAP-egress only

SAP-ingress and SAP-egress

Network ingress

Network egress

When a packet arrives, the PIR bucket depth is checked and the packet is discarded if this bucket is full.

The CIR bucket of a policer is the reserved portion of its PIR bucket.

The CIR bucket of a policer has two thresholds: CBS and HPO.

Packets processed by the PIR bucket at an average rate above PIR will be forwarded as out-of-profile.

Microflow reservations using RSVP

DSCP to EXP translation

Traffic classification

Automatic profiling and policy configuration

Buffer memory management

Traffic scheduling

Several Tier 1, Tier 2, and Tier 3 schedulers can be defined within a policy.

A queue’s parent scheduler must be a Tier-3 scheduler.

The parent must have a higher level in the hierarchy.

If no parent is configured, the queue/scheduler is considered orphaned.

The default forwarding class for ICMP traffic is BE and cannot be changed.

The SAP has been shut down.

Queue 3 has no PIR or CIR configured, and thus cannot hold any packets.

The SAP-ingress policy has not been applied to the SAP.

A customer is complaining that his VoIP traffic is being dropped even though it is sending the correct DSCP markings. Packets are not being dropped on ingress.

A customer is complaining that his VoIP traffic is being dropped even though it is sending the correct DSCP markings. Packets are being dropped on ingress.

A commercial builder has requested numerous dot1Q epipes, VPRNs, and VPLS services to a business park and is only paying up to a maximum 200Mbps.

An equipment manufacturer has requested a NULL epipe service that will transparently pass dot1Q between the new location and national headquarters.

It defines a premium service that effectively creates a dedicated link between peers.

It defines four different AF traffic classes.

Every AF class in each differentiated services node is allocated a certain amount of forwarding resources.

Within each AF class, IP packets are marked with one of three possible drop precedence values.

Router interfaces

Ingress MDA

Ingress Ethernet network ports

Egress Ethernet network ports

Service SAPs

8

16

32

48