4A0-107 Nokia Quality of Service Questions and Answers

Queue 6 within-CIR packets, then queue 5 within-CIR packets, then queue 5 and queue 6 above-CIR packets in round-robin.

Queue 6 within-CIR packets, then queue 5 within-CIR packets, then queue 5 and queue 6 above-CIR packets in biased round-robin.

Queue 6 within-CIR packets, then queue 5 within-CIR packets, then queue 6 above-CIR packets, and finally queue 5 above-CIR packets.

Queue 6 and queue 5 within-CIR packets in biased round-robin, then queue 5 and queue 6 above-CIR packets in round-robin.

An SLA is used to provide automated, real-time testing and alarming for throughput, latency, and jitter across a provider's network.

An SLA is an agreement between a customer and a provider that dictates the treatment of customer traffic across the provider's network.

An SLA allows customers to control all traffic within the service provider's network by prioritizing their traffic over others as desired.

An SLA allows a customer to pre-mark traffic and ensure that traffic is treated as per the agreement within the provider's network.

An SLA is a standard set of network QoS policies that a provider shares to all its customers, allowing them to better understand the treatment of traffic within the provider's network.

There are a maximum of 8 levels of priority serviced using a round-robin algorithm.

The default scheduler will spend an equal amount of time in each queue, as long as there is traffic present

The H1 internal forwarding class will receive its CIR before AF traffic.

Orphaned queues will be scheduled out of the BE queue.

A queue servicing EF and AF traffic will require explicit configuration to set the queue to expedited.

64

8

3

16

1

Real-time

Assured

Best-effort

Self-generated

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.

PIR = 5 Mbps, CIR = 0 Mbps

PIR= 4 Mbps, CIR = 1 Mbps

PIR= 6 Mbps, CIR = 4 Mbps

PIR= 6 Mbps, CIR = 1 Mbps

8

3

4

5

6

Once before going through each of the redundant switching fabrics.

To protect against failure of either ingress or egress card.

Once before going through the switching fabric, and once more before going onto the egress port.

Once to decide if the packet is in-profile or out-of-profile, and once more to process the packet according to its profile.

It will be discarded because the high-priority-only threshold is exceeded.

It will be stored in the queue’s reserved buffer space and become out-of-profile.

It will be stored in the queue’s reserved buffer space and remain in-profile.

It will contend for shared buffer space with packets from other queues.

prec

lsp-exp

src-ip

do1p

A network policy for every network interface configured on the port.

A slope policy for the port on ingress.

A network queue policy for the corresponding MDA on ingress.

A network queue policy for the port on egress.

The egress port scheduler can have up to 17 children spread across 8 levels.

Multiple egress port schedulers can be assigned to a single port with many HQoS children.

Multiple HQoS policies can be children of a single port scheduler.

Multiple egress port schedulers can be children of a single HQoS scheduler.

Self-generated

Real-time

Best-effort

Assured

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

All out-of-profile traffic will be dropped before any in-profile is dropped.

The time average factor of 0 will discard all packets arriving in the shared buffer pool.

When the shared buffer utilization reaches 51%, in-profile packets might be dropped.

The highest probability with which an out-of-profile packet can be dropped is 20%.

When an in-profile packet arrives and the shared buffer utilization is at 69%, the packet will have approximately a 60% likelihood of being discarded.

TRUE

FALSE

SAP-ingress policy

SAP-egress policy

IP-criteria policy

Network-queue policy

Slope policy

Network policy

PIR = 4 Mbps, CIR = 1 Mbps

PIR = 1 Mbps, CIR = 1 Mbps

PIR = 10 Mbps, CIR = 1 Mbps

PIR = 5 Mbps, CIR = 1.25 Mbps

PIR = 1.25 Mbps, CIR = 1.25 Mbps

All out-of-profile traffic will be dropped before that of any in-profile traffic.

The discard probability slope of an in-profile traffic is steeper than that of an out-of-profile traffic.

When the shared buffer utilization reaches 55%, both in-profile and out-of-profile packets may be dropped.

The maximum probability with which an out-of-profile packet can be dropped is higher than that of an in-profile packet.

When the shared buffer utilization is at 61%, only in-profile packets are currently in the shared buffer pool.

1

2

3

4

5

8

It will be queued in the reserved portion of the buffer pool and remain out-of-profile.

It will be queued in the reserved portion of the buffer pool if there are no in-profile packets already in the queue.

It will be queued in the reserved portion of the buffer pool and be in-profile.

It will be queued in the shared portion of the buffer pool but contend for shared buffer space with packets from other queues.

It will be queued in the shared portion of the buffer pool but may be dropped if the buffer utilization exceeds the start-average value of the low slope.

Profile mode queues

Priority mode queues

1 queue

3 queues

3 forwarding classes

1 forwarding class, with 2 subclasses

1 forwarding class, with 3 subclasses

It specifies the maximum rate at which a queue can be serviced.

It specifies the maximum depth of a queue beyond which packets will be dropped.

It specifies the portion of a queue that is taken from the reserved buffer pool.

It specifies the threshold beyond which only in-profile packets will be queued.

It specifies the peak bandwidth that can be attained by the incoming traffic.

2

3

5

6

It will be stored in the reserved buffer space and remain out-of-profile.

It will be stored in the reserved buffer space and become in-profile.

It will contend for shared buffer space with packets from other queues.

It will be discarded because the high-priority-only threshold has been reached.

FC H1, high

FCH1, low

FCAF, high

FCAF, low

Has the ability to distinguish traffic in 32 different ways.

Uses the RSVP protocol to create microflows through a network.

Has the ability to manually configure foiwarding classes through a network.

Uses the RSVP protocol to create macroflows through a network.

Signal degradation, attenuation, line loss

Latency, FIFO, WRED

Delay, jitter, packet loss

SNR, queue depth, latency

Attenuation, dispersion, latency

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.

A point in the network where EXP bits can be mapped to one of eight predefined FCs, each one with its own queue.

A logical point in a service tunnel where all of customer traffic is aggregated.

A point at which the initial classification of customer traffic occurs.

A point in the network where QoS parameters are discarded in favor of lower-level hardware queuing functions, such as LLI (Link Layer Interleave).

A point in the network where traffic flows from multiple different services are queued together, based on forwarding class.