Question 1

A service provider is using GRE for his transport tunnel on the Nokia 7750 SR. How can traffic be marked as it traverses the service provider's network? (Choose two)

Accepted Answer

A)  Using dot1p bits of the 802.1q Ethernet frame header 
B)  Using DSCP bits within the ToS field of the IP packet header. 
C)  Using the IP precedence bits within the ToS field of the IP packet header. 
D)  Using the CLP bit of the ATM cell header. 
E)  Using the EXP bits of the MPLS transport label header.

Question 2

When allocating scheduling resources, which of the following statements BEST describes how the egress port scheduler allocates bandwidth?

Accepted Answer

A)  The egress port scheduler takes the ratio of requested bandwidth to total bandwidth request from all children. It allocates bandwidth fairly, using these percentages and not exceeding the egress interface speed. 
B)  The egress port scheduler allocates bandwidth based on a WRR distribution method that takes into account the CIR and PIR requested at each level and the max speed, either default or configured, on egress. 
C)  The egress port scheduler allocates bandwidth on a first come, first served distribution method that takes into account the total CIR and PIR requested at each level and the max PIR requested from a single level. 
D)  The egress port scheduler will limit the bandwidth offered to the egress port based on the over-subscription factor, provisioned under the router interface, while using a WRR scheduler for the remaining bandwidth. 
E)  The egress port scheduler will use the Russian Dolls Method to allocate bandwidth to each level of requested bandwidth. HPO-Only is automatically set to 100%, allowing only high priority traffic to be buffered during congestion.

Question 3

Which of the following is NOT a factor when deciding if a packet can be accepted into a queue?

Accepted Answer

A)  Profile/priority state of a packet 
B)  Forwarding class 
C)  Queue depth 
D)  HPO setting

Question 4

At which point are internal QoS markings added to the packets?

Accepted Answer

A)  SAP-ingress 
B)  FFPC 
C)  SAP-egress 
D)  network-egress

Question 5

How many queues are available for use on service egress within a VPLS service?

Accepted Answer

A)  1 multipoint and 8 unicast. 
B)  8 queues, regardless of traffic type. 
C)  8 unicast and 24 multipoint. 
D)  8 unicast and 8 multipoint. 
E)  16 queues, distributed as desired.

Question 6

On the Alcatel-Lucent 7750 SR, which of the following QoS-related policies can be configured on a SAP? (Choose three)

Accepted Answer

A)  The slope-policy 
B)  The SAP-ingress policy 
C)  The SAP-egress policy 
D)  The network-queue policy 
E)  The scheduler-policy

Question 7

Which of the following statements are TRUE regarding the remarking of packets arriving on the network interface whose ToS-marking-state is set to trusted and remarking enabled on network egress? (Choose two)

Accepted Answer

A)  Native IP Packets will not be remarked. 
B)  Native IP Packets will be remarked. 
C)  Packets associated with a VPRN service on an upstream node will not be remarked. 
D)  Packets associated with an ES service on an upstream node will be remarked.

Question 8

Which of the following statements regarding policing and shaping on the Nokia 7750 SR are TRUE? (Choose two)

Accepted Answer

A)  The larger the configured MBS value, the lower the amount of shaping performed. 
B)  When policing is enabled on the SAP-ingress, all traffic is considered as in-profile. 
C)  Setting the CIR to 1000 and the PIR to max will enable shapeless policing at 1 Mbps within the SAP-egress policy. 
D)  Configuring MBS to equal CBS will disable shaping. 
E)  Setting the CIR and PIR to equal values disables soft-policing.

Question 9

Which of the following statements regarding egress FC and profile over-ride are TRUE? (Choose two)

Accepted Answer

A)  Packets can be classified into 16 different FCs when using priority mode queuing. 
B)  This feature is available on egress SAPs within any service. 
C)  MPLS EXP bits can be changed based on multi-field classification. 
D)  If a Behavior Aggregate (B
A)  and Multi-field (MF) match occurs, only the MF override parameters will take effect. 
E)  If a Behavior Aggregate (B
A)  and Multi-field (MF) match occurs, the BA classification can override the forwarding class while the MF classification can override the profile.

Question 10

A SAP-ingress policy is configured so that ping traffic is classified as FC L1 and mapped to queue 3; however, all traffic is placed in queue 1. What is the most probable reason for this?

Accepted Answer

A)  The default forwarding class for ICMP traffic is BE and cannot be changed. 
B)  The SAP has been shut down. 
C)  Queue 3 has no PIR or CIR configured, and thus cannot hold any packets. 
D)  The SAP-ingress policy has not been applied to the SAP.

Question 11

Which of the following are the minimum requirements needed to classify traffic marked with DSCP AF11, AF12, and AF13 into the AF forwarding class and provide fair treatment to the drop precedence settings? (Choose three)

Accepted Answer

A)  Profile mode queues 
B)  Priority mode queues 
C)  1 queue 
D)  3 queues 
E)  3 forwarding classes
F) 1 forwarding class, with 2 subclasses
G) 1 forwarding class, with 3 subclasses

Question 12

Which of the following rate-limiting approaches are used on the Nokia 7750 SR? (Choose two)

Accepted Answer

A)  Shapeless policing at SAP-ingress only. 
B)  Shapeless policing at SAP-ingress and egress. 
C)  Biased round robin queuing at ingress only. 
D)  Soft shaping at all network interfaces. 
E)  Soft shaping at network ingress only.

Question 13

On the Alcatel-Lucent 7750 SR, what is a slope policy used for?

Accepted Answer

A)  Defining the slope of the TCP slow-start mechanism for self generated traffic. 
B)  Defining the slope of the scheduling rate per forwarding class when using HQoS. 
C)  Defining the high and low slope values when deploying buffer admission control for UDP traffic in the committed buffer pool. 
D)  Defining the high and low slope values when deploying buffer admission control for TCP traffic in the shared buffer pool. 
E)  Defining the high and low slope values when deploying buffer admission control for TCP traffic in the committed buffer pool.

Question 14

Which of the following fields in packets belonging to a Layer 3 service can be pre-marked on SAP-ingress?

Accepted Answer

A)  Dot1p 
B)  DEI 
C)  EXP 
D)  DSCP/PREC

Question 15

In the image shown above, the SAP-ingress policy is applied properly to a Nokia 7750 SR. A packet is received from an IP address of 192.168.2.2 with DSCP set to AF. Which forwarding class and priority level is assigned to this packet?

Accepted Answer

A)  NC, low 
B)  NC, high 
C)  BE, low 
D)  BE, high

Question 16

Which of the following statements describes an advantage of the DiffServ QoS model over the IntServ QoS model?

Accepted Answer

A)  DiffServ reserves resources dynamically using the RSVP protocol. 
B)  DiffServ only requires packets to be classified into forwarding classes at the first network hop. 
C)  DiffServ provides granular differentiation and superior fairness because it processes traffic streams individually. 
D)  DiffServ is more scalable it treats traffic streams as aggregates.

Question 17

Which of the following statements defines the committed information rate?

Accepted Answer

A)  It is the rate at which a traffic stream is offered to a queue. 
B)  It is the rate at which packets are forwarded out of a queue. 
C)  It is the minimum rate at which packets may be forwarded out of a queue. 
D)  It is the maximum rate at which packets may be forwarded out of a queue.

Question 18

Which of the following statements about the consequences of congestion is TRUE?

Accepted Answer

A)  Negative jitter results in a smaller than expected interval between transmitted packets. 
B)  Jitter does not have any effect on the quality of video applications. 
C)  Serialization delay is not affected by congestion. 
D)  Queuing delay is a fixed form of delay in networks.

Question 19

Which of the following statements BEST describes where shaping mechanisms should be applied?

Accepted Answer

A)  On all ports on the Alcatel-Lucent 7750 SR. 
B)  At the junction of high-speed to low-speed links or at places of traffic aggregation. 
C)  At the junction of low-speed to high-speed links or at places of traffic aggregation. 
D)  On low-speed WAN links. 
E)  Nowhere. Shaping is only performed in hardware and serviced in a round-robin.

Question 20

An IOM3 card of a Nokia7750 SR is enabled with the default scheduler and the policy shown in the image is applied to an access port on this card. In which order will packets be scheduled out of the queues?

Accepted Answer

A)  Queue 3 within-CIR packets, then queue 4 within-CIR packets, then queue 3 and queue 4 above-CIR packets in round-robin. 
B)  Queue 4 within-CIR packets, then queue 3 within-CIR packets, then queue 3 and queue 4 above-CIR packets in round-robin. 
C)  Queue 3 within-CIR packets, then queue 4 within-CIR packets, then queue 3 above-CIR packets, and finally queue 4 above-CIR packets. 
D)  Queue 4 within-CIR packets, then queue 3 within-CIR packets, then queue 4 above-CIR packets, and finally queue 3 above-CIR packets.

Exam 1: Nokia Scalable IP Networks