The IP ToS field consists of ________ bits, of which ________are used. The _________most significant (first) bits define precedence.
- A . 8,6,3
- B . 8,8,6
- C . 16, 8, 4
- D . 8,6,4
- E . 24, 16, 8
Which of the following are examples of metrics for QoS?
- A . Signal degradation, attenuation, line loss
- B . Latency, FIFO, WRED
- C . Delay, jitter, packet loss
- D . SNR, queue depth, latency
- E . Attenuation, dispersion, latency
What is the 6-bit binary representation of DSCP value AF21?
- A . 010011
- B . 100010
- C . 010001
- D . 001100
- E . 010010
Which of the following statements regarding DSCP bits are TRUE? (Choose three)
- A . The three most significant (first) bits define 8 forwarding classes.
- B . The three least significant (last) bits of the DSCP specify the drop probability.
- C . The full 8 bits of the TOS field are used for DSCP.
- D . To convert DSCP to IP precedence, the three most significant (first) bits are matched.
- E . DSCP provides for eight drop probabilities.
Which of the following can be used as classifiers of customer traffic? (Choose three)
- A . DSCP value
- B . 802.1p value
- C . IP DF bit
- D . TCP/UDP port numbers
- E . HTML version number
Which of the following are characteristics of DSCP? (Choose two)
- A . DSCP is part of the Layer 3 header.
- B . DSCP is a 6-bit field.
- C . DSCP specifies eight different priorities.
- D . DSCP specifies four precedence levels.
- E . DSCP is part of the Layer 2 header
- F . DSCP specifies 128 different per-hop behaviors.
What is an SLA? (Choose two)
- A . An SLA is used to provide automated, real-time testing and alarming for throughput, latency, and jitter across a provider’s network.
- B . An SLA is an agreement between a customer and a provider that dictates the treatment of customer traffic across the provider’s network.
- C . An SLA allows customers to control all traffic within the service provider’s network by prioritizing their traffic over others as desired.
- D . An SLA allows a customer to pre-mark traffic and ensure that traffic is treated as per the agreement within the provider’s network.
- E . 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.
How many bits does DSCP use to provide QoS marking options?
- A . 8
- B . 16
- C . 6
- D . 4
- E . 3
Which of the following are major components of QoS functionality on the Nokia 7750 SR? (Choose three)
- A . Microflow reservations using RSVP
- B . DSCP to EXP translation
- C . Traffic classification
- D . Automatic profiling and policy configuration
- E . Buffer memory management
- F . Traffic scheduling
Which of the following are characteristics of 802.1p? (Choose two)
- A . 802.1p adds 16 bits to the Layer 2 header,
- B . 802.1p adds 16 bits to the Layer 3 header.
- C . 802.1p specifies 64 different priority levels.
- D . 802.1p uses a field in the 802.1Q header.
- E . 802.1p uses a field in the Layer 3 IP header
- F . 802.1p defines a 3-bit Class of Service field.
Which of the following BEST describes a SAP when regarding QoS?
- A . A point in the network where EXP bits can be mapped to one of eight predefined FCs, each one with its own queue.
- B . A logical point in a service tunnel where all of customer traffic is aggregated.
- C . A point at which the initial classification of customer traffic occurs.
- D . A point in the network where QoS parameters are discarded in favor of lower-level hardware
queuing functions, such as LLI (Link Layer Interleave). - E . A point in the network where traffic flows from multiple different services are queued together, based on forwarding class.
Individual application streams are considered microflows, whereas __________ are considered macroflows.
- A . SAPs
- B . SDPs
- C . Services
- D . Queues
- E . Schedulers
- F . Forwarding classes
What is the maximum number of SAP-ingress policies that can be applied on a SAP?
- A . 1
- B . 2
- C . 3
- D . 4
- E . 5
- F . 8
Click the exhibit button below.
Based on the configuration shown below, name the forwarding class to be associated with a TCP packet encapsulated inside an Ethernet frame that arrives on SAP 1/1/5 with the following characteristics:
Destination IP address = 120.110.1.1
TCP port number = 23
DSCP value = nc1
Dot1pvalue = 3
- A . H2
- B . NC
- C . L2
- D . EF
- E . H1
- F . BE
Which of the following are possible criteria for classifying packets at the network port ingress on the Nokia 7750 SR? (Choose three)
- A . The EXP bits in the MPLS header.
- B . The packet’s source and destination IP addresses.
- C . The packet’s DSCP bits.
- D . The dot1p bits in the frame header.
- E . The ID of an SDP that is transporting the packet.
A default network policy is applied to all router interfaces associated with network ports.
- A . TRUE
- B . FALSE
Which of the following are NOT ingress matching criteria for a network policy? (Choose two)
- A . TCP port numbers
- B . LSP EXP
- C . DSCP
- D . Source and destination IP addresses
- E . Dot1p priority
Click the exhibit button below.
A partial SAP-ingress policy configuration is shown below. A UDP video stream is sent to a PC with IP address 192.168.1.100.
Given the SAP-ingress policy, to which forwarding class is the traffic matched?
- A . AF
- B . EF
- C . H2
- D . H1
- E . BE
On an Nokia IOM 3, how is buffer memory allocated per forwarding complex?
- A . 512 MB ingress, 512 MB egress
- B . 256 MB ingress, 256 MB egress
- C . 1 GB dynamically allocated between ingress and egress.
- D . 768 MB dynamically allocated between ingress and egress.
- E . 768 MB, with a minimum of 256 MB ingress and egress, and an additional 256 MB dynamically allocated.
WRED can be used to help avoid TCP slow-start synch problems.
- A . TRUE
- B . FALSE
What is the maximum number of forwarding subclasses a forwarding class can have?
- A . 3
- B . 64
- C . 72
- D . 16
- E . 56
Click the exhibit button below.
Given the slope-policy (below), which of the following statements are TRUE? (Choose two)
- A . All out-of-profile traffic will be dropped before that of any in-profile traffic.
- B . The discard probability slope of an in-profile traffic is steeper than that of an out-of-profile traffic.
- C . When the shared buffer utilization reaches 55%, both in-profile and out-of-profile packets may be dropped.
- D . The maximum probability with which an out-of-profile packet can be dropped is higher than that of an in-profile packet.
- E . When the shared buffer utilization is at 61%, only in-profile packets are currently in the shared buffer pool.
Click the exhibit button below.
Given the SAP-ingress policy, which of the following statements are FALSE? (Choose three)
- A . Queue 5 is using priority mode.
- B . UDP traffic can be serviced at a maximum rate of 20 Mbps.
- C . Ping traffic is place in queue 5.
- D . Queues 5 and 6 will receive equal portions of any remaining available bandwidth to meet their above-CIR bandwidth requirements.
- E . Queue 3 is scheduled before queue 5.
Which of the following should be performed if a service provider does not want packets to make use of the shared buffer space when queued?
- A . Set the CBS to 0.
- B . Set the MBS equal to the CBS.
- C . Set the high-priority-only equal to the MBS.
- D . Set the MBS to 0.
- E . Set the high-priority-only to 0.
Which of the following statements BEST describes an MBS parameter?
- A . It specifies the maximum rate at which a queue can be serviced.
- B . It specifies the maximum depth of a queue beyond which packets will be dropped.
- C . It specifies the portion of a queue that is taken from the reserved buffer pool.
- D . It specifies the threshold beyond which only in-profile packets will be queued.
- E . It specifies the peak bandwidth that can be attained by the incoming traffic.
How many queues are available for use on service egress within a VPLS service?
- 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.
If traffic is destined to queue 5, which has a high-priority-only value of 0 in the network-queue policy, all out-of-profile packets will be dropped.
- A . TRUE
- B . FALSE
On the Nokia 7750 SR, where can network-queue policies be applied? (Choose two)
- A . On the network egress port.
- B . On the SDP.
- C . On the access ingress port.
- D . On the egress MDA.
- E . On the SAP.
- F . On the ingress MDA.
Click the exhibit button below.
Given the output of the #show pools 1/2/2 network-egress command on a GigE port, what can the service provider deduce? (Choose two)
- A . QoS is not configured on the router.
- B . Packets in forwarding classes "be" and "12" are being queued.
- C . Traffic belonging to forwarding class "ef" is not experiencing queuing delays.
- D . Traffic belonging to forwarding class "11 "will never make use of the shared buffer pool.
- E . Out-of-profile traffic in the shared buffer pool is being dropped.
A queue is configured with the following attributes:
MBS = 10KB
CBS = 5KB
High-Priority-Only = 20%
Assume that there is no CBS overbooking and that the slope-policy is disabled.
If the current queue depth is 3KB, what will happen to an out-of-profile packet arriving at an egress queue?
- A . It will be queued in the reserved portion of the buffer pool and remain out-of-profile.
- B . It will be queued in the reserved portion of the buffer pool if there are no in-profile packets already in the queue.
- C . It will be queued in the reserved portion of the buffer pool and be in-profile.
- D . It will be queued in the shared portion of the buffer pool but contend for shared buffer space with packets from other queues.
- E . 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.
A physical port has three associated buffer pools.
Which of the following buffer pool combinations is associated to a physical port?
- A . Access ingress, access egress, network egress
- B . Access ingress, network ingress, network egress
- C . Port ingress, port egress, shared bi-directional
- D . Port ingress, port egress, network egress
- E . Port ingress, network ingress, network egress
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)
- 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
Forwarding subclasses are only relevant to, and are therefore applied within the context of, a _____________policy.
- A . network
- B . scheduling
- C . slope
- D . SAP-ingress
- E . network-queue
To manage the shared buffer space at network ports, slope policies are applied on _________ for the ingress direction, and on ________ or _________ for the egress direction.
- A . Interfaces, ports, SAPs
- B . Ports, ports, MDAs
- C . MDAs, MDAs, ports
- D . Interfaces, interfaces. MDAs
- E . MDAs, ports, interfaces
Click the exhibit button below.
A service provider has applied the SAP-ingress policy configuration below on his customer’s SAP. The service provider notices that all of the customer’s traffic is being dropped at the SAP-ingress.
Which of the following actions can resolve the problem, if applied on its own? (Choose three)
- A . Set the CIR of queue 3 to a non-zero value corresponding to the customer’s expected bandwidth requirements.
- B . Set queue 3 to use priority mode.
- C . Set the traffic classification of packets to in-profile.
- D . Set the high-priority-only value to 0.
- E . Map AF traffic to queue 1
Click the exhibit button below.
Given the scheduler-policy (below), how much bandwidth can the best-effort traffic receive (PIR and CIR) when the ingress rate of each queue is 10Mbps?
- A . PIR = 4Mbps. CIR = 1Mbps
- B . PIR = 1Mbps, CIR = 1 Mbps
- C . PIR = 10Mbps, CIR = 1Mbps
- D . PIR = 5Mbps, CIR = 1.25Mbps
- E . PIR = 1.25Mbps, CIR = 1.25Mbps
In the context of hierarchical scheduling, a scheduler is configured with a CIR weight of 0.
Which of the following statements is TRUE?
- A . The scheduler will be allocated its "within CIR" bandwidth before all other children at the same level have received their "within CIR" bandwidth.
- B . The scheduler will be allocated its "within CIR" bandwidth after all other children at the same level have received their "within CIR" bandwidth.
- C . The scheduler will be allocated its "within CIR" bandwidth after all other children at all levels have received their "within CIR" bandwidth.
- D . The scheduler will not be allocated its "within CIR" bandwidth.
Which of the following statements describe the primary objectives of the policing of traffic flows on the Nokia 7750 SR? (Choose two)
- A . Ensure that traffic flows conform to their traffic profile.
- B . Log violations of metered traffic flows exceeding the CIR value set on the entity across which the traffic is moving.
- C . Provide fairness between traffic flows, so that conforming (in-profile) traffic flows are not starved of bandwidth and/or buffer space by non-conforming (out-of-profile) flows.
- D . Minimize packet loss and reduce end to end latency.
- E . Ensure that variable latencies do not cluster short bursts of originally conforming packets and render them nonconforming.
Which of the following entities can scheduler policies be applied to? (Choose two)
- A . Network ingress port
- B . Epipe ingress SAP
- C . ES egress SAP
- D . Ingress MDA
- E . VPRN ingress interface
- F . Shared buffer space
It is necessary for Tier 1 schedulers to obtain bandwidth from a higher tier scheduler.
- A . TRUE
- B . FALSE
In which of the following scenarios is the egress port scheduler useful? (Choose two)
- A . 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.
- B . 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.
- C . 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.
- D . An equipment manufacturer has requested a NULL epipe service that will transparently pass dot1Q between the new location and national headquarters.
Policing improves bandwidth utilization by using buffering to absorb high bursts of traffic.
- A . TRUE
- B . FALSE
On the Nokia 7750 SR, which of the following QoS-related policies can be configured on a SAP? (Choose three)
- A . The slope-policy
- B . The SAP-ingress policy
- C . The SAP-egress policy
- D . The network-queue policy
- E . The scheduler-policy
Which of the following statements BEST describes where shaping mechanisms should be applied?
- A . On all ports on the Nokia 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.
When using an egress port scheduler, on which scheduling loop are orphaned queues serviced?
- A . Level 8 within CIR.
- B . Level 8 between CIR and PIR.
- C . Level 8, once all PIR is serviced.
- D . Level 1 within CIR.
- E . Level 1 between CIR and PIR.
- F . Level 1, once all PIR is serviced.
Which of the following statements regarding the egress port scheduler is TRUE?
- A . The egress port scheduler can have up to 17 children spread across 8 levels.
- B . Multiple egress port schedulers can be assigned to a single port with many HQoS children.
- C . Multiple HQoS policies can be children of a single port scheduler.
- D . Multiple egress port schedulers can be children of a single HQoS scheduler.
Traffic assigned to forwarding classes is placed into queues, while the contents of the queues are serviced in a controlled manner using____________.
- A . WRED
- B . shapers
- C . schedulers
- D . markers
- E . weighted fair queues (WFQ)
To implement Hierarchical-QoS (Multi-tiered scheduling), which of the following actions must be undertaken? (Choose three)
- A . H-QoS capabilities must be enabled globally on the router
- B . A scheduler-policy must be configured.
- C . The queues in the SAP-ingress and SAP-egress policies do not require additional configuration attributes to make use of the hierarchical schedulers.
- D . The network queue policy must be configured to make use of the scheduler-policy.
- E . The scheduler-policy must be referenced in the SAP-ingress and SAP-egress policies.
- F . The scheduler-policy must be applied on the service SAP.
Which of the following statements regarding policing and shaping on the Nokia 7750 SR are TRUE? (Choose two)
- 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.
Click the exhibit button below.
Given this scheduler-policy configuration, which of the following can be said about the scheduler called "high"? (Choose two)
- A . It is a parent scheduler.
- B . It is the top-level scheduler.
- C . It can allocate up to 50 Mbps of bandwidth to scheduler "low" since the bandwidth is not used by another Tier 3 scheduler.
- D . It is a child scheduler.
- E . It can only have queues as children.
At which points can traffic be marked or remarked on the Nokia 7750? (Choose two)
- A . SAP-ingress only
- B . SAP-egress only
- C . SAP-ingress and SAP-egress
- D . Network ingress
- E . Network egress
Which of the following statements regarding egress FC and profile over-ride are TRUE? (Choose two)
- 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 (BA) and Multi-field (MF) match occurs, only the MF override parameters will take effect.
- E . If a Behavior Aggregate (BA) and Multi-field (MF) match occurs, the BA classification can override the forwarding class while the MF classification can override the profile.
Which of the following are trusted boundaries, by default? (Choose two)
- A . An IES SAP
- B . A VPLS SAP
- C . A network port
- D . AVPRN SAP
- E . An access port
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)
- 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.
In which of the following scenarios is self-generated traffic QoS (sgt-QoS) useful?
- A . EXP markings on transit control traffic are not set correctly.
- B . The priority of all self-generated traffic needs to be lowered to allow all other traffic to take precedence.
- C . The priority of various control packets requires special treatment throughout the network.
- D . The BGP process is consuming too many CPU cycles and is impacting OSPF performance.
Which of the following statements are TRUE when discussing self-generated traffic QoS? (Choose two)
- A . In order to mark Layer 2 traffic, sgt-qos will set various ToS bits.
- B . DSCP bits can be set per application, per routing instance.
- C . The DSCP marking stays nc1 for all applications. Only the internal FC is manipulated across different applications.
- D . In order to mark Layer 2 self-generated traffic, network interfaces must be set to dot1Q.
- E . The internal forwarding class for self-generated traffic is set once and applied to the base router and all VPRN instances.
A packet is to be encapsulated inside an MPLS tunnel which consists of two MPLS headers at the first network egress.
Which of the MPLS EXP fields will be marked?
- A . The EXP field in the bottom MPLS header will be marked.
- B . The EXP field in both the top and bottom MPLS headers will be marked.
- C . For Layer 2 services, the top MPLS header will be marked; for Layer 3 services, the bottom MPLS header will be marked.
- D . The EXP field in the top MPLS header will be marked.
- E . Neither the top nor the bottom EXP field will be marked since EXP remarking can only be done on the network ingress.
Which of the following statements are TRUE regarding the building of a QoS-enabled network? (Choose two)
- A . It is important that all packets are classified in the same way at all SAP-ingress points.
- B . Once a packet is classified to a forwarding class, it cannot change across the network.
- C . Packet enters a node will be treated as per the local hop’s configured policy.
- D . Native IP packets entering a network port will be marked at the first network egress by default
- E . Native IP packets entering a network port will not be marked at the first network egress by default.
- F . Native IP packets entering a network port will be marked at the first network egress, regardless of the re-marking configuration.
Click the exhibit button below.
Traffic arriving at router PE 1 is marked with a dot1p value of 4.
Given the network policies applied on the routers in the diagram below, what is the EXP value of packets arriving at router PE 2? Note: Only relevant portions of the network policy are shown.
- A . 2
- B . 3
- C . 5
- D . 6
- E . None of the above.
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)
- 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.
Which of the following statements BEST defines policing?
- A . The process of delaying packets within a traffic stream to have them conform to a defined traffic profile.
- B . The overall treatment of a defined subset of a customer’s traffic within a DiffServ domain.
- C . The process of discarding packets within a traffic stream in accordance with the state of a meter to enforce a defined traffic profile.
- D . The action of setting the DiffServ codepoint of a packet prior to its entry into a downstream DiffServ domain.
- E . A specified algorithm or operation that is implemented in a node in order to realize one or more per-hop behaviors.
Without_______, a customer’s high priority traffic can be dropped before its low priority traffic.
- A . packet filtering
- B . prioritization of traffic flows
- C . least cost routing
- D . OAM functionality
- E . separation between the data plane and the control plane
Which of the following statements are TRUE? (Choose two)
- A . The primary contributors to latency are distance, scheduling, and congestion.
- B . The weighted round robin scheduling algorithm will result in more delay for high priority traffic than the regular round robin algorithm.
- C . The round robin scheduling algorithm will result in less jitter for low priority traffic than a strict priority scheduler.
- D . Packet loss can be reduced by decreasing the amount of buffer space available to a queue.
- E . Latency can be reduced by increasing the amount of buffer space available to a queue.
Click the exhibit button below.
A network operator has configured the SAP-ingress policy below. Ping traffic is expected in queue 3. However, the network operator notices that all traffic is placed in queue 1.
What is the most probable reason for this?
- A . The default forwarding class for all traffic, including ICMP, is BE, which is placed in queue 1.
- B . The SAP has been shut down.
- C . The IP-match criteria has been misconfigured for ICMP traffic.
- D . Queue 3 has no rate or CIR configured and thus cannot hold any packets.
- E . The SAP-ingress policy has not been applied to the SAP.
Which of the following are possible criteria for classifying packets at the SAP-ingress? (Choose three)
- A . The EXP bits in the MPLS header.
- B . The packet’s source and destination IP addresses.
- C . The service ID of the service to which the SAP belongs.
- D . The dot1p bits in the frame header.
- E . The packet’s Ethertype.
Which of the following statements is considered best practice when changing a network policy that has been associated with an interface?
- A . The policy should be placed in a "shutdown" state before changes are made.
- B . A new network policy should be created and applied to the interface, overwriting the previous policy.
- C . The policy must first be removed from the interface, then modified and re-applied to the interface.
- D . Before the policy can be changed, it must be deleted with the no network qos <policy-id> command.
- E . Before any changes are made to the policy, all network interfaces where the policy is applied have to be shut down.
Which of the following statements regarding buffer pool allocation are FALSE? (Choose two)
- A . Each network egress port receives its own buffer pool.
- B . Each SAP-egress port receives its own buffer pool.
- C . All SAP-ingress ports on the same MDA share a buffer pool.
- D . All the network ingress ports on the same MDA share a buffer pool.
- E . Each network ingress port on the same MDA receives its own buffer pool.
Click the exhibit button below.
Given the SAP-ingress policy, which of the following statements are TRUE? (Choose three)
- A . All AF traffic will be marked "in-profile" at the SAP-ingress.
- B . All TCP traffic will be mapped to forwarding class EF.
- C . UDP traffic is placed in queue 3 while ICMP traffic is placed in queue 5.
- D . EF traffic will receive higher scheduling priority than H2 traffic.
- E . Traffic that does not match any of the IP criteria will be placed in queue 3.
On the Nokia 7750 SR, what is a slope policy used for?
- 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.
On the Nokia 7750 SR, how many queues per FC are available for multipoint traffic within a VPLS on service ingress?
- A . 64
- B . 8
- C . 3
- D . 16
- E . 1
A queue is configured with the following attributes:
MBS = 10KB
CBS = 5KB
High-Priority-Only = 30%
Assume that there is no CBS overbooking and that the slope-policy is disabled.
If the current queue depth is 8KB, what will happen to an in-profile packet arriving in the queue?
- A . It will be discarded because the high-priority-only threshold is exceeded.
- B . It will be queued but re-marked as "out-of-profile."
- C . It will be queued in the reserved portion of the buffer pool and remain "in-profile."
- D . It will be queued in the shared portion of the buffer pool but contend for shared buffer space with packets from other queues.
- E . 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.
Click the exhibit button below.
Each router is interconnected by a single GigE link, as shown in the diagram below.
Note: The arrows show the direction of traffic flow.
Traffic from Customer A and Customer B that is classified to the same forwarding class is queued together at the ingress of Router B.
- A . True
- B . False
Click the exhibit button below.
Given that the slope-policy (below) has been enabled and applied on a network port, which of the following statements are TRUE? (Choose three)
- A . All out-of-profile traffic will be dropped before any in-profile is dropped.
- B . The time average factor of 0 will discard all packets arriving in the shared buffer pool.
- C . When the shared buffer utilization reaches 51%, in-profile packets might be dropped.
- D . The highest probability with which an out-of-profile packet can be dropped is 20%.
- E . 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.
Which of the following QoS functions does the slope-policy perform?
- A . Classification
- B . Marking
- C . Queuing
- D . Congestion management
- E . Scheduling
Which of the following are entities of the Nokia 7750 SR on which you can NOT apply a network-queue policy? (Choose three)
- A . Router interfaces
- B . Ingress MDA
- C . Ingress Ethernet network ports
- D . Egress Ethernet network ports
- E . Service SAPs
When allocating scheduling resources, which of the following statements BEST describes how the egress port scheduler allocates bandwidth?
- 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.
Which of the following parameters are used in a hierarchical scheduler-policy to specify the priority of the child scheduler/queue for allocating bandwidth beyond its committed rate? (Choose two)
- A . CIR
- B . CIR level
- C . CIR weight
- D . Rate
- E . Level
- F . Weight
With hierarchical scheduling, up to ___________ tiers are supported on the Nokia 7750 SR.
- A . 8
- B . 3
- C . 4
- D . 5
- E . 6
Based on queue usage, which of the following QoS-policies when combined will allow queue rates to be dynamically allocated? (Choose two)
- A . The slope-policy
- B . The SAP-ingress policy
- C . The network-queue policy
- D . The scheduler-policy
- E . The network-policy
- F . The WRED-policy
- G . The arbitrator-policy
Real-time rate limiting on the service ingress is a feature that performs_____________. Traffic above the defined PIR is ______________.
- A . Policing, expedited
- B . Metering, marked discard eligible
- C . Marking, marked discard eligible
- D . Policing, discarded
- E . Shaping, discarded
Which of the following statements regarding scheduling on the Nokia 7750 SR is TRUE? (Choose two)
- A . 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.
- B . 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.
- C . The greater the difference between PIR and CIR rates in a queue, the less likely a CIR will be provided.
- D . 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.
- E . 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.
Which of the following fields can be marked or remarked for frames belonging to a Layer 2 service?
- A . DSCP
- B . PREC
- C . Dot1p
- D . ToS
- E . Q-in-Q
Click the exhibit button below.
At router PE1, customer packets are arriving tagged with a dotlp value of 6 and marked with a DSCP value of EF.
Based on the configuration shown below for a VPLS service, what will be the DSCP and EXP marking for the packet egressing the network port on this PE router? (Choose two)
- A . The DSCP value will be set to af21.
- B . The DSCP value will be set to af23.
- C . The DSCP value will remain as ef.
- D . The EXP value, in the MPLS headers, will be set to 4.
- E . The EXP value, in the MPLS headers, will be set to 3.
Click the exhibit button below.
All interfaces are using their default trust states and MPLS is used as the transport tunnel. The SAP-ingress, SAP-egress, and network QoS policies have been configured as shown below. Assume that the default network-queue policy is used on each router.
At router PE 1, customer traffic is arriving marked with DSCP BE and tagged with a dot1p value of 3.
Based on the configuration shown below for the VPRN service, what will be the DSCP and dot1p marking for the packet egressing at router PE 2? (Choose two)
- A . The DSCP value will be set to af21.
- B . The DSCP value will be set to be.
- C . TheDSCPvaluewillbesettoaf23.
- D . The DSCP value will be set to af 12.
- E . Thedot1pvaluewillbesetto5.
- F . Thedot1pvaluewillbesetto2.
- G . The dot1p value will be set to 3.
When deploying an Nokia MPLS network with QoS, how are the EXP bits set?
- A . The first 3 bits of the DSCP value are copied directly into the EXP field on the first network egress.
- B . The EXP bits are set on the first network egress, based on a combination of the SAP-ingress classification and the network policy applied.
- C . The 3 priority bits are copied directly from the dot1p header into the EXP field of the first MPLS header.
- D . The EXP bits are set based on a default map that translates DSCP codes into internal forwarding classes on SAP-ingress.
In which policies, on the Nokia 7750 SR. is classification performed? (Choose three)
- A . SAP-ingress policy
- B . SAP-egress policy
- C . IP-criteria policy
- D . Network-queue policy
- E . Slope policy
- F . Network policy
Which of the following are categories of forwarding classes on the Nokia 7750 SR? (Choose two)
- A . Real-time
- B . Assured
- C . Non-conforming
- D . High priority
- E . In-profile
Click the exhibit button below.
The service provider has both a VLL (epipe) service and a VPLS, as shown in the diagram below.
At router PE B, traffic arriving from both services will have the same network-queue policy applied.
- A . TRUE
- B . FALSE
Which of the following statements describe the operation of WRED on the Nokia 7750 SR? (Choose three)
- A . WRED monitors the shared buffer space utilization over a period of time.
- B . WRED disables the TCP slow-start congestion control mechanism.
- C . WRED uses two configurable slopes for each buffer pool: a high slope and a low slope.
- D . WRED uses the shared buffer utilization, instead of the individual queue depth, to get a better picture of the average resource utilization of the shared buffer space.
- E . WRED polices the shared buffer pool and marks all packets above a certain rate as "discard eligible."
Click the exhibit button below.
Given the scheduler-policy (below), which of the following can be done to guarantee that the best-effort traffic receives its configured CIR value?
- A . Change the CIR-level value for the best-effort queue to 8.
- B . Do not change anything; it is already guaranteed to receive its CIR
- C . Change the CIR-level value for the best-effort queue to 1.
- D . Change the CIR-weight value of the AF queue to 0.
Which of the following rate-limiting approaches are used on the Nokia 7750 SR? (Choose two)
- 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.
If a packet is marked on a SAP-ingress, it will be remarked at the first network egress point (if
remarking is enabled in the network egress policy).
- A . TRUE
- B . FALSE
Which of the following statements are TRUE regarding the PE device in a QoS enabled network? (Choose two)
- A . A device that provides no differentiation between customer traffic flows.
- B . A device that classifies and marks customer traffic.
- C . A device that uses MPLS EXP bits to differentiate between traffic flows.
- D . A device that creates macroflows towards the core from multiple customer sites.
- E . A device that passes macroflows while optionally changing QoS markings.
On the Nokia 7750 SR, what is the maximum number of queues that a single SAP-ingress policy can support in a VPLS?
- A . 16
- B . 8
- C . 32
- D . 48
- E . 56
Click the exhibit button below.
A network operator has configured a network-queue policy to map forwarding classes to queues, as shown in the exhibit below.
Based on the default scheduling behavior of the Nokia 7750 SR, in which order will packets be serviced?
- A . All in-profile packets in round-robin, then all out-of-profile packets in biased round-robin.
- B . In-profile EF packets, then in-profile H2 packets, then in-profile AF packets, then out-of-profile EF packets, then out-of-profile H2 and AF packets, and then out-of-profile BE packets.
- C . In-profile EF, H2 and AF packets, then out-of-profile H2, AF and BE packets in biased round-robin.
- D . In-profile EF packets, then in-profile H2 and AF packets, then out-of-profile H2, AF and BE packets in biased round-robin.
- E . In-profile EF and H2 packets, then in-profile AF packets, then out-of-profile H2, AF and BE packets in biased round-robin.
Which of the following statements regarding scheduling are TRUE? (Choose two)
- A . Scheduler policies cannot be children of an egress port-scheduler.
- B . HQoS provides a static method of allocating scheduling resources to each queue and/or child.
- C . Scheduler policies can be applied to the MDA to schedule network ingress traffic.
- D . Every time a scheduler-policy is assigned to a SAP, a new hardware scheduler is created to service the SAP.
- E . A scheduler applied to multiple SAPs within the same service will result in a single hardware scheduler operating across all SAPs within the service.
Which of the following statements regarding the default scheduler in the Nokia 7750 SR are TRUE? (Choose two)
- A . There are a maximum of 8 levels of priority serviced using a round-robin algorithm.
- B . The default scheduler will spend an equal amount of time in each queue, as long as there is traffic present
- C . The H1 internal forwarding class will receive its CIR before AF traffic.
- D . Orphaned queues will be scheduled out of the BE queue.
- E . A queue servicing EF and AF traffic will require explicit configuration to set the queue to expedited.
Click the exhibit button below.
Based on the configuration of the network policy (below), what will be the forwarding class associated with a MPLS encapsulated customer packet that arrives on a dotlQ encapsulated network port 1/1/4:1 on P1 with the following characteristics:
EXP value = 6
DSCP value = cs1
Dot1pvalue = 3
- A . EF
- B . H1
- C . L1
- D . H2
- E . L2
How does an IOM3 improve the queue usage over an IOM2 in an Nokia 7750 SR? (Choose two)
- A . The IOM3 adds more memory to both forwarding complexes which increases the total number of queues available.
- B . The IOM3 only contains a single forwarding complex which reduces the number of queues used.
- C . The IOM3 allows multiple forwarding classes to be assigned to a single queue.
- D . The IOM3 allows queues to be dynamically allocated between ingress and egress.
- E . The IOM3 has a larger CPU capable of tracking active hardware queue utilization and adjusting memory allocation accordingly.
Which of the following statements BEST describes the IntServ model?
- A . Has the ability to distinguish traffic in 32 different ways.
- B . Uses the RSVP protocol to create microflows through a network.
- C . Has the ability to manually configure foiwarding classes through a network.
- D . Uses the RSVP protocol to create macroflows through a network.