The network architect needs to design a native SDN network in a greenfield environment. The network spans 3,000 miles and three data centers. The controllers must be configured in a federated model.

Which aspect of the recommended solution must be considered as the top priority in designing both the scalability and resilience of the new SDN network?

An organization just failed an SEC test audit. Packet flooding and redundancy in an emergency are two problems cited in the audit. The security staff in the organization is advocating for expensive appliances to be purchased. The CTO wants the network architect to investigate SDN.

Which characteristics of SDN are reasons to adopt the CTO's recommendation?

Field trials for an organization's VNF instances have ended with success. Now, VNFs must be deployed across thousands of network segments in the global network. Which organizational goal presents the greatest challenge in the management of the new deployment?

The network engineer wants to design the network to be resilient and be able to continue OpenFlow Switch forwarding even if communications to the SDN Controller is lost.

A Service Provider deployed an SDN system to support 100,000 services. The system has the following configuration:

• 2 SDN controllers in active/active configuration

• Each SDN controller is sized for 100,000 services

The system must grow to support 150,000 services with the same level of redundancy.

What should the network architect do to support system growth?

In a mobile network, several base stations are attached to the core via a single mobile backhaul wireless link. Power is available only at the remote end of the backhaul link. The installation of an SDN switch at the remote end to connect the base stations via the backhaul link to the network core is the first step toward a dynamically configurable network.

Which approach allows the SDN controller located in the core to control the remote SDN switch?

A company is running a simple web service made up of a front-end web server and a back-end database server.

Users connect to the front-end web server as shown. The company has 200 customers that generate the given CPU and memory utilization rates. The company plans to expand and the user base and workload is expected to double. The network architect needs to make the existing service capable of scale-out for the upcoming expansion. The architect also needs to identify additional service components required.

What should the network architect recommend to achieve a minimum design change while maintaining quality of service?

A disaster recovery test revealed insufficient isolation between VNFs and the chance of a security breach affecting a neighboring VNF.

A white box server hosting an SDN controller deployed at the customer site fails during an upgrade process. Connectivity to the controller has been lost.

An SD-WAN is deployed using different transport technologies:

• A low-cost Internet access that provides best-effort transport for traffic (bandwidth of 40 Mbps and expected average delay of 30 ms)

• Premium MPLS transport that provides guaranteed traffic (bandwidth of 10 Mbps and delay below 10 ms)

The following traffic types are expected to cross the SD-WAN. Each traffic type has SLAs such as bandwidth and packet delay:

[1] Business critical applications (packet delay < 5 ms)

[2] Voice and video communications (packet delay < 50 ms)

[3] Social media and web content (packet delay < 10 ms)

[4] Backup of branch-office data (packet delay < 70 ms)

[5] Guest WiFi (packet delay < 100 ms)

A client must make sure the SD-WAN system uses both transport options.

What is the most cost-efficient way to transport the traffic?

The network operator is troubleshooting a connection issue for a user TCP/IP connection through the SDN Network.

A network is experiencing long delays in acknowledging communication between the network switches and the SDN Controllers. The use of multiple protocols between the controllers and the switches is causing an increase in latency. The SDN Controllers were originally Beacon but have been upgraded to Ryu since Beacon failed to meet the network's requirements.

Which approach addresses this problem?

The CTO and management want the SDN applications introduced into production as soon as possible, even if there is a risk that the hybrid SDN solution may not scale. The architect has the promises of all the different vendors - network switch, SDN controller, and SDN applications - that the solution will work. None of those promises are in writing.

What is the most compelling argument for pausing to deploy a formal test lab for SDN applications?

A Service Provider's NFV infrastructure (NFVI) is hosting VNFs from multiple vendors to support real-time applications like VoLTE. The application requirements need to be hosted in multiple data centers connected through WAN and support deployment of both green-field VNFs and VNFs of existing Physical Network Functions (PNFs).

Which three domains can support these requirements within the NFVI architecture?

An administrator is working on the Infrastructure Networking Domain of the NFVI and needs to interconnect the computing and storage resources contained in an NFVI instance.

What should the administrator configure to interconnect these resources?

The MANO component of an NFV system includes a service catalogue, a VNF image store, a VM deployment function, and an SDN controller. A customer of the NFV system is running a vCPE service made up of several VNFs including a vNAT. The customer wants to replace this vCPE from vendor A with a vCPE from vendor B. Images for the new VNFs were loaded to the image store and triggered to redeploy/update the service.

Which step is required for this replacement?

An Enterprise is upgrading a part of its current network of Ethernet switches to SDN with OpenFlow switches. The Enterprise needs to consider the following:

• The legacy Ethernet part of the network uses VLAN 20

• The new SDN part of the network uses VLAN 10

• An OpenFlow-hybrid switch connects the legacy Ethernet part and SDN part to L3 gateway using an IEEE 802.1Q trunk

Which OpenFlow rule should be specified in the hybrid switch to match and forward VLAN 20 traffic to the traditional Ethernet pipeline?

A misbehaving VNF is generating too much traffic and consuming too many resources.

How can the VNF deployment be modified to address this problem?

A customer requests a Service Provider to deploy a VNF that is made up of three Virtual Deployment Units (VDUs). Each VDU requires 4 vCPUs and 8 GB RAM for its operation. Three servers with the following capabilities are identified as NFVI compute resources:

Server A: 64 vCPU and 64 GB RAM

Server B: 32 vCPU and 48 GB RAM

Server C: 12 vCPU and 24 GB RAM

The customer requests node anti-affinity policies to be enforced.

Which VDU placement is appropriate to meet this requirement?

A Service Provider is building their SDN network using an SDN Controller and OpenFlow Switches.

The Service Provider needs to mitigate the following security challenge: attackers may launch a Denial of Service (DoS) attack by sending a high volume of unique flows, which could result in a high volume Packet-In messages from OpenFlow switches to the SDN Controller making the controller inaccessible.

Which solution should the network architect select to keep the SDN controller safe from this DoS attack?

There is a recurring connectivity failure between an SDN Controller and one of the switches. A Network Operator is unable to isolate the issue.

How should the operator resolve these issues?

A customer subscribes to a Service Provider's managed SDN-based service based on a vCPE that includes a virtual router and virtual firewall. All configuration of the VNFs must be performed by the Service Provider.

The customer suffered a security attack and requests that the Service Provider update the firewall policies to address the issue.

Which component should be used by the Service Provider to update the firewall policies?

A network company buys another network company. The engineers and architects must determine how to merge the two networks.

Both have an MPLS backbone with the presence of BGP route reflectors and use various routing protocols in their networks such as IS-IS and OSPF. Both have a mixture of traditional equipment and SDN equipment. For certain applications, they both use ODL. It is recommended to use an SDN architecture.

Which SDN solution should be used for the merge?

A Service Provider is designing a Service Function Chaining (SFC) that includes a DPI VNF and a Load Balancer VNF. The DPI VNF looks into the payload of the subscriber packets to do traffic classification and appends an application ID to be delivered to the Load Balancer VNF using either inband metadata or out-of-band metadata.

The Load Balancer VNF will use the application ID to steer a packet into a link that is assigned to that application ID.

The following information must be considered:

• Total network delay between DPI VNF and Load Balancer VNF for subscriber packets must not exceed 1 ms

• Total network delay for out-of-band metadata including the insert of metadata into a local cache at Load Balancer VNF is 2 ms

• Total number of possible values of application IDs is 5000

• VLAN tag is 12 bits

• MPLS label is 20 bits

Which design should the Service Provider use to map the application ID?

An operator wants to deploy this service chain and support at least 100 Mbps throughput for all traffic between the Users and the Server. Approximately 70% of the traffic is web and video traffic that is directed through the VNF-3.

Which combination of link bandwidth satisfies the required throughput?

Which characteristic of this NFV architecture is highlighted in the diagram?

An Operator is trying to create 6,000 virtualized networks that are interconnected through a common Layer 2 closed user group. The Layer 2 networks must support both unicast and broadcast delivery.

Because there is a 4K limitation when using VLANs, which IP-based overlay can accomplish this task?

A provider is offering services via several VNFs. After a major service outage, engineers find that the outage was due to a bug that caused a few of the VNFs to operate incorrectly. A new software version is available that fixes the problem. The new software also introduces new services that will be used by some of the VNFs. The old services still must be offered to a selected group of VNFs. How should the engineer proceed with the upgrade?

An SDN network is built using OpenFlow version 1.3 as the Southbound API. Both the master and slave SDN Controller have experienced a catastrophic failure. The switches are configured in Fail-Secure mode.

How will the forwarding plane behave in this situation?

An Operator is creating a new service over an NFV system. The service creation process requires the OSS to accept the customer's service order. The OSS will then interact with the NFV system to fulfill the customer's service order.

What should the interaction between the OSS and the NFV system contain?

System architects are planning a new NFV deployment. The architects decide to group the NFV-MANO functional blocks and design the interfaces to all other functional blocks that are part of the architectural framework based on shared reference points.

Based on the NFV architectural framework, which set of functional blocks share reference points with the NFV-MANO?

An operator is trying to edit a deployment template to make changes to the links between connected VNFs on a TOSCA-enabled NFV architecture.

A Service Provider plans to deploy a network made up of 5,000 OpenFlow switches. The switches are partitioned in domains, and each domain is controlled by a separate controller. The controllers are organized in a federated arrangement. Each controller can support up to 1,000 OpenFlow switches, but must be able to completely support another domain if the controller that controls that domain fails.

How many controllers must the Service Provider deploy to support this arrangement?

A Service Provider has installed an NFV software framework into their network. An operator needs to view alerts and events from the deployed VNFs.

An organization has assigned the network architect to design an SDN network in a hybrid switch environment. The network has the following requirements:

• The SDN solution should be OpenFlow 1.3 or later with an open source SDN controller solution

• There has to be encrypted route traffic information between the SDN controllers

What should the architect do to meet the network design requirements?

A company's network infrastructure has been upgraded to OpenFlow-based white box switches. The network architect is selecting an open-source SDN controller. The architect has several options, but none fully support the planned deployment. They all require some extensions.

The goal of the deployment is to implement priority treatment for the network traffic of the company's CEO, who regularly visits branch offices located in many locations around the world.

Based on these requirements, which features are most important for this deployment?

Several employees on the same floor report erratic network behavior. The SDN control channel to the switch on that floor is NOT established.

What is the first step the SDN engineer should do to troubleshoot the OpenFlow connection?

An NFVO system receives a network service instantiation request.

Which components does the NFVO need to interact with to execute request?

A Service Provider plans to provide a service portal to allow customers to interact with an SDN network to be able to view the status and statistics of their services.

Which interface does the service portal use to retrieve this information?

A Service Provider designs an IPS VNF solution that supports auto scaling. In that solution, when the user traffic rate to an IPS VNF exceeds a certain limit, that VNF scaled out.

Which additional components are needed for this autoscaling scenario?

A Service Provider deploys a cloud center with servers built to run VNFs. The host OS is Linux Ubuntu Server version 16.04 and the Open-vSwitch (OVS) version is 2.7.0. The OVS is managed by an OpenDaylight SDN controller. Each server must be able to monitor each VM's Ingress/Egress traffic.

How can each VM's ingress/egress traffic monitoring be done using the NFV architecture?

A Service Provider offers a data plan to customers that contains the following SLAs: a guaranteed rate of 1 Mbps and a maximum rate of 2 Mbps.

The Service Provider deploys OpenFlow switches in their network and wants to implement the SLAs using OpenFlow meters. Customer traffic is subject to a meter band with 2 meters.

What is the proper configuration of the 2 meters in the meter band?

When dealing with third-party proactive SDN applications, a network operator must address the following security challenges:

• An error in the third-party application could cause the SDN controller to crash

• Third-party applications can gain access into the internal data structures of SDN controllers

What is the proper protection mechanism?

An administrator needs to modify the Virtualization Domain, Compute Domain, and Infrastructure Networking Domain within a Service Provider's NFV infrastructure.

Which component is responsible for managing and controlling these domains within the NFVI functional block?

Troubleshooting of a service interruption identified that suboptimal routing occurred that was caused by one specific application.

The Network Service is deployed using NFV technology. The applications are on separate VMs. The VMs run over Open Virtual Switch (OVS).

What action should the SDN engineer recommend to immediately address the problem?

The Service Provider has deployed SD-WAN software in their network. After a controller upgrade, the system administrator tried to deploy a white box branch device, which failed during the usual deployment procedures.

What could be causing the failure of this deployment?

A customer requests its VPN provider to prohibit FTP traffic between its branch offices. The VPN provider's network is fully SDN controlled, but does NOT offer a self-service portal to its customers.

Which SDN component does the VPN provider's SDN support engineer need to interact with?

A Service Provider carries various traffic types: email, voice, video, and web. The Service Provider introduces SDN and NFV service chaining to improve its business model. Each traffic type is routed through its appropriate service chain. For example, the email service chain includes virus, spam, and phishing detection. The web traffic is routed through a chain that includes virus scanning and an Application Delivery Controller (ADC).

What should follow the edge router at the customer premises to implement this NFV service chaining?

The network test engineer is tasked with developing the optimum test environment for evaluating network elements and services for the organization's NFV environment. Security and usability have already been addressed. The test environment is per ETSI-NFV specification, illustrated above. The primary deliverable is to validate the SLA for high availability in convergence failover times in the simulated environment.

What key area needs to be considered in testing to make certain the organization is prepared before these VNFs are introduced in a production context?

An Operator is creating a network service made up of several VNFs in an active NFV system. The Operator's design team needs to execute a set of procedures to create this service.

What should the team do to meet this requirement?

Network operations wants to confirm that the SDN Controller to SDN Switch communication path is functional.

Which protocol should the operator use to verify latency and continuity?

A company considers building an SDN network based on the OpenFlow protocol. The OpenFlow connection setup between an OpenFlow switch and an SDN controller must meet privacy, integrity, and identity security requirements.

Which connection setup should the network architect select to meet the requirements?

A client wants to create a level of network resilience that prevents dynamic SDN traffic sent from the controller to continue in the Switch OpenFlow Pipeline processing if the switch loses connectivity to the SDN Controller. The degraded operation will result in the switch continuing to operate in its native underlying switch or router mode.

Which configuration mode will provide this level of functionality?

An enterprise customer subscribes for a low-delay 10 Mbps pipe from the Service Provider and requests a network service to allow all traffic to pass through Firewall and IDS functions before reaching their remote sites. The NFV Orchestrator deploys two virtual functions (1 for Firewall and 1 for IDS) to deliver this network service. Each virtual function has two virtual NICs connected to the virtual switches within the hypervisor. The NFVI infrastructure has 10 Gbps and 40 Gbps ports.

To enable service to this customer, what operations must be performed by the SDN Controller?

Why do Service Providers offer SD-WAN services with Quality of Service utilizing MPLS and Public Internet?

The Service Provider is deploying this SDN topology with the following configuration:

• OpenFlow channel used to exchange OF messages between the controller and the OF switches is on a dedicated network using the out-of-band OF switch interface

• The subnet address of this dedicated network is 192.168.1.0/24

• The connection to the SDN controller must be secured

After establishing the above connections and rebooting the switches, the OF switches failed to establish connection with the SDN controller. The IT Administrator suspected that it is a connection URl configuration problem in the OF switches.

What should the IT administrator verify when troubleshooting this problem?

Network Operations wants to be notified whenever a new switch or device is added to the SDN Network.

What type of SDN application is needed?

A Service Provider is implementing an SDN solution. Due to budget constraints, the Service Provider will implement incremental network upgrades and leverage the legacy switching network.

Which southbound protocols must the SDN Controller support to facilitate this architecture?

Which characteristic of NFV architecture is highlighted?

As part of the SDN deployment, the SDN Controllers must be secured. The controllers are deployed in a High Availability (HA) configuration. The Linux OS servers are hardened to avoid malware hosts, and the data center has been physically hardened.

How can the administrator avoid the insertion of unauthorized controllers ("controller-in-the-middle") that could hijack the controller infrastructure?

A Service Provider deploys SDN Controllers in a hierarchical configuration. The parent SDN Controller interacts with child SDN Controllers. Each child SDN Controller manages the respective networking domain.

Which method should be used to minimize network downtime?

An Operator is upgrading a legacy network to SDN. The upgrade should be transparent to the legacy networking devices.

What should the Operator do to meet this requirement?

An organization is deploying a virtualized network over its existing network infrastructure. The CTO has requested that the organization use NFV service chains. The network designer will instantiate resources including compute, memory, and grouping in NFV service chains.

Which element of the NFV infrastructure should be used to instantiate these service chains?

An Operator plans to deploy an NFV system. The system must be able to manage the VNF infrastructure and orchestrate the workflow of instantiating the VNFs, as well as configure them and manage their lifecycle.

Which architectural building block as defined by ETSI NFV Industry Specification Group (ISG) should the Operator use to configure an instantiated VNF?

A customer has an existing network and wants to extend it with new OpenFlow switches.

What southbound protocol must customer use to manage the legacy switches?

A media content provider struggles with data growth on its SDN network and adds an SDN controller to distribute the load and increase robustness.

Which communication interface should the SDN controllers use to synchronize their operation and provide a single controller view to the applications?

A Service Provider deploys VNFs from various vendors to build a single Service Function Chain (SFC). A software upgrade on one of the VNFs (VNF A) is planned.

The Service Provider is building a testbed to test the new version of VNF A to minimize interoperability issues.

How should the Service Provider build the testbed?

An SDN application subscribes to Emergency Alert Systems for the locations where SDN Switches are present. The application receives an earthquake alert.

What should the SDN Controller do to mitigate connectivity loss to customer-facing traffic?

An Operator is creating a service using a set of service components located on the customer premises.

How should the Operator perform this task?

A company is evaluating the move to SDN. The CTO fears that the implementation of the OpenFlow protocol throughout the environment may have a performance impact that affects business operations.

How can the company mitigate risk while still being able to deploy SDN technologies?

In a Service Provider NFV deployment, a VM is declared unavailable if it does NOT respond in the following configured periods:

• VM supporting VoLTE VNF: 10 ms

• VM supporting VoLTE Business Support System (BSS): 2000 ms

Live migration of a VM takes 1000 to 1500 ms for any workload. High availability is NOT configured for any of the VMs. The Service Provider plans a live migration of VMs to manage data center resources.

Which strategy should be used to support live migration?

A user is deploying an SDN solution to upgrade a decade-old legacy routed network. The user prefers to deploy the SDN network in a mixed mode/hybrid fashion with some devices managed via OpenFlow and other devices managed via NETCONF/YANG.

Which SDN Controller should the user select?

A Service Provider needs to create a network service that contains an Intrusion Detection System (IDS) to detect malicious traffic. The network uses OpenFlow switches.

Solution requirements:

• Minimize delay for user traffic

• Minimize processing load on the IDS system

How should the Service Provider implement the IDS system?

A company is planning to roll out all of its new applications to take advantage of SDN. They need to use OpenFlow 1.3. The new network equipment will be deployed in three phases. The existing network supports 1,200 nodes.

Which critical variable should the network architect consider when specifying the new applications to the development team?

An SDN controller is using NETCONF to configure SDN switches. An engineer is attempting to provision a new service that requires configuring multiple switches along the traffic path. However, one of the nodes along the path is NOT responding.

What should the SDN controller do?

The new "Aggregation 2" switch must to be added to handle the traffic growth. The entire network is controlled through the SDN Controller.

Which configuration must be performed to integrate the new Aggregation 2 switch into the SDN network?

The operator wants to deploy the service chain shown. To avoid customer dissatisfaction, the operator defines performance constraints. One constraint is the network delay through the service chain. A processing delay of 3 ms per VNF occurs.

Which combination of link delays satisfies a delay limit of 20 ms for the whole service chain?

A Service Provider offers data and voice services to its customers. The Service Provider offers a link with a capacity of 10 Gbps between two OpenFlow switches. The Service Provider wants to limit the data traffic to 70% of the link capacity and leave the remaining capacity for voice services.

The network administrator created an OpenFlow queue that was attached to the port and connected to the link. The link directed all data traffic (NOT voice) to that queue.

What is the proper configuration of the queue?

An Operator plans to deploy a network service composed of a chain of VNFs.

When deploying the service, what should the Operator create and configure?