350-501 Practice Test 14 — 15 Questions

Question 1

Which access technology uses a passive optical splitter to deliver broadband services to multiple subscribers over a single fiber?

Accepted Answer

GPON. GPON (Gigabit Passive Optical Network) uses passive splitters to share fiber among multiple subscribers.

Answer

Cable (DOCSIS)

Answer

Metro Ethernet

Answer

DSL (Digital Subscriber Line)

Question 2

Which TWO are key features of IOS XR architecture? (Choose two.)

Accepted Answer

Distributed OS with process separation. IOS XR is a distributed OS with process separation and a commit/rollback model. Monolithic kernel and shared memory are not features.

Answer

Configuration applied immediately without validation

Answer

Monolithic kernel with shared memory address space

Answer

Single process for all routing protocols

Question 3

What is the primary function of the aggregation layer in a service provider network?

Accepted Answer

Aggregate traffic from the access layer and forward to the core. The aggregation layer collects traffic from access nodes and forwards it to the core, often performing QoS, filtering, and subscriber management.

Answer

Provide direct customer connections

Answer

Perform deep packet inspection

Answer

Provide high-speed backbone connectivity

Question 4

A service provider wants to provide a point-to-point Ethernet service between two customer sites with strict Service Level Agreements (SLAs). Which MEF service type should be used?

Accepted Answer

E-Line. E-Line is a MEF standard for point-to-point Ethernet services, providing dedicated bandwidth and SLA guarantees.

Answer

E-LAN

Answer

E-Access

Answer

E-Tree

Question 5

Which THREE are MEF-defined Ethernet service types? (Choose three.)

Accepted Answer

E-LAN. MEF defines E-Line, E-LAN, and E-Tree. E-Access is also defined but is not part of the three main types. E-WAN is not a standard MEF service.

Answer

E-Access

Answer

E-WAN

Question 6

Which MEF service type is used for multipoint-to-multipoint Ethernet connectivity, such as a corporate LAN extension across multiple sites?

Accepted Answer

E-LAN. E-LAN provides multipoint-to-multipoint connectivity, emulating a LAN across multiple locations.

Answer

E-Line

Answer

E-Tree

Answer

E-Access

Question 7

An ISP wants to create separate virtual networks over a shared physical infrastructure to serve mobile broadband (eMBB), IoT (mMTC), and mission-critical services (uRLLC). Which technology enables this segmentation with per-slice resource guarantees?

Accepted Answer

Network Slicing using IETF and 3GPP frameworks. Network slicing divides the physical network into multiple virtual networks, each with dedicated resources for different service types. L3VPN, MPLS-TE, and VPLS do not provide per-slice resource guarantees natively.

Answer

MPLS Traffic Engineering

Answer

L3VPN with VRF

Answer

VPLS

Question 8

An SP uses Cisco ASR 9000 routers with IOS XR. Which statement correctly describes the commit/rollback configuration model in IOS XR?

Accepted Answer

Changes are staged in a candidate configuration and applied only after 'commit'; rollback to a previous commit is possible.. IOS XR requires a 'commit' to apply changes; it supports rollback to previous committed configurations, allowing safe changes.

Answer

Only 'commit replace' is supported; rollback requires manual re-entry.

Answer

The router automatically commits changes every 10 minutes.

Answer

Changes take effect immediately without commit; rollback is not supported.

Question 9

Which statement about the commit/rollback configuration model in IOS XR is true?

Accepted Answer

If a commit fails, the system automatically rolls back to the last committed configuration. IOS XR uses a two-phase commit: the user commits, and if successful, the configuration is applied; otherwise, it rolls back. There is no need for explicit rollback commands.

Answer

Rollback requires manual deletion of uncommitted changes

Answer

Configuration is applied to all cards simultaneously without validation

Answer

Changes take effect immediately without a commit command

Question 10

In an IOS XR system, CPU and memory resources are allocated per line card. What is the primary reason for this design?

Accepted Answer

To ensure that a failure on one card does not impact others. Distributed architecture with per-card allocation improves scalability and fault isolation. It does not directly reduce cost or simplify management; instead, it enhances performance and resilience.

Answer

To reduce hardware cost by sharing resources

Answer

To simplify software licensing

Answer

To centralize management in the route processor

Question 11

Which Cisco platform is designed for high-capacity core/backbone routing with support for MPLS, Segment Routing, and large-scale BGP?

Accepted Answer

Cisco CRS. Cisco CRS (Carrier Routing System) is a high-end core router designed for large service provider backbone networks, supporting MPLS, SR, and massive scale.

Answer

Cisco NCS 5500

Answer

Cisco 8000 series

Answer

Cisco ASR 9000

Question 12

In IOS XR, what is the primary purpose of the commit/rollback configuration model?

Accepted Answer

To apply changes atomically and roll back if needed. The commit/rollback model allows changes to be applied atomically and rolled back if errors occur, ensuring configuration consistency.

Answer

To automatically back up configurations to a remote server

Answer

To enforce role-based access control

Answer

To verify configuration syntax before applying

Question 13

Which TWO are correct about network slicing? (Choose two.)

Accepted Answer

Each slice can have its own dedicated bandwidth and latency guarantees.. Network slicing divides a physical network into multiple virtual networks, each with dedicated resources. Slices can be tailored for specific services like eMBB, uRLLC, mMTC. They are not limited to 5G core but also include transport.

Answer

Network slicing is only applicable to the 5G core network.

Answer

Network slicing requires a separate physical infrastructure for each slice.

Answer

Network slicing eliminates the need for QoS mechanisms.

Question 14

An SP is using Cisco ASR 9000 routers with IOS XR. They need to apply a configuration change and ensure that if the change causes issues, it can be easily reverted. Which IOS XR feature supports this?

Accepted Answer

Commit/rollback. IOS XR uses a commit/rollback configuration model. Changes are staged in a candidate configuration and committed; if issues arise, rollback to a previous commit is possible.

Answer

Configuration replace

Answer

Synchronization to standby

Answer

Archive and restore

Question 15

In EVPN, what is the purpose of Ethernet Segment Identifier (ESI)?

Accepted Answer

To uniquely identify an Ethernet segment for multi-homing. ESI is used to identify a multi-homed site or Ethernet segment for all-active or single-active redundancy and to prevent loops.

Answer

To identify a VXLAN tunnel

Answer

To assign a VLAN ID to a customer

Answer

To enable MPLS label distribution