4A0-100 Exam Dumps : Nokia IP Networksand Services Fundamentals

Tier 1 ISPs: Haveglobal reachabilityand exchange traffic via peering. Theydo not payfor transit.

Tier 2 ISPs: Purchasetransit services from Tier 1and provide transit to Tier 3 or other Tier 2 ISPs.

Tier 3 ISPs: Providelast-mileconnectivity to end users and donot provide transit services.

Option A is correct– Tier 1 and Tier 2provide transit services.

In MPLS architecture, theIngress LER (Label Edge Router)is responsible for:

Pushing labelsonto unlabeled packets and injecting them into the MPLS domain.

Acting as thestarting point of the Label Switched Path (LSP).

From the diagram:

R1is thestarting point (Ingress LER)for both LSP A and LSP B.

R4is theEgress LER, which wouldpopthe labels at the end of the LSP.

So,R1 is responsible for label push (imposing)at the start of both LSPs.

Option A is correct– R1 pushes labels for both LSP A and LSP B.

Option Bis incorrect – R4 is an egress router, not ingress.

Option C/Dare incorrect – the LSPs both start at R1.

On theNokia 7750 SR, theControl Processor Module (CPM)includes two compact flash slots,CF1 and CF2, which are used for storing crucial system files. These include:

Runtime software image

Configuration files

Logs and backup configurations

BothCF1 and CF2are used for redundancy and flexibility. Typically, CF1 is designated as the primary storage location for the active software image and configuration, while CF2 serves as a backup. In some configurations, the router can boot from either CF1 or CF2 depending on system settings and availability.

This redundancy is essential for high availability and fast recovery in the event of a failure or manual software update.