Implementing Cisco Collaboration Devices (CICD, legacy) — Question 66

On the PSTN gateway, a network engineer runs sh isdn status and finds the Layer 2 state of each interface to be "TEI_ASSIGNED". What is the status of PSTN connectivity from this gateway?

Answer options

• A. The T1 interfaces are established and operational.
• B. This information does not indicate the status of PSTN connectivity from the gateway.
• C. The T1 interfaces are down.
• D. The T1 interfaces are affected by frame loss from service provider side. C

Correct answer:

Explanation

The correct answer is B because the 'TEI_ASSIGNED' state indicates that the interfaces are configured and have been assigned a TEI, but it does not confirm if they are connected to the PSTN. Options A and C are incorrect as they make assumptions about the operational state, and D is incorrect since it implies connectivity issues that cannot be determined solely from the TEI status.