The switching function of a Frame Relay switch operates at what layer of the OSI model?

For an OC-48 signal (2.5Gb/s), what is the BER (bit error rate) if there is 1 bit error every four days?

One advantage of using loop start over ground start is that:

Given an address of 10.1.1.1 with a subnet mask of 255.255.255.224, how many hosts can be addressed in this subnet?

A new Cisco router has no configuration defined. Which methods can be used to configure the router for the first time? (Select four)

What is an advantage of cell technology?

A 1024-byte frame is:

With TM 4.1 RM cells, which of these are relevant? (Select two)

Exhibit

You work as a network engineer at Domain.com. Assume IP Videoconference station Certkiller A places a 384Kb call to IP Videoconference station Certkiller B and the Workstations are transferring files back and forth between themselves during the same time period. What Cisco feature should be used on both routers to avoid unwanted jitter and guarantee the videoconference will get enough bandwidth for the duration of the call?

Exhibit

The diagram shows a campus with an L2 switched backbone. The backbone has a single VLAN (= subnet) with no loops. The links into the backbone are routed interfaces, not VLAN trunks. Switch X is the STP root of the core VLAN and switch Y is the standby root. The connection between X and Y is an EtherChannel. The network architect wants to add more redundancy by connection the L3 switches in the distribution layer to both X and Y.
What best describes that plan?