Which PPP subprotocol negotiates authentication options?

A network administrator needs to configure a serial link between the main office and a remote location. The router at the remote office is a non-Cisco router. How
should the network administrator configure the serial interface of the main office router to make the connection?

Which encapsulation type is a Frame Relay encapsulation type that is supported by Cisco routers?

Which Layer 2 protocol encapsulation type supports synchronous and asynchronous circuits and has built-in security mechanisms?

What is the result of issuing the frame-relay map ip 192.168.1.2 202 broadcast command?

Which command is used to enable CHAP authentication, with PAP as the fallback method, on a serial interface?

What are three reasons that an organization with multiple branch offices and roaming users might implement a Cisco VPN solution instead of point-to-point WAN
links? (Choose three.)

What can be done to Frame Relay to resolve split-horizon issues?(Choose two.)

The command show frame-relay map gives the following output:
Serial 0 (up): ip 192.168.151.4 dlci 122, dynamic, broadcast, status defined, active
Which statements represent what is shown?(Choose three.)

At which layer of the OSI model does PPP perform?