Which of the following describes an industry-wide standard suite of protocols and algorithms that allows for secure data transmission over an IP-based network that functions at the layer 3 Network layer of the OSI model?

It is very important to remember when studying the CCNA exam objectives, and when configuring Frame Relay with point-to-point subinterfaces, that you do not put an IP address on the physical interface.

In a modern network, hybrid fibre-coaxial (HFC) is a telecommunications industry term for a network that incorporates both optical fiber and coaxial cable to create a broadband network.

Please do not freak out because ATM is an answer to this question. ATM is not covered in depth on the CCNA exam. PPP is mostly used for dial-up (async) services, but ATM could be used as well, though it typically is not used anymore since PPP is so efficient.

Ethernet and Token Ring are LAN technologies and cannot be configured on a serial interface. PPP, HDLC, and Frame Relay are layer 2 WAN technologies that are typically configured on a serial interface.

PPP is your only option, as HDLC and Frame Relay do not support these types of business requirements. PPP provides dynamic addressing, authentication using PAP or CHAP, and callback services.

A allows the creation of private networks across the Internet, enabling privacy and tunneling of non-TCP/IP protocols. A VPN can be set up across any type of link.

If you have a Cisco router on one side of a Frame Relay network and a non-Cisco router on the other side, you would need to use the Frame Relay encapsulation type of IETF. The default is Cisco encapsulation, which means that a Cisco router must be on both sides of the Frame Relay network.

PPPoE encapsulates PPP frames in Ethernet frames and uses common PPP features like authentication, encryption, and compression. PPPoA is used for ATM.

ATM is the Data-Link layer protocol that's typically used over the DSL layer 1 connection from the CPE and terminated at what's known as the DSLAM-an ATM switch that contains DSL interface cards, or ATU-Cs.

If you have a router in your Frame Relay network that does not support IARP, you must create Frame Relay maps on your router, which provide known DLCI-to-IP address mappings.