Which of the following best describes the main function of OSI Layer 1 as used in WANs?
Framing
Delivery of bits from one device to another
Addressing
Error detection
In the cabling for a leased line, which of the following typically connects to a fourwire line provided by a telco?
Router serial interface without internal CSU/DSU
CSU/DSU
Router serial interface with internal transceiver
Switch serial interface
Which of the following is an accurate speed at which a leased line can operate in the United States?
100 Mbps
100 Kbps
256 Kbps
6.4 Mbps
Which of the following fields in the HDLC header used by Cisco routers does Cisco add, beyond the ISO standard HDLC?
Flag
Type
Address
FCS
Two routers, R1 and R2, connect using an Ethernet over MPLS service. The service provides point-to-point service between these two routers only, as a Layer 2 Ethernet service. Which of the following are the most likely to be true about this WAN? (Choose two answers.)
R1 will connect to a physical Ethernet link, with the other end of the cable connected to R2.
R1 will connect to a physical Ethernet link, with the other end of the cable connected to a device at the WAN service provider point of presence.
R1 will forward data link frames to R2 using an HDLC header/trailer.
R1 will forward data link frames to R2 using an Ethernet header/trailer.
Which of the following Internet access technologies, used to connect a site to an ISP, offers asymmetric speeds? (Choose two answers.)
Leased lines
DSL
Cable Internet
BGP
Fred has just added DSL service at his home, with a separate DSL modem and consumer-grade router with four Ethernet ports. Fred wants to use the same old phone he was using before the installation of DSL. Which is most likely true about the phone cabling and phone used with his new DSL installation?
He uses the old phone, cabled to one of the router/switch device’s Ethernet ports.
He uses the old phone, cabled to the DSL modem’s ports.
He uses the old phone, cabled to an existing telephone port, and not to any new device.
The old phone must be replaced with a digital phone.
