Flashcards in Chapter 3 Flashcards - Sheet1 Deck (25):
Name the different terms for a leased line
Leased circuit, serial link/line, point-to-point link/line, T1, WAN link, private line
Type of leased line that transmits at 1.545Mbps
Central Office - Location of equipment for telcos providing leased lines
Channel Service Unit / Data Service Unit (Modem / Connection equipment to a WAN)
Customer Presmises Equipment
Examples of CPE:
Router, serial interface card, CSU/DSU. The CSU/DSU may be integrated into the serial interface card in the router.
Typical connection from a telco to the CSU/DSU
Data terminal equipment cables. Serial cables normally used between a router and an external CSU/DSU
DTE Cable equivalent of a crossover cable
DCE - Data Communications Equipment Cable
Function of the CSU/DSU that tells the router when to send each bit through signaling over a serial cable.
Two most popular data link layer protocols used for leased lines (WANs) are
HDLC (High Level Data Link Control) and PPP (Point to Point Protocol), Ethernet WANs(!)
All data link protocols perform this similar role
Control correct delivery of data over a physical link of a particular type.
HDLC frames have less work to do than Ethernet because --
The source and destination are implied. There are only two endpoints. Despite this, HDLC still has an address field, b/c telcos used to offer multidrop circuits w/more than 2 devices
Lists the HDLC fields and their Ethernet equiv
Flag (Preamble), Address (Destination Address), Type (Type), Data (Data), FCS (FCS)
Size of the HDLC's flag
Size of the HDLC's Address
Size of the HDLC's type
Size of the HDLC's FCS
Size of the HDLC's control
Ethernet Over MPLS. AKA Ethernet Emulation. An Ethernet WAN service.
DSL Access Multiplexer - Housed at the TelCo's central office, splits phone from data traffic. Sends phone traffic through PSTN, sends data through a router.
DSL speeds are ______, meaning the down speed is different than the up speed
A serial communications circuit between two points, provided by some service provider,
typically a telephone company (telco)