Video Content Lesson 7 Flashcards

Question

Various Topologies

Answer 1

Star (multiple machines connected through one) Bus (multiple machines connected through bus) Ring (multiple machines connected to its neighbor) Tree (variation of Bus Topology) Mesh (most complex of topologies)

Answer 2

All nodes are connected to a central device All Messages must travel through the center advantage simple, disadvantage single point of failure

Answer 3

All nodes are connected to a shared media, often called the backbone or bus the messages travel the length of the bus end of bus must be terminated

Answer 4

each computer is connected to its neighbor on each side messages travel from node to node until they reach their destination advantage no sigle point of failure because NIC passes message automatically if disconnected

Answer 5

Variation of Bus Topology (nodes may be connected to more than one bus) multiple bus connections create the branches of the tree single point of failure only exists on the node that crosses multiple branches

Answer 6

every node is connected to every other node very complex, but highly fault tolerant partial mesh (not connected to all machines but to many so there are multiple paths)

Answer 7

``` Ethernet Other Access Methods Signaling Types Network Types Dial-up ISDN DSL Wireless-Cable ```

Answer 8

Most common LAN access method IEEE 802.3 standard uses CSMA/CD (Carrier Sense Media Access with Collision Detection) Listen first and then talk (Carrier signal is sampled off physical media, hardware listens for carrier signal (if carrier signal is heard this tells it that noone else is talking, headware sends message off wire) (listens to what is being echoed back to him, if same message then it was correctly sent otherwise retransmits) Cable standards (ThinNet-10Base2, coaxial up to 185 meters; ThickNet-10Base5, coaxial up to 500 meters; most common used is UTP-10BaseT, 100BaseT, 1000BaseT used with central hub (Star Typology))

Answer 9

ARCnet (one of earliest LAN technologies, token passed methods, have to hold token to talk, uses bus or ring typology Ring typology uses MAU Multistation Access Unit which has all end nodes connected to it FDDI Fiber Distributed Data Interface (token passing method, 100 Mbps using dual fiber-optic rings, rings operate in opposite directions, if one ring breaks, other ring is used to maintain a complete network)

Answer 10

``` Baseband transmission (digital signal, entire media filled with one signal) Broadband (analog signal, Cable TV, multiple communication channels used simultaneously, tranmitted in channels on a carrier, digital data must be modulated first) ```

Answer 11

LAN Local Area Network (Group of networked computers and devices in relatively close proximity to one another) WAN Wide area network (Network of computers and devices that spans a large geographic area) Remote access/telecommuting (method of connecting to a WAN or LAN through dial-up or high-speed access lines

Answer 12

POTS Plain Old Telephone Service (uses MODEM 56 Kbps, speed based on proximity to central office, condition of line, noise on the line, multiplexing, bandwidth artificially limited)

Answer 13

Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) (Two 64-KB channels (digital, audio, video, communication) and one 16-KB channel (digital transfer) Primary Rate Interface (PRI) (23 64-KB channels and one 16-KB channel) Expensive

Answer 14

Digital Subscriber Line (higher speed connection than dial-up using existing twisted pair) inexpensive option ADSL (Asynchronous digital subscriber line) used at home because higher speed for downloads and slower speeds for uploads SDSL (Synchronous digital subscriber Line) same upload and download capability VDSL (Very-high-speed digital subscriber line) DSL Lite (doesn't require splitter used by ADSL, SDSL, and VDSL)

Answer 15

Wireless (networking without wires) Several emerging standards (802.11a, 802.11b, 802.11g) Cable Modems (great alternative to DSL) (can be substantially faster than DSL if number of concurrent users is not excessive)

Answer 16

``` VPN PPTP IPSec Connection Security User Authentication Node Authentication ```

Answer 17

Virtual Private Network Tunnel (like envelope--encapsulation technique) often associated with secure transmissions can connect two systems or two networks offers an inexpensive secure communication using public networks

Answer 18

Point-to-Point Tunneling Protocol Built to provide encrypted PPP tunnel After negotiation all PPP traffic is encrypted L2F Layer 2 Forwarding (developed by Cisco to provide mutual authentication tunneling) L2TP Layer 2 Tunneling Protocol (extended PPTP and L2F, supports TACACS+ and RADIUS)

Answer 19

``` Operates as a standalone VPN protocol OR along with L2TP can provide encryption for L2TP Transport mode (payload is encrypted but header is NOT) for connecting two systems Tunnel mode (both payload and header are encrypted) for connecting two networks ```

Answer 20

Remote access without VPN SSH - Secure Shell (more secure than Telnet) provides a sure method to access a remote machine SSL/TLS - Secure Sockets Layer (secures communication between client and web server) (ONLY encrypts communication between client and web server not behind them)

Answer 21

Centralized remore user authentication 1-RADIUS Remote Authentication Dial-in User Service 2-TACACS - Terminal Access Controller Access Control System TACACS+ (adds two-factor authentication)

Answer 22

Password Authentication Protocol (PAP) (this is standard authentication protocol for PPP; no encryption; user IDs and passwords passed in the clear) Challenge Handshake Authentication Protocol (CHAP) (similar to PAP; encrypts user IDs and password; operates over PPP)