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CNT |! Final |! Exam |! with |! precise |! detailed |!
answers
Four |! characteristics |! of |! Effectiveness |! - |! Correct |! answer |! ✔Delivery, |! Accuracy, |! Timeliness, |! Jitter Types |! of |! topology |! - |! Correct |! answer |! ✔Mesh, |! Bus, |! Star, |! Ring UART |! stands |! for |! - |! Correct |! answer |! ✔Universal |! asynchronous |! receiver |! transmitter Which |! of |! the |! following |! connection |! type |! is |! used |! by |! bus |! topology? |! - |! Correct |! answer |! ✔Point |! to |! multipoint Name |! of |! network |! of |! networks |! - |! Correct |! answer |! ✔internetwork, |! or |! simply |! an |! internet |! (lowercase!) Criteria |! for |! a |! Network |! - |! Correct |! answer |! ✔Performance, |! Reliability, |! Security For |! n |! devices |! in |! a |! network, |! what |! is |! the |! correct |! number |! of |! cable |! links |! required |! for |! a |! "star" |! topology? |! - |! Correct |! answer |! ✔n
Primary |! attributes |! of |! Performance |! - |! Correct |! answer |! ✔Transit |! time, |! Response |! time, |! Throughput, |! Delay Which |! of |! the |! following |! topology |! is |! used |! typically |! in |! a |! home |! network? |! - |! Correct |! answer |! ✔Star Two |! main |! ways |! this |! switching |! can |! be |! done? |! - |! Correct |! answer |! ✔Circuit |! Switched |! or |! Packet |! Switched Baseband |! audio |! - |! Correct |! answer |! ✔ 300 |! ~3400 |! Hz Current |! LANs |! are |! mostly? |! - |! Correct |! answer |! ✔Star Internet |! Society |! standards |! and |! protocols |! - |! Correct |! answer |! ✔Internet |! Architecture |! Board Internet |! Engineering |! Task |! Force (IETF) Internet |! Research |! Task |! Force RFC |! Maturity |! Levels |! - |! Correct |! answer |! ✔Proposed, |! Draft |! and |! Internet |! Standard Historic Experimental
Name |! of |! item |! on |! the |! network |! layer |! - |! Correct |! answer |! ✔datagram Name |! of |! item |! on |! the |! data |! link |! - |! Correct |! answer |! ✔frame Name |! of |! item |! on |! the |! physical |! - |! Correct |! answer |! ✔bits How |! many |! layers |! are |! there |! in |! the |! OSI |! model? |! - |! Correct |! answer |! ✔ 7 Which |! layer |! is |! responsible |! for |! encryption |! and |! decryption |! in |! the |! OSI |! model? |! - |! Correct |! answer |! ✔Presentation |! layer Which |! layer |! is |! responsible |! for |! routing |! in |! the |! OSI |! model? |! - |! Correct |! answer |! ✔Network |! layer Order |! of |! TCP/IP |! Layers |! - |! Correct |! answer |! ✔Application, |! Transport, |! Network, |! Data |! Link, |! Physical Order |! of |! OSI |! Layers |! - |! Correct |! answer |! ✔Application, |! Presentation, |! Session, |! Transport, |! Network, |! Data |! Link, |! Physical What |! is |! the |! length |! of |! a |! typical |! IP |! datagram |! header? |! - |! Correct |! answer |! ✔ 20 |! bytes
Which |! of |! the |! following |! protocol |! is |! added |! to |! an |! email |! message |! to |! provide |! error |! free |! end |! to |! end |! delivery |! assurance |! - |! Correct |! answer |! ✔TCP How |! does |! the |! Applications |! send |! and |! receive |! messages? |! - |! Correct |! answer |! ✔The |! Transport |! Layer Communication |! at |! the |! Application |! Layer |! is |! a |! _____. |! - |! Correct |! answer |! ✔Process |! to |! process |! communication What |! is |! another |! name |! for |! a |! link |! layer |! address? |! - |! Correct |! answer |! ✔Physical |! (MAC) |! address The |! logical |! connection |! at |! network |! layer |! is |! between |! _____. |! - |! Correct |! answer |! ✔hosts Which |! layer |! is |! responsible |! for |! packet |! delivery |! from |! source |! to |! destination? |! - |! Correct |! answer |! ✔Network |! layer What |! is |! the |! core |! protocol |! of |! network |! layer? |! - |! Correct |! answer |! ✔IP Sine |! Waves: |! three |! parameters |! - |! Correct |! answer |! ✔Amplitude, |! Frequency, |! Phase In |! case |! of |! periodic |! signals, |! one |! full |! iteration |! of |! a |! pattern |! is |! called |! a |! - |! Correct |! answer |! ✔Cycle
What |! is |! the |! frequency |! of |! Direct |! Current? |! - |! Correct |! answer |! ✔ 0 |! Hz Given |! the |! frequency |! f |! = |! 1 |! MHz, |! find |! the |! period |! T |! - |! Correct |! answer |! ✔ 1 |! μs If |! we |! are |! transferring |! data |! at |! 50 |! Mbps, |! what |! is |! the |! rate |! in |! MBps? |! - |! Correct |! answer |! ✔6.25 |! MBps A |! change |! in |! the |! signal |! level |! is |! called |! a? |! - |! Correct |! answer |! ✔baud The |! higher |! the |! frequency |! the? |! - |! Correct |! answer |! ✔higher |! the |! loss Amplifier |! gain |! is |! usually |! expressed |! in? |! - |! Correct |! answer |! ✔decibels AMPLIFER |! GAIN |! (equation) |! - |! Correct |! answer |! ✔ 10 |! log10(P2/P1) The |! Signal-to-Noise |! Ratio |! is |! defined |! as |! simply |! - |! Correct |! answer |! ✔SNR |! = |! average |! signal |! power/average |! noise |! power Transmission |! methods |! send |! the |! digital |! pules |! directly |! on |! a |! medium? |! - |! Correct |! answer |! ✔Baseband SNR |! DB |! equation |! - |! Correct |! answer |! ✔ 10 |! Log10 |! (SNR)
What |! is/are |! (a) |! component |! of |! latency? |! - |! Correct |! answer |! ✔Propagation |! time |! Transmission |! time |! Queuing |! time |! Processing |! delay 0dBm |! = |!? |! - |! Correct |! answer |! ✔1.0 |! mW What |! is |! Propagation |! time |! - |! Correct |! answer |! ✔the |! time |! it |! takes |! for |! the |! first |! data |! bit |! from |! the |! Sender |! to |! get |! to |! the |! Receiver Attenuation |! (definition) |! - |! Correct |! answer |! ✔When |! a |! signal |! travels |! through |! a |! medium |! it |! loses |! some |! of |! its |! energy Figure |! this |! one |! out |! yourself: |! log2(8) |! = |!? |! - |! Correct |! answer |! ✔ 3 Long |! coax |! and |! Ethernet |! cables: |! - |! Correct |! answer |! ✔act |! like |! low |! pass |! filters Baud |! rate |! (definition) |! - |! Correct |! answer |! ✔is |! the |! rate |! of |! line |! changes |! per |! second log |! 2 |! (8) |! - |! Correct |! answer |! ✔Log10(8) |! / |! log10(2) |! = |! 3
Guided |! Media |! - |! Correct |! answer |! ✔Cables What |! can |! be |! increased |! for |! faster |! data |! throughput |! without |! increasing |! the |! occupied |! bandwidth |! of |! a |! broadband |! digital |! signal? |! - |! Correct |! answer |! ✔Baud |! rate Color's |! in |! RJ45 |! - |! Correct |! answer |! ✔Green, |! Orange, |! Blue, |! Brown The |! bandwidth-delay |! product |! defines |! - |! Correct |! answer |! ✔the |! number |! of |! bits |! that |! can |! fill |! the |! link. How |! do |! they |! send |! 1000 |! Mbps |! FDX |!? |! - |! Correct |! answer |! ✔By |! sending |! TX |! and |! RX |! data |! at |! 250 |! Mbps |! simultaneously |! on |! each |! pair! Propagation |! Modes |! - |! Correct |! answer |! ✔Multi-mode, |! Step |! Index |! / |! Multi- mode, |! Graded |! Index |! / |! Single |! Mode Freq |! range |! (VHF) |! - |! Correct |! answer |! ✔ 30 |! to |! 300 |! MHz Freq |! range |! (Microwave) |! - |! Correct |! answer |! ✔ 1 |! to |! ~20 |! GHz Propagation |! Methods |! - |! Correct |! answer |! ✔Ground |! Propagation, |! Sky |! Propagation, |! Line |! of |! Sight |! Propagation
What |! is |! taken |! as |! the |! True |! signal |! level |! from |! a |! twisted |! cable? |! - |! Correct |! answer |! ✔difference |! between |! two |! signals |! carried |! by |! the |! conductors More |! twists |! per |! length |! in |! the |! twisted |! pair |! cable |! means |! - |! Correct |! answer |! ✔better |! interference |! cancellation, |! so |! less |! interference. Light |! travels |! in |! a |! _________ |! path |! through |! substances |! of |! uniform |! density. |! - |! Correct |! answer |! ✔straight When |! do |! we |! have |! refraction? |! - |! Correct |! answer |! ✔Angle |! of |! incidence |! I |! < |! Critical |! angle, |! Angle |! of |! incidence |! I |! = |! Critical |! angle When |! do |! we |! have |! reflection? |! - |! Correct |! answer |! ✔Angle |! of |! incidence |! I |! > |! Critical |! angle How |! many |! ways |! to |! move |! light |! through |! a |! fiber |! optic |! cable? |! - |! Correct |! answer |! ✔ 3 How |! are |! optical |! fibers |! specified? |! - |! Correct |! answer |! ✔Diameter |! of |! the |! core |! / |! diameter |! of |! the |! cladding Which |! of |! the |! following |! can |! be |! a |! composition |! of |! a |! fiber |! optic |! cable? |! (From |! outermost |! layer |! to |! the |! innermost |! layer) |! - |! Correct |! answer |! ✔PVC |! jacket, |! kevlar, |! plastic |! coating, |! cladding, |! core
What |! are |! the |! sublayers |! of |! Data |! Link |! Layer? |! - |! Correct |! answer |! ✔Data |! link |! control |! and |! media |! access |! control How |! many |! types |! of |! addresses |! are |! typically |! defined |! by |! the |! Link |! Layer |! protocols? |! - |! Correct |! answer |! ✔ 3 What |! does |! ARP |! stand |! for? |! - |! Correct |! answer |! ✔Address |! resolution |! protocol What |! is |! the |! command |! to |! get |! the |! IP |! address |! and |! MAC |! address |! that |! are |! reporting |! on |! you |! LAN? |! - |! Correct |! answer |! ✔arp |! -a How |! many |! bytes |! are |! Ethernet |! MAC |! addresses? |! - |! Correct |! answer |! ✔ 6 How |! many |! bytes |! are |! IPv4 |! addresses? |! - |! Correct |! answer |! ✔ 4 What |! are |! the |! two |! basic |! Block |! Coding |! Schemes? |! - |! Correct |! answer |! ✔Forward |! Error |! Correction |! (FEC), |! Error |! Detection |! only What |! is |! the |! central |! concept |! in |! detecting |! and |! correcting |! errors? |! - |! Correct |! answer |! ✔Redundancy In |! case |! of |! RS232, |! which |! bit |! is |! sent |! and |! received |! first? |! - |! Correct |! answer |! ✔LSB
In |! CRC |! decoder, |! if |! the |! syndrome |! is |! zero, |! then |! we |! can |! say: |! - |! Correct |! answer |! ✔There |! is |! no |! error A |! CRC |! code |! is |! defined |! as |! C |! (8,5). |! What |! is |! the |! number |! of |! data |! bits? |! - |! Correct |! answer |! ✔ 5 Suppose |! we |! have |! a |! parity |! checker |! defined |! as |! C |! (6,5). |! What |! is |! the |! number |! of |! actual |! data |! bits? |! - |! Correct |! answer |! ✔ 5 To |! detect |! errors, |! we |! need |! to |! determine |! _________ |! - |! Correct |! answer |! ✔that |! any |! bit |! has |! changed ___________ |! side |! sum |! includes |! the |! checksum |! - |! Correct |! answer |! ✔Receiver Which |! of |! the |! followings |! are |! collectively |! known |! as |! Data |! Link |! Control? |! - |! Correct |! answer |! ✔Flow |! and |! error |! control What |! does |! ARQ |! stands |! for? |! - |! Correct |! answer |! ✔Automatic |! repeat |! request, |! Automatic |! repeat |! query Traditionally, |! which |! protocol(s) |! has/have |! been |! defined |! for |! the |! Data |! Link |! Layer |! to |! deal |! with |! flow |! and |! error |! control? |! - |! Correct |! answer |! ✔Stop |! and |! Wait, |! Simple, |! Go |! back |! N, |! Selective |! Repeat
What |! is |! a |! FSM? |! - |! Correct |! answer |! ✔Finite |! State |! Machine How |! many |! reactions |! are |! associated |! with |! each |! event |! in |! a |! FSM? |! - |! Correct |! answer |! ✔Could |! be |! any |! number |! depending |! on |! what |! actions |! any |! event |! needs |! to |! have |! performed What |! is |! added |! to |! each |! data |! frame |! to |! detect |! corrupted |! frames |! in |! Stop |! and |! Wait |! protocol? |! - |! Correct |! answer |! ✔CRC A |! PPP |! connection |! begins |! at |! ___________ |! - |! Correct |! answer |! ✔the |! dead |! State What |! are |! the |! phases |! before |! PPP |! enter |! the |! open |! data |! transfer |! phase? |! - |! Correct |! answer |! ✔Establishment, |! authentication |! and |! network |! phase What |! does |! LCP |! stand |! for? |! - |! Correct |! answer |! ✔Link |! Control |! Protocol What |! could |! be |! the |! first |! step |! of |! a |! PPP |! connection's |! lifecycle? |! - |! Correct |! answer |! ✔Link |! layer |! configuration Which |! packet |! is |! used |! for |! configuration? |! - |! Correct |! answer |! ✔Configure- request PPP |! defines |! or |! provides: |! - |! Correct |! answer |! ✔The |! frame |! format Link-establishment |! negotiation
Data |! exchange Authentication Network |! address |! configuration PPP |! does |! not |! define |! or |! provide: |! - |! Correct |! answer |! ✔Flow |! control Sequencing Error |! control |! beyond |! detect-and-discard What |! does |! AT&T |! stand |! for? |! - |! Correct |! answer |! ✔American |! Telephone |! and |! Telegraph In |! the |! 'Plain |! Old |! Telephone |! System', |! how |! is |! a |! telephone |! connected |! to |! the |! central |! office? |! - |! Correct |! answer |! ✔Outdoor |! UTP Before |! a |! company |! could |! sell |! any |! device |! that |! connects |! to |! the |! PSTN, |! it |! needs |! to |! pass |! FCC |! Part |! ___ |! rules. |! - |! Correct |! answer |! ✔ 68 Which |! portion |! of |! the |! 7-digit |! number |! identified |! the |! central |! office |! in |! the |! old |! telephone |! system? |! - |! Correct |! answer |! ✔First |! 3 |! digits How |! did |! the |! trunk |! lines |! handle |! communication |! between |! offices? |! - |! Correct |! answer |! ✔Multiplexing/Demultiplexing
How |! do |! the |! bidirectional |! amplifiers |! in |! cable |! systems |! get |! power? |! - |! Correct |! answer |! ✔Coax |! cables |! carry |! the |! DC |! power What |! is |! the |! range |! of |! frequencies |! for |! data |! upstream |! and |! data |! downstream |! in |! DOCSIS? |! - |! Correct |! answer |! ✔05- |! 42 |! MHz, |! 550-750 |! MHz Why |! there |! is |! a |! gap |! between |! the |! data |! upstream |! (5 |! - |! 42 |! MHz) |! and |! the |! video |! band |! (54 |! - |! 550 |! MHz)? |! - |! Correct |! answer |! ✔To |! allow |! filters Why |! some |! of |! the |! channels |! may |! remain |! idle |! in |! Synchronous |! TDM? |! - |! Correct |! answer |! ✔Some |! devices |! have |! no |! information |! to |! send |! and |! their |! slots |! remain |! empty. |! But |! the |! frame |! is |! still |! transmitted |! which |! creates |! idle |! channels On |! fiber |! optic |! link, |! why |! is |! important |! in |! data |! recovery |! to |! extract |! the |! data |! clock |! on |! the |! receive |! end? |! - |! Correct |! answer |! ✔To |! ensure |! that |! the |! data |! bit |! is |! sampled |! in |! the |! middle |! of |! the |! bit |! period What |! is |! the |! data |! rate |! of |! OC1? |! - |! Correct |! answer |! ✔51.84 |! Mbps Who |! modulates |! and |! demodulates |! the |! light |! on |! the |! fiber |! optic |! cable? |! - |! Correct |! answer |! ✔STM What |! does |! STM |! stands |! for? |! - |! Correct |! answer |! ✔Synchronous |! Transfer |! Module
Why |! do |! we |! need |! regenerators? |! - |! Correct |! answer |! ✔To |! strengthen |! a |! weak |! signal Why |! do |! we |! need |! protections |! rings |! in |! bidirectional |! switching |! ring? |! - |! Correct |! answer |! ✔To |! have |! backup |! for |! interface |! or |! hardware |! failure What |! is |! ATM? |! - |! Correct |! answer |! ✔Asynchronous |! Transfer |! Mode |! - |! Correct |! answer |! ✔Connection |! oriented, |! Unreliable ATM |! switches |! act |! like |! a |! ________? |! - |! Correct |! answer |! ✔Router What |! is |! the |! size |! of |! ATM |! frames? |! - |! Correct |! answer |! ✔ 53 |! bytes According |! to |! the |! recent |! redefinition |! by |! FCC, |! what |! is |! the |! download |! and |! upload |! speed |! requirements |! of |! Broadband |! Wireless |! system? |! - |! Correct |! answer |! ✔At |! least |! 25 |! Mbps, |! at |! least |! 3 |! Mbps What |! does |! ISM |! stand |! for? |! - |! Correct |! answer |! ✔Industrial |! Scientific |! and |! Medical What |! is |! the |! meaning |! of |! Wi-Fi? |! - |! Correct |! answer |! ✔Wireless |! Fidelity
