2009年5月全國計算機軟考網(wǎng)絡(luò)工程師練習(xí)(19)

每個空格對應(yīng)一個序號，有A、B、C、D四個選項，請選擇一個最恰當(dāng)?shù)倪x項作為解答。
    ●(1)In the strength of the carrier signal is varied to represent binary1 or 0．
    (2)is a system that can map a name to an address and conversely an addressto an name．
    (3)is a three-way handshaking authentication protocol that it's packets areencapsulated inthe point-to-point protocol
    (4)is an approach that enables an ATM Switch to behave like a LAN switch．
    (5)is an guided media which is made of glass or plastic and trans mitssignals in the form of light．
    (1)A．ASK
    B．PSK
    C．FSK
    D．FDM
    (2)A．NAT
    B．NCP
    C．DDN
    D．DNS
    (3)A．PPP
    B．PAP
    C．CHAP
    D．LCP
    (4)A．VLAN
    B．LANE
    C．VPN
    D．IPOA
    (5)A．Coaxial cable
    B．Optical fiber
    C．Unshielded Twisted-pair Cable
    D．Shielded Twisted-pair Cable