单项选择题

Which is not a reason that Internet Service Providers prefer to use PPP over Ethernet (PPoE)?（）

A.access control and billing can be done on a per-user, rather than a per-site basis
B.supports Link Fragmentation and Interleaving
C.provides the ability to connect a network of hosts over a simple bridging access device
D.provides a consistent means of authenticating users (RADIUS for example)

<上一题目录下一题>

热门试题

多项选择题WhenisitappropriatetoenableLinkFragmentationandInterleaving(LFI)onDSLconnectionsforTeleworkers?（）

A.uplink speed less than 768kbps
B.supporting Voice-over-IP
C.using PPPoE encapsulation
D.using PPPoA encapsulation
E.uplink speed greater than 768kbps

单项选择题Acustomerindicatestheyrunamission-criticalapplicationwhichmarksitspacketsbest-effort(DSCP=0).Howcanyouguaranteedeliveryofthistraffic?（）

A.Remark the traffic on ingress and prioritize on egress.
B.Enable CEF and Netflow.
C.Configure the MS-Windows QoS Scheduler to prioritize this traffic.
D.Enable WRED.

单项选择题Refer to the exhibit. With an IPSec tunnel established between remote Router A and head-end router B, with Compressed Real-Time Protocol (cRTP) configured on the serial interface of Router A, what impact will the cRTP configuration have on the Voice over IP packets flowing through the IPSec tunnel from a Cisco 7960 IP phone?（）

A.Twenty bytes of header will be replaced with five bytes.
B.If the IPSec transform set includes Authentication Header, the receiving IPSec peer will discard the packets.
C.The IPSec packets will be dropped by Router A's compression logic.
D.The voice packets will not be compressed.

多项选择题WhataretheDSL-specificfactorsthatrequireadditionalbandwidthwhensupportingVoice-over-IPoveranIPSecVPN?（）

A.A voice packet is sent via multiple fixed-length cells; a portion of the last cell is padding, requiring more bandwidth.
B.ADSL typically uses PPPoE encapsulation, which adds additional overhead to each voice packet.
C.A voice packet is sent via multiple fixed-length cells; each cell has about 10% Layer-2 header overhead.
D.IPSec requires additional overhead for the header and hash.
E.ADSL carrier band requires additional bits to be carried over the wire to the DSL Access Concentrator.

单项选择题Refer to the exhibit. With an IPSec tunnel established between remote Router A and head-end router B, how can the Service Provider Edge Router identify Voice over IP packets flowing through the IPSec tunnel from a Cisco 7960 IP phone?（）

A.UDP ports 16384 through 32727
B.ESP packets less than 113 byes
C.DiffServ codepoint EF Expedited Forwarding
D.RTP ports 6970 through 6999