各课程学习通信网理论基础-netheory nettheory

1、传输控制交换与路由控制接纳控制管理面管理面管理面面管用户面层理管理AAL ATM层物理层AALATM层物理层面用户控面制用面户控面制面控制Cp1F(1-p)p2Ap: 正确概率，1- p: 出错概率 = p + 2(1-p)p + 3(1-p)2p = 1/pCH1.addressFH2.addressAH3.addressA到H1Address H1.addressH1到AAddress H1.addressPollAFinalMax (N) = 7Max (N) = 127AReceive Ready (RR) Receive Not Ready (RNR)Reject (REJ)Sele

2、ctive Reject (SREJ)N(S)01234567A+1+1+1+10011110100000FullAddressEmptyAHead = TailHead =0Head = TailHead ：第一个待读地址Tail = 1Tail：第一个可存入地址Frame 0Frame 1Frame 2Frame 3Frame 4Frame 5Frame 6Frame 7Frame 0000001010011100101110111停止发送N(S)0123456AN-07N(S)01234567A1N(R)0w = 2N(S)012345670A121w = 7w = 6w = 0w =

3、2AFrame 2Frame 3Frame 4Frame 5Frame 6Frame 0Frame 1Frame 2Frame 3Frame 4Frame 5Frame 6Frame 0N(S)01234N23A12N22N(S)01234N25A12201234Atp = len/c = 1000 m/2*108tf = size/bwm/s = 5us= (1000+48 bit)/9600 b/s = 109 ms= 48 bit/9600 b/s = 5 mslensizeW301234Ata = 2tp + tf+ tf = 114 mstp = len/c = 1000 m/2*1

4、08 m/s = 5ustf = size/bw= (1000+48 bit)/9600 b/s = 109 ms= 48 bit/9600 b/s = 5 ms同步轨道？W301234Ata = 2tp + tf= 839 ms= 7.7ftp = len/c = 2*36000 km/2*108 m/s= 360 ms= (1000+48 bit)/9600 b/s = 109 mstfWindow s ze W,ransmisime = 1,propagation time = aCase 1: W = 2a + 1Sender A cat amcontinuous y wh nopau

5、se and normalized throughput is 1.0Case 2: W N(S) ACKN-N RWIN明示对方，原因是什么？Prob. 与HDLC一致？SYNSYN+ACKACKSYNSYN+ACKACKringingwaitingpick- upEC311F261D3A4B时序一帧16个数字间隔50ms录波结果基于DTMF的状态上报 DTMF原始波形 经PCMA编码VoIP传送后恢复的波形 经SPEEX编码VoIP传送后恢复的波形FXS/FXOFXS/FXO上行通道TDM传输PCCR下行通道CCIP cloudNGN传输：P: PanelR: ReceiverIAD：eg

6、rated Acs DeviceSG：Signaling Gateway MG：Media GatewayIADIADSGSGMGMG传输控制交换与路由控制接纳控制EC3H211F261D3H1A4BA收到来自H1、去往H2的IP分组，向B、E、F三个节点的哪个转发？C向D、F通告，到H2的距离权值为0F向A、B、E通告，到H2的距离权值为1E通告A，到H2的距离权值为4； B通告A，到H2的距离权值为2A计算，经B到H2的距离权值为6；经E到H2的距离权值为5；经F到H2的距离权值为7EC311F261D3H1A4B192.168.4.x/22192.168.6.X/24. .192.168

7、.5.x192.168.6.xProb. 目标地址为R128./101 2叉树查找，复杂度为O(log2N)127./1192.168.4.x/22 Prob. O(1)的查询方法？ 192.168.6.x/23简单链表查找，复杂度为O(N)Lookup目标地址为分组192.168.4.x/22192.168.6.X/23前缀数为NEC311F261D3A4B管理面管理面管理面HTTPRIP面管理用户面用户控面制用面户控面制面控制面层管TDPIP NIFUDPIPTCP/UDP IP网络接口理NIFOSPF/ISIS/BGP/LDP/RSVPDHCPDNSNATCDNMG/SGMIPHIP/L

8、ISPBAS/BRAS传输控制交换与路由控制接纳控制蹭网者(Free Rider)目标：POTS接入控制终端无计算处理功能，控制极易完成IP接入认证()上网BAS/BRASExtee Authentication Protocol)VoIP呼叫接纳控制面向QoS保障认证方EAPoR/ CHAP/认证提供认证方PAP的服务PAE受控端口不受控端口EAPoLLANPAE: Port Acs EntityProb. 抗能力CHAP: Challenge-Handshake Authentication Protocol PAP: Password Authentication ProtocolEAP

9、oR: EAP over RADIUS认证服务器请求者请求者 PAE仅对VoIP的业务流，不影响普通数据业务对实时性或时延敏感的业务，依据网络负载情况接收到呼叫 无CAC的VoIP 有CAC的VoIPht/c/en/us/td/docs/ios/solutions_docs/voip_solutions/CAC.pdf本地决策依据历史经验，设置固定的允许呼叫的上限；基于测量的决策发启方通过测量到达目标节点的丢失率和延时，决定呼叫的接续与否；基于资源的决策计算所需与可用的资源，或者执行资源预留操作，再决定呼叫的接续与否。98%以上的接通率？ MOS 4.5语音质量？Prob. 保障与POTS相同等级的QoS小区内因信道pb小区间切换因信道导致的呼叫导致的掉话pf多次切换导致的掉话通话完成的概率Ghaderi, Majid, and Raouf Boutaba. Call admiscontrolobile cellular networks: a comprehensive survey. Wireless communications and mobile computing 6.1 (20