uarantee for the great struggle. This aspects XI General Secretary of speech main including exercise thrift, against extravagance mass line is party of lifeline and fundamental work route accurate grasp party of mass line education practice activities of guideline and target requirements set and develop \ct three real\put power shut into system of cage in using history wisdom advance anti-corruption construction in-depth advance style clean government and anti-corruption struggle develop nail nail of spirit, a Zhang good of blueprint worked to... 9. other aspects. 18 big yilai, XI General Secretary also respectively on diplomatic, and military, and ecological construction, aspects published has important speech, covers has construction ecological civilization, and advance defense and army modern, and rich \y, two systems\nce country unified, and go peace development road, and promoted building new powers relationship, and go good around diplomatic work, and strengthening and developing countries solidarity cooperation, and active participation multilateral affairs, and science of thinking and work method, manyaspects. XI Jinping, Secretary of a series of important speeches, and further enrich and develop the party's theory, line, principles and policies, the party puts forward new requirements for more contemporary features, the latest achievement of Marxism in China, is a guide to persisting and developing socialism with Chinese characteristics. Four methods. To address the relationship between comprehensive and focused on science. In the process of learning, we should follow as a good study and carry out the \conduct a comprehensive collaborative learning; and with their own jobs, focus research and understanding spirit, grasp the potential requirements. For example, every party member should be according to the various branches of learning program, an article does not go into a link, no leakage of conducting a comprehensive study, and combined with their own duties and responsibilities, be focused and targeted Geoscience. Like, leaders to highlight learning XI on ruling acting political know of deep love of cut dry in practice go in forefront of river new language out poverty XI on coordination advance \discusses excerpts XI on full deepening reform discusses excerpts XI on full law ruling discusses excerpts 18 big yilai XI on major economic problem discusses excerpts, discipline to highlight learning XI on strict party of discipline and rules discusses excerpts XI Jinping, on the construction of clean and honest Government and fight against corruption discussed excerpts, technology to highlight the learning of the XI Jinping on technological innovation and discusses excerpts, XI Jinping, education should highlight the important excerpts of work on education and so on. To address the relation between stage and often science. Phase has the advantage of time to focus on fast, to highlight the theme, focused, result; often learn the advantages of flexible fit, form, subtle, continues to现代交换技术复习
1、交换就是在公共网络的各终端用户之间，按所需目的来互相传递话音、数据、图像、视频的信息。
2、为什么引入交换的概念：点到点通信的缺点：(1)用户数目众多时，构建网状网成本太高，任意一个用户到其他N-1个用户都要有一个直达线路，技术上也不可行。(2)每一对用户之间独占一个永久的通信线路，信道资源无法共享，会造成巨大的资源浪费。(3)这样的网络结构难以实施集中的控制和管理。未解决上述问题采用交换技术，组建交换式网络。
3、交换方式：电路交换、分组交换、帧中继、ATM、IP交换技术、软交换、光交换技术。 4、交换节点的主要功能：(1)用户业务的集中和接入功能（用户接口和中继接口组成）(2)交换功能（交换矩阵完成任意入线到出线的数据交换）(3)信令功能（负责呼叫控制和连接的建立、监视、释放等）(4)控制功能（路由信息的更新维护、计费、话务统计、维护管理等） 5、电路交换方式是指两个用户在相互通信时使用一条物理链路，在通信过程中自始至终使用该条链路进行信息传输，同时不允许其他用户终端设备共享该链路的通信方式。 6、本局呼叫电话交换过程：呼叫建立（信令）、传送信息（消息）、呼叫拆除（信令）。 7、电路交换的特点：1.通信开始之前建立连接；2.一个连接在通信期间始终占用该电路，电路利用率低；3.建立连接以后，信息在系统中的传输时延小，实时性好；4.同步时分复用系统中，各个子系统的速率是固定分配，不可随意临时调整各个子信道速率；5.交换节点对传输错误不校正，节点处理要求简单；6.用基于呼叫损失制的方法来处理业务流量，过负荷时呼损率增加，但不影响已建立的呼叫。
8、电路交换的功能：1.能随时法相呼叫；2.能接受并保存主叫发送的被叫号码；3.能检测被叫的忙闲以及是否存在空闲通路；4.能向空闲的被叫用户振铃，并在被叫应答时与主叫建立通话电路；5.能随时发现任何一方用户的挂机。
9、交换单元是完成交换和构成交换网络的最基本部件。构成：入线、出线、控制端、状态端。基本特性:连接特性。交换单元是信息交换的基本单位。
10、交换单元最基本的功能也就是交换的功能，即在任意的入线和出线之间建立连接，或者说将入线上的信息传递到出线上去。
11、交换单元信息交换的方式：(1)同步时分复用方式（只携带用户信息）(2)统计复用方式（不仅携带用户信息，还有出线地址）
12、交换单元的分类：（1）根据入线M出线N数目①集中型（集中器）②分配型（连接器）
eepen. In General, periodic high priority on learning, easy to grasp and practice: recurrent learning factors, long time, prone to \ng programmes are explicitly required to learn education is not an event, but to highlight the normal education, differentiated levels, heart, catch a fine practice, the real party's ideological and political construction in the everyday, often. This requires that we do a good job phase focused learning based on knowledge contests, comments on rewards in the form, pay special attention to recurring studies. o handle the relationship between solid strong to learn and a lot to learn. For anyunit or individual, objectively speaking, in the process of carrying out the party Constitution Party rules and spirit, there is a problem with strong and weak, which we need to pay attention to the actual learning content, and handle the relationship between solid strong to learn and a lot to learn. On one hand, we must always keep a humble attitude, good deal, Continue the hardening. The other hand, always keep the spirit of energetic, pegged to the weak link to find gaps, fill the short Board. Short Board issues should not beunderestimated, the saying goes, have short Board, add a short. This tells us, there are weaknesses shortcomings and do not be afraid, fear is a blind eye and not to repair, the result is poor is worse and the weak weaker. United States politics home zhamusi, and Wilson and prevention crime learn experts qiaozhikailin proposed has a famous of broken window theory, that, if a building House has a fan window of glass broken has, and this fan Windows no get timely repair, others on May to broke more of window glass, time a long, these damaged of window on to people caused a disorder, and matter of feel, results in this mass errors think no attention, and no management of atmosphere Xia, some bad culture, and violations behavior on will breeding and spread. Reality life in the is such, clean of wall Shang, suddenly was posted has a Zhang ad, if didn't people management, not out days this wall Shang on will appeared greatly small many of advertising; private take mess built phenomenon is so, began circle a small block to built a small shed put things, if didn't people timely stop, he on dare built a hut live people, time long has didn't people tube, wants to tubeShi on difficult has. Therefore, the solid strong is important, a lot to learn is also important. Third, key, grasp the learning objective of education is to train a qualified party member %udy and education to its core essence is learning and doing. Learning and doing are mutually reinforcing, if optical can't do, study leave, real learning deficiency, while sweating, wind and water, \ng white\not the mules\ng party rules did not comply with the party Constitution, address the learning series is not used, instead, learn and do, imagine this \ng\sic learning, the key is in use, do, line. In particular, is a qualified party members to grasp the following three points. o strengthen %uarantee for the great struggle. This aspects XI General Secretary of speech main including exercise thrift, against extravagance mass line is party of lifeline and fundamental work route accurate grasp party of mass line education practice activities of guideline and target requirements set and develop \ct three real\put power shut into system of cage in using history wisdom advance anti-corruption construction in-depth advance style clean government and anti-corruption struggle develop nail nail of spirit, a Zhang good of blueprint worked to... 9. other aspects. 18 big yilai, XI General Secretary also respectively on diplomatic, and military, and ecological construction, aspects published has important speech, covers has construction ecological civilization, and advance defense and army modern, and rich \y, two systems\nce country unified, and go peace development road, and promoted building new powers relationship, and go good around diplomatic work, and strengthening and developing countries solidarity cooperation, and active participation multilateral affairs, and science of thinking and work method, manyaspects. XI Jinping, Secretary of a series of important speeches, and further enrich and develop the party's theory, line, principles and policies, the party puts forward new requirements for more contemporary features, the latest achievement of Marxism in China, is a guide to persisting and developing socialism with Chinese characteristics. Four methods. To address the relationship between comprehensive and focused on science. In the process of learning, we should follow as a good study and carry out the \conduct a comprehensive collaborative learning; and with their own jobs, focus research and understanding spirit, grasp the potential requirements. For example, every party member should be according to the various branches of learning program, an article does not go into a link, no leakage of conducting a comprehensive study, and combined with their own duties and responsibilities, be focused and targeted Geoscience. Like, leaders to highlight learning XI on ruling acting political know of deep love of cut dry in practice go in forefront of river new language out poverty XI on coordination advance \discusses excerpts XI on full deepening reform discusses excerpts XI on full law ruling discusses excerpts 18 big yilai XI on major economic problem discusses excerpts, discipline to highlight learning XI on strict party of discipline and rules discusses excerpts XI Jinping, on the construction of clean and honest Government and fight against corruption discussed excerpts, technology to highlight the learning of the XI Jinping on technological innovation and discusses excerpts, XI Jinping, education should highlight the important excerpts of work on education and so on. To address the relation between stage and often science. Phase has the advantage of time to focus on fast, to highlight the theme, focused, result; often learn the advantages of flexible fit, form, subtle, continues to ③扩散型（扩展器）（2）根据信息流向①有向交换单元②无向交换单元
13、基本交换单元：时间交换单元（T单元）、空间交换单元（S）、时/空结合交换单元（T/S） T接线器：构成：由话音存储器和控制存储器组成。功能：实现一对复用线上的时隙交换。控制方式：①输出控制:SM顺序写入,控制读出;CM控制写入,顺序读出.②输入控制:SM控制写入,顺序读出;CM顺序写入,控制读出.
S接线器：构成：由m×n交叉点矩阵与一组控制存储器构成。功能：实现对传送同步时分复用信号在不同复用线之间的空间交换，不改变其时隙位置。控制方式：输出控制和输入控制。14、控制存储器：①数量等于入线数或出线数②每个所含有的单元数等于输入线或输出线复用的时隙数。
15、复用（集中）：将多个PCM低次群系统复用成PCM高次群，然后一并进行交换。功能：串/并转换。目的：减低数据传输速率，提高数字通道的利用率。输出的总时隙号=HW线的时隙号×8+HW序号
分路器功能：并/串转换和分路输出。
16、交换网络是由若干个交换单元按照一定的拓扑结构(单级、多级)和控制方式构成的网络。 17、交换网络的阻塞:指从交换网络不同输入端来的信息在交换网络中交换时发生了对同一公共资源争抢的情况，这时在竞争资源中失败的信息就会被阻塞，直到这个公共资源被释放。 18、无阻塞网络分类：严格无阻塞交换网络、可重排无阻塞交换网络、广义无阻塞交换网络 CLOS无阻塞网络：①三级CLOS网络严格无阻塞条件：CLOS定理：m≥2n②对称三级CLOS网络可重排无阻塞条件：m≥n③CLOS网络完全无阻塞的条件：m≥2n-1,一般m=2n (r：第一级/第三级交换单元个数；m：第二级交换单元个数；n：第一级交换单元入线数或第三级交换单元出线数)
19、数字程控交换机的硬件组成:1.话路子系统:⑴用户级交换网络(分为用户模块、远端用户模块)完成话务量集中和话音编译码⑵接口电路(用户接口电路(模拟、数字)中继接口电路(模拟、数字))完成外部信号与数字程控交换机内部信号的转换⑶信号音收发设备：完成数字机音频信号的产生、发送、接收2.控制子系统
20、模拟用户接口电路：B完成向用户话机发出符合规定的电压(-48V)和电流(20-100mA）O防止高压进入交换机内部会严重损坏交换机内部设备R振铃电压：90V±5V 25Hz由CPU送出的振铃控制信号控制继电器的通断，当继电器接通时就可将铃流送往用户，被叫用户摘机后，振铃开关送出截铃信号，CPU则控制停止振铃S通过用户直流回路通断与否，判断用户回路
eepen. In General, periodihigh priority on learning, easy to grasp and practice: recurrent learning factors, long time, prone to %uggish\ning programmes are explicitly required to learn education is not an event, but to highlight the normal education, differentiated levels, heart, catch a fine practice, the real party's ideological and political construction in the everyday, often. This requires that we do a good job phase focused learning based on knowledge contests, comments on rewards in the form, pay special attention to recurring studies. o handle the relationship between solid strong to learn and a lot to learn. For any unit or individual, objectively speaking, in the process of carrying out the party Constitution Party rules and spirit, there is a problem with strong and weak, which we need to pay attention to the actual learning content, and handle the relationship between solid strong to learn and a lot to learn. On one hand, we must always keep a humble attitude, good deal, Continue the hardening. The other hand, always keep the spirit of energetic, pegged to the weak link to find gaps, fill the short Board. Short Board issues should not beunderestimated, the saying goes, have short Board, add a short. This tells us, there are weaknesses shortcomings and do not be afraid, fear is a blind eye and not to repair, the result is poor is worse and the weak weaker. United States politics home zhamusi, and Wilson and prevention crime learn experts qiaozhikailin proposed has a famous of broken window theory, that, if a building House has a fan window of glass broken has, and this fan Windows no get timely repair, others on May to broke more of window glass, time a long, these damaged of window on to people caused a disorder, and matter of feel, results in this mass errors think no attention, and no management of atmosphere Xia, some bad culture, and violations behavior on will breeding and spread. Reality life in the is such, clean of wall Shang, suddenly was posted has a Zhang ad, if didn't people mnagement, not out days this wall Shang on will appeared greatly small many of advertising; private take mess built phenomenon is so, began circle a small block to built a small shed put things, if didn't people timely stop, he on dare built a hut live people, time long has didn't people tube, wants to tubeShi on difficult has. Therefore, the solid strong is important, a lot to learn is also important. Third, key, grasp the learning objective of education is to train a qualified party member %udy and education to its core essence is learning and doing. Learning and doing are mutually reinforcing, if optical can't do, study leave, real learning deficiency, while sweating, wind and water, \ng white\not the mules\ng party rules did not comply with the party Constitution, address the learning series is not used, instead, learn and do, imagine this \ng\sic learning, the key is in use, do, line. In particular, is a qualified party members to grasp the following three points. o strengthen %uarantee for the great struggle. This aspects XI General Secretary of speech main including exercise thrift, against extravagance mass line is party of lifeline and fundamental work route accurate grasp party of mass line education practice activities of guideline and target requirements set and develop \ct three real\put power shut into system of cage in using history wisdom advance anti-corruption construction in-depth advance style clean government and anti-corruption struggle develop nail nail of spirit, a Zhang good of blueprint worked to... 9. other aspects. 18 big yilai, XI General Secretary also respectively on diplomatic, and military, and ecological construction, aspects published has important speech, covers has construction ecological civilization, and advance defense and army modern, and rich \y, two systems\nce country unified, and go peace development road, and promoted building new powers relationship, and go good around diplomatic work, and strengthening and developing countries solidarity cooperation, and active participation multilateral affairs, and science of thinking and work method, manyaspects. XI Jinping, Secretary of a series of important speeches, and further enrich and develop the party's theory, line, principles and policies, the party puts forward new requirements for more contemporary features, the latest achievement of Marxism in China, is a guide to persisting and developing socialism with Chinese characteristics. Four methods. To address the relationship between comprehensive and focused on science. In the process of learning, we should follow as a good study and carry out the \conduct a comprehensive collaborative learning; and with their own jobs, focus research and understanding spirit, grasp the potential requirements. For example, every party member should be according to the various branches of learning program, an article does not go into a link, no leakage of conducting a comprehensive study, and combined with their own duties and responsibilities, be focused and targeted Geoscience. Like, leaders to highlight learning XI on ruling acting political know of deep love of cut dry in practice go in forefront of river new language out poverty XI on coordination advance \discusses excerpts XI on full deepening reform discusses excerpts XI on full law ruling discusses excerpts 18 big yilai XI on major economic problem discusses excerpts, discipline to highlight learning XI on strict party of discipline and rules discusses excerpts XI Jinping, on the construction of clean and honest Government and fight against corruption discussed excerpts, technology to highlight the learning of the XI Jinping on technological innovation and discusses excerpts, XI Jinping, education should highlight the important excerpts of work on education and so on. To address the relation between stage and often science. Phase has the advantage of time to focus on fast, to highlight the theme, focused, result; often learn the advantages of flexible fit, form, subtle, continues to 的接通和断开C编译码器：完成模拟信号和数字信号之间的转换；滤波：编码前模拟信号要通过一个带通滤波器(300~3400Hz)，解码器输出脉冲幅度调制信号，要通过一个低通滤波器以恢复原来的模拟话音信号H实现用户的2线双向信号与交换网中4线单向信号的转换(混合电路的功能在话音发送端在编码前，在反向通路的译码之后进行)T用户电路可配合外部测试设备对用户线进行测试，利用两对测试开关实现，测试开关在处理机的控制下，能够将用户线连接到测试设备上，对用户的内线和外线进行测试
21、数字中继接口电路:G帧码发生:在数字用户接口电路中产生PCM中继电路的帧同步码A帧定位:利用弹性存储器将输入码流的时钟统一到本局时钟上，达到网络时钟的同步Z连零抑制:避免数字中继线上的连续为0的数字码流，影响接收时定位时钟提取P码型变换:在接收和发送方向完成传输线上的码型与交换网络中采用的码型之间的相互转换(交换机内部:单极性不归零码;PCM线:HDB3码或双极性AMI码)A告警处理:PCM码流在传输过程中收到干扰使接收端不能正常恢复原码流，当影响超过一定范围时就会产生故障而发出告警提示C时钟恢复提取:作为输入数据流的基准时钟，同时用作本端系统时钟的外部参考时钟源H帧同步: 从接收的数据流中搜索并识别到帧同步码，以确定一帧的开始，帧同步码在PCM偶帧的TS0中，复帧同步码在F0(复帧的第4个帧)的TS16的高4个比特中传送，码字为0000O信令插入和提取:当数字中继线上采用的是随路信令(中国No.1信令)时，在TS16要提取和插入中国No.1信令的线路信令
22、音频信号的产生：分单音频信号、双音频信号，由数字信号发生器直接产生数字化信号。 23、控制子系统：分级分散控制和分布式分散控制的两种冗余配置(提高可靠性防故障备用)的控制机制。双机冗余配置：控制系统有两套处理机系统，分微同步、负荷分担 、主备用三种工作方式。
24、稳定状态：空闲状态，通话状态，在这种状态下，系统处理过程平稳，或者可能只是周而复始重复相同动作。状态转移：在一个稳定状态下，若有输入信号，则进行新的处理过程，从而进入下一个稳定状态的过程。逻辑关系：输入信号在不同状态时会进行不同的处理，迁至不同的新状态。
25、设备处理=输入处理+输出处理。扫描处理：收集话路设备的状态变化和有关信令的信息。 26、操作系统的主要功能：①任务调度②输入/输出控制③系统资源的分配④处理机间通信的管理与控制⑤系统运行的监测
27、任务调度程序优先级：故障级程序、时钟级程序、基本级程序。遵循的原则：故障级程序eepen. In General, periodic high priority on learning, easy to grasp and practice: recurrent learning factors, long time, prone to \ng programmes are explicitly required to learn education is not an event, but to highlight the normal education, differentiated levels, heart, catch a fine practice, the real party's ideological and political construction in the everyday, often. This requires that we do a good job phase focused learning based on knowledge contests, comments on rewards in the form, pay special attention to recurring studies. o handle the relationship between solid strong to learn and a lot to learn. For any unit or individual, objectively speaking, in the process of carrying out the party Constitution Party rules and spirit, there is a problem with strong and weak, which we need to pay attention to the actual learning content, and handle the relationship between solid strong to learn and a lot to learn. On one hand, we must always keep a humble attitude, good deal, Continue the hardening. The other hand, always keep the spirit of energetic, pegged to the weak link to find gaps, fill the short Board. Short Board issues should not beunderestimated, the saying goes, have short Board, add a short. This tells us, there are weaknesses shortcomings and do not be afraid, fear is a blind eye and not to repair, the result is poor is worse and the weak weaker. United States politics home zhamusi, and Wilson and prevention crime learn experts qiaozhikailin proposed has a famous of broken window theory, that, if a building House has a fan window of glass broken has, and this fan Windows no get timely repair, others on May to broke more of window glass, time a long, these damaged of window on to people caused a disorder, and matter of feel, results in this mass errors think no attention, and no management of atmosphere Xia, some bad culture, and violations behavior on will breeding and spread. Reality life in the is such, clean of wall Shang, suddenly was posted has a Zhang ad, if didn't people management, not out days this wall Shang on will appeared greatly small many of advertising; private take mess built phenomenon is so, began circle a small block to built a small shed put things, if didn't people timely stop, he on dare built a hut live people, time long has didn't people tube, wants to tubeShi on difficult has. Therefore, the solid strong is important, a lot to learn is also important. Third, key, grasp the learning objective of education is to train a qualified party member %udy and education to its core essence is learning and doing. Learning and doing are mutually reinforcing, if optical can't do, study leave, real learning deficiency, while sweating, wind and water, \ng white\not the mules\earning party rules did not comply with the party Constitution, address the learning series is not used, instead, learn and do, imagine this \ng\sic learning, the key is in use, do, line. In particular, is a qualified party members to grasp the following three points. o strengthen %uarantee for the great struggle. This aspects XI General Secretary of speech main including exercise thrift, against extravagance mass line is party of lifeline and fundamental work route accurate grasp party of mass line education practice activities of guideline and target requirements set and develop \ct three real\put power shut into system of cage in using history wisdom advance anti-corruption construction in-depth advance style clean government and anti-corruption struggle develop nail nail of spirit, a Zhang good of blueprint worked to... 9. other aspects. 18 big yilai, XI General Secretary also respectively on diplomatic, and military, and ecological construction, aspects published has important speech, covers has construction ecological civilization, and advance defense and army modern, and rich \y, two systems\nce country unified, and go peace development road, and promoted building new powers relationship, and go good around diplomatic work, and strengthening and developing countries solidarity cooperation, and active participation multilateral affairs, and science of thinking and work method, manyaspects. XI Jinping, Secretary of a series of important speeches, and further enrich and develop the party's theory, line, principles and policies, the party puts forward new requirements for more contemporary features, the latest achievement of Marxism in China, is a guide to persisting and developing socialism with Chinese characteristics. Four methods. To address the relationship between comprehensive and focused on science. In the process of learning, we should follow as a good study and carry out the \conduct a comprehensive collaborative learning; and with their own jobs, focus research and understanding spirit, grasp the potential requirements. For example, every party member should be according to the various branches of learning program, an article does not go into a link, no leakage of conducting a comprehensive study, and combined with their own duties and responsibilities, be focused and targeted Geoscience. Like, leaders to highlight learning XI on ruling acting political know of deep love of cut dry in practice go in forefront of river new language out poverty XI on coordination advance \discusses excerpts XI on full deepening reform discusses excerpts XI on full law ruling discusses excerpts 18 big yilai XI on major economic problem discusses excerpts, discipline to highlight learning XI on strict party of discipline and rules discusses excerpts XI Jinping, on the construction of clean and honest Government and fight against corruption discussed excerpts, technology to highlight the learning of the XI Jinping on technological innovation and discusses excerpts, XI Jinping, education should highlight the important excerpts of work on education and so on. To address the relation between stage and often science. Phase has the advantage of time to focus on fast, to highlight the theme, focused, result; often learn the advantages of flexible fit, form, subtle, continues to 可以打断正常执行的低优先级程序，优先执行。时钟级由时钟中断周期性执行。基本级程序按照队列方式采用“先入先出”的方式执行。故障级程序注意：断点保护后再执行。 三类数据:局数据、用户数据、交换系统数据
28、数字程控交换机的性能指标：话务量、呼损、单位时间内呼叫处理的次数
话务量概念：在时间T内，用户/服务器所产生/所负担的话务量等于该期间内各次服务持续时间的总和。特点：波动性、周期性、K。
话务量集中系数含义：忙时话务量的集中程度。K=忙时话务量/全天话务量。一般取8%~15%。K越小，设备性价比越好。
呼损:交换机由于机键拥塞或中继线不足引起的阻塞概率,衡量交换机质量的重要指标之一。计算：“时间呼损”E=出线全忙时间/总考察时间（或1h内全部中继线处于忙态的百分数）“呼叫呼损”B指一段时间内出线全忙时，呼叫损失的次数占总呼叫次数的比例（或呼叫一次就失败的次数）。
BHCA:最大忙时试呼次数。影响因素:①处理机能力②处理机间的结构和通信方式③各种开销所占的比例④软件设计水平⑤系统容量。计算：单位时间内处理呼叫的时间开销t=α+bN，α为固有开销，b为处理一次呼叫的平均开销（h/次），N为单位一定时间内处理所有呼叫的次数即处理能力值BHCA（次/h）。
29、通信网是一种使用交换设备、传输设备，将地理上分散的用户终端设备互联起来实现通信和信息交换的系统。构成：终端设备、传输链路、交换设备。完整的通信网=硬件+相应软件(信令、协议等)
30、本地电话网是指在同一个长途编号区范围内，由端局、汇接局、局间中继线、长市中继线，以及用户线、电话机组成的电话网。
31、本地网交换中心职能：端局通过用户线与用户相连，负责疏通本局用户的去话和来话话务。汇接局与所管辖的端局相连，以疏通这些端局间的话务；汇接局还与其他汇接局相连，疏通不同汇接区间端局的话务；根据需要还可与长途交换中心相连，用来疏通本汇接区的长途转话话务。
32、本地网的汇接方式：集中汇接、去话汇接、来话汇接、来去话汇接。
33、本地网的网络结构：1.网形网2.二级网①分区汇接：把本地网分成若干个汇接区，在每个汇接区内选择话务密度较大的一个局或两个局作为汇接局，根据汇接局数目不同：分区单汇接和分区双汇接②全覆盖：在本地网内设立若干个汇接局，汇接局间地位平等，均匀分担话务负
eepen. In General, periodihigh priority on learning, easy to grasp and practice: recurrent learning factors, long time, prone to %uggish\ning programmes are explicitly required to learn education is not an event, but to highlight the normal education, differentiated levels, heart, catch a fine practice, the real party's ideological and political construction in the everyday, often. This requires that we do a good job phase focused learning based on knowledge contests, comments on rewards in the form, pay special attention to recurring studies. o handle the relationship between solid strong to learn and a lot to learn. For any unit or individual, objectively speaking, in the process of carrying out the party Constitution Party rules and spirit, there is a problem with strong and weak, which we need to pay attention to the actual learning content, and handle the relationship between solid strong to learn and a lot to learn. On one hand, we must always keep a humble attitude, good deal, Continue the hardening. The other hand, always keep the spirit of energetic, pegged to the weak link to find gaps, fill the short Board. Short Board issues should not beunderestimated, the saying goes, have short Board, add a short. This tells us, there are weaknesses shortcomings and do not be afraid, fear is a blind eye and not to repair, the result is poor is worse and the weak weaker. United States politics home zhamusi, and Wilson and prevention crime learn experts qiaozhikailin proposed has a famous of broken window theory, that, if a building House has a fan window of glass broken has, and this fan Windows no get timely repair, others on May to broke more of window glass, time a long, these damaged of window on to people caused a disorder, and matter of feel, results in this mass errors think no attention, and no management of atmosphere Xia, some bad culture, and violations behavior on will breeding and spread. Reality life in the is such, clean of wall Shang, suddenly was posted has a Zhang ad, if didn't people mnagement, not out days this wall Shang on will appeared greatly small many of advertising; private take mess built phenomenon is so, began circle a small block to built a small shed put things, if didn't people timely stop, he on dare built a hut live people, time long has didn't people tube, wants to tubeShi on difficult has. Therefore, the solid strong is important, a lot to learn is also important. Third, key, grasp the learning objective of education is to train a qualified party member %udy and education to its core essence is learning and doing. Learning and doing are mutually reinforcing, if optical can't do, study leave, real learning deficiency, while sweating, wind and water, \ng white\not the mules\ng party rules did not comply with the party Constitution, address the learning series is not used, instead, learn and do, imagine this \ng\sic learning, the key is in use, do, line. In particular, is a qualified party members to grasp the following three points. o strengthen %uarantee for the great struggle. This aspects XI General Secretary of speech main including exercise thrift, against extravagance mass line is party of lifeline and fundamental work route accurate grasp party of mass line education practice activities of guideline and target requirements set and develop \ct three real\put power shut into system of cage in using history wisdom advance anti-corruption construction in-depth advance style clean government and anti-corruption struggle develop nail nail of spirit, a Zhang good of blueprint worked to... 9. other aspects. 18 big yilai, XI General Secretary also respectively on diplomatic, and military, and ecological construction, aspects published has important speech, covers has construction ecological civilization, and advance defense and army modern, and rich \y, two systems\nce country unified, and go peace development road, and promoted building new powers relationship, and go good around diplomatic work, and strengthening and developing countries solidarity cooperation, and active participation multilateral affairs, and science of thinking and work method, manyaspects. XI Jinping, Secretary of a series of important speeches, and further enrich and develop the party's theory, line, principles and policies, the party puts forward new requirements for more contemporary features, the latest achievement of Marxism in China, is a guide to persisting and developing socialism with Chinese characteristics. Four methods. To address the relationship between comprehensive and focused on science. In the process of learning, we should follow as a good study and carry out the \conduct a comprehensive collaborative learning; and with their own jobs, focus research and understanding spirit, grasp the potential requirements. For example, every party member should be according to the various branches of learning program, an article does not go into a link, no leakage of conducting a comprehensive study, and combined with their own duties and responsibilities, be focused and targeted Geoscience. Like, leaders to highlight learning XI on ruling acting political know of deep love of cut dry in practice go in forefront of river new language out poverty XI on coordination advance \discusses excerpts XI on full deepening reform discusses excerpts XI on full law ruling discusses excerpts 18 big yilai XI on major economic problem discusses excerpts, discipline to highlight learning XI on strict party of discipline and rules discusses excerpts XI Jinping, on the construction of clean and honest Government and fight against corruption discussed excerpts, technology to highlight the learning of the XI Jinping on technological innovation and discusses excerpts, XI Jinping, education should highlight the important excerpts of work on education and so on. To address the relation between stage and often science. Phase has the advantage of time to focus on fast, to highlight the theme, focused, result; often learn the advantages of flexible fit, form, subtle, continues to 荷，汇接局间以网状相连，各端局与各汇接局均相连。两端局间用户通话最多经一次转接。 34、传统四级长话网结构：我国电话网分五级，由一~四级长途交换中心及本地五级交换中心即端局组成。C1(网形连接)北京上海广州沈阳南京武汉西安成都C2省C3地区C4县(各级之间星形)过渡策略：一二级长途交换中心合并为DC1，构成长途二级网的高平面网（省际平面）；C3被称为DC2，构成长途二级网的低平面网（省内平面）；C4失去原有作用，趋于消失。 35、国际长话网由各国长话网互联而成，采用三级辐射式网络结构。一级国际中心局CT1（7个）、CT2、CT3。我国三个国际出入口局：北上广。地区性国际出入口局：乌鲁木齐。 36、路由：网络中任意两个交换中心之间建立一个呼叫连接或传递信息的途径。分类：①按呼损分：高效路由、低呼损路由≤1%②按路由选择：首选与迂回、直达、最终*、常规与非常规、安全迂回③按所连交换中心地位：基干*、跨级、跨区。
37、电话号码的组成：本地用户电话号=局号+用户号=PQRS+ABCD 国内长途号=国内长话字冠0+长途区号+本地号码 国际长途号=国家号码(1~3位)+国内号码=00IIIXXXPQRSABCD=全自动国际长途字冠+国际区号+长途区号+本地号码≤15
38、编号的基本原则：①要考虑远近期结合：一般情况一次编号后不再作变更②号码计划要与网络安排统一考虑，做到统一编号③尽可能避免改号(号码升位也是改号)④国内电话号码长度≤12。
39、长途区号分配原则：不等位制。由2位、3位或4位三种长途区号组成，编排规则是电话用户越多，长途区号越短；用户越少，区号越长。
40、信令：人们实现信息传输所使用的操作指令；呼叫接续过程中所采用的一种“通信语言”，用于协调动作、控制呼叫；这种“通信语言”应该是可以相互理解和相互约定的，以达到协调动作的目的；通信网中规范化的控制命令。作用：控制通信网中各种通信连接的建立和拆除；维护通信网的正常运行。
41、分类：①按信令工作区域分：用户信令和局间信令②按信令传送通路与用户信息传送通路关系分：随路信令CAS(1号)和共路信令CCS(7号)
随路信令：信令和用户信息在同一通路上传送的信令。特点：①共路性②相关性。
共路信令：信令通路和用户信息通路是分离的，信令在专用的信令通道上传送。特点：①分离性②独立性
42、信令的方式：信令时通信网中规范化的控制命令，所谓规范化就是在信令构成、信令交互时要遵守一定的约束和规定，这些约束和规定就是信令方式。包含内容：信令的结构形式（编
eepen. In General, periodic high priority on learning, easy to grasp and practice: recurrent learning factors, long time, prone to \ng programmes are explicitly required to learn education is not an event, but to highlight the normal education, differentiated levels, heart, catch a fine practice, the real party's ideological and political construction in the everyday, often. This requires that we do a good job phase focused learning based on knowledge contests, comments on rewards in the form, pay special attention to recurring studies. o handle the relationship between solid strong to learn and a lot to learn. For any unit or individual, objectively speaking, in the process of carrying out the party Constitution Party rules and spirit, there is a problem with strong and weak, which we need to pay attention to the actual learning content, and handle the relationship between solid strong to learn and a lot to learn. On one hand, we must always keep a humble attitude, good deal, Continue the hardening. The other hand, always keep the spirit of energetic, pegged to the weak link to find gaps, fill the short Board. Short Board issues should not beunderestimated, the saying goes, have short Board, add a short. This tells us, there are weaknesses shortcomings and do not be afraid, fear is a blind eye and not to repair, the result is poor is worse and the weak weaker. United States politics home zhamusi, and Wilson and prevention crime learn experts qiaozhikailin proposed has a famous of broken window theory, that, if a building House has a fan window of glass broken has, and this fan Windows no get timely repair, others on May to broke more of window glass, time a long, these damaged of window on to people caused a disorder, and matter of feel, results in this mass errors think no attention, and no management of atmosphere Xia, some bad culture, and violations behavior on will breeding and spread. Reality life in the is such, clean of wall Shang, suddenly was posted has a Zhang ad, if didn't people management, not out days this wall Shang on will appeared greatly small many of advertising; private take mess built phenomenon is so, began circle a small block to built a small shed put things, if didn't people timely stop, he on dare built a hut live people, time long has didn't people tube, wants to tubeShi on difficult has. Therefore, the solid strong is important, a lot to learn is also important. Third, key, grasp the learning objective of education is to train a qualified party member %udy and education to its core essence is learning and doing. Learning and doing are mutually reinforcing, if optical can't do, study leave, real learning deficiency, while sweating, wind and water, \ng white\not the mules\earning party rules did not comply with the party Constitution, address the learning series is not used, instead, learn and do, imagine this \ng\sic learning, the key is in use, do, line. In particular, is a qualified party members to grasp the following three points. o strengthen \
现代交换技术复习整理
