| 1. | Destination user prompting dup
提醒被叫用户 |
| 2. | The originating switch analyzes the number in order to route the call to the b number , the number of the called party
最初的交换机分析该号码，从而将该呼叫发送至b号码，即被叫用户。 |
| 3. | For intra - network calls , the vpmn use can either dial the short number defined by the group or the real number of the called user
在进行网内呼叫时， vpmn用户有两种拨号方式，既可以拨集团定义的短号码，也可以拨被叫用户的真实号码。 |
| 4. | The telephone communication requisitions in factory are not satisfied , so a new type of factory communication system should be developed
为此需要研制一种具有拨号功能、可拨打外线、对其他非被叫用户无干扰、并具有较高通信针对性新型电话通信系统。 |
| 5. | The whole calling process of the system is just like that the calling party calls the called one through dialing , and then the called party picks up the telephone after hearing the ring
该系统的呼叫过程是主叫用户通过拨号呼叫被叫用户，被叫用户听到振铃声后接听电话。 |
| 6. | But this system can not be in contact with users who are out of factory lacking of dialing . we can not call the correct user and the disturbance is boring to other users
但是该系统不具有拨号功能，无法与外界进行电话联络，并且系统呼叫的针对性差，不能准确地找到被叫用户，同时对其他用户有着不必要的干扰。 |
| 7. | The internal user can call single user , a group of users and all of users by dialing different numbers . call pertinence is improved and the disturbance to others is not existed
而且具有拨号功能，拨号简便、快捷，对内部用户实现了单呼、群呼、全呼三种呼叫方式，提高了呼叫的针对性，消除了对非被叫用户的干扰。 |
| 8. | According to the setting of the user , the called user may choose the real or short number of the calling user of the same group as the calling number to be displayed , and may call back by dialing the number chosen
根据用户的设置，被叫用户对可以选择同属于一个集团（网内呼叫）时来电显示方式：可以是主叫的短号码，也可以是主叫的真实号码。 |
| 9. | The working space in the fields such as oil , chemistry , metallurgy , coal mining and medicine always requires a communication system which can make sure the calling party shortly and easily get in touch with the called one in the inflammable and explosive , large - scaled and strong - noised working space
石油、化工、冶金、医药、煤炭等行业中的生产场所要求通信系统能够在易燃、易爆、大范围、强噪声的生产场所使主叫用户快速、简便地与被叫用户取得联系。 |
| 10. | The dialing is slow and the system ca n ' t ensure the calling party fast and accurately put through the called one who is asked for receiving . 5 . the bell ring is so low that the workers ca n ' t hear in the large - scaled working space with strong noise
它存在的缺点有：工程布线麻烦、费用高；电话线路成本高且利用率低；系统可靠性差；呼叫速度慢，并且不能保证主叫用户快速、准确地找到需要接听的被叫用户；振铃声难以保证在大范围、强噪声的生产场所下的工作人员接听到。 |
