E1接口(T1接口用于外国)（国外英文资料）.docVIP

E1接口(T1接口用于外国)（国外英文资料） T1 and E1 refer to the trunk type, i.e., the users PBX connection to the telecommunication authority Trunk type. T1 is mainly used in North America, Europe and Hong Kong China USES E1 relay. One of the benefits of E1 is that the number (ANI) can be transmitted. E1 can transmit 30 simultaneous calls simultaneously, while T1 can transmit 24 lines at the same time ............ E1 is the European standard, and our country USES this standard, 2048K; T1 is the north American standard, and Japan seems to be the same, 1544K. The transmission is very common. E1 is the most original usage when used as a voice switches, digital relay is a E1 as 32 64 k, but the time slot 0 and time slot 15 is use transmission control signal, so a voice E1 can pass 30 road. This is the E1 that is said on the access server (such as huawei 8010, north electric, CVX1800, etc.) and is somewhat different from the E1 concept, which is usually said on the router. The E1 on the router is not divided by the time gap, only for 2M. The bandwidth of CE1s transmission line is 2048K, and the difference between it and E1 is that E1 does not divide the time gap, CE1 can divide the time gap. The CE1 gap is 64K, a total of 32 slots, which can be divided into n * 64K, for example, 128K, 256K, etc. CE1 0 and 15 time slot is not to the users data traffic, 0 time slot is transmission synchronization, 15 slots transfer of control signal, so the actual use of only 30 time slot, so in the specific configuration CE1 divided time slot, to pay attention to. CE1 and E1 are also interlinked, but CE1 must be used as E1, which is non-separable. CE1 is more flexible, so we can often encounter CE1. An E1 is a link of 2.048 M, encoded by PCM. The frame length of an E1 is 256 bits, divided into 32 slots, a gap of 8 bits. There are 8k E1 frames per second through the interface, which is 8k * 256 = 2048kbps. Each time slot occupies 8bit in E1 frame, 8 * 8k = 64k, or an E1 contains 32 64k. E1 frame structure