Connection to the 3G network card of Huawei e1750 is suspended (handled)

After connecting to the 3G network card of China Unicom (Huawei e1750 terminal), I went home for a try and found that the Internet could not be accessed normally. When I clicked the connection, I was prompted that the connection was suspended.
In Connection tests, I have seen that all the signals are normal, and text messages can also be sent normally. This is a strange thing. I suspect that the firewall or anti-virus software is the cause, so all the messages are stopped and the fault persists ~
No, so I had to reinstall the system in another hard disk. I just installed the system and tested it to access the Internet normally. However, after optimization, I disabled the infrequently used services, when the connection is terminated, You have to enable the disabled service one by one, and finally identify telephony (providing TAPI supportProgramControl the Local Computer) this damn service is a zombie. If you don't know what it is, why do you have something to do with this service. No matter how much it is, you can enable it for normal use.