The reaction colleagues previously outpoint，Line on the phone can send messages correctly，But can not send pictures，Also the use of a network that is normally。Research for a while，Thought it would not be a problem MTU，Sonet network is just the problem of mining pppoe dial-up，Internet search will recommend value，General advice is 1492 or 1484，The default value is 1500 Sonicwall firewall，After adjustment，Line normal to send pictures。
Yesterday overseas MIS reaction，After Internet failure recovery，Open page becomes very slow，But with ping tests are normal，He worked overtime to test more than eight still no solution，Then I remembered again，MTU will not be a problem，They asked him to search the Internet recommended value of China's telecommunications network，Query results are the same as 1492 and 1484，After modification to solve the problem immediately。
[Modifications]
「Network」-「Interfaces」-「Configure(Internet interface)」-「Advanced」，Find below the "Interface MTU"，1492 can be changed。
Also after the dial-up Internet access road，But also to the "Protocol" found MTU value of Server，As a reference。
