For a relatively small or medium-sized image file (a few megabytes to a few dozen megabytes) for the purposes of the transfer, ISDN, within a few minutes will transfer out.

• 差于相差较小或洋等不小小的图像文件（几兆字节到几十兆字节不相等）传输而言，ISDN在几分钟边不离迟缓传输不出去。