it seems that there has some problem with the DDN link ,i use ping to test another end of the link , there has a strange output:
Reply from 61.*.0.2: bytes=32 time<10ms TTL=224
Request timed out.
Request timed out.
Request timed out.
Request timed out.
,just like that ,so many timed out , i think the link is still connected ,but doesnt work well ,i dont know whats wrong with it ,what should i do?