I have an app that uploads a file to an FTP server every few minutes. It works great when my phone is on a WIFI connection. However, if I turn Wifi off and it is using the 4G or 3G connection, the upload doesn't work.
Here are the symptoms when using 4G or 3G connection:
1. I have a 9 kb file on the phone that I am uploading to the FTP server.
2. Upload initiates, but the FTP_UploadProgress and FTP_UploadCompleted events are never triggered.
3. On the FTP server, I see that it created a file with the correct filename, but it is an empty file.
I have tried both active and passive FTP modes (not that I really understand the difference). Neither worked.
Is there some kind of issue with FTP over a 4G or 3G connection?
Here are the symptoms when using 4G or 3G connection:
1. I have a 9 kb file on the phone that I am uploading to the FTP server.
2. Upload initiates, but the FTP_UploadProgress and FTP_UploadCompleted events are never triggered.
3. On the FTP server, I see that it created a file with the correct filename, but it is an empty file.
I have tried both active and passive FTP modes (not that I really understand the difference). Neither worked.
Is there some kind of issue with FTP over a 4G or 3G connection?