That's number of bytes transferred.
I have a question concerning codes in our log file. We are using SFTP to transmit a file. The status code returned is 0; however, the next line in our log has a value of "" and we would like to know what it indicates. Here are several lines from our log.
< 2015-09-14 16.00.18.507 Type: SSH_FXP_STATUS, Size: 35, Number: 521
< 2015-09-14 16.00.18.507 Status code: 0
. 2015-09-14 16.00.18.507 Transfer done: 'C:\INTERF\DUMMYFILENAME.2015091410'