Problem

-- Every transmission of files that are larger than 9 MB from WS_FTP 12 to B2Bi 2.3.1 and later fails with an "Error 84350000 sending sftp packet" in the WS FTP logs.

-- Debug logging shows this information:

[2018.05.07 15:43:32.575] Server Window of 34000 not enough for data of 34032 on channel 0760a2ce
[2018.05.07 15:43:32.575] Waiting for 65 seconds for server to adjust channel window

** Debug logging in WS_FTP can be turned on by doing the following to steps:

• In the client itself: Tools -> Options -> Logging -> "Enable debug logging"
• Then add the line "EXTRASSHLOGGING=1" to C:\Users\<username>\AppData\Roaming\Ipswitch\WS_FTP\wsftp_options.ini file

Resolution

WS_FTP client and B2Bi are reaching a point where both client and server are waiting for each other. B2Bi is waiting for more data,. WS_FTP is waiting for B2Bi to increase the Windowsize.

To avoid this lock, do the following:

1. Edit the [B2Bi_installDir]/Interchange/conf/jvmArguments.xml
2. Find the TE node section by looking for:
   <NodeType type="TE" class="com.axway.clusterold.startup.Boot">
3. Insert the line:
   <Property key="ssh.minWindowSpace">35000</Property>
4. Restart B2Bi