The doc says.. Mode B Sets the block mode. In block mode, data is transmitted as a series of data blocks, preceded by one or more header bytes. Block mode preserves the logical record boundaries of the data set or file. When MOde is set to B, the data transfer type must be EBCDIC.
Mode S Sets the stream mode. In stream mode, data is transmitted as a stream of bytes. Any data transfer type can be used with stream mode. *Stream mode is efficient because data block information is nottransferred.* *________________* Why worry about EBCDIC? as it is z/OS to z/OS you want binary mode. *___* With Mode S it may send data in chunks for the send and receive size (so up to MB chunks). With Mode B it may send a count of records before wait, - which may be in 100's of bytes. If you issue TSO NETSTAT ALL ( PORT 22 it will display data for all FTP connections. For the one of interest, look at SendBufferSize: / ReceiveBufferSize: CongestionWindow: MaximumSegmentSize: DSField: Round-trip information: Smooth trip time: SmoothTripVariance: ReXmt: ReXmtCount: DupACKs: RcvWnd: With Dynamic Right Sizing you should have Send buffers > 64KB - perhaps 1MB ( and receive buffer at the remote end) Bytes Out/Segments out give you a rough measure of the amount of data sent per packet. If you send me the data from each end, I can have a look at if for you Colin On Thu, 28 Mar 2024 at 14:32, Jousma, David < [email protected]> wrote: > Max, > > As mentioned, the 50Gb file with MODE B and EBCDIC is slow. Same file > just binary mode, it is fast. Of course, cant transmit a DSS dump as just > binary. > > Dave Jousma > Vice President | Director, Technology Engineering > > > > > > From: IBM Mainframe Discussion List <[email protected]> on behalf > of Massimo Biancucci <[email protected]> > Date: Thursday, March 28, 2024 at 10:26 AM > To: [email protected] <[email protected]> > Subject: Re: Slow FTP's > Dave, it becomes more interesting. Could it depend on the file data itself > ? Have you tried a BIG file, EBCDIC with mostly the same data inside ? Same > kind of transmission, MODE B and EBCDIC. Regards. Max. Il giorno gio 28 mar > 2024 alle ore > > > Dave, > > > > it becomes more interesting. > > Could it depend on the file data itself ? > > > > Have you tried a BIG file, EBCDIC with mostly the same data inside ? > > Same kind of transmission, MODE B and EBCDIC. > > > > Regards. > > Max. > > > > > > > > This e-mail transmission contains information that is confidential and may > be privileged. It is intended only for the addressee(s) named above. If > you receive this e-mail in error, please do not read, copy or disseminate > it in any manner. If you are not the intended recipient, any disclosure, > copying, distribution or use of the contents of this information is > prohibited. Please reply to the message immediately by informing the sender > that the message was misdirected. After replying, please erase it from your > computer system. Your assistance in correcting this error is appreciated. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
