Windowing is meant to cut down on the number of ACKS, if data your trying to send is larger than your MTU (Maximum transmission unit) size.
I would start with looking at the windowing settings. Basically for Ethernet MTU is usually set to 1500 bytes Windowing is negotiated up front by the two hosts in the conversation (or maybe just by the sender, I'm not sure). They agree on using a windowing size of let's say 16k or 32k. Instead of sending an ACK for every 1500 bytes of data, they send one after the 16k or 32k window gets reached. Windowing is a parameter that you can set on your operating system. You should probably compare the windowing sizes on Solaris to Z/Linux and see if their the same. A quick Google search pulls up dozens of hits on how to view and set your windowing size. The other thing to note here is that WINDOWING only is used if your packet is larger than the MTU size. It may very well be that the packets your sending are smaller than the MTU size, so each one HAS to get ACK'd. -----Original Message----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of Karel Gentens Sent: Wednesday, November 07, 2007 10:28 AM To: LINUX-390@VM.MARIST.EDU Subject: Network traffic with DB2 Connect on zLinux and other Unix Hy list, I have 2 students here, who are compairing different db2Connect installations. They notice an important difference in network traffic between the z/Linux installation, and a Solaris installation. The network lady took a TCP/IP trace and she saw that with z/Linux, there was an ACK sent for each datapacket, with Unix there were not that many ACKs Nbr packets MB Sent Unix 33000 41MB Linux 44000 42MB Question thus: have you an idea how we could tell DB2/Connect on z/Linux not to request an ACK for each packet? If you don't know, no problem, we're searching at various places. Could it be that the TCP window size is a problem? Thanx in advance. Karel Gentens KBC Groep NV VM - Systemen (CCM1 - CMI) Egide Walschaertsstraat 3, 2800 Mechelen 015/35.24.52 0499/96.53.18 [EMAIL PROTECTED] This e-mail and any attached files are confidential and may contain information which is protected by intellectual property rights. If you are not the addressee named above any disclosure, reproduction, copying, distribution, or other dissemination or use of this communication is prohibited. If you have received this transmission in error, please notify the sender immediately and destroy this e-mail. This e-mail does not contain any professional advice and does not constitute an offer regarding any financial, banking, insurance or other product service toward the addressee. If you like to obtain specific information, professional advice, an offer, or want to contract you have to contact the KBC company mentioned above, its branch or agent. E-mail transmission cannot be guaranteed to be secure or error free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message, and shall have no liability for any loss or damage suffered by the user, which arise as a result of e-mail transmission. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - This message is intended only for the personal and confidential use of the designated recipient(s) named above. If you are not the intended recipient of this message you are hereby notified that any review, dissemination, distribution or copying of this message is strictly prohibited. This communication is for information purposes only and should not be regarded as an offer to sell or as a solicitation of an offer to buy any financial product, an official confirmation of any transaction, or as an official statement of Lehman Brothers. Email transmission cannot be guaranteed to be secure or error-free. Therefore, we do not represent that this information is complete or accurate and it should not be relied upon as such. All information is subject to change without notice. -------- IRS Circular 230 Disclosure: Please be advised that any discussion of U.S. tax matters contained within this communication (including any attachments) is not intended or written to be used and cannot be used for the purpose of (i) avoiding U.S. tax related penalties or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
