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FredR_30652's avatar
Icon for Nimbostratus rankNimbostratus
Jul 12, 2012

Nagle Kills attachment Downloads

Hi All,



Since our deployment of Exchange 2010 Cas Array using F5 3.5 deployment guide, users complains about long time duration downloading attachment over the Wan (10Mo -> 45 sec).


Tcpdump/Wireshark help us to see that, for RPC MAPI calls from Outlook 2003, Nagle's algo on the Virtual server and DelayedAck client side mecanism add at least 25 sec of wait time (Client waiting for Data, Virtual Server waiting for the ACK).



Disable Nagle in the wan optimized tcp profile and the download only takes 15 sec.



It could help.








2 Replies

  • mikeshimkus_111's avatar
    Historic F5 Account
    Hi Fred, thanks for the input. Can you tell us what the bandwidth/latency are on your WAN link, so we can attempt to reproduce this?


  • Hello,



    Sorry for the late answer , 20 ms of latency and 15 M to 20 M of bandwidth on the link i've take a tcpdump (Client : Outlook 2003 on Windows XP).



    With a big-ip you can have problems but you 've got always a solution.