Periodic Re-Transmit Times for Packets

 Last reviewed: November 11, 1997
Article ID: Q135360
3.10 3.50 3.51 WINDOWS kbnetwork

The information in this article applies to:

  • Microsoft Windows NT operating system version 3.1
  • Microsoft Windows NT Advanced Server version 3.1
  • Microsoft Windows NT Workstation versions 3.5 and 3.51
  • Microsoft Windows NT Server versions 3.5 and 3.51

SUMMARY

Some network traffic occurs simply because the network is active. For example, some network traffic occurs as a result of periodic retransmission of packets as "keepalive" requests, browser requests, polling, and the acknowledgment packets sent for each of these requests.

MORE INFORMATION

The following table documents packet types and their default send intervals. 

Packet Type    Protocol   Transport           Interval
-----------    --------   ---------           --------

NetLogon       SMB        TCP/IP & NetBEUI    300 seconds
Browse         SMB        TCP/IP & NetBEUI    300 seconds (Windows NT 3.1)
                                              720 seconds (Windows NT
3.5x) 
KeepAlive      NetBIOS    TCP/IP               60 minutes (Windows NT
3.5x) 
SessionAlive   NetBIOS    NetBEUI              30 seconds (LAN Manager)
Poll/Final     LLC         NetBEUI             30 seconds (or ACK to Poll)
KeepAlive      NetBIOS     IPX                 30 seconds
Echo SMB       SMB         Direct Host IPX    240 seconds
NOTE: The Browse packet type mentioned above indicates network traffic between a Windows NT primary domain controller (PDC) and its backup domain controllers (BDCs).

The Windows NT redirector echoes an SMB every 30 seconds to each server that has an associated Long Term Request outstanding.

Some of the default values can be adjusted by changing the appropriate values in the Windows NT registry. For more information about these settings, query on the following words in the Microsoft Knowledge Base: 

   winnt registry keepalive | session timeout
For additional information on adjusting PDC browse broadcasts, please see the following article in the Microsoft Knowledge Base: 

   ARTICLE-ID: Q134985
   TITLE     : Browsing & Other Traffic Incur High Costs over ISDN Routers

KBCategory: kbnetwork
KBSubcategory: ntprotocol nttcp NTSrvWkst
Additional reference words: 3.10 3.50 3.51 prodnt polling pulse background
bdc keep alvie time out
Keywords : NTPROTOCOL NTSrvWkst nttcp kbnetwork
Version : 3.10 3.50 3.51
Platform : WINDOWS

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Last reviewed: November 11, 1997
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