This article was previously published under Q150350
This article has been archived. It is offered "as is" and will no longer be updated.
Your ISDN TCP/IP router telecommunication connection costs appear to bevery high.
Your network spans two or more sites.
You use ISDN TCP/IP routers.
You use an ISDN service that charges you based on connection time.
Install Windows NT 3.51 Service Pack 5.WARNING: Using Registry Editor incorrectly can cause serious, system-wideproblems that may require you to reinstall Windows NT to correct them.Microsoft cannot guarantee that any problems resulting from the use ofRegistry Editor can be solved. Use this tool at your own risk.
You can now set the pulse to a maximum of 172800 (2A300h).
Microsoft has confirmed this to be a problem in Windows NT version 3.51.This problem was corrected in the latest Windows NT 3.51 U.S. ServicePack. For information on obtaining the Service Pack, query on thefollowing word in the Microsoft Knowledge Base (without the spaces):
S E R V P A C K
The following example outlines a common scenario involving ISDN routers.
One primary domain controller (PDC), with a significant number of backupdomain controllers (BDCs), connects to one PDC via ISDN. Each time anetwork frame is exchanged between a BDC and the PDC, it costs one ISDNconnection.
In this case, the PDC may handle many user account transactions so that SAMchanges are common and occur often. Each time the PDC detects a SAM change,it contacts all the BDCs. Having purchased ISDN routers, the you may notnecessarily desire to have the BDC's SAMs updated every hour. Because ofthe cost of activation, you may want to update the BDCs as little as onceevery 48 hours.
Currently, if the Pulse parameter is set to its maximum, the cost fortransaction updates is the number of BDC connections every hour. If thereare 50 BDCs, there are 50 connections per hour. For 120 BDCs, the cost is120 connections per hour.
Looking at this on a monthly basis, the cost of connections becomes evenmore apparent: 120 connections x 24 hours a day x 30 days a month = 86,400connections.
NOTE: For additional information on reducing domain browsing and WINSreplication traffic over slow links, please see the following article inthe Microsoft Knowledge Base:
134985Browsing & Other Traffic Incur High Costs over ISDN Routers