> >5. Out of band (OOB) data - Potentally a problem specific to NT SP 3
> >6. The use of Delphi's Event Alerter component can produce OOB.

Out of Band - Directly related to way event alerters are used.

With local connections, in the InterBase Classic model, notification of an
event occurrence was easy - you simply signaled the waiting process with a
wakeup. There is even an API call clients can use to register an AST
handler.

With Remote protocol, there are two ways we can notify the remote client.
The method used depends on the capabilities of the underlying network
software.
if the protocol supports Out-of-Band data (as some do) then the sender
sends a packet but with a flag that the data is out-of-Band. The OS will
generate an interrupt on the receiving side to notify that unexpected data
is available.
If we can't use Out-of-band, a 2nd network connection is made, simply for
the purpose of event notification. Messages are sent on this connection with
the URGENT flag, so that the client receives an interrupt signal to handle
the data.
On NT there was a problem (until SP3+)

cf.

Client application will not see events if NT Service Pack 2 or 3 is
installed.

Answer:
This is caused by a new TCPIP.SYS that modified some Out of Band data
routines,
which InterBase heavily relies on for event processing. The solution is to
download the Microsoft teardrop fix (which includes a new TCPIP.SYS) from:

ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/nt40/
hotfixes-postSP3/teardrop2-fix/

NOTE: This fix supercedes the ICMP-fix, the OOB-fix, and the Land-fix
hotfixes.
Firebird/InterBase Version: 4.x & 5.x

Operating System: Windows NT



Regards
Paul Beach
Main Tel (UK):+44 (0) 1844 354465
Mobile: (UK): +44 (0) 7764 188603