Sockets and DCOM

[Nicholas Robinson]

Hi,

Can someone explain what the difference between the socket connection and
the dcom connection is? As far as the client is concerned, the COMisms in
the MIDAS client are the same, yet the transportation is different.
Currently we have problems using the TSocketConnection component as
corporate customers are having trouble gaining access to the server outside
a firewall. How does the TSocketConnection work with COM calls?

Any advice on this would be most appreciated.

Thanks.

Nick.

[Dan Miser [TeamB]]

TSocketConnection makes your application look like you're using straight
TCP/IP on one port. When a call is passed from TSocketConnection to
scktsrvr, it is done with an RPC, so the server can figure out what COM call
needs to be called on the server.

Basically, you just need to make sure you're not using early-binding, and
that the firewall is open for the correct port, and it should be a seamless
conversion between the 2 transports.
--
Dan Miser
http://www.distribucon.com
(TeamB cannot answer questions received via EMail)

[Nicholas Robinson]

Thanks for that Dan. As it turns out the question I was asked to investiage
relates to the OleEnterprise. How does OLEEnterprise work - it requires
that certain DCOM ports are open so what does OLEEnterprise actually do?

Thanks.

Nick.
Dan Miser [TeamB] <dmi...@distribucon.com> wrote in message
news:7tu6am$3n...@forums.borland.com...

[Dan Miser [TeamB]]

OLEnterprise runs with DCOM. There is absolutely no reason to use this
product any more. It provided 3 major things:

* Ability to use Win9x as a COM server
* Fault-tolerance
* Load balancing

COM servers have had the ability to be hosted on Win9x for some time (see my
web site). Fault-tolerance and load balancing are provided in the
TSimpleObjectBroker component. People seem to still use this technology, but
not one person has given me a compelling reason why, especially given the
enormous client-side distribution requirements.

[Nicholas Robinson]

Hi Dan,

Yes I agree with your comments. The client I am now working with believed
OLEE was the correct way to move forward, but now it seems to be causing a
whole plethora of problems Howeve rone problem which relates to DCOM is
that of firewalls. As I understand it, there is now the facility to make a
DCOM access via port 80 (HTTP port) if using IIS4 on the server. The
quandry at this stage for me is, will OLEE which is installed with an
already large client base, support this new feature of IIS4? If OLEE is in
bed with DCOM, will using this port still work, or will a true
TDCOMConnection component be required?

Thanks for your help Dan.

Nick.

Dan Miser [TeamB] <dmi...@distribucon.com> wrote in message

news:7tvkvv$fl...@forums.borland.com...

[Dan Miser [TeamB]]

I really have no idea if OLEE will work with CIS or not. Either way, CIS is
far from a perfect solution. It merely bootstraps the COM calls over HTTP.
It is NOT an HTTP tunneling solution.

If you want to obliviate firewall issues, then I would suggest looking at
TWebConnection. If you want a generic replacement for it, look for Chad
Hower's message where he offers a free replacement to the Delphi-supplied
one, which requires WININET.DLL on the client and IIS/Netscape.

[nr@nrobin.demon.co.uk Nicholas Robinson]

Hi Dan,

Thanks for the info, I will look into your suggestions.

Nick.
Dan Miser [TeamB] <dmi...@distribucon.com> wrote in message

news:7u4sfp$rg...@forums.borland.com...