If you're fixed on going the remoting over TCP route, you will find the
following 2-part sample useful.

..NET Remoting Authentication and Authorization Sample - Part I
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/html/remsspi.asp

..NET Remoting Authentication and Authorization Sample - Part II
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/html/remsec.asp

If you do go this route, you will have more recoding work to do moving to
Longhorn/Indigo, than if you choose WS or ES (or even remoting over http).

A couple of things here.

1. Web services and .Net remoting (when used over the Http channel ie. via
IIS) are pretty much the same speed. Web services can even exceed .Net
remoting in this scenario (does't matter what formatter, but SOAP formatter
is slowest of all in .Net remoting).
2. .Net remoting using the TCP channel; is faster than Web services.
3. COM+ components by default, will use DCOM. DCOM is the fastest of all
these protocols. Currently, neither remoting (over any channel) or Web
services can match it for speed. It is only really used in Intranet
scenarios though as configuring a firewall to allow the right ports through
for DCOM to work can be tricky.
4 COM+ components/Enterprise Services/DCOM do have much better security
support. .Net remoting really has nothing at all. If you use .Net remoting
via IIS, you can take advantage of windows integrated authentication (which
itself slows things down a little due to the 5 way conversation that takes
place for a successfull authentication. Note: This is assuming NTLM,
Kerberos can be better but it depends). When using IIS, you also have the
option to use SSL for encrypting your traffic.
5. COM+ gives you some nice features that Daniel mentions below, but unless
you really want them, using COM+ might be overkill. To invoke a COM+
component requires some performance overhead, so even though DCOM might be
faster, the total time it takes for a remote call to get from client to end
of processing, might be longer via COM+. This is really something that needs
to be tested though, and cannot be measured generally.
6. Another consideration is WSE (Web Service Enhancements 2). The security
setup is relatively easy, and the performance is good. Its inline with
future direction, and is well aligned to take advantage of Indigo
technology, when its made available which is "supposedly" going to match
across the wire performance, with that of DCOM, only its web services based.


--
- Paul Glavich
Microsoft MVP - ASP.NET


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