Can "NIC teaming" decrease contention, for multiple sites with separate application pools? (connecting server w/ IIS, and server w/ SQL Server)

Question

SUMMARY: if sites have separate application pools, can their traffic avoid contention through "NIC teaming"?

((Let me know if this is better posted on http://networkengineering.stackexchange.com))

DETAILS: Our hosting provider has priced a scenario where NIC teaming could be done, between the server hosting our websites, and the server hosting our databases.

Tech details (in case they matter):
(1) The websites are hosted on a server running Windows Server 2008, with IIS 7.0.
(2) The databases are hosted on a server running Windows Server 2003, with SQL Server 2005.
(3) NIC teaming scenario they described would involve each of the two servers having a 10GBE dual-port NIC card, with crossover cables between.
(4) Each site has its own web.config, and its own application pool in IIS.
(5) Currently, the connection strings to SQL Server, for each website, all look exactly the same, but we could make each website use a different connection string.

HOWEVER, the hosting provider told us we will only see "bandwidth aggregation" if
(A) Our application is coded to use the NIC teaming (it is not), or
(B) Our communication goes over more than one TCP stream.

So, here's my first 2 questions... call this "PLAN A" --
(I) because our sites all have separate application pools (detail #4 above -- resulting in "w3wp.exe" appearing over 10 times, in Task Manager), would that mean we have more than one TCP stream?

(II) could there be any effective decrease in network contention -- that is, could the traffic from the different sites / different application pools travel on separate tNICs?

My third question... call this "PLAN B":
(III) If the answer to both the above is "No", then I still see a possibility of giving ONE of our sites a separate SQL Server connection string, to give it a separate NIC, or separate tNIC. Does that make sense?

It sounds like it does, if I'm understanding another post here at StackOverflow:
.NET SqlConnection NIC usage

But I'd still PREFER plan a -- automatic decrease of contention, based on separate application pools -- because I trust a NIC Teaming Solution to direct traffic in a much more intelligent way -- based on varying demand -- than it would be to exclusively dedicate a port to one site's SQL Server.

Please forgive if this is TMI... feedback welcome.

Thanks for your interest...

Answer 1

The number of application pools does not determine the number of TCP streams. Each HTTP request to your server will be a separate TCP stream, unless a client reuses an existing connection (HTTP keep-alive).

If you are experiencing network contention, using a teamed NIC should help you decrease it. You are creating another physical path to the server, but the router or switch will have to know to use it.