Re: WinXP and 2K: Inbound Connections Limited to 10?

From: Arkady Frenkel (arkadyf_at_hotmailxdotx.com)
Date: 02/06/05 

Date: Sun, 6 Feb 2005 14:06:24 +0200

Open few times IE and you'll see much more that 10 listening and established
sockets , I opened 20 Internet Explorers and each one have 5-6 opened
sockets without any problem ( obviously if you have enough RAM )
Arkady

"Robert Bogard" <RobertBogard@nospam.hotmail.com> wrote in message
news:OVcIG6gCFHA.956@TK2MSFTNGP12.phx.gbl...
> Thank you all for your replies. These answers (plus some more research on
> the Web) have convinced me that my server will work just fine and that
> WinXP
> and Win2k are not somehow "crippled" beyond 10 sockets.
>
> The "10 socket limit" is apparently a legal issue involving the terms of
> the
> EULA, which explains the cryptic sentence in the above links to the effect
> that the "TCP connection limit is not enforced, but it may be bound by
> legal
> agreement to not permit more than 10 clients". Since it's a licensing
> issue, Microsoft itself naturally enforces a 10-connection limit in its
> IIS
> server (which it provides for-free with non-server editions of XP).
> Microsoft might probably take the position that a program (like my server)
> that opens more than 10 connections would cause the end-user to break the
> terms of his EULA, but the OS itself would not do anything to prevent it.
>
> The "Winsock Programmer's FAQ" includes a brief confirmation that the "10
> socket limit" is a licensing issue. At
> http://tangentsoft.net/wskfaq/intermediate.html#high-load entitled "What
> platform should I deploy my server on?", it mentions the following:
> Quote:
> "A less important difference from a practical standpoint is that the EULA
> for Microsoft's workstation-class operating systems prohibit running a
> program that handles more than than 10 connections concurrently. I don't
> know of any recent version of Windows that enforces this limit in the
> kernel."
>
> As for the practical limit, the same FAQ puts it in the several thousands.
> See http://tangentsoft.net/wskfaq/advanced.html#maxsockets entitled "How
> many simultaneous sockets can I have open with Winsock?" which concludes:
> Quote:
> "...I have seen reports of a 64 MB Windows NT 4.0 machine hitting the wall
> at 1,500 connections, a 128 MB machine at around 4,000 connections, and a
> 192 MB machine maxing out at 4,700 connections. ... So, adjusting our
> "average" size down to 6 KB per socket, NT 4.0 could handle about 22,000
> sockets and Win2K about 44,000 sockets. [I think these numbers refer to
> machines with maxed-out memory]. The largest value I've seen reported is
> 16,000 sockets on Windows NT 4.0. ..."
>
> Since this is a Microsoft-sponsored newsgroup, I'm a little embarassed
> about
> asking how to get around a limit imposed by the EULA. Sorry about that.
>
> I also posted a similar question on the CodeGuru forum, which elicited
> similar responses and which you can read here:
> http://www.codeguru.com/forum/showthread.php?t=326643
>
> Thanks again for your help,
> Robert
>
>
> "Robert Bogard" <RobertBogard@nospam.hotmail.com> wrote in message
> news:ukUVY5kBFHA.4008@tk2msftngp13.phx.gbl...
>> Hi all,
>>
>> I'm trying to write a Windows-based server with a design goal of handling
>> around 150 clients simultaneously. Minimum OS would be Win2k or WinXP.
>> The
>> server would be written using pure Winsock API calls (i.e., not with
>> MFC's
>> CSocket or CAnyncSocket), TCP/IP protocol, and would be accessed over the
>> Internet.
>>
>> I'm trying to understand the significance of this MSDN KB article
>> "Inbound
>> connections limit in Windows XP" found at
>> http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B314882 .
>> According to the article:
>>
>> Quote:
>> For Windows XP Professional, the maximum number of other computers that
> are
>> permitted to simultaneously connect over the network is ten. This limit
>> includes all transports and resource sharing protocols combined. For
> Windows
>> XP Home Edition, the maximum number of other computers that are permitted
> to
>> simultaneously connect over the network is five.
>>
>>
>>
>> (There is a similar article for Win2k at
>> http://support.microsoft.com/kb/128167/EN-US/ )
>>
>> It was my understanding that this limit of 10 connections was a limit
>> only
>> on incoming connections established for the purpose of sharing resources
> of
>> the workstation (like printers and drives), or incoming connections
>> established when running Microsoft's IIS web server. Specifically, I did
> not
>> think that incoming connections established with my server would count
>> toward the limit of 10. For example, the same page cited above also
> includes
>> this:
>>
>> Quote:
>> Per development: The connection limit refers to the number of
>> redirector-based connections and is enforced for any file, print, named
>> pipe, or mail slot session. The TCP connection limit is not enforced, but
> it
>> may be bound by legal agreement to not permit more than 10 clients.
>>
>> There seems to be a few discussions on the IIS newsgroups that suggest
> that
>> my server would not be limited. For example, some have said that an
> Apache
>> web server is not limited to 10 inbound connections, even when running on
>> WinXP Home/Pro. This to me suggests that plain-vanilla inbound TCP
>> connections are not limited to 10. One example is
>>
> http://groups-beta.google.com/group/microsoft.public.inetserver.iis/browse_thread/thread/19c42d3e29d1e817/808852bccfd9fbca
>>
>> So, my question is, would my server be limited by the
> 10-inbound-connection
>> limit?
>>
>> And if so, short of specifying a minimum OS of Windows Server Edition, is
>> there any way to overcome the limit?
>>
>> Robert
>>
>> PS: Please note from the headers that I have posted this to two groups
>> simultaneously
>>
>>
>
>

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