Halboffene Verbindungen unter Win7

Dabei seit
Juni 2007
Ich habe mir heute als Betriebssystem Windows 7 aufgespielt.

Nun ist ein Porblem aufgetaucht, dass ich seinerzeit schon bei Windows XP hatte.

Vuze / Azureus läuft nur sehr zögerlich bis langsam. Das hängt mit der Limitierung der
halboffenen Verbindungen unter Windows zusammen.

Der wurde seinerzeit bei Windows XP ab ServicePack2 auf 10 Verbingen limitiert, konnte aber mit diversen Patches wieder aufgehoben werden. Da lief mein Azureus ohne Probleme.

Jetzt unter Win7 habe ich wieder eine Limitierung von 10 Verbinungen und mein Azureus knickt ein.

Suche nach einer Möglichkeit unter Win7 (64bit) die Limitierung aufzuheben bzw. heraufzusetzen.


Lt. Commander
Dabei seit
Sep. 2008
Ähm, es handelt sich um ein Bittorrent App, wenn du denkst das man da nur illegale Sachen lädt, weiß ich nicht wo du die letzten Jahre verbracht hast...



Da ist alles erklärt.


Edit Nachtrag:

Real answer: It was never about limiting the number of connections. This mechanism used to limit the number of "half-open" TCP sessions in an effort to slow the propagation of malware from infected machines.

A TCP session between any two machines starts off with what's known as a "3-way handshake", even though there's only two machines . The name stems from the 3 packets required to "establish" the session:

1) Initiator sends a SYN packet informing the target of its intention to communicate and its own "synchronisation" sequence number offset.

2) Target responds with a SYN-ACK letting the initiator know that the first packet has been received ("acknowledged"), and informing the initiator of its own starting sync offset.

3) Initiator responds with an ACK, thereby completing the handshake sequence.

After all that, the session is established and the two sides can send information to each other until they decide to tear the session down.

A "half-open" session is one where the initial SYN (step 1) has been sent, but no response has yet been received. In other words, there's nothing yet to indicate that the target is willing to talk to us, or that it even exists on the IP/port that the SYN was sent to.

The "half-open" throttling mechanism used to limit the number of those not-yet-fully established sessions to a maximum of 10 at any time, because MS (rightly) felt that anything more constituted burst-type activity which was likely associated with malware trying to spread itself as fast as possible.

Given a latency of say 100ms, malware which is throttled in this way will spread much, much slower than if it's completely unbridled and able to initiate thousands of concurrent half-open sessions in an opportunistic fashion (fire off a crapload of SYNs all at once and just work with the targets which respond).

While the vast majority of legit applications don't behave in this manner, the two notable exceptions were torrent clients (stretching the definition of "legit" of course) and server-style apps which some companies ran on Windows clients to decrease their licensing costs. Torrent clients would sometimes bump up against the 10 half-open limit, and that would cause a scary-looking event to be logged. Many torrenters ended up "patching" the TCPIP.SYS driver in an attempt to knock out the throttling mechanism, and that brought problems of its own in the form of BSODs and similar issues.

In the end, I guess MS decided the level of additional security didn't warrant the additional chaos caused by driver patchers and the flak they were getting in the press, and hence decided to remove the mechanism as of Vista SP2.
Quelle: http://www.sevenforums.com/368470-post14.html

Das Tool ändert afaik immernoch Registryeinträge in Win7 ab, und wenn die Torrent Clients bei dir nicht laufen würde ich sagen "give it a try"
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