Hi all, I had asked this question in Microsoft Answers Forum and was redirected here for a more "Pro" audience. The summary of the problem is that I am having issues connecting more than 16 nodes in a Windows 7 ad hoc network. Does anyone know if there is a limit on the number of nodes that can join a windows 7 ad hoc network? Now for the details: I am using Windows 7 Ultimate version, but not on all the machines. Some of them have Windows 7 Professional. When I create the ad hoc network and start joining nodes, everything goes smoothly until 16 nodes are joined to the same network. When the 17th node is connected, it can only talk to the the original node that started the ad hoc network and not to the other 15 nodes already in the ad hoc network. When the 18th node is connected, it connects fine, get the IP address (static) but is unable to send or receive any data. Wireshark reveals that it is only able to receive broadcast data but no unicast data is sent or received. And the behavior is same for any more nodes that are connected to the network. When one of the first 16 nodes leaves (disconnects from) the adhoc network, the 17 nodes starts working fully and 18th node can now connect to the parent node. What this suggests is that somehow windows 7 limits the number of nodes in the network. Do not know how or why. Please share your experience if you have had success or failure with windows ad hoc network using large number of nodes. Yes! there is a reason why I want to put that many nodes in a ad hoc network. Yes! I understand that "typically" an AP is used to in such scenarios. Nonetheless, I still have a use case for this scenario. Explanations, suggestion, testing scenarios, thoughts are all welcome! Fixes would be great too...

The issue is not related to Windows 7. You need to check the configuration of the AP. Configuring a Wireless Access Point http://www.dummies.com/how-to/content/configuring-a-wireless-access-point.html The issue should be caused by limitations from the AP configuration. For detail instructions, please refer to the manual from the device manufacturer, or contact the support.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Yikes Arthur!I thought I made it clear in my posting that I am NOT using an AP. Perhaps I was not clear. So let me clarify. I am using an ad hoc network created through Windows 7 utility: http://www.dummies.com/how-to/content/how-to-set-up-a-wireless-ad-hoc-network.html So, the problem is with the way Windows 7 networking administers and manages an ad hoc network.

John980 wrote: Yikes Arthur!I thought I made it clear in my posting that I am NOT using an AP. Perhaps I was not clear. So let me clarify.  I am using an ad hoc network created through Windows 7 utility: http://www.dummies.com/how-to/content/how-to-set-up-a-wireless-ad-hoc-network.html So, the problem is with the way Windows 7 networking administers and manages an ad hoc network. Although I don't know of a documented limit for an ad hoc network via WLAN there could pretty well exist such a limit as it it quite complicated to get more than 16 PCs physically arranged in such a way, that all PCs can reach each other over the air. BTW it could be also a limit of the WLAN card as they would have to maintain 16 different connections concurrently on each PC that makes altogether 256 different connections. Wolfgang

Actually a Windows ad-hoc wireless network consists of up to 9 wireless clients. Configuring Windows XP IEEE 802.11 Wireless Networks for the Home and Small Business http://technet.microsoft.com/en-us/library/bb457016.aspxPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

I had come across the link you posted previously. I am not sure why there is a limit (and why that is set to 9) in Windows XP. I was hoping that Windows 7 would not have that limitation. I guess it still does, but the limit has been changed to 15 because I am able to successfully connect 15 nodes. All guesses at this point. The problem is that this all seems very vague. There is no clear documentation (and no documentation for windows 7 whatsoever) on the ad hoc network limit. There is no fundamental reason for limiting the number of nodes in an ad hoc network. There are working systems with hundreds of nodes using other operating systems. Of course, the throughput could go down with increasing number of nodes, but that is a performance issue. Wish this thread would garner attention from someone in Microsoft who actually knows this particular issue.

Wolfgang, The problem of wireless connectivity between the devices is irrelevant to the limit I mentioned. For the record, it is not at all a problem to place more than 16 nodes so that they can hear (transmit and receive from) each other. As to your second point, while it is possible that the WLAN card driver implementation may have some limitation, wireless connectivity is asynchronous by nature. There are no physical or logical connections to maintain. Unless I misunderstood your comment.