Có giới hạn về số lượng thiết bị mà một bộ định tuyến có thể xử lý đồng thời không?

I am going to buy a new router, but I have just realized that for nearly all the routers I have looked at (Belkin, Netgear, D-Link), they do not state the maximum number of devices that can connect concurrently.

I have a D600 and have looked on their website, through the manual, and also found no mention of the limit (which I really need to know if there is one due to debugging another issue).

The new router will be a gift for a friend. The issue is, they have 12 devices in their house, all of which require Wi-Fi, and another 3 devices which will be hard wired.

Since the router websites do not mention any limitations, can I assume there is a general limit on what the number of concurrently connected devices can do? Or is the issue more about understanding that, the more devices that are connected, the worse the performance will be due to the sharing of the resource?

My question is, without physically trying it, is there any way to know that a certain device will work with a given number of concurrently connected devices?

I do not think there is a limit to the number of devices that can connect. It would make more sense that most routers are limited by their hardware, and will experience performance degradation as the number of devices increases.

This I suppose, largely depends on the speed of the router’s CPU and available RAM, but it would also largely depend on the services running on the router, i.e. is NAT enabled, QoS, VPN, access control, is wireless open or password protected, etc. I think the amount of traffic that devices create is also an important factor to the limit.

I think this might also be the reason why manufacturers do not specify the number of devices that can connect, because it depends on many factors.

There is a (theoretical) absolute limit of 65,535 concurrent connections. When using SNAT or MASQUERADE, that is. As such, the maximum feasible number of devices would be somewhere near 800, to account for closing and opening connections.

Naturally, this would require a network larger than /24, which poses no problem with OpenWrt and the like. Still, the connection tracking load would be quite high.