[Dprglist] Roborama & wireless networking

[John Swindle]

Folks,
 
Maybe the connectivity problems at Makerspace are limits in the routers.
 
Routing table limits:
 
I have a grid of more than 30 PCs searching for some interesting numbers. I've discovered that Linksys routers have hard limits of no more than 32 connections, regardless of the size of the DHCP table. The 32 connection limit is not in any documentation, but it's easy to prove by disconnecting one client and trying to connect another client. The router itself is one of the addresses, leaving 31 for me to use, and I need lots more connections. It seems that the limit is due to the size of the MAC routing table in the router.
 
DHCP limits:
 
At Makerspace, even with multiple routers connected to the same Internet connection, a low limit may have been set on the number of addresses that DHCP can hand out. Even if that limit is high, there is nevertheless a hard upper limit which I expect would be exceeded when each gadget (robot, tool, IoT thing) is using several addresses.
 
Even if DHCP isn't the limiting thing, I think its dynamic behavior could be disrupting connections. The routers try to hand out addresses that match what a host had previously, but that information is in a cache in the router, and it's going to thrash when there are lots of temporary connections.
 
The above are problems I've had to deal with in my little grid.
 
Having said all that, if the problems were occurring with your own access points, then it's a channel problem. Everyone shouting and no one can hear.
 
Question:
 
What consumer-grade (cheap) router do you recommend that allows for, say, 100 connections? Every time I see this question online, people jump in and say there is no answer, and that it depends on the traffic. Not so. Routers have HARD limits in them (as I've learned), and I want one that has a higher hard limit.
 
As to the traffic: My grid is exchanging about a dozen bytes per CPU core (not GPU cores) per fifteen minutes, so there's almost no traffic, regardless of the number of connections.
 
Sorry I missed Scott's presentation and the competition earlier. I've been traveling.
 
Best to y'all,
John Swindle
 


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