A deep dive into why Wi-Fi kind of sucks

Post by scurvy » Tue, Mar 07, 2017, 4:11 AM UTC

hchenji wrote: post #175

dboreham wrote: post #141

Earlier quoted context omitted.

Do today's wired networks (1G+/FD/Cat6/fiber) still use CSMA/CD? I was under the impression that they don't.

No, since wired networks are full duplex and are their own collision domains. No need to do carrier sensing at all.

Not entirely true. You can run half duplex gigabit connections on hubs. Not sure why you would, but you can. IEEE 802.3 covers all Ethernet standards and it still lists CSMA/CD. Largely for historical purposes, but it is in the spec.

Starting with 10gig, full duplex is required so that was the first IEEE speed that did away with CSMA/CD.

Post by scott_karana » Tue, Mar 07, 2017, 10:21 PM UTC

fulafel wrote: post #144

olivierlacan wrote: post #4

This article should be read by everyone working in open space offices across the world expecting to get decent speed and reliability out of Wi-Fi with more than a dozen people in a single room. An open space office (or any office) for a company that depends on the Internet for any of its work without Gigabit Ethernet cables sticking out of every workstation is pretty damn foolish.

5 GHz has plenty of non-overlapping channels (24?), so in this situation you can use multiple APs in different room corners set to low power.

Only if the other floors in your building aren't doing the same thing. Which is exactly why this approach is no longer viable with 2.4GHz. ;)

Re: A deep dive into why Wi-Fi kind of sucks

Re: A deep dive into why Wi-Fi kind of sucks