Wireless N devices with 10/100 ethernet ports... makes sense

kunal_nba

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Aug 8, 2006
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I've been looking all this new Wireless N devices, specially Wireless Access points, as I need one for My office.

I see they come with very hi speeds, like 320 Mbps. The thing is that the WAN connector, that I would normally plug into the HUB in my LAN is a 10/100 RJ45 ethernet port..


My question is.. If I have a Wireless link from my laptop to the AP of 320 Mbps, what's the use of this if the connection to the LAN in only of 100 Mbps???

And If I connect like 5 laptops... wouldn't it make more sense for manufacturers to put a Gigabit ethernet connection??
 

Iceblue

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Sep 9, 2006
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Several things....

1) While I haven't seen the figures on 802.11n yet, all wireless to date has significantly higher overhead than wired does. The rule of thumb is actual throughput = spec'ed bit rate / 3. In an ideal set up (strong signal, no interference, etc.) you might get that up to spec'ed / 2.

Using this, then, your 320Mbps (assuming that is even real) is cut to more like ~100Mbps to ~160Mbps. That's why 802.11n is sometimes called "true" 100Mbps (compared with the 108Mbps technology's "false" 100Mbps!).

2) Wireless is a shared medium, whereas wired is a star topology. This means that if you have 4 wireless client machines all accessing the wireless with a high-bandwidth-demainding task at the same time, each client will see something more like 25 - 40 Mpbs actual throughput.

Putting it another way, 802.11n ain't no gigabit!
 

kunal_nba

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Aug 8, 2006
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So anyway.. if I just use one client for the access point, as you say I might get soemthing from 100 to 160... If I just stay next to the AP, so in this best case scenario having a 10/100 port makes the "real 100 Mbps wireless-N" device useless...