Date: Tue, 01 Mar 2005 23:04:52 -0800 From: Christopher Kelley <bsd@kelleycows.com> To: Bob Johnson <bob89@wb4jcm.org> Cc: freebsd-questions@freebsd.org Subject: Re: Does 802.11b use a lot of resources? Message-ID: <42256594.8040008@kelleycows.com> In-Reply-To: <200503020126.46489.bob89@bobj.org> References: <421EB26B.5050608@kelleycows.com> <200503020126.46489.bob89@bobj.org>
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Bob Johnson wrote: >On Friday 25 February 2005 12:06 am, Christopher Kelley wrote: > > >>Have I tried too hard to squeeze usability out of an old computer? >> >>I have a Pentium-166 that has been a faithful router & firewall (FreeBSD >>5.3 and pf) for a couple years now. It has no trouble with the 3 to 4 >>Mbps I get from my broadband connection, at least not with ethernet. >> >>I wanted wireless, so I could use my laptop around the house. I >>dutifully read the section in the manual about setting up FreeBSD as an >>access point. I'm using a Netgear MA311 802.11b card (Prism 2.5 >>chipset). And it does work, except it's very slow. Now I know that I >>can only expect about 50% of the rated speed with wireless, but I >>figured even if I got only 4Mbps, I'd be fine. But I get less than >>1Mbps. I've updated the firmware, added a signal booster and hi-gain >>antenna, and I have "excellent" signal strength throughout my house. >> >>So my question is, is there more overhead with wireless than with >>ethernet? TOP doesn't seem to show that I'm taxing it too hard, idle >>never goes below about 70% with polling enabled (Hz=1000), and never >>below about 80% with polling disabled. Am I expecting too much out of >>an old Pentium-166? >> >> >> > >My experience is that: > >1) 50% throughput is probably the best you should expect. I generally plan on >3-4 Mbps for an 11 Mbps 802.11b card. > >2) Using 128-bit encryption (WEP) will significantly slow down some (many?) >cards. The WEP processing is done on the card (I think), and they simply >don't have hefty processors. If you use 128-bit WEP, try 64-bit WEP and see >if that speeds things up. 64 bit WEP is adequate to keep out casual >snoopers, and 128 bit is not adequate to keep out a serious attacker, so the >difference in security may not be as important as some believe. 64-bit WEP >is also known as 40-bit, and similarly for 128-bit WEP. > >3) Turning on power management seriously slows things down for me, to well >below 1 Mbps. Do a "wicontrol" and make sure Power Mgmt is "0". > >- Bob > > > > Well, 3-4 Mbps would be fine, as that's about what my broadband runs at anyways. At the risk of being pedantic, when you say 3-4 Mbps, do you mean including overhead or not? In other words, if you use say the bandwidth tester extension for firefox, would you expect to see 3-4 Mbps, or rather somewhat less than that due to overhead? I realize it may seem a stupid question, I just want to make sure I'm comparing apples to apples. Just for testing, I turned off WEP completely, and verified that power management was off. No change. Drat. Now I am wondering if it's very firmware sensitive. I'm using Primary 1.1.1 and Station 1.8.0 - I guess I could "downgrade" the firmware to either 1.3.4 or 1.4.9 - I had figured that more recent would be better, but now I'm wondering. The man page is 2 years old, though, so I don't know what versions were actually available when it was written. Thanks for your help, I really do appreciate it, even if it doesn't actually "solve" my problem. Christopher.
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