> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Tim Daneliuk > Sent: Saturday, September 08, 2007 2:01 PM > To: RW > Cc: freebsd-questions@freebsd.org > Subject: Re: ADSL Bandwidth Monitoring > > > RW wrote: > > On Sat, 08 Sep 2007 15:27:38 -0500 > > Tim Daneliuk <[EMAIL PROTECTED]> wrote: > > > >> Amitabh Kant wrote: > >>> On 9/8/07, Bahman M. <[EMAIL PROTECTED]> wrote: > >>>> I tested the connection by downloading 2~3 files simultaneously > >>>> and used 'bmon' as Mel suggested in another reply (thanks to > >>>> him). As I'd already guessed the RX don't get bigger than 30~40% > >>>> of the expected bandwidth. I performed the test with some other > >>>> files and there was no difference. > >>>> > >>>> Thanks, > >>>> > >>>> Bahman > >>> The bandwidth being advertised by your ISP would be the maximum > >>> thoughput allowed on your DSL lines with multiple DSL users sharing > >>> the same bandwidth, something that is generally known as contention > >>> ratio. > >>> > >>> See this link: > >>> http://en.wikipedia.org/wiki/Contention_ratio > >>> > >>> Amitabh > >> But you should be able to hit the advertised bandwidth. To the best > >> of my knowledge, DSL itself is NOT a shared medium. It is a point-to- > >> point technology from your premise to the Central Office. The > >> bandwidth *behind* the CO may be shared, but should be so large > >> as to not be a bottleneck. > > > > It depends on your circumstances. Some people are constrained by > > contention ratio some aren't. Some ISPs offer a better ratio for a > > more expensive accounts. > > I don't understand this. If the actual DSL circuit is point-to-point - > i.e., not shared between the premise and the DSLAM in the CO, just > exactly *where* is the contention occuring?
Inside the ISP's router. However even cheap ISP routers you can buy off Ebay for a couple grand have enough bandwidth to route between multiple 100BaseT connections. For example the 7206 has 2 800Mbt backplanes. That would mean you could run 500 1.5Mbt DSL customers at full bore to a server on your local network before contention would set in. And an ISP with that many customers can afford a more powerful router than a couple K used 7206. The upshot is his ISP doesen't know how to troubleshoot DSL. Ted _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
