Date: Sun, 9 Sep 2007 22:35:23 +0100 From: RW <fbsd06@mlists.homeunix.com> To: freebsd-questions@freebsd.org Subject: Re: ADSL Bandwidth Monitoring Message-ID: <20070909223523.55df5779@gumby.homeunix.com.> In-Reply-To: <BMEDLGAENEKCJFGODFOCAEGACAAA.tedm@toybox.placo.com> References: <70e8236f0709081933k5f2352d2y389c6e2bb7599b16@mail.gmail.com> <BMEDLGAENEKCJFGODFOCAEGACAAA.tedm@toybox.placo.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sat, 8 Sep 2007 23:16:35 -0700 "Ted Mittelstaedt" <tedm@toybox.placo.com> wrote: > ... > However, the thing that most people (who don't work at telcos) do not > understand is that the telcos found very quickly that they cannot put > contention into an ATM network comprised of a DSL atm circuits for a > very simple reason. > > ... > SO, the cost of discarding a single 56 byte ATM cell means the ATM > cloud will have to get another 1400 bytes of data retransmitted > through it. > > It doesen't take a rocket scientist to see that introducing contention > into an ATM circuit carrying a DSL circuit will cause a massive > increase in traffic in the switch, and wipe out any gains from > contention. I don't know much about DSLAMS, but ATM switches have been able to drop whole AAL5 frames for a long time. Do DSLAMS really not have EPD/PPD? However the contention is done, it definitely happens in the UK.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070909223523.55df5779>