On Tue, 2005-02-22 at 13:47 +0530, Ashwin Mansinghka wrote: > >> Hi, > >> > >> Does this mean if I go for a 2Mbps line for my business then also i will > >> get the 30-80 kbps > > If you are talking about Download speeds as against available bandwidth, I > > guess you are making a very small mistake with your calculations. When an > > ISP > > gives you a 256K connection, they are giving you a 256 kilobits per > > second(Kbps) connection = 32 KBps(Kilo Bytes per second) 8bits=1 Byte, > > remember?? There isnt anything wrong with the connection..Not as of now at > > least. > > There are others on the list, who would disagree with 8b = 1B. Why ? Because > Andrew Tannenbaum says so.......they are of the view that 10b=1B as per the > popular author. Indians are known for their strong (blind) believes and > faiths ;)
You are forgetting error correction codes. :) Besides, 8 bits = 1 byte inside computers. 10 bits = 1 byte worth of data for networks other than LANs. It's kinda like 1024 bytes = 1 Killobyte for RAM and 1000 bytes = 1 Kilobyte for hard disks :) That's the way the world works. Incidentally, before you start berating Prof. Tanenbaum, I'd like to inform you that he's a fellow of the IEEE, the standards body that is responsible for creating standards like the Ethernet (I forget the working group), WiFi (working group 802.11) and WiMax (802.16). > Well it is a different thing that the same author talks about his experience > with serial connections where start and stop bits are relevant i.e. 8+2 = 10 > (2 bits are signalling overhead) and the same are not relevant in case of > other media types like DSL / ISDN etc. As an example when we use 2 channels > on ISDN we mention 128kilobits/sec but actually it is 144kilobits the > remaining 16kilobits is for signalling. > 256kilobits is the bare channel payload i.e. when spoken in bytes, the bare > channel payload is 256 / 8 = 32 Kilobytes. Now each IP packet will have its > overhead, which comes to around 11% to 12% in general i.e. actual data will > be about 28 Kilobytes (as shown by an Internet Explorer download or FTP > download). I thought I mentioned the words "thumb rule". Not many people have access to the equipment that you have, so not many people have the ability to measure data transfer speeds as accurately as you can. > We need to understand the speeds being measured at different levels of the > Network stack ....... physical , datalink , network > layer.........application and the resulting overheads being stripped off. As > the complete packet with all layer overheads enters the bare pipe only upto > the capacity offered by the pipe and occupies the full space. On reaching > the destination the same packet is stripped off the headers as it climbs > through the respective layers till we see the application layer data, now we > as users generally do not tend to look below the application layer and > therefore we get confused and misguided. Well said ! > Wait there is a catch, the 2Megabits may not be 2Megabits. There are options > of compression which when enabled to lower per month rental can make the > 2Megabits to a trickle of 128kilobits i.e. a compression of 1:16 especially > at peak hours. Becareful of what you choose as tariff. Didn't quite understand what you mean. Your previous post threw a lot of jargon at us (me ?). Let's not get into the technicalities of leased lines vs. dsl vs. the god-knows-what-technology used in DIAS. Since this is a thread with DSL as its focus, let's keep it that way. -- Soumyadip Modak [EMAIL PROTECTED] [EMAIL PROTECTED] http://soumyadip.blogspot.com -- To unsubscribe, send mail to [EMAIL PROTECTED] with the body "unsubscribe ilug-cal" and an empty subject line. FAQ: http://www.ilug-cal.org/node.php?id=3
