- This topic has 10 replies, 1 voice, and was last updated 2 years, 9 months ago by Mahmoud.
4th February 2003 at 17:07 #35039Manoj Kumar C.Guest
I am on an effort to find out a genuine formula to calculate the time needed to transfer certain amount of data (say 200MB) across a 64K leased line ( terrestrial). The formula should also include the actual delay and stuff like that. Is there any? or can you help me to find it out.
Thanks & Cheers,
Manoj Kumar5th February 2003 at 07:35 #35040Anwer JalilGuest
A leased line of 64 kilobit per second can carry 64/8 kilobytes per second for bytes consisting of 8 bits. Therefore, a file of 200MB data will take 200,000/8/60/60 hours i.e. about 7 hours. However, please keep in mind that a leased line of 64kb/s never delivers true 64k, so you should put some margin for that
Anwer Jalil5th February 2003 at 13:00 #35041Manoj Kumar C.Guest
Many Thanks for the information.
Note that in an actual scenario it took around 12.5 hours to complete this transfer. Do you think the margin should be that big?
Thanks & Cheers,
Manoj Kumar6th February 2003 at 02:39 #35042Don McKGuest
The 64kb is the speed of the data on the line and it should be a true 64kb, after all, that is what you are paying for.
You are probably using a networking protocol which places some overheads on the data, for exaple both IP and Frame relay add additional data packets (for addressing, error detection etc). You may also be using a file transfer application which does its own error detection and asks for some data to be re-sent.
This additional data is an overhead on your file, but it must be included in the total data transmitted. For instance a 20% overhead adds 40Mb or approximately an additional 84 minutes.
The transfer speed will also depend upon the efficiency of the network at either end, (getting from PC to router and router to PC) and the efficiency of the router (It may be operating at near capacity and queuing data)
There are lots of areas where delays can be introduced, it can be a very specialised task to actually find the cause and a very expensive exercise to ‘fix’ it.
Don McK1st May 2003 at 20:42 #35043ZahidGuest
One more thing I mean question in the same context, how MRTG shows the bandwidth utilization??25th July 2003 at 04:54 #35044Need HelpGuest
Appreciate it you could help me to calculate the time needed to transfer the amount of data 24KB across a 16Kbps analog line with 16Bytes CIR. Please show the geneine formula on the calculation.
Thanks in advance.10th September 2003 at 08:53 #35045MarlonGuest
Would appreciate for an answer about a calculation that I am not sure of.
I have 2Mbps leased line to access the internet.
I have a network that allows many computers to access the internet via my leased line using dial-up networking.
What is the maximum number of dial-up computers that can connect with a minimum speed of 32Kbps?
Should I just divide the 2MB to the number of dial up computers and come up with 32Kbps?
Thank you.11th September 2003 at 00:42 #35046dmckGuest
Marlon, your calculation assumes that all computers are using 32Kb continuously whilst connected to the internet. IN fact they are using the 32Kb or more for only relatively short durations (sometimes only seconds)usually during upload/download. Down loads are usually bigger files. To calculate the maximum number you need to know the average time they are downloading data and divide this into 1 hour or find the average download file size (in bits) and divide into 2M x 3600 (bits per hour).
These calcs wil more closely approximate the max number of PC’s to connect.28th October 2015 at 13:42 #35047samir p vyasGuest
how to calculate 10 MBPS leased line , If i download one file and so me as a 1280 KBPS. Then it is Correct or Not ?14th July 2016 at 07:17 #35048AjitGuest
How much bandwidth is sufficient to cater to normal internet surfing by 150 users plus uploading video data 12 cameras?6th December 2017 at 06:02 #35049MahmoudGuest
i have a daily transaction of 4GB from 200 concurrent users, so what is the leased line bandwidth i will required ?