--- aditya newalkar adityanewalkar@yahoo.com wrote:
Hi, I read in the COMPUTERS magazine published by IEEE society that there is a raging debate in the world about the broadband access and the touted speed.
According to what I read (and what I recollect) is : broadband at a times can get slower than dialups. This is a fact. So if one is constantly experiencing 8-10KB/s it is possible in the future that he/she will be experiencing 1/2KBps if ALL the users in the area log on simultaneously.
That is because all these systems use shared bandwidth, which is linearly distributed among users unless someone does traffic engineering.
Second question that jumps into my mind is that WHY PURCHASE CABLE MODEMS?? These cablewallahs are giving u access thr. LAN cards worht 900-700 rs. why go for 15000/- cable modem. Will the cable modem boost the speed. Can anybody throw light on this as I am very weak at fundamentals of networking.
Actually, the cable modem is the interface to the broadband CATV connection. The cable modem extracts the data off the CATV line and converts it into ethernet baseband mode, which can then be fed to a client's ethernet card. If instead you feed the output of a cable modem to a hub/ switch (directly if the operator has assigned enough addresses, or through a NAT/ proxy if not), then multiple people can access it.
This should not be a problem even using 10 MBPS ethernet, since the maximum limit of a cable modem connection is only about 6 - 8 MBPS. The reality is that most cable modem operators have back-end bandwidths of 2 MBPS (one E1 line of 2.048 MBPS) - at least, this is the information I got from the InCablenet guy. Divide this by 500 users, and you get (2*10^6/500) = 4 KBPS per user. This is not a lot of bandwidth. However, things are actually a little better than this, because there is the question of the duty cycle - not all users are logged on all the time, and not all of those logged on make access requests simultaneously. Hence, we can generally expect an average load factor of about 30%, so that you can expect a bandwidth of around 10 KBPS normally - unless a lot of people decide to get online simultaneously. Therefore, a 10 MBPS Ethernet connection can very well be shared among a number of people,with no deterioration in the bandwidth.
HTH,
Krishnan
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