Internet downlink/uplink confusion


#1

I am all confused right now. Telephone exchanges are connected for DSL with how much speed, 2Mbps, 4Mbps? Same goes for University these days which have been connected by HEC's project.

What I don't understand is that if the exchange is getting 2Mbps, how many users of say 2Mbps will that exchange support? If a user subscribes for a 2Mbps package, shouldn't that finish up all that 2Mbps which exchange is getting. This does sound silly I know but I want to know what exactly do they do that their exchange link is say 2Mbps and they can provide DSL to hundreds of users with good speed, including 2Mbps users. I know the share ratio thing exists but PTCL users have reported constant downloading speed most of the times.

This example fits on my brother's University as well. They have hooked the Uni up with 2Mbps. They get a constant download speed of 120-180 KB/s on the computers there. How is it possible? For a home user, 2Mpbs would result in a speed of 200+ KB/s, for a single computer downloading stuff. Why isn't it the same case with them?

A list of Universities and the speed of Internet they are hooked up with!

http://www.pern.edu.pk/status_reports/PERN_status.htm


#2

in ur bros university he isnt gettin speeds in 200 KBps coz remember the whole university is sharin the connection so that is why gettin full speed of a 2mbit connection is really hard


#3

Another thing I want to know is this, the share ratio, how is it implemented. Is it implemented on basis of individual speed/package? i.e.

512kbps user will share the connection with FIVE 512kpbs users

1024kbps user will share the connection with FIVE 1024kbps users

2048kbps user will share the connection with FIVE 2048kbps users

Correct?

How do they implement it? i.e. 3 users subscribe for 512kbps connection, those 3 users are put on the same place, sharing one slot each of 1:5, or they get three different to themselves, i.e. User 1 is put on 1:5, User 2 on another 1:5 and User 3 on another 1:5, and later on when more users subscribe, they are given place with either of the 3 above. This way would make sure users get good speed all the time since they'll be distributed equally across all available slots instead of congestion, or this way is not used? and they stack up users with each other on the same port?


#4

[quote=", post:, topic:"]

in ur bros university he isnt gettin speeds in 200 KBps coz remember the whole university is sharin the connection so that is why gettin full speed of a 2mbit connection is really hard
[/quote]

Computers in library, most of them are used by students and teachers to download torrents etc. lol and getting 120-180 KB/s speed in such situation is not bad at all.

I understand in case of University. I’ll just consider it same as home connection being shared, what is there behind the Exchange link? How do they manage it?


#5

[quote=", post:, topic:"]

Another thing I want to know is this, the share ratio, how is it implemented. Is it implemented on basis of individual speed/package? i.e.

512kbps user will share the connection with FIVE 512kpbs users

1024kbps user will share the connection with FIVE 1024kbps users

2048kbps user will share the connection with FIVE 2048kbps users

Correct?

How do they implement it? i.e. 3 users subscribe for 512kbps connection, those 3 users are put on the same place, sharing one slot each of 1:5, or they get three different to themselves, i.e. User 1 is put on 1:5, User 2 on another 1:5 and User 3 on another 1:5, and later on when more users subscribe, they are given place with either of the 3 above. This way would make sure users get good speed all the time since they’ll be distributed equally across all available slots instead of congestion, or this way is not used? and they stack up users with each other on the same port?

[/quote]

yes it is based on the speed of the package

the way it is implemented is that a certain amount of bandwidth is alloted to a specific pool of 5 ppl

eg 600 Kbps is alloted to 5 ppl usin 512 package so that there is some bandwidth left for the other users if one of them is downloadin


#6

[quote=", post:, topic:"]

Computers in library, most of them are used by students and teachers to download torrents etc. lol and getting 120-180 KB/s speed in such situation is not bad at all.

I understand in case of University. I’ll just consider it same as home connection being shared, what is there behind the Exchange link? How do they manage it?

[/quote]

home connections arent managed in the same way in home connections there is some spare bandwidth in a pool so thats is why everybody gets good speeds


#7

^ Want to know about exchange. I mean if an exchange is getting 4Mbps, if its same as home/universities, should it not run out after FOURTY 512kbps connections? i.e.

4096kbps/512kbps = 8 x 5 (share ratio) = 40

???


#8

For example, http://www.ptcl.com.pk/contentb.php?NID=75

Now what's the difference between 2Mbps users can get for Rs.5,000/- (on copper or fiber line through local exchange) and 2Mbps for $2000 per month which Call Centers/ISPs get? Just assume there's no share ratio for usual customers and the customer at home is getting a good constant speed on 2Mbps.

Will that speed be same as the one that call centers get for $2000???


#9

[quote=", post:, topic:"]

What I don’t understand is that if the exchange is getting 2Mbps, how many users of say 2Mbps will that exchange support?
[/quote]

What makes you think that your local exchange is only getting 2Mbps ?


#10

[quote=", post:, topic:"]

For example, http://www.ptcl.com.pk/contentb.php?NID=75

Now what’s the difference between 2Mbps users can get for Rs.5,000/- (on copper or fiber line through local exchange) and 2Mbps for $2000 per month which Call Centers/ISPs get? Just assume there’s no share ratio for usual customers and the customer at home is getting a good constant speed on 2Mbps.

Will that speed be same as the one that call centers get for $2000???

[/quote]

those are dedicated connection and on those connections there are nbo fluctuations or speed drops u will get solid 2 mbit speed at all times


#11

^^ I don't know how much the Exchange is getting. If anyone can tell how much they give to an exchange, shall be thankful

^ ruhaan, so no speed difference other than it being without any fluctuation?

Thanks for replies :)


#12

[quote=", post:, topic:"]

^^ I don’t know how much the Exchange is getting. If anyone can tell how much they give to an exchange, shall be thankful

^ ruhaan, so no speed difference other than it being without any fluctuation?

Thanks for replies :)

[/quote]

well in pakistan most ppl dont use their connections to the max but if u were to be in a pool in which there was a person who downloaded alot then there wud be a speed diffrence but mostly there isnt much speed diffrence