# Whats the difference between CIR and normal 'shared' DSL?

DSL of most of the companies is shared with contention ratios like 1:5 etc. The 512 kbps of connection provided by LDN or PTCL costs Rs. 1200/ only and one gets average speed of 40 to 55 kBps (320 kbps to 440 kbps). Whereas a CIR or un-shared line of 512 costs more than Rs. 15,000/-. It gives constant 57-59 kBps.

I want to ask why is there so much price difference when the bandwidth diff. is only of 15-20 kBps?

If 512k normal DSL is shared among 5 users, how can each get 40+ bandwidth all day long?

Check this out for a explanation of how shared or contention ratio based connections work: http://www.wiredpakistan.com/forums/viewtopic.php?pid=1788#p1788

CIR is a committed rate which means that you have dedicated 1:1 usage of the your bandwidth i.e. 512Kbps is always available to you.

From what i understand is that a certain ammount of speed is allocated to you when you use a CIR connection hence the cost which the ISP's bear for a CIR connection is pretty high. Lets say a 512K connection costs 15000rs

In order to cut costs and make dsl more cheaper, they increase contention ratios so the same 512K dsl is now shared in lets say 8 users for example. Now the ISP can give the same speed to 8 users at the same time while in CIR they were giving only to 1 user.

Speed varies in shared connections though.. But not all 8 users sharing a connection are online at a certain time together.. Not are they all downloading at the same time together which is why speed is not divided into 8.

its kind of like water where if u and a friend pay for a bottle together u have to share it

while if u pay 4 the whole bottle urself u get to drink the whole bottle

The important thing is that in the shared connections, time gets divided not the speed. Thats why despite share ratio of 1:100 they always say its 1mbps or 512kbps or whatever the ISP is offering.

I can understand that CIR is 1:1 but others are shared, 1:5 for LDN.

But LDN 1:1 line (512k) = 17,500/-

and LDN 1:5 line (512k) = 1200/- but it should be 17,500/5 =3500/- ???????

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I can understand that CIR is 1:1 but others are shared, 1:5 for LDN.

But LDN 1:1 line (512k) = 17,500/-

and LDN 1:5 line (512k) = 1200/- but it should be 17,500/5 =3500/- ???

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Or 1200 x 5 = should be Rs. 6000 (not 17,500).

They are looting on one side of equation or (my guess is) looting on both sides of equation

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

The important thing is that in the shared connections, time gets divided not the speed. Thats why despite share ratio of 1:100 they always say its 1mbps or 512kbps or whatever the ISP is offering.
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Faisal Qureshi is spot on, its the time that gets divided not the speed, if for example an ISP has a total bandwidth of 10 MB and they have given 50 connections of 1 MB, which makes the equation 1MB for every 5 users, now not all the 50 users will be downloading to a maximum of 1MB at the same time which ultimately gives each user a decent download speed

Farhan

I am using Multinet connection 256k