Ds18b20 long wire problem

Hello, well I'm developing a system to get the temperature but I need put 20 sensors but the distance its too long, so I was trying with cat 5 ethernet cable, first I try with 3 sensor on each wire (using one wire) but I lost many data, so I try with 2 sensors in each wire, and I'm using 220ohm resistors but its change depending the long of the wire, is this ok or what can I do.

Put the computer closer to the data, and use some other means of transmission.

Maxim provides an appnote discussing this:

If you want better answers you should provide more detail as to your topology and how long your cables are.