I want to know that the DSL with 8 Mbps speed and DSL with 12 Mbps speed will work smoothly with copper wire if the quality of copper wire is good?
You need Line Statistics from your router to determine that with:
- Attenuation (determines max rate limit): It denotes signal degradation over the length of the line ... if you have shorter line length (you live closer to the exchange), you'll have low attenuation and if you have longer line length, you are likely to have higher attenuation
- SNR Margin (determines stability): This signifies the margin of safety you have per your attenuation for the sync rate before you start getting errors and start suffering disconnections ... normally ISPs keep sync rate and bandwidth separate with some sort of dynamic line management that automatically lowers sync increasing the margin of safety in case of noise but PTCL likes to limit your sync to your bandwidth or connection speed ... anyways 6dB of margin is considered as minimum for stability and the higher it is the better the stability is going to be ... keep in mind that the Noise tends to be random and the Margins may change over time!
Given the mostly older copper lines and poor infrastructure (lines going across roads), PTCL has implemented FTTC (you still get to have copper wire at home) and offers "Fiber/ONU" connections in order to help those with noisy lines (and offer faster connections to the lucky few who have a good line) ... if your area exchange offers this type of connection, you may go for it though there are problems with this type as well (search the forum) or you may try to get a better line pair if you are stuck with copper and your line isn't good enough (very tough to get one)!
So, you have to post your stats if you already have a connection and a router/modem of course!
Here are some (under optimum conditions) speed calculators: