Some ADSL questions.

[Mars]

So I been poking around in routers and I've been seeing the same terminology over and over.
I realised that I don't know what all this means, or how to set these things effectively.
Please can someone(s) enlighten me.

ATM/PVC - Asynchronous Transfer Mode Permanent Virtual Circuit.

It seems on my current router I can have up to 8 of these. Would I use this to switch between accounts?

VPI/VCI Virtual Circuit Identifier, Virtual Path Identifier

These can only be set to 8/35, is that correct?

PCR/SCR/MBS PCR Peak Cell Rate, Sustain Cell Rate and Maximum Burst Size

4000/4000/10 - is it possible to tweak these settings, and what difference would it make?

MTU Maximum transmission unit

mine is set to 1492. How would you determine whats best for you line?

 

[Roman4604]

Nothing really for you to tune. These parameter are set by the network operator on the DSLAM and your ADSL device just needs to match them.

The top 3 parameters are a carry over from ADSL's design origins, which were based on the (then prevalent) ATM protocol. Modern DSL is based on Ethernet (or IP) backhaul so ATM's cell relay technology is only used between the client device and the DSLAM.

That said much of Telkom's ADSL access network is still based on ATM backhaul, but that still doesnt mean theres anything you can really optimise.