Alan,
I have to agree unless the ADSL provder would guarantee you a level of QoS, unlikely, then this should never go over ADSL.
I dont know what your set up is but you could look at GRE tunnels to impliment some form of QoS
http://www.cisco.com/en/US/tech/tk543/tk545/technologies_tech_note09186a008017405e.shtml
or if you can get it you could look at a V3PN connection.
http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/V3PN_SRND/V3PN_SRND.html
But yes due to the nature of ADSL and the internet latency this should not have been promoted as a solution for an effective voice network. Even if you do add qos to the router then this will not be carried over by the ISP and will in effect be dropped, so the next step would be to look at the GRE tunnel but again this can be affected by the internet latency, though better than nothing. Suggest you speak to your supplier and let me know there solution does not work so how do they propose to sort it
You can get DSL that will have QoS that would help but from what your are saying this is not in your case. Check with whoever is providing your DSL and find out what QoS if any they can provide
Hope this helps
Paul
