enabling and disabling trellis codding at cisco dsl router command

[zahid77]

well i have a cisco dsl 800 series router. I configred it properly but unable to get the link properly. The line is working fine. What somebody told me that u need to play with trellis codding. but i am unable to find any coomand which can disable or enable the trellis codding..any body can help me regrading this. I attach the sh run of the router. thanks

[r-simpson]

Enabling this attribute allows trellis coding to be used in both upstream and downstream directions. If neither the modem supports trellis coding, the link will revert to no trellis coding (i.e., trellis coding must be used in both directions if it is to be used).