A DSNDING ACR FREIGHTER WAS GIVEN A HARD ALT FOR DSCNT. LATER THE CTLR GIVES A PROFILE DSCNT CLRNC AND A RWY CHANGE AFTER THE ACFT HAS DSNDED PAST THE LOWER ALT ON THE PROFILE. WHEN ATC IS QUESTIONED AS TO WHAT ALT THEY SHOULD BE AT; THE CTLR SIMPLY SAYS TO'...CHK YOUR DME...'

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OUR FLT WAS CLRED TO 7000 FT AND DIRECT TO WATERLOO VOR FOR THE ADF RWY 6L. RWY 6R WAS CLOSED. THERE WAS NO MENTION OF A PROFILE DSCNT; WHICH WOULD HAVE HAD A XING RESTR 50 DME AT OR BTWN 12000-14000 FT FROM YYZ VOR. OUR ATTN WAS NOW ON THE ADF APCH AND A GOOD DSCNT RATE WAS ESTABLISHED TO GET DOWN AND SLOW DOWN FOR APCH. AFTER DSNDING FROM FL240 AND PASSING 15000 FT (APPROX) CTR CLRED US FOR PROFILE DSCNT RWY 6R ILS (RWY CHANGE). I MADE SEVERAL ATTEMPTS TO TELL TORONTO CTR OUR SIT. WE LEVELED OFF AT 10500 FT. TORONTO EVENTUALLY ANSWERS (SARCASTIC); LOOK AT YOUR DME. (WHICH ONE?) I REPLIED 59 DME FROM YYZ VOR. TORONTO REPEATS THIS. LOOK AT YOUR DME. I THEN SAID; WE ARE AT 10500 FT; WHAT ALT DO YOU WANT US AT. TORONTO SAID 12000 FT. 12000 FT WAS OBTAINED AT APPROX 50 DME YYZ. OBVIOUSLY TORONTO WAS NOT CONCERNED ABOUT OUR ALT. THE ATTITUDE OF THE CTLR SHOULD HAVE BEEN THAT OF RESOLUTION OF THE SIT INSTEAD OF MAKING GRAY REQUESTS; LEADING TO CONFUSION AND EXTREME CONCERN. CAUSE: THE DSCNT CLRNC WAS GIVEN WITHOUT THE EXPECT OR ACTUAL CLRNC FOR THE PROFILE DSCNT WHICH THEN PUT THE CREW IN THE APCH PHASE MINDSET WHICH PRECLUDED A GOOD DSCNT RATE TO PREPARE FOR AN ADF APCH. PREVENTION: A CLRNC BELOW THE PROFILE DSCNT ALT SHOULD BE GIVEN WITH THE CLRNC TO FLY THE PROFILE DSCNT; NOT SEPARATE AS IN THIS CASE. THE PROFILE DSCNT SHOULD NOT BE GIVEN SO CLOSE TO THE APCH PHASE; COMPOUNDED WITH RWY CHANGE AND ESTABLISHED IN A GOOD DSCNT RATE. THERE WAS OPPORTUNITY WITH THE DSCNT RATE CAPABILITIES OF THE B727 TO HAVE BEEN LEVEL AT 7000 FT BEFORE THE PROFILE DSCNT WAS GIVEN IN THIS CASE. SUPPLEMENTAL INFO FROM ACN 407749: AT 10500 FT WE FINALLY GOT HIM TO SAY HE WANTED US AT 12000 FT/50 DME YYZ. WE WERE APPROX 53 MI AT THE TIME. I IMMEDIATELY CLBED BACK TO 12000 FT. NO STAR WAS ISSUED OR 'TO EXPECT' SO NONE WAS BRIEFED. ACFT BEHIND US WERE GIVEN THE STAR WHILE STILL AT ALT. CLRNC SHOULD HAVE BEEN MORE SPECIFIC WITH HIS QUESTION 'CHK YOUR DME;' SINCE WE WERE ALREADY CLOSE TO THE LIMIT AND OBVIOUSLY GOING TO 7000 FT. NOT ANSWERING US LED TO CONFUSION. CLRING US FOR A PROFILE DSCNT WHEN WE HAD ALREADY BEEN CLRED BELOW; THE FIRST LIMIT POINT WAS WRONG. NOT ANSWERING OUR QUESTIONS IN A TIMELY MANNER CONTRIBUTED TO THE DEV.