Narrative:

We were level at FL360; and had been for a while. About 120 mi east of the crl VOR on J554; we received a frequency change to ZOB on 120.07. I switched over; and noticed the frequency was busy. The WX was clear where we were; but apparently there was a lot of deviating traffic near cle. My first check-in went unanswered; so I figured the controller was busy. I waited 30 seconds or so and tried again; but got no answer. I waited 30 or 40 seconds to try again. Just after my third check-in attempt; which went unanswered; we received a TA on opposite direction traffic about 12-15 mi ahead; +500 ft and descending. At about 9 mi; we received a climb RA of at least 1500 FPM. At that time; the traffic was about +200 and still descending. We disconnected the autoplt and complied with the RA. I called ATC and reported we were in a TCAS climb; which still went unanswered. It happened very quickly; and I estimate that at the 5 mi point; there was about 1000 ft of separation. We then received a 'monitor vertical speed;' and then a 'clear of conflict.' we were about FL366. I called ATC and reported that we were descending back down to FL360; and he replied roger. We never heard another thing about it.

Related reports:

Google
 

Original NASA ASRS Text

Title: B737 FLT CREW IN ZOB AIRSPACE CONTACTS ATC SEVERAL TIMES WITH NO RESPONSE AND ENDS UP RESPONDING TO A TCAS RA CAUSED BY CONVERGING TFC.

Narrative: WE WERE LEVEL AT FL360; AND HAD BEEN FOR A WHILE. ABOUT 120 MI E OF THE CRL VOR ON J554; WE RECEIVED A FREQ CHANGE TO ZOB ON 120.07. I SWITCHED OVER; AND NOTICED THE FREQ WAS BUSY. THE WX WAS CLR WHERE WE WERE; BUT APPARENTLY THERE WAS A LOT OF DEVIATING TFC NEAR CLE. MY FIRST CHK-IN WENT UNANSWERED; SO I FIGURED THE CTLR WAS BUSY. I WAITED 30 SECONDS OR SO AND TRIED AGAIN; BUT GOT NO ANSWER. I WAITED 30 OR 40 SECONDS TO TRY AGAIN. JUST AFTER MY THIRD CHK-IN ATTEMPT; WHICH WENT UNANSWERED; WE RECEIVED A TA ON OPPOSITE DIRECTION TFC ABOUT 12-15 MI AHEAD; +500 FT AND DSNDING. AT ABOUT 9 MI; WE RECEIVED A CLB RA OF AT LEAST 1500 FPM. AT THAT TIME; THE TFC WAS ABOUT +200 AND STILL DSNDING. WE DISCONNECTED THE AUTOPLT AND COMPLIED WITH THE RA. I CALLED ATC AND RPTED WE WERE IN A TCAS CLB; WHICH STILL WENT UNANSWERED. IT HAPPENED VERY QUICKLY; AND I ESTIMATE THAT AT THE 5 MI POINT; THERE WAS ABOUT 1000 FT OF SEPARATION. WE THEN RECEIVED A 'MONITOR VERT SPD;' AND THEN A 'CLR OF CONFLICT.' WE WERE ABOUT FL366. I CALLED ATC AND RPTED THAT WE WERE DSNDING BACK DOWN TO FL360; AND HE REPLIED ROGER. WE NEVER HEARD ANOTHER THING ABOUT IT.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.