You cannot do CCBS in the release you are running. You may be getting this from some pre-Release 24 NTP's, or an older Avaya configuration whitepaper.
Currently you have CCBO defined in your RCAP, and in talking to the Avaya you are going to need Integer Value coding or CCBI.
Remove the CCBO from the RCAP by doing XCCB at the RCAP prompt.
You will then be able to add CCBI to the RCAP. Also while you are in there, get rid of the RLS ID of 6. It is not doing anything for you. Remember Q.Sig in machine agnostic, and therefore if any vendor can be on the far end, RLS ID is sort of a moot point.
The one exception to this rule is when running Q.Sig to another Meridian. Then BOTH sides should have the lowest common RLS ID between the 2 switches. For example a Release 25 switch talking to a Release 24 switch would have '24' as the RLS ID on BOTH sides. By putting a '6' there, you are confusing the Nortel to think that a Release 6 Nortel is at the far end. That's a ways off I think
Generally the Avaya likes 'I'nteger Value coding RCAP settings opposed to 'O'ject ID coding options on their Q.Sig integration.
The 'S' values in the RCAPS are no longer used. These would try to inteligently identify if the remote side was using Object ID Coding, or Integer Value coding. This option did not always resolve correctly, and as part of the Q.Sig compliance code initiative done in Release 24, this option was removed and replaced with hard settings to avoid misconfiguration.
Good question! I miss not being able to answer these as much as before!