I'm not too sure what you are asking so I will present a couple of options. Beyond this, you may need to be more specific.
If you are refering to a DID number that you own on the PRI and want to block it totally, then I would suggest not programming a destination for that DID. Then the caller will hear "I'm sorry that number is not in service" from the PRI provider.
If you want to limit the amount of available B channels that the DID number can use or what specific B channels to use,the PRI provider may be able to help. Typically, if a B channel is available, the CO will present the call.
If you are refering to blocking calls originating from a specific number, then I would suggest contacting your PRI provider to do that. I am unaware of a way to do this via the Mitel equipment. If it is possible, then I would be very interested to see how.
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