I don't fully understand what you mean by "channel". Can you please re-phrase your question?
Usually, a service provider will provide you with a SIP account with a user ID and credentials for your VoIP devices to register with. The SIP account can have one or more phone numbers associated with it. (also known as direct inward dial (DID) numbers).
Make sure you are using firmware version 7.4.8 for your testing.
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