A concurrent inbound connection is the inbound twin of a concurrent session, and a separate entitlement rather than the same pool: it is how many callers your AI receptionist can be talking to at the same moment. The two sides of the product are bought separately, which is what makes the answering capacity dependable: your own dialer at full pace cannot take a connection you bought to answer with.
A purchased connection is reserved rather than shared. It is subtracted from what your own outbound campaigns may claim, at the tenant level and again at the fleet level, so a campaign you launched cannot starve the inbound capacity you are paying for. The reservation runs against your own traffic, which is the only traffic it can honestly run against.
Only the step where the AI actually answers claims one. A menu, a ring through to your own team, a forward, or a static spoken message runs on the carrier’s own leg: no conversation slot, no model, no meter. Under BYO those seconds are billed to you by your own carrier, exactly as every other second on your line is.
When every connection you bought is busy, that is an ordinary operating state of a product sold by the connection rather than an error — the caller advances to whatever you configured next, usually voicemail. The plan price, the included count and the price of an additional connection are published on the pricing page; what the inbound product does with a call once it answers is on the receptionist page.