Your Merkato administrator must configure the maximum bandwidth capacity for a link in the NSC (Network Service Controller). The administrator can then divide that bandwidth among one or more Merkato markets, or keep it on unused until demand in a market increases.
You can divide a single link among any number of Spot or Reservation markets. In general, the only reason to create multiple markets of the same type (for example, multiple spot markets) is when there is some feature that distinguishes bandwidth in each market, and this feature affects the value buyers place on that bandwidth. In general, it is best to have as many buyers as possible in a single market to create a more competitive environment.
For each Reservation market, you must enter the total capacity available into the NSC and the capacity currently available into the Resource agent. (The capacity currently available must be less-than or equal to total capacity.)
The Merkato administrator sets these values and can increase or decrease them as desired. Of course, the administrator should never reduce the capacity below the amount currently under contract (and in use) by buyers.
The Spot market has multiple ways to control total capacity. The maximum is set at both the NSC and the Resource agent. The current capacity is controlled on-demand by sellers via their agents. Changes take effect at the beginning of the next auction round.