Subtype of Structure

The following exchanges take place:
1) At swap's inception the asset swap buyer receives the underlying bond from the swap seller in exchange of cash equaling the bond's market price P = N*D/100 at that time, where N, D are the bond's notional and dirty price respectively at swap's inception.
This transaction is computationally equivalent to a zero upfront payment, since the net worth of the exchange vanishes.
2) During the swap's life, the coupons earned by the underlying bond are then exchanged for floating interest rate, i.e. the asset swap buyer pays the asset swap seller the coupons earned by the bond in exchange for ibor plus spread.
The floating coupons are calculated based on a scaled notional equalling the market price P.
More details on the calculation of the ibor cash flows are available in
3) At swap's maturity, the swap buyer pays the bond's redemption amount to the the asset swap seller in exchange of P.
Note the coupon exchange is meant to continue until the swap's maturity, even if the bond defaults, meaning that the asset swap buyer retains the credit risk of the bond.