Par

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 par, i.e. cash equaling the bond's notional.
This transaction is computationally equivalent to an upfront payment from the swap seller to the swap buyer of (D-100)/100*N, where N, D are the bond's notional and dirty price respectively at swap's inception.
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.
More details on the calculation of the ibor cash flows are available in
Index
3) At swap's maturity, the swap buyer pays the bond's redemption amount to the the asset swap seller in exchange of N.
It follows that in the usual case where the bond's redemption amount equals N the net exchange at maturity is 0.
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.