Payer swaption, MBS, CDO and CDS

MBS is said equivalent to call on bond, CDO is also equivalant to call on bond, but why CDS buyer and payer swaption is equivalant to put on bond

CDS buyer will pay fixed premiums to insure against some Credit Risk. Payment of fixed premiums at fixed intervals is equivalent to paying Coupons when you issue a Bond. So, buying CDS is like issuing/selling a bond. Payer Swaption is right to enter into an Interest Rate Swap, by paying fixed rate. Again, we are paying a fixed amount at regular intervals, which is equivalent to paying fixed coupons on a bond you have issued/sold. Hope this helps.

thanks, but you only explain the second half, can you explain the first half? MBS is said equivalent to call on bond, CDO is also equivalant to call on bond,

Just understand it as: any security that pays you a fixed amount regularly (whether it is MBS or CDO or any other security), is like you bought a Bond and are getting its regular stated coupon. Which is equivalent to a Call (buy) on a Bond.

thanks. very valuable