Appendix A. Pseudocode for Index Determination

Appendix A. Pseudocode for Index Determination

The following is an example of pseudo-code for the algorithm to determine the index i of an SRTP packet with sequence number SEQ. In the following, signed arithmetic is assumed.

     if (s_l < 32,768)
        if (SEQ - s_l > 32,768)
           set v to (ROC-1) mod 2^32
        else
           set v to ROC
        endif
     else
        if (s_l - 32,768 > SEQ)
           set v to (ROC+1) mod 2^32
        else
           set v to ROC
        endif
     endif
     return SEQ + v*65,536