[ns] a question about rtp.cc

[cheng_wx <dis_cheng@263.net>]

Hi:
   anybody know what's mean of advanceby function in the rtp.cc.
the function:

void RTPAgent::advanceby(int delta)
{
        maxpkts_ += delta;
        if (seqno_ < maxpkts_ && !running_)
                start();
}               

thanks.