Has anyone had any experience using Envision SL software (video relay for the hearing impaired) behind a PIX? I am at 6.3.1. The software's gateway server appears to be initiating a control channel on ports 15328-15338. The h323 fixup is not allowing this back in and PIX blocks it. I am assuming it is not RFC compliant. The 1720 traffic seems to be working OK. Is there a way to tweak the h323 fixup to include these ports also? Any other suggestions? Thanks.