I'll concur with Dennis. I use IP Cam Viewer on my Android and iPad and they work fine. There are several apps that seem to do the same thing. The rub is that you have to hit each camera directly, not via the server. And typically you have to use a mpeg or mjpeg feed, not h264.
Following is a decent post talking about some of the technical aspects since few (if any) of these apps have native drivers for the Cisco cams, in my experience.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...