by Scott Morris
We've run into a network issue. I work for a company that has software to manage and monitor digital video cameras. We have an installation in Mexico where the network is using wireless to send video back to the main building. The municipality there doesn't want to allow us to see their network configuration since they are managing it, but I'm stumped as to what might cause this.
I'm going to try and simplify the problem instead of loading up with background info. When we ping a camera, we have consistent 4-8 ms ping times. When we look at the video, however, we have virtually no frames coming in. I can see data coming in to the server using a packet sniffer, but it must be incomplete data as the frames are not shown. The cameras are set for a constant bit rate of 1,024 kbps using MPEG-4 TCP, but the data I see varies from 400-1,000 kbps. It is clear there's something blocking the data or at least corrupting it, but my confusion comes in when we are getting good, consistent pings.
For me, it seems like I'm missing a piece of information somewhere. I don't have my CCNA yet (I'm studying now), but I believe someone can define different routes for ICMP packets than TCP packets if they wanted to. Do you have an idea of what we can check? Or maybe some extra troubleshooting tips we can do if we are able to access some of the network devices? Or maybe there's something I can see using the "tcpdump" utility on the Linux server.