Latency = time delay
Maximum latency = maximum time delay
When we're talking about time, we mean the time that it takes for a packet to travel from the thinkbroadband firebrick to your router (ping) and then from your router back to the thinkbroadband firebrick (pong).
This delay is variable during the normal operation of a network because the Internet connection is used for all sort of things (e.g. downloads/uploads) besides the ICMP packets which are used here for measuring the time delay (latency) between the thinkbroadband router and your router.
The ICMP packets are small and usually fit in the connection without too much trouble. However, if the connection is congested because there are already too many packets trying to use it at a particular moment, then some of the ICMP packets will have to queue up and wait for their turn to use the connection. This is what is causing the "maximum latency".
The question is what is causing the congestion in your Internet connection. Here's some suggestions:
1. The remote server/router you are measuring your latency against, is busy.
2. Your ISP's network is busy (because they have not purchased enough capacity and at busy times things slow down).
3. Your ISP is applying traffic shaping and purposefully slow down certain types of packets (usually at busy times).
4. Your router's throughput is poor, because its chipset and memory are inadequate for full blast packet processing.
5. Your network hardware has connectivity problems, e.g. faulty ethernet cable, faulty NIC.
6. You're using wireless which is patchy and not operating at full capacity, or it is being shared at the time with other PCs.
It could be a combination of any of the above.
