Ping is simple echo protocol. Essentially you send a message to server that contains message "PING" and receive a copy of the message back. "Round Trip Time" (or RTT) that it takes a packet to reach a server. That is, it calculates how long takes for the packet to reach the server and to be sent back.
It's actually slightly more complicated, because when you ping something you actually send a whole bunch of these "PING" messages. You do this so you can average the results to get a more realistic measure of how long it took for the packet to reach the server. This can also be used to determine how stable your connection is, by measuring how many "PING" messages are dropped on sending. (I believe speedtest calls this "jitter" testing)
The RTT is usually measured in microseconds. So if you have a ping of 79 on speedtest.net that means for whatever server you were testing against it took an average of 79 ms for a packet to reach it and be sent back.
So what does this mean in terms of how good it is? Well it's hard to talk in specific terms because it really depends on what you are doing online (for instance, for gaming you usually want really low ping but for video streaming it doesn't matter as much). In general though I would go with these rules of thumb: less than 50ms ping is really good, less than 100ms ping is good to average, 150ms is where you are going to start having problems with games, and above 150 ms ping you may experience lag and such in games.
Not on your end. Its something that is entirely determined by how you connect to the internet. So if you change your ISP, get a better plan, or something like that then your ping might improve (but it depends on the plan and such). If you are worried about gaming, 79ms should be fine for gaming.
An IP TTL is set initially by the system sending the packet. It can be set to any value between 1 and 255; different operating systems set different defaults. Each router that receives the packet subtracts at least 1 from the count; if the count remains greater than 0, the router forwards the packet, otherwise it discards it and sends an Internet Control Message Protocol (ICMP) message back to the originating host, which may trigger a resend.
The point of the TTL/hop limit is to keep streams of undeliverable packets stuck in routing loops (perhaps due to incorrect routing tables) from circulating forever and clogging up the networks in question. In Multiprotocol Label Switching (MPLS) clouds, the MPLS TTL is copied from the IP TTL when the IP packet enters the cloud. On egress, the MPLS TTL value is copied into the IP TTL field (as long as it is less than the value in the field).
An IP TTL is set initially by the system sending the packet. It can be set to any value between 1 and 255; different operating systems set different defaults. Each router that receives the packet subtracts at least 1 from the count; if the count remains greater than 0, the router forwards the packet, otherwise it discards it and sends an Internet Control Message Protocol (ICMP) message back to the originating host, which may trigger a resend.
The point of the TTL/hop limit is to keep streams of undeliverable packets stuck in routing loops (perhaps due to incorrect routing tables) from circulating forever and clogging up the networks in question. In Multiprotocol Label Switching (MPLS) clouds, the MPLS TTL is copied from the IP TTL when the IP packet enters the cloud. On egress, the MPLS TTL value is copied into the IP TTL field (as long as it is less than the value in the field).
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