Ping Time
Ping measures Round Trip Time (RTT), records any packet loss, and prints when finished a statistical summary of the echo response packets received, the minimum, mean, max and in some versions the standard deviation of the round trip time.
A lower value for Ping Time is better.
Time To Live (TTL)
There is no optimum value for TTL.
- TTL or Time To Live is an integer value between 0 and 255. It specifies the number of router hops a packet is allowed to travel before it must be discarded or returned.
- TTL is sometimes used as a hop count limit and other times as a time limit. The hop count function is critical to network functionality. It ensures that packets do not looping infinitely in a network. The time limit function is used by transport protocols such as TCP to ensure reliable data transfer.
- Each router that handles a packet MUST decrement the TTL by at least one, even if the elapsed time was much less than a second. Time-to-Live functions as a hop count in this perspective. Since this is the case most of the time, TTL is effectively a hop count limit on how far a datagram can propagate through the Internet.
- When a router forwards a packet, it MUST reduce the TTL by at least one. If it holds a packet for more than one second, it MAY decrement the TTL by one for each second. In this way, TTL is used as a time count.
- When TTL gets to zero, the router discards the IP Packet and an ICMP "TTL Expired in transit" message is sent back to the sending IP Address.
- Ping, Tracert, and Pathping all make use of the TTL value to attempt to reach a target host or to trace a route to that host.
- TTL has been renamed renamed "Hop Limit" in IPv6. It ha the same function as TTL in IPv4.