How does TCP Ping or Traceroute Work?

How does the tcp ping or traceroute work? Does it take in account just the time it takes to establis the TCP handshake?

Also in ICMP ping you can specify the packet size, can this be achieved in TCP ping?

I believe you are referring to these utilities:

http://www.vdberg.org/~richard/tcpping.html

http://michael.toren.net/code/tcptraceroute/

Since tcpping requires tcptraceroute, I'll start with tcptraceroute.

The author of tcptraceroute states that unlike a traditional traceroute, "By sending out TCP SYN packets instead of UDP or ICMP ECHO packets, tcptraceroute is able to bypass the most common firewall filters."

Further: It is worth noting that tcptraceroute never completely establishes a TCP connection with the destination host.

So, tcptraceroute does not measure the time it takes to complete the three-way handshake because that never happens. It measures the time from the initial SYN to the SYN/ACK. This is sometimes referred to as a half-open connection scan.

From the nmap manpage:

          This technique is often referred to as half-open scanning,
          because you don’t open a full TCP connection. You send a SYN
          packet, as if you are going to open a real connection and then
          wait for a response. A SYN/ACK indicates the port is listening
          (open), while a RST (reset) is indicative of a non-listener. If
          no response is received after several retransmissions, the port
          is marked as filtered. The port is also marked filtered if an
          ICMP unreachable error (type 3, code 1,2, 3, 9, 10, or 13) is
          received.

As to your packet size question, the above description also has the answer. Since tcptraceroute sends a standard SYN packet, it should be a small packet, perhaps 64 bytes.