TCP Threeway Handshake

1
TCP Three-way Handshake
Initiating Application Port Number (Port 21) FTP
Sequence Number 1
Sequence Number 1

• The delta value between frames 1 and 2 can be
  used as a TCP transport connect baseline value.
• Other important information gathered from this
  handshake
• Window Size (BUFFER SIZE)
• SACK
• Maximum Segment Size
• Window Scale Option value
• To measure the retransmission algorithm, connect
  with an application and unplug your connection
  while sniffing.