| tcp.ack | Acknowledgement number | Unsigned 32-bit integer | |
| tcp.analysis.ack_rtt | The RTT to ACK the segment was | Time duration | How long time it took to ACK the segment (RTT) |
| tcp.analysis.acks_frame | This is an ACK to the segment in frame | Unsigned 32-bit integer | Which previous segment is this an ACK for |
| tcp.analysis.flags | TCP Analysis Flags | No value | This frame has some of the TCP analysis flags set |
| tcp.checksum | Checksum | Unsigned 16-bit integer | |
| tcp.checksum_bad | Bad Checksum | Boolean | |
| tcp.dstport | Destination Port | Unsigned 16-bit integer | |
| tcp.flags | Flags | Unsigned 8-bit integer | |
| tcp.flags.ack | Acknowledgment | Boolean | |
| tcp.flags.cwr | Congestion Window Reduced (CWR) | Boolean | |
| tcp.flags.ecn | ECN-Echo | Boolean | |
| tcp.flags.fin | Fin | Boolean | |
| tcp.flags.push | Push | Boolean | |
| tcp.flags.reset | Reset | Boolean | |
| tcp.flags.syn | Syn | Boolean | |
| tcp.flags.urg | Urgent | Boolean | |
| tcp.hdr_len | Header Length | Unsigned 8-bit integer | |
| tcp.len | TCP Segment Len | Unsigned 32-bit integer | |
| tcp.nxtseq | Next sequence number | Unsigned 32-bit integer | |
| tcp.port | Source or Destination Port | Unsigned 16-bit integer | |
| tcp.seq | Sequence number | Unsigned 32-bit integer | |
| tcp.srcport | Source Port | Unsigned 16-bit integer | |
| tcp.urgent_pointer | Urgent pointer | Unsigned 16-bit integer | |
| tcp.window_size | Window size | Unsigned 16-bit integer | |