Decoded TCP segment (RFC 9293) — fixed header, options trailer, and the application-layer payload.
The 13th and 14th header bytes are split into two byte-aligned bit-packed
fields: dataOffsetReserved (header length in 32-bit words plus 4 reserved
bits) and flags (the 8 control bits). NS (RFC 3540) was deprecated by
RFC 8311 and folded back into reserved.
sourcePort: number
destinationPort: number
sequenceNumber: number
acknowledgmentNumber: number
dataOffsetReserved: { dataOffset: number; reserved: number; }
flags: { cwr: number; ece: number; urg: number; ack: number; psh: number; rst: number; syn: number; fin: number; }
window: number
checksum: number
urgentPointer: number