Segment

TCP Segment

Source PortDestination PortSequence NumberAcknowledgement NumberHeader LengthReservedControl BitsWindow SizeChecksumUrgentOptionsApplication Layer Data
2 bytes2 bytes32 bits32 bits4 bits6 bits6 bits2 bytes2 bytes2 bytesSize VariesSize Varies

UDP Datagram

Source PortDestination PortLengthChecksumApplication Layer Data
2 bytes2 bytes2 bytes2 bytesSize Varies

Packet

IPv4 Packet Fields

VersionInternet Header LengthDifferentiated Services (DS)Total LengthIdentificationFlagsFragment OffsetTime-to-LiveProtocolHeader ChecksumSource IP AddressDestination IP AddressOptionsPadding
4 bits4 bitsDSCPECN2 bytes2 bytes3 bits13 bits1 byte1 byte2 bytes32 bits32 bitsVariable maximum
40 bytes padded with 0’s
6 bits2 bits

IPv6 Packet Fields

VersionTraffic ClassFlow LabelPayload LengthNext HeaderHop LimitSource AddressDestination Address
4 bits1 byte2 bytes2 bytes1 byte1 byte128 bits128 bits

Frame

Generic Frame Fields

HeaderPacketTrailer
Frame StartAddressingTypeControlDataError DetectionFrame Stop

Ethernet II Frame Fields

PreambleDestination AddressSource AddressProtocol TypeDataFrame Check Sequence
8 bytes6 bytes6 bytes2 bytes46 – 1500 bytes4 bytes

IEEE 802.3 Frame Fields

PreambleDestination AddressSource AddressLength802.2 Header and DataFrame Check Sequence
8 bytes6 bytes6 bytes2 bytes46 – 1500 bytes4 bytes

IEEE 802.3ac Frame Fields

PreambleDestination AddressSource Address802.1Q VLAN Tag802.2 Header and DataFrame Check Sequence
8 bytes6 bytes6 bytes2 bytes46 – 1500 bytes4 bytes
802.1Q VLAN Tag
Tag Protocol ID 0x8100User PriorityCanonical Format IndicatorVLAN ID
2 bytes3 bits1 bit12 bits

PPP Frame Fields

FlagAddressControlProtocolDataFrame Check Sequence
1 byte1 byte1 byte2 bytesvariable2 or 4 bytes

Wireless Frame Fields:

Frame ControlDuration/IDDestination AddressSource AddressReceiver AddressSequence ControlTransmitter AddressFrame BodyFrame Check Sequence
Fragment NumberSequence Number
2 bytes2 bytes6 bytes6 bytes6 bytes4 bits12 bits6 bytes0-2312 bytes4 bytes
Frame Control
Protocol VersionTypeSubtypeTo DSFrom DSMore FragmentsRetryPower ManagementMore DataWEPOrder
2 bits2 bits4 bits1 bit1 bit1 bit1 bit1 bit1 bit1 bit1 bit