Segment
TCP Segment
Source Port | Destination Port | Sequence Number | Acknowledgement Number | Header Length | Reserved | Control Bits | Window Size | Checksum | Urgent | Options | Application Layer Data |
2 bytes | 2 bytes | 32 bits | 32 bits | 4 bits | 6 bits | 6 bits | 2 bytes | 2 bytes | 2 bytes | Size Varies | Size Varies |
UDP Datagram
Source Port | Destination Port | Length | Checksum | Application Layer Data |
2 bytes | 2 bytes | 2 bytes | 2 bytes | Size Varies |
Packet
IPv4 Packet Fields
Version | Internet Header Length | Differentiated Services (DS) | Total Length | Identification | Flags | Fragment Offset | Time-to-Live | Protocol | Header Checksum | Source IP Address | Destination IP Address | Options | Padding |
4 bits | 4 bits | DSCP | ECN | 2 bytes | 2 bytes | 3 bits | 13 bits | 1 byte | 1 byte | 2 bytes | 32 bits | 32 bits | Variable maximum 40 bytes padded with 0’s |
6 bits | 2 bits |
IPv6 Packet Fields
Version | Traffic Class | Flow Label | Payload Length | Next Header | Hop Limit | Source Address | Destination Address |
4 bits | 1 byte | 2 bytes | 2 bytes | 1 byte | 1 byte | 128 bits | 128 bits |
Frame
Generic Frame Fields
Header | Packet | Trailer | ||||
Frame Start | Addressing | Type | Control | Data | Error Detection | Frame Stop |
Ethernet II Frame Fields
Preamble | Destination Address | Source Address | Protocol Type | Data | Frame Check Sequence |
8 bytes | 6 bytes | 6 bytes | 2 bytes | 46 – 1500 bytes | 4 bytes |
IEEE 802.3 Frame Fields
Preamble | Destination Address | Source Address | Length | 802.2 Header and Data | Frame Check Sequence |
8 bytes | 6 bytes | 6 bytes | 2 bytes | 46 – 1500 bytes | 4 bytes |
IEEE 802.3ac Frame Fields
Preamble | Destination Address | Source Address | 802.1Q VLAN Tag | 802.2 Header and Data | Frame Check Sequence |
8 bytes | 6 bytes | 6 bytes | 2 bytes | 46 – 1500 bytes | 4 bytes |
802.1Q VLAN Tag | |||
Tag Protocol ID 0x8100 | User Priority | Canonical Format Indicator | VLAN ID |
2 bytes | 3 bits | 1 bit | 12 bits |
PPP Frame Fields
Flag | Address | Control | Protocol | Data | Frame Check Sequence |
1 byte | 1 byte | 1 byte | 2 bytes | variable | 2 or 4 bytes |
Wireless Frame Fields:
Frame Control | Duration/ID | Destination Address | Source Address | Receiver Address | Sequence Control | Transmitter Address | Frame Body | Frame Check Sequence | |
Fragment Number | Sequence Number | ||||||||
2 bytes | 2 bytes | 6 bytes | 6 bytes | 6 bytes | 4 bits | 12 bits | 6 bytes | 0-2312 bytes | 4 bytes |
Frame Control | ||||||||||
Protocol Version | Type | Subtype | To DS | From DS | More Fragments | Retry | Power Management | More Data | WEP | Order |
2 bits | 2 bits | 4 bits | 1 bit | 1 bit | 1 bit | 1 bit | 1 bit | 1 bit | 1 bit | 1 bit |