The datagram length field in an IP header is 16 bits in length. Therefore, the maximum datagram size an IP datagram can support is 2^16 - 1 = 65,535 bytes
maximum size is 512 bytes without header
Total number of bytes in the datagram, including the header.The length of an IP datagram itself is technically measured in bytes. The length field represents the size of both the header and the data portions of the datagram.
The minimum length of an IP datagram is 20 bytes. This includes the minimum size of the header, which is 20 bytes when no options are included. The total length of an IP datagram can be greater if additional options or data are included, but the base header size remains 20 bytes.
20 bytes, without options
Header is always a multiple of 4bytes and so we can have a maximum length of the field as 15, so maximum size of the header is 60 bytes out of which 20 bytes are mandatory.
TCP (Transmission Control Protocol) uses a variable header size that typically ranges from 20 to 60 bytes. The standard header size is 20 bytes, which includes fields such as source and destination ports, sequence number, acknowledgment number, and control flags. Additional options can extend the header size, but the maximum size for a TCP packet, including the header and data, can be up to 65,535 bytes.
The size of a TCP segment encapsulated by an IP header does not have a fixed size and can vary based on the data being transmitted. However, the maximum size of a TCP segment is typically constrained by the Maximum Transmission Unit (MTU) of the network, which is commonly around 1500 bytes for Ethernet. Given that the IP header is 20 bytes, the maximum TCP segment size would be approximately 1480 bytes if there are no additional headers or options. In practice, the exact size would depend on the TCP header size and any options included.
IP datagram can be used to describe a portion of IP data. Each IP datagram has set of fields arranged in an order. The order is specific which helps to decode and read the stream easily. IP datagram has fields like Version, header length, Type of service, Total length, checksum, flag, protocol, Time to live, Identification, source and destination ip address, padding, options and payload. MTU:- Maximum Transmission Unit is the size of the largest packet that a communication protocol can pass. The size can be fixed by some standard or decided at the time of connection Fragmentation is a process of breaking the IP packets into smaller pieces. Fragmentation is needed when the datagram is larger than the MTU. Each fragment becomes a datagram in itself and transmitted independently from source. When received by destination they are reassembled.
IP datagram can be used to describe a portion of IP data. Each IP datagram has set of fields arranged in an order. The order is specific which helps to decode and read the stream easily. IP datagram has fields like Version, header length, Type of service, Total length, checksum, flag, protocol, Time to live, Identification, source and destination ip address, padding, options and payload. MTU:- Maximum Transmission Unit is the size of the largest packet that a communication protocol can pass. The size can be fixed by some standard or decided at the time of connection Fragmentation is a process of breaking the IP packets into smaller pieces. Fragmentation is needed when the datagram is larger than the MTU. Each fragment becomes a datagram in itself and transmitted independently from source. When received by destination they are reassembled.
The maximum permissible size for an IPv4 packet is 65,535 bytes, which includes both the header and the data payload. Since the maximum size of the header is 60 bytes, this allows for a maximum data payload of 65,475 bytes. However, in practical use, the Maximum Transmission Unit (MTU) often limits the size of packets on networks, typically to 1,500 bytes for Ethernet.
2^16 bytes - size of TCP header
maximum 60 octets minimum 20 octets