Search results
Results from the WOW.Com Content Network
Ethernet packet. The SFD (start frame delimiter) marks the end of the packet preamble. It is immediately followed by the Ethernet frame, which starts with the destination MAC address. [1] In computer networking, an Ethernet frame is a data link layer protocol data unit and uses the underlying Ethernet physical layer transport
A frame is "the unit of transmission in a link layer protocol, and consists of a link layer header followed by a packet." [2] Each frame is separated from the next by an interframe gap. A frame is a series of bits generally composed of frame synchronization bits, the packet payload, and a frame check sequence.
In the seven-layer OSI model of computer networking, packet strictly refers to a protocol data unit at layer 3, the network layer. [2] A data unit at layer 2, the data link layer, is a frame. In layer 4, the transport layer, the data units are segments and datagrams.
A non-uniform frame size configuration in the network using jumbo frames may be detected as jabber by end nodes. [citation needed] Jumbo frames are not part of the official IEEE 802.3 Ethernet standard. A packet detected as jabber by an upstream repeater and subsequently cut off has an invalid frame check sequence and is dropped. [65]
The Layer 3: network layer PDU is the packet. The Layer 2: data link layer PDU is the frame. The Layer 1: physical layer PDU is the bit or, more generally, symbol. Given a context pertaining to a specific OSI layer, PDU is sometimes used as a synonym for its representation at that layer.
With the normal untagged Ethernet frame overhead of 18 bytes and the 1500-byte payload, the Ethernet maximum frame size is 1518 bytes. If a 1500-byte IP packet is to be carried over a tagged Ethernet connection, the Ethernet frame maximum size needs to be 1522 bytes due to the larger size of an 802.1Q tagged frame.
The packet transmission time in seconds can be obtained from the packet size in bit and the bit rate in bit/s as: Packet transmission time = Packet size / Bit rate. Example: Assuming 100 Mbit/s Ethernet, and the maximum packet size of 1526 bytes, results in Maximum packet transmission time = 1526×8 bit / (100 × 10 6 bit/s) ≈ 122 μs
In telecommunications, frame synchronization or framing is the process by which, while receiving a stream of fixed-length frames, the receiver identifies the frame boundaries, permitting the data bits within the frame to be extracted for decoding or retransmission.