Welcome to Bucaro TecHelp!

Bucaro TecHelp
Maintain Your Computer and Use it More Effectively
to Design a Web Site and Make Money on the Web

About Bucaro TecHelp About BTH User Agreement User Agreement Privacy Policy Privacy Site Map Site Map Contact Bucaro TecHelp Contact RSS News Feeds News Feeds

Victims of Sandy Hook

Stop the Slaughter of Innocents. Congress is bought and paid for by gun lunatics and gun promotion groups. If you want to live in a safe America, help buy Congress back for America. Send a donation to Mayors Against Illegal Guns, 909 Third Avenue, 15th Floor New York, NY 10022

What's the Difference Between a Packet and a Frame?

Protocol Data UnitLayer 7 Application
Layer 6 Presentation
Layer 5 Session
SegmentLayer 4 Transport
PacketLayer 3 Network
FrameLayer 2 Data Link
BitsLayer 1 Physical

When speaking of the data in a network, people often call everything a packet. A more proper generic term would be protocol data unit or PDU. The specific name for a PDU depends on at what layer the data unit is in the OSI model.

At layer 5, 6, or 7 of the OSI model, the actual construction of the PDU depends upon the specific application. At these levels you could just call the PDU data.

At layer 4, the transport layer of the OSI model, if the protocol stack is TCP, the PDU is called a segment. This is because at the transport layer the data is segmented it into chunks, and a TCP header is added.

At layer 3, the Network layer of the OSI model, if the protocol stack is TCP, the PDU is called a packet. The Network layer encapsulates each TCP segment into an IP packet by adding a header that includes the destination IP address.

At layer 2, the Data Link layer, the PDU is called a frame. The Data Link layer encapsulates one or more packets into a frame by adding the physical address of the source and destination, and adds a frame sequence number.

At layer 1, the Physical layer, the PDU is the bit. The Physical layer is the electronic network circuitry and connection media like fiber optic cable. Its the layer where data is physically moved across the network.

More Networking Protocols and Standards:
• What's the Difference Between a Packet and a Frame?
• IPv6 Address Types and Scopes
• Video - Network Layer (Layer 3) of OSI Networking Model
• IPv4 Address Classes
• Network Routing Protocols - IGRP, EIGRP, OSPF, ISIS, BGP
• Network Gateways
• IP version 6 (IPv6) Advantages and Implementation
• The OSI Physical Layer
• Understanding IP Routing
• TCP/IP Features

RSS Feed RSS Feed

Follow Stephen Bucaro Follow @Stephen Bucaro

Computer Networking Sections

Fire HD
[Site User Agreement] [Privacy Policy] [Site map] [Search This Site] [Contact Form]
Copyright©2001-2017 Bucaro TecHelp 13771 N Fountain Hills Blvd Suite 114-248 Fountain Hills, AZ 85268