Internet Protocol, or IP, is basically a network layer protocol, that ensures that the packets reach the right destination. Packets may often be characterized by the protocol they’re using. So, a packet using an IP header is called an IP packet.
The IP header contains significant details, like what’s the source IP address of the packet, how large it is, what’s the destination IP address, and how long would network routers be required to continue before actually dropping the packet. It also contains details that if the packet can be fragmented.
Reading all this, you must be thinking about what a packet itself is. A packet is basically a small part of a large message. Data sent to computer networks using the internet is split into packets. Once the computer receives these packets, they are recombined.
What is an IP Packet Structure?
Internet Protocol (IP) belongs to Layer 3 (network layer) of the Open Systems Interconnection (OSI) model. So, it takes data components from Layer 4 (transport layer) and splits them into packets. The IP packet encapsulates the data unit obtained from the layer above and adds it to its own header information.
The encapsulated data is also known as IP Payload. The IP header possesses all the information to deliver the packet at the other end.
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IP header includes a lot of relevant details. These include:
- Version: The version number of IP used, like IPv4.
- IHL: The length of the IP header, be it IPv4 header or IPv6.
- DSCP: A service type called Differentiated Services Code Point.
- ECN (Explicit Congestion Notification): Possesses details about the congestion faced in the router.
- Total Length: IP packet’s complete length, including IP Payload and IP header.
- Identification: In the case of a fragmented IP Packet, all fragments possess the same identification number to discover the IP packet they belong to.
- Flags: If an IP packet is too big, then the flags tell if they can be fragmented into segments or not.
- Fragment Offset: Informs the exact location of a fragment in an IP packet.
- Time to Live: A TTL value is set on every packet that informs the network about the number of routers the IP packet can cross.
- Protocol: Informs the Network Layer about which Protocol the packet belongs to at the destination host.
- Header Checksum: Keeps the entire header’s checksum value, which is later utilized to check if the packet has no errors.
- Source Address: The 32-bit address of the sender.
- Destination Address: The 32-bit address of the receiver.
- Options: A field that’s optional and utilized only when the IHL value is > 5.
Why Use Packets?
Network or IP Packets are used all across the internet, including on webpages and emails, to transmit information between users and their recipients. This method is quite reliable as it ensures that the data isn’t sent in one large file.
While it’s possible to send data and files using the internet without splitting them into tiny bits of information, the approach gets labeled as impractical when over two computer systems are involved.
The internet can be called the packet switching network. It refers to the capabilities of the networking equipment to separately process packets. It also means that the IP packets can take different paths until they reach the same destination.
Due to this, packets from various computers can travel in any order through the same wires. This allows various connections to take place over the same networking equipment simultaneously.
What are the Three Parts of an IP Packet?
A Network/IP Packet is divided into three parts; header, payload, and trailer. All these parts contain values that basically are attributes of it:
1. Packet Header:
The network packet header contains the source and destination addresses, packet number, and protocol. The source address tells where the packet is coming from, while the latter indicates the receiving IP. Every type of IP address contains this information in the packet.
Every packet comes with two numbers for identification. The first denotes how many pieces the information was split into, the other number signifies the individual packet’s position as part of the total information.
Finally, the protocol helps you determine the kind of packet being transferred – web page, email, video, or more.
2. Packet Payload:
Payload, also called data, refers to the actual data being transported by the network packet. The data size can be range between 48 bytes to 4 kb depending on the network. Payload is basically data received from either the source or destination, as the information is stripped from the network header after reaching the destination.
3. Packet Trailer:
The packet trailer’s content differs between every type of network. Usually, a packet trailer contains some bits, notifying the receiving device that it has reached the packet’s end, along with CRC (Cyclic Redundancy Check), allowing the device to determine if all the packets were fully received.
FAQs – IP Packet
What is an IP packet vs IP address?
An IP address is basically a series of digits used for the identification of a device. Whereas, an IP packet includes an IP address along with the data meant for the device determined by the IP.
How an IP packet is formed?
IP, belonging to layer 3 of the OSI model obtains segments of data from layer 4 and separates them into packets. The data unit received from the layer above is encapsulated by the IP packet and added to its header information. The encapsulated data is also known as IP Payload.
What is IP packet delivery?
Packet delivery refers to when the packets are actually delivered between the appropriate hub routers. Failure of packet delivery between the appropriate hub routers is called Packet loss.
Within the IP packet header, what is the value in the upper layer protocol field?
The value of the upper layer protocol field is ICMP.
What is done to an IP packet before it is transmitted over the physical medium?
An IP packet is encapsulated in the Layer 2 frame before being transmitted over the physical medium.
We hope our detailed guide gave you all the information you require related to IP packets. The large amount of data sent by you efficiently reach the receiver using an IP packet. Similarly, the ability to receive heavy videos and images without any errors has been uncomplicated with these packets.
Each IP packet is formed on a set structure and has three parts with their own significance; the header contains a few basic details about the packet, the payload is the actual data, and the trailer runs checks and notifies of the received data.
Understanding the concept of an IP packet may be a bit complicated if you’re not tech-savvy. So, in case of any questions, feel free to ask us in the comments.