Stack Overflow
Stack Overflow

Questions tagged [packet]

A packet is one unit of binary data capable of being routed through a computer network.

This is a small amount of computer data sent over a network. Any time you receive data from the Internet, it comes to your computer in the form of many little packets.

Each packet contains:

  • A label which uniquely identifies it
  • The IP address of its origin and destination
  • A sequence number (for sorting)
  • A checksum (for error checking

The process of sending and receiving packets is known as "packet-switching." Packets from many different locations can be sent on the same lines and be sorted and directed to different routes by various computers along the way, the packets are then sorted by their sequence number once they reach their destination. It works a lot like the post office, except billions of packets are transferred each day, and most packets take less than a few seconds to reach their destination. Even FedEx same-day delivery can't compete with that.

Packet Definition. 2013. Packet Definition. [ONLINE] Available at: http://www.techterms.com/definition/packet. [Accessed 30 April 2013].

1562 questions
8
votes
3 answers

How is data divided into packets?

Hi sorry if this is a stupid question (I just started learning network programming), but I've been looking all over google about how files/data are divided into packets. I've read everywhere that somehow files are broken up into packets have…
Edgepad
  • 83
  • 1
  • 5
8
votes
2 answers

What is an ASN file and how do I use it?

I am trying to work with a communication protocol (S1AP to be specific) and I am trying to define messages to test. The LTE 36.413 specification details this protocol and also give an ASN.1 file definition at the bottom of the pdf. I have seen ASN…
Edwin
  • 797
  • 2
  • 14
  • 23
8
votes
2 answers

what is the packet size unit of ffprobe(similar to ffmpeg)?

I am developing thumbnail extractor with ff- series(means ffmpeg, ffplay, ffprobe). I need to know the location of frames, so I use a command like below which I found another posting in stackoverflow. ffprobe -show_frames -select_streams v…
Juneyoung Oh
  • 7,318
  • 16
  • 73
  • 121
7
votes
1 answer

Processing packets with unknown IPv6 extension headers

Question Should one discard a packet with an unknown IPv6 extension header? Details I could not find an answer to this question by examining the RFC. The book IPv6 Essentials states on page 22: If a node is required the next header but cannot…
mavam
  • 12,242
  • 10
  • 53
  • 87
7
votes
1 answer

Python Twisted proxy - how to intercept packets

I'm trying to print out the body of a HTTP response using Python. Here is my code sofar: from twisted.web import proxy, http from twisted.internet import reactor from twisted.python import log import sys log.startLogging(sys.stdout) class…
Eamorr
  • 9,872
  • 34
  • 125
  • 209
7
votes
1 answer

How to convert a hex-encoded string to a byte string in Perl?

My original code is in Python, but I need to convert it to Perl for some libraries that I don't have at my disposal in Python. In Python I would do…
Nowayz
  • 1,882
  • 4
  • 21
  • 34
7
votes
2 answers

How to use tun/tap interface to split packets, tunnel and then reassemble. (similar to MLPPP)

I am looking to create a client/server application that I can use to slit network packets in half, tunnel each half of the packet over a separate udp connection (because each udp connection will be going over a different wifi link) and then…
wtip
  • 138
  • 1
  • 6
7
votes
2 answers

How to reassemble TCP packets in Python?

How to reassemble TCP packets in Python? Is there any existing tools for this? Thanks! :-)
Tianyang Li
  • 1,755
  • 5
  • 26
  • 42
7
votes
3 answers

Sniffing and displaying TCP packets in UTF-8

I am trying to use tcpdump to display the content of tcp packets flowing on my network. I have something like: tcpdump -i wlan0 -l -A The -A option displays the content as ASCII text, but my text seems to be UTF-8. Is there a way to display UTF-8…
Alexandre Dupuis
  • 139
  • 1
  • 3
  • 9
7
votes
1 answer

How can we extract the RTP packet sequence number from AVPacket (ffmpeg)

We are trying to extract the "Sequence Number" from the RTP header of a packet. We use av_read_frame in order to read the packets into AVPacket structs. We tried using the AVPacket.data field, hoping it holds the original payload, but we didn't…
Nech
  • 331
  • 3
  • 11
7
votes
5 answers

HTTP Data chunks over multiple packets?

What is the correct way for a HTTP server to send data over multiple packets? For example I want to transfer a file, the first packet I send is: HTTP/1.1 200 OK Content-type: application/force-download Content-Type:…
myforwik
  • 195
  • 1
  • 2
  • 6
7
votes
5 answers

How to debug packet loss?

I wrote a C++ application (running on Linux) that serves an RTP stream of about 400 kbps. To most destinations this works fine, but some destinations expericence packet loss. The problematic destinations seem to have a slower connection in common,…
Gene Vincent
  • 5,237
  • 9
  • 50
  • 86
7
votes
1 answer

Where is the source and destination address fields in TCP header?

From what I've read, TCP sits on the layer between the application and IP, and handles setting up the packets, checking for errors, ordering etc so the application itself doesn't have to do it. However, when I looked at the TCP header I became…
CodyBugstein
  • 21,984
  • 61
  • 207
  • 363
7
votes
1 answer

how can we set up Proxy server dealing with UDP packets?

Usually we can set up a proxy server by some kind of tools such as CCProxy which provides proxy services for HTTP, SOCKS, FTP packets etc. Also, Proxifier or Proxycap is used to forward the packets of specific application on the client PC. However,…
Network study
  • 83
  • 1
  • 2
  • 6
7
votes
2 answers

How to find the packet loss in Wireshark?

I need to test packet loss for an FTP application. I used the Wireshark packet sniffer, and I got TCP Stream. How do I find the packet loss using Wireshark?
krishnakumar
  • 2,187
  • 5
  • 21
  • 24
1 2 3
…
99 100