I have a .pcap file captured from my network adapter using Wireshark. I'm trying to analyses its contents using a python script. The problem is that I can't find anything specific to RTP packets in the Wireshark. Note that I don't want to use the port numbers to detect the protocol. I want to inspect the raw data and detect the RTP protocol packets. Is there any way to do that? I mean is there anything special in RTP packets that I can use that statistic to detect RTP packets among a lot of other protocols packets?
Wireshark analyses the VOIP signaling messages to know which UPD ports are being used for RTP. Apart from the version number bits (and thats really too short), the RTP packets themselves don't have much you can use to identify them by themselves.
There is a setting in wireshark that allows RTP detection without signaling:
Edit menu -> Preferences -> Protocols -> RTP -> Allow subdissector to reassemble RTP streams
Related
When I enable Wireshark capture on my laptop, the application becomes slow because it captures all the packets. I am running about 100 Mbps of traffic with different packet sizes.
Let's say, I only need to capture rtp,sip packets and ignore the other UDP, TCP, DHCP etc.
How can I do it using Wireshark?
Note: I know the filter option to view only the packets I need, but the request is to only capture rtp packets
From the Wireshark SIP wiki page:
Capture Filter
You cannot directly filter SIP protocols while capturing. However, if you know the UDP or TCP or port used (see above), you can filter on that one.
For help with writing capture filters, refer to the pcap-filter man page.
I am currently trying to read some PCAP files using WinPCAP-API.
With this example I managed to read the data, timestamp and length. But I do not get how to read the source and destination IP-adresses and ports?
But I do not get how to read the source and destination IP-adresses and ports?
By dissecting the raw packet data that WinPcap gives you; libpcap/WinPcap provide no APIs for dissecting raw packet data (because different libpcap/WinPcap applications have different needs - an intrusion detection application such as Snort and a packet analyzer such as tcpdump or Wireshark do different things with the data).
See, for example, libtins as a C++ library for doing packet dissection, or the libpcap tutorial for an example of how to do the dissecting yourself.
I have a great confusion about tshark.
What is the basic unit of the messages captured by tshark? Ip, tcp, or http?
I see TCP http or ssl and so on in the protocol column in wireshark.
These protocols are in different layer.
In addition, what is the tshark command to capturing the http message with tshark.
See the man page. To quote:
TShark is a network protocol analyzer. It lets you capture packet data from a live network, or read packets from a previously saved capture file
Packets are usually either TCP or UDP (you can find a list of protocols here), When wireshark states that it is HTTP or SSL, then it is based on introspection of the packet (Probably based on destination port).
I have an incoming RTP stream on one computer (called, "server1") connected to another computer (called, "client1") over a LAN. However, the Ethernet header (MACDA/MACSA), IPv4 header (IPDA/IPSA), and UDP header (dstport/srcport) for all of the packets belong to another network and different computers. Furthermore, the client computer did not request or initiate the stream. It is "just there"! :)
I am not interested in controlling (stopping, starting, track jumping, etc.) the stream. I just want to see and hear it in a VLC client.
I have complete control over the packets, so that I can change all of the header info as it leaves the server.
How can I modify the packets, so that VLC will play them? I can point VLC at my server, and I can mangle the packets, so they appear to have been sourced by the server and destined for the client. But, I do not know the destination port opened by VLC on the client. What am I missing?
Thanks!
I may not have the best answer, but here's a little something that might help...
"I was trying vlc player and I says, Sdp required, cannot play rtp with dynamic payload type. Is it possible to play rtp with dynamic payload type by other player, or somehow create sdp protocol using libjitsi. Thanks a lot."
Reply:
"You need an SDP description.
I found on stackoverflow a minimal SDP description. Minimum SDP for making a H264 RTP stream?.
You can try to replace the IP address, port number and payload type by the ones you’re using, maybe that’ll work."
I want to parse packets captured by wireshark offline using libpcap. I am capturing packets from a wireless network in monitor mode. I have read that "libpcap" can be used to capture and parse packets captured in the ethernet. Can it be used for wireless networks too? If yes, can anyone suggest me some tutorial? and if No, which library is suitable for it and how to use it?
libpcap, and its Windows port, WinPcap can be used to capture network traffic (in fact, they're what Wireshark uses to capture network traffic), as well as to read a capture file in pcap format (the default format for Wireshark's existing releases) and, in libpcap 1.1 and later, to read some capture files in pcap-ng format (the default format for the current development version of Wireshark; it should write out files that libpcap 1.1 and later can read).
They can handle a number of network types, including Ethernet and Wi-Fi.
They do not, however, support parsing any packet types; that's the job of the code that uses them, whether it's tcpdump/WinDump, Wireshark, or some other application. There's a library called WiFiPcap that is:
A C++ wrapper around libpcap that parses 802.11 frames, and the most common layer 3 (IPv4, IPv6, ARP) and layer 4 protocols (TCP, UDP, ICMP) contained within them. Also works without link-layer headers. Works in Linux and Windows.
(copied from its web page, but edited to fix the protocol layer numbers to match the OSI model).
I have not looked at it, but it might do what you want.
There might also be other libraries that could be used to parse the packets.