As far as I search, All WebRTC handshakes are done through any signaling server [ HTTP, WebSocket, etc..] even through Mail or Whatsapp.
But I expect to connect without using any of them. Is there any way to archive this?
If yes, please give me a brief solution. ThankYou!
WebRTC (as implemented in browsers) requires signalling. You can choose a different medium for signalling such as a piece of paper or calling someone on the phone, but it needs signalling.
If you want to be able to initiate unsolicited connections you need to use TCP or UDP directly which (if we ignore NAT and firewalls) don't have that restriction.
Related
I'm writing my own simple soft phone, but I fail to understand the basics of how SIP works, so I wanted to see on a low level how a server responds to messages like the REGISTER request. I have a simple OpenWRT PBX in my router at home, and a couple of hard and Android softphones are working normally - they seem to register, perform calls both between themselves and outside too, so I'm sure it's functional. It's serving requests over UDP and port 5060.
But when I try to get a response from the server on a low level, how I used to do with tcp and telnet, just to see what's going on when a phone is working, the server doesn't seem to respond anything.
Can you please guide me how I can use netcat or some other telnet-like tool to see how the server responds over udp to any request, be them good or malformed?
Use tcpdump tool over telnet
Tcpdump Commands – A Network Sniffer Tool
check the link below.
https://www.tecmint.com/12-tcpdump-commands-a-network-sniffer-tool/
The good tool is Wireshark very good support for SIP message flow and RTP/RTCP.
You may capture the packets from the OpenWRT PBX and from your development device in order to compare things. Good learning!
These days, I'm really into webRTC technology, and I've been studying webRTC. But, I'm faced with a problem.
I understand that webRTC is using the ICE framework, which has TURN, STUN sever for relay and signaling. But as this article said, webRTC doesn't need a TURN server.
So I'm really curious whether it is possible to connect successfully every time without a TURN sever?
If it is, please tell me the way, and if it isn't, how often are peers using the TURN server in average?
Thank you.
(PS, Azar (one of the biggest apps using webRTC) also said they don't use the TURN sever on their website)
Yes it's possible to connect without a TURN server. Every time? Yes. Everyone? No. Because firewalls.
The Holy Grail of WebRTC is a direct client-to-client network connection without going through an intermediary server (a relay).
TURN is an intermediary server. It's used as a fallback when peers are behind symmetric NATs.
Negotiating this, is the purpose of ICE. There are articles written on how, but in short, "ICE agents" (browsers) collaborate on both ends, communicating through your JS signaling channel, to poke holes from inside the firewall on each end to connect up.
This related answer suggests TURN usage is ~20%.
STUN is not a relay, but merely a mirror server for agents to learn their own external IPs.
I am beginner level.
I try to broadcast data to the browsers in local area ( Same router by sending . . . 255 ).
I should implement the real time streaming service to the local level browsers.
But it will occur high traffic when the client browsers is increased.
To broadcast data, it seems to need UDP protocol.
But web browser base on TCP.
So i investigated the webRTC that is based on UDP.
But i don't really know how to use this.
Is it possible to broadcast the data to the web browser like chrome in local area ?
If not, why it is impossible to implement ? just for hazard of DDOS ? How can i solve this high traffic problem ?
( It really occur high traffic when each clients respond to every data from server (TCP) or the server send same data to the every client amount to number of clients (not broadcasting).
I just want to implement that the server just send one broadcasting datagram packet to the local area and each clients in local level receive same one data from the server but not respond to that. )
From a web app (not a modified web browser itself), you cannot create nor manipulate raw (UDP/TCP) sockets.The sandboxing and other mechanisms won't let you.
with webRTC, you will need to make an handshake, and use ICE.
=> You cannot push to a peer knowing only his IP/port
=> You have to have the receiver accept and acknowledge the transfer
you might have more change with WebSockets, but that requires additional mechanisms as well and not all parties will be able to support web socket (or accept the upgrade from http to WS).
For illustration purpose, you can see the work of Jess on a web-based bit torrent. He has exactly the same problems. https://github.com/feross/webtorrent
In my setup, I have a custom server in the cloud handling audio and video so I don't need (and don't want) the whole "where am I and what's my private and public address etc." discovery process. Essentially I want the SDP offer and don't care about the IP-address/port; that offer goes to the server, the server chooses codecs and gets the SRTP key and replies with an SDP answer to the browser which would contain a public address, the codec choice and it's key. Ideally the browser starts sending media to the server and the server simply sends "peer" media back from whence it came (which would tunnel back through any UDP friendly NAT devices).
I know this is technically possible because I already do this with Win32/OSX desktop clients... the question is, is this possible with WebRTC and RTCPeerConnection? I've tried a few configuration types, e.g. {} and { "iceServers": [] } but it still seems to go through discovery gyrations. Are there perhaps other ways to shortcut the process? Thanks!
No, you cannot skip the process, since the WebRTC implementation forces the use of ICE and STUN checks, to fix some security problems. So, the current Chrome implementation will force that the STUN checks are made to the ip/ports negotiated in the ICE candidates.
But yes, there are many applications working without this requirement. One day we have to change to better and more secure implementations. The day is now...
No, you can t skip it in webrtc browsers, but webrtc devices (here your gateway) can simplify the process by only implementing ICE Lite.
My task is to write a Messenger program for both internal and external staffs, I actually made it. However, I thing this is really not a good approach by using the client software keep "check-mesg" from server. So I think I am just simulating the IM program.
I want to make the client app become a listening server, and let user p2p talking without a "mesg-centre" at the main server(unless offline mesg happen). The question is how do I tell the external user ( other client app ) my location while I am behind a router ?
Are those other IM programs running on the client machine as a server too? and how do they get through ?
Thanks in advance!
It's quite complicated to connect to systems behind a router and not always possible. A well-documented way to do this with UDP is the STUN protocol (used mainly for SIP-based VoIP). If it is not possible to get behind the router, you can only use a server in the open network as intermediator (some P2P systems also promote well-connected peers to such intermediators). SIP uses TURN for as intermediator protocol. SIP's protocol to find out the right solution for a client is ICE.
See also NAT traversal.