I have done a few captures with wireshark on my computer, and I see ARP messages, which are think they are coming form the the VoIP phone, which is connected to the computer(USB cable). I think they should not be there, but I wonder how I can capture and indentify VoIP traffic in my computer.
I have typed the following filters but I see none:
sip.CSeq.method eq INVITE
sip.Request-Line contains INVITE
Try to capture the traffic from the USB. See https://wiki.wireshark.org/CaptureSetup/USB how to setup such a capture.
Related
I'm very unfamiliar with Linux so forgive me if this has been answered before, I've read quite a few answers but I'm never sure if they actually relate to my question.
I have a headless raspberry pi that connects to my phone's bluetooth automatically, my phone shares its internet access by tethering. I use this initial and reliable connection to SSH to my raspberry pi, and use the desktop with VNC viewer.
I would like to connect to a WiFi network that uses a captive portal, but the browser always uses the bluetooth connection so it never redirects me to the portal page. The bluetooth connection is just to be able to use the desktop so I can get through the portal, then I would like to either disconnect bluetooth or just not use it, mainly because of the low bandwidth it provides.
I've added wlan0 as a priority interface with ifmetric, but that hasn't worked.
I was thinking that forcing all HTTP connections through the wlan0 interface could solve the problem, but there may be a simpler way, feel free to tell me.
Can you explain in "simple" terms the best way to achieve this ?
Of course, there are multiple solutions. The simplest is making sure that there is only one correct default route.
There are 3 situations:
You are only connected via bluetooth via ssh
You are connected via bluetooth and via wifi, but not yet through the splash
You are through the splash
Each will require a different network configuration.
In 1, your network config will probably be:
some IP address (let's call it IP-bt) and network mask
Default gateway is your phone
With route -n you can verify this.
In 2, the network config will depend a bit on the wifi network, but in general, your network config will be:
you'll still have IP-bt
you will have a new address on the wifi adapter (which we call IP-wifi)
the default gateway should be the gateway on the wifi network.
When you verify this with route -n, you might still see a route with destination 0.0.0.0 towards your phone. You can delete this route. Your phone should be on a directly connected network and your ssh session should therefore not break.
If the default gw is not on the wifi network, you can still remove the route that sets your phone as default gw.
Under 3, the default gw must be on the wifi network, and not on the phone. You will still be able to use your phone, because it is directly connected.
Something to watch out for in this scenario is that your phone will act as a DHCP server. That means once in a while your DHCP lease will refresh, and the bluetooth default route may re-appear. Disconnecting bluetooth will prevent this.
The second solution is to use ifmetric. Instead of making wlan0 a lower metric, make your bluetooth a higher metric. Again verify with route -n that the metrics are as you want them to be. Verify with a traceroute how the packets are moving.
A third, and most complex option would be to install Quagga and configure correct routing.
I'm working on a software written by a developer that didn't leave any documentation for the company and I've to understand how a server communicate with a device.
I think it sends it some strings over a socket (to log-in in the device and check some parameters), I've the public IP address of the server and the public IP address of the device.
I'd like to know if there is a way to see what the server 'tells' to this device and vice-versa, I gave a quick look to Wireshark but I can't understand how to use it correctly.
Can anyone please tell me if it is possible to publish the voice from an IP based telephone to a RTP based media server - like a Wowza Media Server or Flash Media Server?
Thanks
You probably need to give more info if you want a more specific answer, but a quick response is that yes it is possible.
If the IP phones is something you are building or can modify then you can simply send any outgoing RTP packets both to the other end of the call and the media server, and forward any received RTP packets to the media server.
If you are not able to modify the phone, then you may still be able to achieve what you are looking for by 'mirroring' the RTP packets that are sent to and received from the IP phone, to the RTP media server (see http://en.wikipedia.org/wiki/Port_mirroring for an overview of port mirroring, and www.audiocodes.com/filehandler.ashx?fileid=43289 for some specific discussion on 'tapping' phone calls).
Note, that you need to be aware of the law if this is to record or 'tap' live calls. Even if they are your own calls on your own phone, different countries have different laws about what can and cannot be recorded and what notification you have to give the parties involved in the call (this is why calls to call centers etc often start with a message that the call may be recorded for training or other purposes).
What hardware/software do I need to setup a machine that monitors incoming text ("SMS") messages on a phone connection? The software needs to be able to read the message, copy it to a database and then delete it.
Three ideas:
Use google voice instead of a cell phone, and your received SMS will arrive as email
Obtain a cheap phone that features a serial port on the headset connection and can use AT commands (AT+CMGR or something like that) to receive SMS, connect this to a computer's serial port using a cable with level translation
Use an Android phone and write an application which does this.
Is it possible to have a j2me app on a mobile to act as a "SMS gateway" that will handle incommming messages, do a query on a database via GPRS and reply the user back?
This is entirely possible on any J2ME handset that supports JSR 120 (i.e.: most of them). However as Wonil said, you can't just process ANY incoming SMS message. It has to be an SMS sent to a port number on which your app is listening (using a server connection as Wonil explained).
It wouldn't be automatic unless the app was signed (as confirmation is generally required for sending SMS and network access).
Another approach is to tether your phone to a PC using a USB cable/bluetooth/IR, open a serial connection using the phone as a modem, and write a program to listen for new SMSs using AT+CGML as described here. This would allow ANY incoming SMS to be processed (no port number required), and without any annoying confirmation prompts.
HTH
I think you should check about JSR-120 documentation to confirm.
But, in my thought it might be impossible. If you want to receive message by using JSR-120, you should assign specific end point(port number) to listen as like below:
serverConn = (MessageConnection)Connector.open("sms://:5000");
So, you can't catch all SMS messages. It can't be a gateway then.
It probably depends if your phone supports it. Have a look at the J2ME Wireless Messaging API:
The Wireless Messaging API (WMA) is an optional package for the Java 2
Platform, Mobile Edition (J2ME) that
provides platform-independent access
to wireless communication resources
like Short Message Service (SMS).
http://java.sun.com/products/wma/overview.html
This article has some examples which can probably serve as a starting point for what you want to achieve: http://www.ibm.com/developerworks/wireless/library/wi-extendj2me/
Edit: as others have pointed out, you might not be able to receive all messages.