I want to add one feature of Push To Talk kind of application for communication between my Team in my application. Beside this I also need some kind of text messaging. But I want it to be able to work in Gprs.I found that SIP API can be used for making voice calls but it says that it Requires WIFI. I want to make it run on Wifi as well as GPRS.
Can somebody give me some idea where to start from?
Push To Talk in SIP is just a regular call, with RTP doing the tricky floor control.
There's usually a media server involved broadcasting the voice bursts to all participants to save on the scarce upload bandwidth. The server usually has a public address simplifying NAT traversal for participants.
But if you are rolling your own, and don't need interoperability with other SIP services or IMS, and the whole thing resembles instant messaging more than phone calls, XMPP might be a simpler option.
I'm not sure about the Android aspect, but apart from the new, built-in SIP support which might be limited on purpose, there's always the SIP stack from SIPDroid, right?
Related
I have been looking for a way to set up the Android SIP stack to be able to establish a SIP call between two devices on the same network, in an ad-hoc manner. i.e without REGISTERing to a SIP server.
I have not been able to get this to work, as the SIP Demo includes server registration, and I cannot get it to make or receive a call without this step.
I am not even sure if this is supposed to be possible. The little mention of this I have been able to find is conflicting (some say it can be done with a specific set up which they do not say what is, and some say the Android SIP API is not meant for this).
I was wondering if anyone has got this to work or has any clues as to how I could go about configuring the API for this, as I would like to use the built in SIP API before looking at third party ones.
The application I am developing is an internal one which will always be running on the same devices, so the fact that the SIP API is not present on all devices will not be an issue for me.
I have been stuck on the same problematic.
If you can make it without the android sip api, you can look at the rtp api which gives you a bit lower-level tools to make a P2P VOIP application without the need of a server.
To support audio conferencing and similar usages, you need to
instantiate two classes as endpoints for the stream:
AudioStream specifies a remote endpoint and consists of network
mapping and a configured AudioCodec. AudioGroup represents the local
endpoint for one or more AudioStreams. The AudioGroup mixes all the
AudioStreams and optionally interacts with the device speaker and the
microphone at the same time.
The counterpart is that you have to write your own device discovery protocol in order to know the port used by the audiostream peer as explained in this answer
The problem is not so hard if you only intend to make one-to-one conversation but is a little bit trickier if you want to make one-to-n conversation.
For a one-to-n conversation, the conference host has to instanciate n audiostream for each remote device he wants to call. Each remote peer has only one audiostream linked to one of the host audiostream.
You can do this with CSipSimple, which is open source: http://code.google.com/p/csipsimple/
You set up local accounts, register to yourself instead of a server, then make a phone call using TXT mode and dial remote_account_name#remote_ip_address.
Sip peer is like an extension number used to configure in sip phone . Please find details for creating sip peer . I am using centos 6.9 64 bit and having installed asterisk 11
You can create sip peer using asterisk server .
Goto vi /etc/asterisk/sip.conf
[1001]
username=1001
secret=123
qualify=yes
type=friend
disallow=all
allow=ulaw,alaw,gsm
host=dynamic
For more detail and easy understanding. Please refer given below link
https://youtu.be/27wm-fu25SM
or
http://rulariteducation.blogspot.in/2017/07/how-to-add-sip-peer-in-asterisk.html
I'm currently working on an android project and I am trying to find the best way to go about setting up communication between two android phones.
One android phone will be docked on a mobile platform e.g. an R/C car. I want this phone to receive simple control signals ("forward", "backward", "left", "right", "gotoCoordinate") sent from another android phone. I also want the docked phone to be able to return status signals.
Preferably I want the communication to happen via GPRS. I'm aware of the difficulties concerning P2P-communications and I'm currently looking into "Android Cloud To Device Messaging." (http://code.google.com/android/c2dm/index.html)
I'd like to hear about your experience with Android C2DM (glad to hear about delay from transmit to receive) and your thoughts on utilizing it in my project. I'd appreciate other suggestions on how to go about this. I'm expecting to have to deal with relatively high latency using this method, but of course preferably lowest possible.
C2DM makes no guarantee about the "delivery or order" of the messages, and it is limited in the number of messages you can send (a high limit, but still a limit). It's not really for low-latency stuff like controlling an RC car. It's better for non-realtime events.
http://code.google.com/android/c2dm/
For lower latency stuff using GPRS you can setup a third party server on your own and have both phones communicate through it. I've done that for several Android apps using straight up TCP sockets and it works reasonably well (and it would be even faster/better if you went UDP). Using GPRS may still have too much latency, depending on your needs, but it's a tradeoff (it's very convenient, almost always there, other methods are not).
The ideal way to do this would be to combine whatever is available and fallback gracefully, and test the latency once connected to make sure the network is up to par, or bail out. For example, use the local WiFi network if it's available. That is to say, have both devices "register" with a third party server as they startup, then if they're both on the same WiFi just have them communicate directly (run a server on or both, and clients on one or both, get information about discovery and such from the registration). If they are not on WiFi then fall back to GPRS, but realize there will be more latency, of course. Finally, once any method has been established send some test messages to check latency.
I know this isn't really an "answer," it's more of a stream of consciousness about this, but it wouldn't fit in a comment, and I thought it might help ;).
(Full disclosure: I've worked on Android apps that connect multiple mobile devices and multiple TVs, some over GPRS, some Wifi, some directly. I work for a company (MOVL) that makes a platform for stuff like that, it's more focused on mobile-TV-mobile, but it supports mobile-mobile also. In all it's not too hard to do yourself with regular networking, the tricky part is getting the latency down and picking the correct method for each device.)
I am implementing a real time - multi user voice transfer application for Android.
I have read that, as a standard - RTP packets are encapsulated into SIP and then sent to destination(s). What is the advantage of doing so?
my idea was to use a server, just to receive control messages from nodes and open sockets. All these nodes would be in 1 group. THen, I send out the IP addresses of each of these nodes, so that a single sender can multicast its packets directly to the destination.
is there a fatal flaw here? ( iam not concerned about the power consumption)
How does SIP do better? or does it ?
Thanks
RTP isn't "encapsulated into SIP packets". SIP is a signalling protocol. RTP is a media stream protocol. SIP is used to negotiate and set up (and tear down) media streams.
TCP is a horrible choice for media (RTP) packets; it's not clear from your writing if you're suggesting that.
Multicast is unlikely to work for many network paths/recipients.
routers play merry hell with incoming data; you'll need more than just SIP to deal with users on the open net. See STUN, TURN, ICE, UPnP, etc.
SIP or Session Initiation Protocol is a protocol that was designed specifically to address the problem you're trying to solve. Generally, the reason you should reuse (rather than reinvent the wheel) is because other people have studied the same problem and presumably have come up with a better solution as a collective group than you could as an individual. Of course that's not always true, but generally speaking it holds!
If you want to learn about SIP you could study the RFC 3261 specification, or start with the Wikipedia entry if you want a quick overview.
That being said, if you don't need the overhead of a complete and carefully tested protocol you could roll your own but make sure that when you're making that decision you know what you're foregoing and have a good reason to do so.
SIP is a signaling protocol that usually runs over TCP (although not required) and if you look at it closely you will see it is very similar to HTTP in many respects. Just like HTTP it can transport a great deal of payloads and it does so with text headers, much like HTTP can be used to transport HTML, XML, plain text or any arbitrary binary payload.
In the most simple system, you could just use Voice packets over RTP over UDP.
But you'd have no way to turn audio off, and would have to know IP addresses, port numbers, they type of codec and its characteristics beforehand.
In an overly simple view, SIP is a way to:
1. find the ip address of another endpoint from a URL. (May need STUN, TURN, ICE, etc)
2. agree on which codec to use and its options
There's a lot more to SIP than that, you may want to investigate SIP's conferencing features based on what you wrote.
You may write your own signaling protocol, and if this is for a school project, that will work just fine.
But if you are doing a commercial project, bear in mind that there is a lot more to telephony than meets the eye. The original SIP spec was greatly revised and is now a cluster of RFCs which are still being modified and added to. I recommend that you take advantage of this work rather than possibly reinventing the mistakes others have made.
can anybody confirm what are the currently allowed methods for peer-to-peer communications within the Android framework? I need to transfer json strings and I'm currently using SMS which works ok but the problem is that the data also ends up as lots of text messages. I've read Reto Meier's first edition of Professional Android Application Development where he says that the data transfer options were not implemented due to security concerns.
Has this changed at all and how would you do peer-to-peer transfer of data?
Have you looked at Qualcomm's AllJoyn library? It is designed to work over Bluetooth or wifi, so may fit, though if you're connecting over 3G or wider range networks it won't work.
Given the variation and reliability of networks between two remote devices not on the same network, I'd question whether peer-to-peer is the best solution, and would venture to suggest considering using an application server in between, so you could then use Cloud to Device Messaging [deprecated] (perhaps in tandem with Google App Engine). i.e. to send a message the sender passes it to the server, and the server then passes it on to the recipient.
In theory all devices on the net have a unique IP address and can talk to each other, but it's rarely that simple as routers/firewalls are configured differently so you'd need to pay great attention to the ports you use, especially considering many inbound ports are blocked by default for security reasons.
You can simply use UDP/TCP sockets. In a separate thread you set up the server-side listener socket and that's it. Of course your application has to be started first (or should run in the background all the time). Here's an example:
http://thinkandroid.wordpress.com/2010/03/27/incorporating-socket-programming-into-your-applications/
If you also need peer discovery that will make the thing more difficult.
You should also take a look at peerdroid, an open source project available here. I've been looking in to peer communication options from the point of view of having a collection of federated devices (pre-paired, if you like, similar to Bluetooth pairing); this library looks like it may give you the foundation for what you are trying to do.
If you are on your own network (for example a home or office WiFi) then you should be able to query for other connected devices. If the network you are on is not under your control (the mobile network or a public wifi) then the network will have been configured to isolate each device from everything else. In this case you will have no choice but to put a server up to act as the man in the middle. That brings its own architectural compromises - every device has to regularly poll the server or keep a connection open - unless you use Google App Engine which supports push notifications over Google's own infrastructure.
Thanks for your answer ldx but I would need peer discovery as you indicated. Some further research appears to indicate XMPP as a suitable technology and there are now some services on offer, although these appear to be aimed at 'server' to client notifications. There is a good discussion here on XMPP and some more here although it would appear that there are still some issues to deal with such as polling v push, long-running open http connections and battery life. Xtify looks promising, especially their web service. I hope this provides suitable information to others looking at the topic of peer-to-peer data communication.
I want to send and receive information between Emulators in Android.i am using two systems and i have installed android in both the systems and i have to consider one emulator as server and another as client.Now i want to send data from one to another.Anyone knows regrading this please help me with some sample code.
What sort of information do you want to send between the emulators?
You can transmit SMS messages, or simulate phone calls, from one emulator to another using the target emulator's console port number as the number to dial. The Android Developer Site describes the process in more detail under "Sending a Voice Call or SMS to Another Emulator Instance"
If you want to transmit data, unfortunately Android doesn't currently provide any P2P or Instant Messaging APIs, so there's no generic technique available through the SDK you can use.
Your best alternative is to create your own server-based solution (or your own P2P API, though that might be a little more complicated).
Take a look at Java Socket.