Similar to subscription do we have support for SCAN in the milo SDK client to collect the data? For SCAN, the timer will be at the client-side; for UA-Server, it is like a demand read. Please share more information about classes get used for SCAN.
Answered here: https://github.com/eclipse/milo/discussions/1018
SCAN isn’t an actual OPC UA concept, but it sounds like you’re talking about issuing a periodic call to the Read service.
You can do this, of course, but you’ll have to set up the timer yourself.
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I am building a WebRTC videoconferencing service for iOS and Web. We have so far used tokBox, they deliver the whole package (client API (ios and web) + TURN server. Their solution also takes care of generating tokens and session ID etc. But we want to have our own setup, and a partner has given us a TURN server. But, what do we miss to be able to have a webRTC video conference between iOS and a web client? What service will let us just plug in the TURN server address/credentials and have it work both from a web and iOS client? Are these suitable packages: EasyRTC, SkyLink, AppRTC ? We don't need a lot of features, just 1-1 videocall with no bugs. Which one is best?
at minima you will need a signaling server.
apprtc is a complete application, it is not suitable for what you have.
tokbox is a PaaS, so you could replace it with another PaaS (skylink, forge, ...)
easyrtc gives you the code of a signaling server, but not the infrastructure (load balancing, ...), you can use it if you re ok to host it.
you might want to go for peerJS (open source, both hosted and DIY options) if you really want to do it yourself. Otherwise, just changing PaaS is not making a lot of sense. You have to think about everything you're gonna lose as well (recording, archiving, media server, ...).
If your use case is well defined, you can ping me offline, and i'll point you to additional resources.
You can look to Kurento media server.
You can use the service provided by anyconnect SDK. They provide the leading Peer to Peer connectivity between any two nodes whether browser, desktop or mobile platforms. They also provide STUN,TURN and Signaling (SIP,XMPP) server support. Using their SDK will let you just plug in your server credentials and transfer any type of data.
Hope u guys are doing great.
I want to make a realtime turn based game in iOS .
I know this can be achieved by using GAME CENTRE in iOS , but i have to play this between browser and iOS app. WEB TEAM is using node js for making this game on web browser , they also suggested me to use node js in iOS game as well.
Have anyone has idea how to use node js for this kind of purpose.
Thanking you all! :)
You can have websocket server written in node js and then just connect to it from your ios app using some websocket library (hope it exists). Then sockets connected from browser and your app can realtime exchange information.
You could use a pub/sub messaging service like Realtime (the company I work for) http://framework.realtime.co/messaging/
Both your node.js server and your ios devices could exchange data through Realtime pub/sub channels, using the node.js and ios SDKs.
The cool part is that since it's a managed service you don't need to worry about the server and networking administration, Realtime will take care of that for you.
I'd like to add some words in favor of #Edgar's answer.
For production, using only WebSocket is not reliable. In environment where WebSocket is not available due to antivirus, enterprise firewall, and so on, a kind of full duplex connection over HTTP should be available utilizing long polling or streaming in terms of reliable real-time connection.
Also such connection might be disconnected for a while e.g. moving away from Wi-Fi zone and then some messages which had to send through that connection may be lost so that a way to recover such messages is required e.g. here is some messages you couldn't receive.
Therefore, you need a reliable framework to write such real-time web application. Here's features which are required to write a real-time web application I think. (It's called Cettia and I'm the author of that project. As it doesn't provide iOS client, it's not right choice for you here. Just focus on features and roadmap to see what features you may be needed and evaluate a framework you will choose based on them.)
On Node.js world, socket.io framework has a great community so I'm sure someone already wrote iOS client for socket.io. Anyway, make sure that the framework you finally chose has features you need to write your real-time webapp.
The type of content isn't really important for this question, but let's just say I wanted to implement a (native mobile) shopping list app that allowed multiple users to collaborate on a shared list.
How are sync features like this usually implemented that work automatically (without explicit user interaction)? Is the preferred way to pull every few seconds to check for newer versions and update if necessary, or is it possible to push changes?
A polling solution would be (relatively) easy to implement I guess using something like AWS, Google App Engine or even from scratch on a LAMP stack and REST. But I'm worried about traffic resulting from continuous polling.
Would it be practical to try to implement this using push updates? If so, what technologies, services or design principles should I look into? Is something like this possible with AWS or Google App Engine? Or is pulling (and reducing traffic as much as possible) the way to go?
On app engine you should look into the channel API. From the overview:
The Channel API creates a persistent connection between your application and Google
servers, allowing your application to send messages to JavaScript clients in real time without the use of polling. This is useful for applications that are designed to update the user about new information immediately or where user input is immediately broadcast to other users. Some examples include collaborative applications, multi-player games, and chat rooms. In general, using Channel API is a better choice than polling in situations where updates can't be predicted or scripted, such as when relaying information between human users or from events not generated systematically.
You can use a few of Amazon Web Services to create an effective and responsive service.
If you check out the IOS SDK that you can download from AWS site, you can find in it an example for a service that is using such services: S3_SimpleDB_SNS_SQS_Demo
First you can use SQS, which is the queueing service, which has long polling that will help you to lower the number of requests.
Second you can use SNS, which is the notification (pub/sub) service. It is integrated with SQS, and you can subscribe queues to listen to notifications.
These services (and others) are accessible through the iOS SDK, as well as with other SDKs (Java, .NET, Android...) and REST and SOAP APIs.
I'm familiar with SOAP and Webservices for peer-to-peer or client/server messaging on other platforms. What is the Apple equivalent for messaging?
I'm trying to put together an application server that will manage a collaborative work environment. It will have an average of 200 and maximum of 1000 mobile clients on a LAN. For example, one Mac and 200 iPhones. I'm planning to use Apple's Enteprise approach to distribute our private (commercial) app to each of our iPhones clients.
The server can push configuration settings to each client. The server will also push small sets of data to the clients. The clients will perform tasks on this data locally, and eventually report back status to the server. The clients can request more data sets from the server. These exchanges can be managed asynchronously.
There is also be a need to have synchronous exchanges for critical processes. This is rare, but it is a requirement.
The data that needs to be exchanged is reasonably small. These client/server processes are time dependent, so performance is critical requirement.
The network won't be shared, but needs to be tightly controlled (and fast). E.g. it can be Bonjour if there is a compelling reason for that.
I'm looking for a recommendation on which components of the Mac/iOS SDKs to leverage. Please leave 3rd party software out of this discussion. I must know what Apple already offers and what gaps exist before considering outside software. Thanks.
If you are only going to be using Mac and iOS products then Bonjour is really your best bet. There are a ton of native ways to transmit data in either byte or object forms.
There were a couple great videos from WWDC 2012 showing what the new Xcode can do to create client and server applications. It is under NDA, but you may want to take a look there: https://developer.apple.com/videos/wwdc/2012/.
Also you said you did not want third party, any particular reason? Would you use an open source layer on top of Bonjour?
I have a lot of experience writing Delphi 6 Pro apps using the Skype API. I don't use the COM object but instead I interface directly with the Skype client using the SendMessage() system. My current application acts as a full duplex audio proxy with video transmit. To transport audio I use ALTER CALL with the PORT parameter to establish a duplex audio connection with the Skype client via a pair of sockets. For sending video I have a DSPACK based DirectX filter that I instruct the Skype client to select as the chosen video device. This works fine but since it's the Skype API I have the awkwardness of interfacing with the Skype client as a separate entity.
Now along comes SkypeKit which apparently allows a developer to integrate Skype in a much more integrated manner. I'm about to dive into it and I wanted to hear from any developers out there that switched over from the Skype API to SkypeKit. Some questions:
Was there anything missing from SkypeKit that is offered via the Skype API that made your app conversion difficult if not impossible?
Do you have any tips on making the transition as smooth as possible, especially when it comes to avoiding any design choices that can really come back to haunt you when you get far down the SkypeKit path?
Did you find any web resources or documentation from other developers that were really helpful in saving you time or trouble? (Please share links if so).
I am using SkypeKit in my chat-centric Java application so I haven't dealt with A/V.
SkypeKit is just a “black box” program that interacts with Skype protocol by iteslf. It is an executable that starts a process which listens on local port. The process is lightweight, only 20mB on my Windows-based developer machine. It runs completely in background, there are no any notifications at startup/messaging/shutdown.
Your client program interacts with it by sending byte structures via local SSL tunnel. These structures are wrapped by API for C++, Java and Pyton. Java API is easy. You start the process, create new Skype() object and login with your Skype account credentials and get your program callbacks execution when some events happen.
So #Whiler is not completely right, you always need a host application, but in this case this one is small and fast.
I don't know how hardware-based kit works but I think it is a more low-level way.
You can read the Java API here, C++ API (with examples) here, and Python (with examples) here.
Oh, and at least one small difference between desktop API and kit-based one: you can post XML text in the chat.
SkypeKit is no longer supported - https://support.skype.com/en/faq/FA12322/is-skypekit-being-discontinued
Disclosure: I used work for Microsoft/Skype
The main difference between SkypeKit and the other solutions (sendmessage, COM) is that the Skype client application is not needed... you can directly interact with the skype network...
I haven't dig this solution as the access is not free (not expensive, but without real projet, this was a no go for me...).
So this can be very useful if you plan to replace the real skype client with your own software on final machine... but if you just want to interact with an existing one, I'm not so sure.