Is it possible to send Java Applet through SMS.
The requirement is to download a Java applet through SMS to a mobile. Later install it.
SMS is probably not going to work very well with this. The limit for a single message is 140 bytes (which gives you 160 7-bit characters), and (according to Wikipedia) the standard only supports up to 255 segments in a long message. This means you are limited to 140 * 255 = approx 35Kb, which is fairly small.
It will also get expensive very quickly if you pay per message sent or received.
You are probably better off just using the internet. Any phone that can run an applet probably has proper internet access.
SMS is just 160 printable bytes :-) You can send a link to download applet at best.
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I'm implementing a bacnet library to read and write some object instances.
But I don't understand, why with a PC and with an application like Yabe if I ask to a common controller to read more than 300 objects, the segmentation is supported, instead with a mobile phone and on the same request to the same controller the segmentation is not supported.
Both the PC and the smartphone are in the same network on Wifi.
So what is the problem/difference?
It is nothing to take with a PC or a mobile phone. Any IP compatible devices mobile phone, desktop, laptop, Arduino chips will work with BACnet.
Your problem is segmentation. You will have to handle the segmented messages coming from the Controller.
Every BACnet controller vendor specifies the MaxApduLength (i.e max length of data to be transferred within one UDP packet). The standard APDU length is 1476 bytes. So a BACnet controller cannot send the data more than the length of APDU specified within it.
Requesting 300 objects from a controller results definitely in a large APDU than the controller's limit. In this case Controller will send you segmented messages each with sequence number. You will have to handle this all segmented messages and combine them in one message then only you will get exact response. This is same with Yabe and other BACnet clients.
I have also written BACnet libraries for our mobile applications in Java and Swift 4.0 and both can read any number of objects from controller with segmentation support added. I have tested these with controllers having more than 400 objects.
Segmentation is used for APDUs (responses) that are too large to fit in one frame on the datalink. If both devices support segmentation, then great. If one of the device does not support segmentation, and the APDU does not fit, then "Segmentation not supported" error is issued. (and you have to then retry a smaller request).
I'm doing research on different communication protocols used in Internet of Things (IoT).
I'm sending "Hello" massage from one Raspberry Pi to another,because I want to measure speed, bandwidth etc.
How could I set massage size? I would like to try sending 32 bytes massages up to 4032 bytes massages.
Edit: I'm testing MQTT, AMQP and SOAP communication protocols.
Check nats.io Benchmark and Tune NATS.
It mainly focuses on nats.io but the output could be used to bench your systems against other protocols.
Here you could find more info about how it is being used for IoT.
Regarding the message size https://nats.io/documentation/faq/#msgsize:
NATS does have a message size limitation that is enforced by the server and communicated to the client during connection setup. Currently, the limit is 1MB.
I have couple of question:
1) what is the max number of users that can receive video?
2) Is it possible only to watch remote streams without access to my camera/microphone? Imagine that I only want to watch debate between Dawkins and Pope Francis. :)
Regards
Answer to #1:
The maximum number of users that can be simultaneously sending video to each other is limited by the capabilities of the hardware to encode and decode video streams. There is no hard limit.
If you are looking to do a single sender and multiple receivers, then again you are limited by the local machine. The sender will need to encode a separate stream for each receiver since the available bandwidth to each receiver will be different and impact the quality of video that can be sent.
Answer to #2:
You do not have to send audio and video. Even if you give permission to access your camera and microphone, you can later mute them (https://vline.com/developer/docs/vline.js/vline.MediaStream)
Also, take a look at this page for some more thoughts on this:https://www.webrtc-experiment.com/webrtc-broadcasting/
I try to understand and implement the MQTT-Client for node.js, which can be found at: http://jahbromo.blogspot.de/2011/12/client-mqttt-javascript.html
When I publish playloads lower than 128 bytes there's no problem and the message gets directed correctly, but when the payload is larger, node.js prints out "Connection closed by broker" right after the publishing. Because i'm relatively new to websockets and node.js I don't understand why this node.js-server-implemenatation mentioned above can't handle playloads larger than 128 bytes.
Because I need to send larger payloads, it would be great if someone could help me to increase the limitation.
Thanks.
You'll notice down in the limitations of the code you link to (which is actually a modified version of https://github.com/yilun/node_mqtt_client ):
Can not handle payloads larger than 128 byte.
This is a limitation of the client library, not of MQTT.
To add support for larger payloads, you need to implement full "remaining length" support for the PUBLISH packet as described in the spec: http://public.dhe.ibm.com/software/dw/webservices/ws-mqtt/mqtt-v3r1.html#fixed-header
hai..
how to generate raw pockets and send to another system using winpcap in vc++.i had done capture packets(sniffer) using winpcap in vc++
kindly help me
Thanks
You can send packets using WinPcap, it's part of its interface (the basic function is called pcap_sendpacket).
In order to generate packets, you can simply write the packets' bytes.
What type of packets do you want to send? I have some experience creating packets, but I did that in C# (If you want to do that in .NET, you can create and send packets easily using Pcap.Net).