Vote for the best protocol for the given scenario

Question

I have a design decision to make. I need your advice.

Requirements:

• A server and a client. client is typically a mobile phone.
• Connected through the Internet.
• Server and client want to talk to each other.
• Exchange of text, multimedia between the client and the server.
• Text would be some standard format. that is predecided.
• Real time requirements
• Session would typically last for 5-15 minutes. In some cases for under a minute. assume 5 minutes as the session duration.
• The protocol should adhere to standards.
• It must be efficient.

Option 1 A binary protocol that I design for my application.

Option 2 Implement my server as an HTTPServlet. Client sends post requests and the query in the post message and servlet sends response in the message. However, I think that for real time interaction, this is not a good option as a new thread would be created for each post request even for the same client and session. Please comment on the efficiency of this.

Option 3 Use a normal servlet. Would face the same problem as above.

Option 4 Use SOAP

Option 5 Use REST

Option 6 Use Google Wave (I haven't read the specification yet)

Option 7 Suggest some other protocol

Right now, I don't have experience with web services, but if it is the option then I don't mind investing time in it.

Basically, I want the speed and efficiency of option 1 with a standard way of doing things.

Thank you

Answer 1

Option 7 Why don't you go for XMPP?

• It's a standard

• it allows messages in both directions.

• you may use existing XMPP infrastructure (clients might connect using their Google Talk accounts for instance) or easily build your own using open source XMPP servers

• I also like the fact, that you basically only write client code (as the server is also an XMPP client) - assuming server and client are both written in same language, you may even use the exact same code.

• file transfers are supported.

• easily extensible to your needs

• it's buzzing (Google Wave) ;)

The only thing people might argue about is its efficiency - or the efficency of XML in general. I don't think it's a problem though.

Answer 2

Sounds like to me that you would be best served by the HTTP protocol. It has a low overhead, already well accepted. Uses TCP [which is a requirement for mobile communication], it has session negotiation [well connection wise not the actual state of the session]

Use a different protocol for sharing of video and audio, but set the connection up with the http one.

Using SOAP/web services would not be optimal, due to the processing required. From personal experince webservice clients on mobile machines is easier but the processing required is tremedious and can create a bottleneck in your application. [Mobile machines don't handle threads too well]

Also: Since you are sending data over wireless you also have to account for the additional issues dealing with unguided media.

Your requirements:

• A server and a client. client is typically a mobile phone. : Yep
• Connected through the Internet. : Yep, depends on how your device network is setup
• Server and client want to talk to each other. : Yep
• Exchange of text, multimedia between the client and the server. : HTTP works well with text and images, but you need to switch to something unreliable like UDP for video.
• Text would be some standard format. that is predecided. : Yep
• Real time requirements : This is impossible, but can be attempted.
• Session would typically last for 5-15 minutes. In some cases for under a minute. assume 5 minutes as the session duration.: There are headers to keep the session open
• The protocol should adhere to standards. : RFC Something
• It must be efficient. : The only processing you have to do is line by line parsing of Key: data.

Also, I forgot to mention SOAP/Webservices is XML over HTTP.