Comments on Tomek on Software: WCF net.tcp protocol in Silverlight 4

WCF is slow with comparison to raw socket http://w...

2011-01-19T20:08:42.296-08:00

WCF is slow with comparison to raw socket
http://www.udaparts.com/document/articles/fastsocketpro.htm

I am not sure what your message exchange pattern i...

2010-11-12T12:29:14.843-08:00

I am not sure what your message exchange pattern is, but you may want to check out http://laharsub.codeplex.com for an open source pub\sub solution that uses HTTP long polling and supports Silverlight, JavaScript (jQuery) and .NET as clients.

We also had a hard time getting the HTTP Polling D...

2010-11-12T12:26:26.174-08:00

We also had a hard time getting the HTTP Polling Duplex protocol to work reliably for us. We spent a lot of time troubleshooting strange, nonreproducible errors. Things got much, much better when we switched over to Net.TCP.

When I used to write an HTTP polling duplex applic...

2010-11-12T11:53:14.114-08:00

When I used to write an HTTP polling duplex application to allow clients to stay up to date information from MSSQL in a period of time, the system almost always crashes after a few times to browse, or speed will become increasingly slow - not even always updated. I really feel the HTTP polling duplex is not a good solution if it's too bad performance like this.
So, hope you have a better solution for the HTTP polling duplex in a near future to come.

i hope your team improve performance for http-dupl...

2010-11-12T11:48:31.302-08:00

i hope your team improve performance for http-duplex-polling in next version of silverlight. Because with now performance, it not value for use in real scenario.

Ahmed, the Windows Mobile 7 does not support TCP i...

2010-09-15T12:06:13.959-07:00

Ahmed, the Windows Mobile 7 does not support TCP in this release. In Silverlight, there is no TcpClient, but you can use System.Net.Socket directly, or use WCF net.tcp binding.

Lex, the net.tcp support in Silverlight is subject...

2010-09-15T11:18:15.284-07:00

Lex, the net.tcp support in Silverlight is subject to the same port restrictions as System.Net.Sockets. Rationale for the restrictions is outlined at http://msdn.microsoft.com/en-us/library/cc645032(VS.95).aspx.

Im interested in the reason for restricting the ne...

2010-09-13T17:24:00.316-07:00

Im interested in the reason for restricting the net.tcp so effectivly it only work is usable for Intranets.
It seems far superior to Http polling, and the restriction must have been added for a reason- or am I missing something?

Hey There, I'm keen on building a cross web b...

2010-09-09T21:13:00.447-07:00

Hey There,

I'm keen on building a cross web browser/Windows Mobile 7 MMO using silverlight, however I found that the TCPClient which exists in regular C# is no where to be found in silverlight. I was wondering if there was an alternative I could use which would work in silverlight for both windows mobile 7 and PC/Mac?

Cheers

You are correct, HTTP long polling is not a good c...

2010-08-06T11:28:03.006-07:00

You are correct, HTTP long polling is not a good choice for enabling asynchronous notifications from the server on a mobile device, as battery power consumption impact would be very similar to keeping an open TCP connection. In fact mobile devices are sufficiently different in that respect to warrant their own solution. On Windows Phone 7 one should consider using Push Notifications instead. A good post by Nick Harris on the topic is at http://www.nickharris.net/tag/how-to-receive-microsoft-push-notification/.

Good point. But if you're going to be doing t...

2010-08-06T11:09:26.061-07:00

Good point. But if you're going to be doing the sort of application that would reasonably require HTTP Polling Duplex (say, a mobile version of the collaboration app we're working on), it seems like keeping the Long Poll open would be maybe even harder on the battery. (Haven't tested it, obviously, and you know the internal details about 100x better than I do. :-)

On the other hand, battery power is oftentimes the...

2010-08-06T00:12:20.626-07:00

On the other hand, battery power is oftentimes the limiting factor for application design on mobile devices, and to that end keeping an open TCP connection puts a strain on the battery.

Nothing solid at this point. But it makes sense, ...

2010-08-05T19:22:37.081-07:00

Nothing solid at this point. But it makes sense, right, that (especially) on a wireless system, you'd want the fastest, least chatty protocol available, right?

As far as I know there was only time and resources...

2010-08-05T17:18:56.662-07:00

As far as I know there was only time and resources that prevented net.tcp from being in WP7 - we are looking at adding this functionality in future releases. It would help if you could share more details about the kind of application that would benefit from net.tcp on the Phone platform.

Tomek -- will Net.TCP ever be available? Or jus...

2010-08-05T11:01:12.100-07:00

Tomek -- will Net.TCP *ever* be available? Or just not right away? As I recall, the current WP7 version of Silverlight is a branch of Silverlight V3, but presumably future versions will be based on V4 (or V5), and hence would presumably have the new features...right?

Net.tcp protocol is not going to be available on t...

2010-08-05T10:33:59.312-07:00

Net.tcp protocol is not going to be available on the Phone 7 platform.

Is tcp.net going to be available on the Phone 7 im...

2010-08-05T05:30:17.397-07:00

Is tcp.net going to be available on the Phone 7 implementation of Silverlight?

Tomasz, Where is your online project template for...

2010-07-21T14:38:52.483-07:00

Tomasz,

Where is your online project template for Visual Studio 10 to facilitate hosting of the TCP socket policy? Seems that the link is broken

Ken, generally this seems like a great approach to...

2010-03-18T10:10:14.371-07:00

Ken, generally this seems like a great approach to me. One aspect to pay attention to are some behavioral differences between proxies that use net.tcp vs polling duplex that may or may not be relevant to how your application functions. For example, polling duplex will use TCP connections out of the browser enforced connection limit, while net.tcp will not. There are also differences in how net.tcp and polling duplex channels are faulted in case of a communication error.

Tomasz, is there any reason an approach like this ...

2010-03-11T12:52:42.216-08:00

Tomasz, is there any reason an approach like this wouldn't work?

- On the server, expose your WCF service using both Net.TCP and PollingDuplexHttpBinding.
- On the client, try to open a connection to the web service using Net.TCP.
- If that succeeds, use Net.TCP.
- If that fails, fallback to the PollingDuplexHttpBinding.

That's the approach we're currently taking, and it seems to be working. Any reason why it wouldn't, or any reason why we shouldn't?

A cross-platform communications protocol that supp...

2010-02-10T20:15:23.546-08:00

A cross-platform communications protocol that supports real call-backs and that works across the Internet and firewalls is ICE (http://zeroc.com).

They have Silverlight 2/3 support as well.

Is it possible to have data validation attributes ...

2010-02-05T13:41:04.695-08:00

Is it possible to have data validation attributes in the classes on the server side and when adding a service reference to the server to have the classes generated with the data annotations on them?

Florin, you are right - polling duplex protocol is...

2010-02-02T10:16:04.106-08:00

Florin, you are right - polling duplex protocol is the way to go on the public internet.

So if I want to deploy a Silverlight 4 app which w...

2010-02-02T06:10:16.216-08:00

So if I want to deploy a Silverlight 4 app which wants to take advantage of a duplex wcf service over the web, I would need to expose the wcf service through a PollingDuplexHttpBinding endpoint? (because I cannot rely that everyone has the tcp outgoing port allowed - 4502-4534)

SCollard, a net.tcp WCF channel maps to a single u...

2010-01-14T13:32:09.386-08:00

SCollard, a net.tcp WCF channel maps to a single underlying TCP connection. This means that messages client sends over an instance of a net.tcp WCF channel will always reach the same instance of the backend service despite there being an NLB between them. If the net.tcp WCF channel instance is closed or faulted and subsequently recreated by the client, a different backend server may be used to serve the client in the absence of NLB affinity. So the key question is whether your application requires or relies on client affinity to any resources maintained by the server side with lifetime exceeding the lifetime of a net.tcp WCF channel. If you are building a pub\sub system, the question translates to whether your subscriptions are durable or not. If the answer is yes, you may have to look at mechanisms to share the durable state across backends, and Velocity is one technology that can speed it up.