35 replies to this topic

[Charles]

I am working on a project that could be sold to consumers without any IT knowledge. Your everyday consumer doesn't know anything about static IP addresses or DHCP. Let's say my product uses a Netduino Plus with DHCP. That's nice, but how is the consumer going to find out the IP address of the device if the device's only user interface is a web page it hosts? You and me might log into our routers and look up the DHCP IP address assigned to the router, but that is over the heads of most consumers.

Now let's say that you have Netbios implemented and you give the Netduino Plus a name (e.g. "SuperWidget"). Then in your setup instructions or manual you can tell the consumer to open their Internet browser and go to the website "http://superwidget/index.html" to configure or use the device. In my case giving the product a Netbios name is fine because there will only be one of these devices on a LAN inside a house.

My response would be to take the same angle of any other device manufacturer - Custom client software or uPnP. I can't think of any consumer network equipment that uses NetBIOS in that way.

I think what you want is Universal PnP support.

[phantomtypist]

My response would be to take the same angle of any other device manufacturer - Custom client software or uPnP. I can't think of any consumer network equipment that uses NetBIOS in that way.

I think what you want is Universal PnP support.

Creating client software to be run or installed on a computer results in higher support costs compared to a web application. That and I'm sure most non-tech people don't want to install software or put discs in computers. It's just easier to say "hey, go to this website".

Read this nice blog post by Patrick McKenzie talking about why he decided to discontinue his desktop software in favor of his web application.

[Illishar]

... create a complete math library that adds all the missing functions but as a DLL that can be added to projects as needed bud doesn't eat the flash space if it is not. Could that be done?

If you mean a managed dll, then it's already possible. (And also already done, I imagine.)

It would be much more interesting however, if you mean an unmanaged (native) dll. Being able to deploy native code in netmf would solve a ton of problems in small boards like Netduino. (And it would also be priceless in big boards, due to performance.) And it's not unthought of either. GHI has something called "RLP" and Secret Labs are working on something similar they say. (But then again, what aren't they working on ;p
Microsoft doesn't seem to be that hooked on the idea right now though. Sadly.

[Jim Davies]

Hi phantomtypist,

You said:

how is the consumer going to find out the IP address of the device if the device's only user interface is a web page it hosts?

Why not just display the device's current IP address on the web page - I guess I'm missing something?

Jim

[Illishar]

If you don't know the IP or the NetBIOS name, you can't enter the webpage. You need one or the other. Still all hw I've worked with so far, has used static IPs. Usually they're preconfigured with something like 192.168.1.50 etc.

[Chris Walker]

NETBIOS would be a cool addition, and it sounds like it would be easy to do via a managed library (with a few small tweaks to lwIP). Per the work that pascal06 has done.

We'll take a deep look into this. If it's small and doesn't create security concerns I don't see any reason why we can't add this to the current v4.1.1 firmware branch.

The big question is how to integrate it into the object model. To start with, we can easily create a private method and create an extension method for Microsoft.SPOT...NetworkInterface.

Chris

[Valkyrie-MT]

Your everyday consumer doesn't know anything about static IP addresses or DHCP.

Thanks phantomtypist! I could not have said it better myself. -Valkyrie-MT

[Valkyrie-MT]

Why not just display the device's current IP address on the web page - I guess I'm missing something?

OK, lets say you have a Netduino Plus running your app and a webserver. Now you take that and give it to someone to plug into their network. What address do they go to? Most systems use DHCP to dynamically assign the IP, so how does the end user figure it out? They have to log into their router, look up the IP address that was assigned to the MAC address on the sticker on the netduino. Then they have to type that into their browser. That is just not a reasonable thing to ask of an end user.

Imagine the simplicity of having the NetduinoPlus come with a default webserver and Netbios name of perhaps "http://netduino". We could craft a simple web page that allows anyone to turn the Outputs on/off and read from the inputs. I think you would find a ton of people out there that might be too afraid to do the programming and just use the web page.

P.S. I don't consider a static address to be a good idea because you have no idea what a valid address would be on another network. What if the subnet is different? A static address won't work in all cases.

-Valkyrie-MT

[Charles]

Why not just display the device's current IP address on the web page - I guess I'm missing something?

Ummm... How do you get to the web page?

[Charles]

I don't consider a static address to be a good idea because you have no idea what a valid address would be on another network. What if the subnet is different? A static address won't work in all cases.

Static only in the sense that it doesn't use DHCP by default. Ship it with 192.168.1.50 and allow the user to go to a web page at that address and change it to whatever they want if necessary. Many devices work this way now... In fact, I can't think of a single consumer network device that doesn't operate in this manor.

Also keep in mind that NetBIOS is not a silver bullet. Even if the N+ is announcing itself with NetBIOS, the unit will be inaccessible if the IP address is not reachable from the user's computer.

NetBIOS is a layer 5 name resolution protocol - The layer 3 (IP) address it resolves to still has to be reachable.

[Julian de Wit]

<NM>

[Jim Davies]

Ummm... How do you get to the web page?

Sorry - too much Czech lager.

+1 from me for:

Ship it with 192.168.1.50 and allow the user to go to a web page at that address and change it to whatever they want if necessary. Many devices work this way now.

I had the same problem, and found an alternative simple-minded approach that works well for me (ahem):

Scan the local range 192.168.?.? using a short-timeout HTTP GET, and have the server respond with a 200 for some request string, e.g.

http://192.168.?.?/xyzconnect

Get the PC's local IP (e.g. mine's currently 192.168.11.6) and first scan the range 192.168.11.0 - 192.168.11.255. If that doesn't work, scan all the addresses 192.168.?.?.

This works fine here, and quick using the above with a timeout of 100 ms or less.

Of course this approach requires a PC app to do the work, but I think you could also do it in Javascript on the user's browser. Wouldn't this cover most situations with a router or whatever providing local DHCP?

FWIW,
Jim

[CW2]

Scan the local range 192.168.?.?

Theoretically, you'd need to scan all private ranges, and that's a lot of addresses. For example, home networks with ADSL modem often use A-class addresses (10.x.x.x).

[Illishar]

Port scans are not always appreciated in established networks either. A HTTP HEAD might be better suited btw.

[Jim Davies]

Port scans are not always appreciated in established networks either.

A HTTP HEAD might be better suited btw.

Agreed. I was thinking small network / one-off scan.

[Chris Walker]

I have got to throw my vote on the Misc. Bug fix.

Not being able to unplug and plug in the ethernet port on the N+ is a MAJOR show stopper in my book. Until this and other significant networking/general bugs are fixed the rest of it is just academic in my opinion.

Charles, quick update: both this and the D2 issue (and the DHCP issue) should now be fixed in v4.1.1 alpha 6 (and v4.1.0.6 RC1).

Chris