Embedded Ethernet and Corporate LAN

We have an embedded system, that has a SMSC 91C111 Ethernet Chip, ARM Processor, and Windows CE 3.0. Our system works great when not exposed to a "Corporate Ethernet" environment. When we put our system on a DSL line, it works great. We get massive buffer overflows on a typical LAN network. I have been looking for others who have embedded products, that have similar experiences. Does anyone develop embedded products, that go onto LAN environments? What did you do to reduce "House Keeping" signals (DHCP OFFERS, ARP REQUESTS, DNS, NETBIOS BROADCASTS)?

Sorry if this is the incorrect group for this question, but found it on embedded.com website.

Thank you

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Unlike many posts here, this is probably the right group.

I would guess that the problem is broadcasts. The broadcast traffic level can get pretty high on some networks, and every one of those has to have at least some processing done on it. You have to minimize that processing time, especially for packets that you don't need.

Unless you are a DHCP server, you should be able to ignore broadcast DHCP, and maybe all broadcast IP. The one you can't ignore is ARP, so you need to quickly detect if the ARP is for you, and ignore it if it isn't. You didn't say you were doing IP, but in any case you have to identify the TYPE field as soon as possible, and flush it if it is the wrong type as fast as possible.

-- glen

Reply to
glen herrmannsfeldt

I see this from time to time with commercial network equipment.

A fix that I have been able to use is to block unwanted traffic. Typically network equipment does not need to receive IP broadcasts. Blocking IP broadcasts still allows ARP to operate.

Other than that you will need to make your code more efficient at rejecting unwanted traffic. This is in effect the same thing as I have already said I guess.

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Quotes vanished! - see later

10M is a fine idea.

I use Google Groups for news and I suspect that it now does all sorts of weird things. I have been too lazy to try to figure out what it is doing. The editor presents in HTTP with proportional fonts for example.

The default view of messages has quotes folded into a link, I don't know if these are quotes explicitly in the message of if they are "helpful" links to the message actually responded to.

I had suspected that my netiquette was slipping but with the massaged google view that I get it is quite hard to figure out what is going on.

I will have a look and comment to google if applicable but I hold out little hope that they will change anything.

'tis the way of the world it seems -- magic fixups everywhere

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(please don't trim the quote from the message the next time. thanks.)

If CE will let you try setting the properties on the NIC to 10MB/half duplex.

Reply to
Al Dykes

My ISP will sell you a shell account on a fully configured unix machine for $10/mo with 50MB of disk space and a personal web server included.


One of the oldest internet-connected services.

I have no relationship to Panix other than being a satisfied customer for almost 15 years. I've used trn for my news reader ever since then and I can't imagine having to use a GUI news reader.

Reply to
Al Dykes

snipped-for-privacy@hotmail.com wrote: [snip]

Ever since my shell account was revoked (years ago), I've been on a constant search for a decent newsreader. Xnews, was OK. Gravity was pretty decent. Agent was semi-OK. Then I found XanaNews. Perfect news reader for me! For those using Windows, it's definitely worth a look.

Reply to
Hansang Bae

Warning - Way off topic. (And longish now too).

I hope you like the hand quoted message _a lot_:-)

To use XanaNews or similar I guess that I would need a newsfeed from somewhere, somewhere to store it, and then I would not be able to access it other than from somewhere with access to my home network. Can you suggest a free newsfeed?

Google groups are somewhat convenient for me but clearly if the sent messages are causing problems that that is something to consider.

I would not now consider using anything other than a GUI for interactive work:) It is not necessary to have a bit mapped display though. I have used very satisfactory Windows-pointer-mouse-menus interfaces that were based on character mode displays. e.g. Turbo Pascal (V4 or later IIRC), or Turbo Debugger. The latter being my candidate for the best software ever created considering the complexity of the task (machine code symbolic debugger) and the ease of use of the software. I can't recall ever needing the manual once the thing was loaded and running in the desired mode. (Hobby use only) In comparison I couldn't use MS Codeview without applying both hands to the manual and being restricted to typing with my elbows and nose.

Since the man who I believe did it is the .NET development tool architect I would guess that the new MS stuff is top notch too. His name is I suspect Anders Hejlsberg.

Amazingly enough, well it is to me, Xananews is written with Delphi which is the successor to Turbo Pascal.

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snipped-for-privacy@hotmail.com wrote: [snip]


I still remember the day I took the shrink wrap off of Turbo Pascal from Borland. I loaded it up on my 286-16 Austin computer and was BLOWN away. Up until then, I only had rudimentary tools available on VAX compilers. I once had to cycling through my program on a piece of paper to catch a "off by one error" problem.

It truly was a nice piece of work! There are very few things I consider a "true classic." Turbo Pascal is one of those. My HP-41CV was another classic. Man I loved that calculator. My buddy still has one and I considered whacking him just to get my hands on that calculator! :)

Reply to
Hansang Bae

Many years ago, I was using Turbo C++ in a class I was attending and used Borland C++ for OS/2, at home. Worked great, though I had to worry about minor details such as integer sizes, when moving between the two. I also used to do my Fortran homework on a VAX 11/780.

Reply to
James Knott

You don't need a news _feed_, you need a news _provider_--a news _feed_ is what the providers get and it's expensive--to use a feed you need to be running your own news _server_, not a _client_ like Xananews.

One provider that seems to be decent and is free is . used to be free and is now ten Euros a year, whatever that works out to in dollars, which seems pretty reasonable to me.

Your ISP may also have a news server--most used to but some are discontinuing service.

Google Groups used to be an archive--it is _not_ how most USENET users access USENET.

You should be able to access your USENET provider from anywhere, not just your home network. If it's an ISP server then you'd probably have to be logged into that ISP's service, if it's a third party server like news.sunsite.dk or news.individual.net then you can access it from any Internet connection that doesn't have NNTP or the specific addresses blocked.

Reply to
J. Clarke

"If you want to post a followup via groups.google.com, don't use the broken "Reply" link at the bottom of the article. Click on "show options" at the top of the article, then click on the "Reply" at the bottom of the article headers." - Keith Thompson

Thanks everyone for pointing out my errors and especially for the suggestions.

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what about your SMSC 91C111 driver for Windows ce on ARM board? Did you write it or find it somewhere? I'm looking for one, free or commercial. Could you please send me some information?



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