This is the third installment of my article about the Serial Console Server for the Poor. First installment here, Second installment here.
The first part of the article having covered the hardware and the udev part creating the device nodes, and the second part explaining how to solve the software part using ser2net, this part explains why ser2net was ditched in favor of cereal and how the console server operates with cereal now.
Continue reading "Serial Console Server for the Poor III"
Schon seit etwa anderthalb Jahren hat sich ein Kunde mit seinen Büroräumen auf ein anderes Gebäude ausgedehnt. Zwischen den beiden Gebäuden gibt es zwar Glasfaser, aber keine Kupferverkabelung. Trotzdem möchte man auch im neuen Büro gerne telefonieren können; dort sollen Nebenstellen der am alten Ort vorhandenen Alcatel OmniPCX Enterprise aufgestellt werden.
Daraus entsteht die logische Entscheidung, die Telefone im neu hinzugekommenen Bereich des Gebäudes per IP anzubinden: Das geht nämlich über die vorhandenen Glasfasern, während man für digitale Endgeräte an der TK-Anlage entweder Kupfer werfen, oder den neuen Standort mit einem (teuren!) Gateway zum Umsetzen von IP auf die digitalen Endgeräte ausstatten müsste.
Also bietet sich die Möglichkeit, ein bisschen über IP-Telefonanlagen in überlasteten Netzen zu lernen.
Continue reading "Quality of Service im Ethernet fuer Telefonieanwendungen"
This is just a small reminder (for me and others) that Debian is currently migrating from console-tools to kbd (back again, yes, those who have been around for a few years remember).
This information is obviously a closely-guarded secret. Console-tools is still Priority: important, and kbd is still Priority: extra. However, kbd seems to be much better maintained (current uploads happening, while console-log has seen its last maintainer upload two years ago), and unfortunately, neither package description suggests which package is the way to go. And Debian-installer still installs console-tools by default.
However, a few bugs were filed a year ago by the console-tools maintainer to drop console-tools from depends as console-tools is going away. So I guess that he knows what he's doing...
Before I get around to adding console-tools back to console-log's depends (as I almost did accidentally), I'll better blog this to remind people of console-log going away. Maybe we'll get the Priorities changed just in time for lenny.
Mein lieber 300-dpi-4-Seiten-Laserdrucker Oki OL400e, Du hast mich vierzehn Jahre meines Lebens begleitet. In vier Jahren hättest Du den Führerschein machen können.
Du warst damals, 1994, der erste Laserdrucker unter der magischen 800-Mark-Grenze für geringwertige Wirtschaftsgüter. Du konnest vier Seiten in der Minute mit 300 dpi bedrucken, hattest einen unglaublich robusten Einzelblatteinzug (manche Leute sagten, mit Dir könnte man sogar eine Wurstscheibe bedrucken) und einen sehr viel zickigeren Einzug aus der Papierkassette. Wenn ich ehrlich bin, kann ich mich nicht mehr daran erinnern, wann Du zuletzt ein einzelnes Blatt Papier aus der Kassette unfallfrei eingezogen hast.
Continue reading "OL400e R.I.P."
Ich habe mich endlich auf einen USB-Stick-Typ geeinigt, den ich in Zukunft bevorzugt verwenden möchte: Den SanDisk Cruzer Micro. Zwar nicht besonders klein, aber auch nicht besonders groß, mit halbwegs günstigem Preis, und zurückziehbarem USB-Verbinder. Das bedeutet, dass keine Kappe verloren gehen kann und das Ding auch robust genug ist für das Schlüsselbund. Die dazugehörige "U3-Software", die einem Windows ganz unkompliziert das Kaffeekochen beibringen soll, ignoriere ich völlig und benutze die Sticks halt als wären es ganz normale USB-Sticks.
Als USB-ZIP-Disk formatiert booten alle Rechner ganz prima von den Sticks. So gehört es sich ja auch. Nur gewisse hp-Server zicken.
Continue reading "Von Kompatibilitätslisten und USB-Sticks"
This is the second installment of my article about the Serial Console Server for the Poor. First installment here.
The last part of the article having covered the hardware and the udev part creating the device nodes, this part addresses the part of the software that connects the user to the device node.
Continue reading "Serial Console Server for the Poor II"
The serial port is still the way to access network components out of band. It is slow, but reliable, and remarkably well standardized. It does not have technical whiz-bangs that can fail when one needs things to just work. That makes it the natural way to access critical infrastructure and still being sure that this access vector still works when most other things are down.
Every communication link has two sides, so there is a market for devices with a network link and a bigger number of serial ports to connect the actual devices to. Commercial vendors have a broad choice of serial console servers. Most of them, especially the small products with five to ten ports, are quite expensive, so I have been investigating how do build a serial console server with el cheapo hardware.
Continue reading "Serial Console Server for the Poor I"
Today, I had the opportunity to try my UMTS initialization mechanism that I built this weekend with more recent hardware, a newer Option Globetrotter 3G Express Card with Vodafone branding (reporting itself to be a "Globetrotter HSDPA Modem" with Vendor ID 0xaf0 and Product ID 0x6701). To get the card connected to my test Notebook, a hp compaq nc8000, I had a "Expresscard in a PC card slot" adapter and a passive "Expresscard at a normal USB port" adapter. The USB adapter had cost about ten Euros, and I don't imagine the PC card adapter to be much more expensive.
Continue reading "Works with a more recent card as well"
Ich möchte ein Notebook hp nc 8000 per Wake-on-LAN aufwecken, um sicherzustellen, dass es möglichst immer läuft. Leider habe ich im BIOS keine Einstellung für Wake-on-LAN gefunden, und ein per etherwake oder wakeonlan gesendetes magisches Paket wird ignoriert. Also versuche ich mal den hp-Supportchat, vielleicht bin ich ja nur zu doof zum suchen.
Continue reading "hp Supportchat völlig unbrauchbar"
For mobile UMTS/GSM, I have been using an Option 3G Data Card for two and a half years now. I blogged about getting the card to work (in German, sorry) on Linux in July 2005. I never found the time - until now - to automate the card initialization so that I had been using a horrible chat script for card initialization when the PPP connection was built.
I recently took the time to automate this, so that the PIN is transmitted to the card automatically when the card is plugged in. This article documents what I did.
On a side note: Unfortunately, the vendors' attitude towards Linux hasn't changed since 2005. Their Hotlines still deny that their products can be used with Linux at all, and they surely do not publish any documentation that can be of help. Otoh, Vodafone has published a software that supposedly aids usage of their products under Linux. I haven't tried it yet since it is not packaged yet for Debian. Additionally, Vodafone support media and sales do not seem to know about this effort, they still deny that their products work with Linux. Windows users happily install proprietary software products that do little more than sending a handful of AT commands to the emulated USB modem and hand over the connection to Windows' PPP Stack. A very unsatisfying situation.
Just for the record: Dear Vodafone DE, a week ago you missed the sale of a new USB UMTS interface because you don't even document it on Linux. This motivated me to look into the drawer that holds the old, non-HSDPA PC cards that have been decommissioned at the customers' site and use an old, used device. Your fault.
Continue reading "Automatic initialization of a Option 3G Datacard"
