Fresh Toast

Welche Faktoren beeinflussen LTE Geschwindigkeit

admin — Tue, 23 Nov 2010 11:41:24 +0000

LTE Geschwindigkeit – was beeinflusst sie?

DSL Speedtests sind mittlerweile vielen Menschen bekannt. Diese Menschen messen mit ihnen die tatsächlich erreichte DSL Geschwindigkeit ihres Computers im Internet. Und manchmal sind diese Menschen enttäuscht, weil die realisierte Geschwindigkeit deutlich unter der liegt, die sie eigentlich gebucht haben. Breitband-Geschwindigkeit ist halt von vielen Faktoren abhängig. Weitere DSL Informationen auf dsl.sc. Das gilt auch für LTE Geschwindigkeit. „LTE“ steht für „Long Term Evolution“, ist neuer Mobilfunkstandard und derzeit in aller Munde. Eine LTE Geschwindigkeit von 100MB/sec oder gar bis zu 300 MB/sec schwirrt derzeit als Möglichkeit im Raum herum. Als künftiger LTE Nutzer wird man hier etwas vorsichtig sein müssen und darf nicht jede angebotene LTE Geschwindigkeit für bare Münze nehmen. Wer etwa die tatsächlich realisierte Geschwindigkeit bei seinen UMTS/HSDPA Anschluss ans mobile Internet mit gebuchten maximalen 7,2 MB/sec misst, mag manches Mal enttäuscht sein. Beim LTE Anschluss könnte das bisweilen ähnlich werden.

Wie die UMTS/HSDPA Geschwindigkeit hängt auch die LTE Geschwindigkeit von unterschiedlichen Faktoren ab. Zu diesen Faktoren zählen die Entfernung des Nutzers zur Basisstation, eventuelle Störsignale und die Anzahl derjenigen, die im selben Funknetz die gebuchte LTE Geschwindigkeit erreichen möchten. Wenn die ersten buchbaren LTE Tarife auf dem Markt sind, dauert es möglicherweise auch bis zum ersten verfügbaren LTE Speedtest nicht mehr lange. LTE Kunden sollten ihn nutzen und von ihren Erfahrungen berichten. LTE Geschwindigkeit wird schnell sein, aber wie schnell, das wird sich erst zeigen.

Um LTE Geschwindigkeit nicht zu sehr durch Poweruser zu belasten, die Internetanschlüsse intensiv nutzen und hohe Datenmengen auf ihren Computer laden, setzen LTE Provider bei UMTS/HSDPA Tarifen auf die so genannte Fair Flat. Die gebuchte Geschwindigkeit gilt dann nur bis zu einer bestimmten herunter geladenen Datenmenge pro Monat und wird anschließend deutlich gedrosselt. Generell gilt nämlich: Je mehr Nutzer viele Daten im UMTS/HSDPA Netz transportieren, desto mehr sinkt die verfügbare Geschwindigkeit für jeden einzelnen. Mit LTE Geschwindigkeit ist es ähnlich. Vodafone hat daher in seine derzeit bereits vorgestellten, aber noch nicht buchbaren LTE Tarife ebenfalls eine Fair Flat integriert. Auch die Fair Flat hat Einfluss auf die LTE Geschwindigkeit.

Beim Vodafone Angebot mit einer LTE Geschwindigkeit von bis zu 50MB/sec liegt das Limit downloadbarer Daten pro Monat etwa bei 30 Gigabyte. Anschließend wird die LTE Geschwindigkeit für den Rest des Monats auf reines UMTS-Niveau abgesenkt (384 kbit/sec). Voice over IP (Internet-Telefonie) und Peer-to-Peer Kommunikation sind nicht gestattet.

Ownlinux Revision 1019

admin — Tue, 01 Aug 2006 16:25:36 +0000

OK, the build is done. I got the nvidia kernel modules compiled after I booted the new kernel *yeah*
There still are some glitches, like me building the kernel with the wrong .config but this is beeing fixed as I type this.
All that is missing now is setting up some config files and then I shoud be ready to go! *grin*

Postfix users mailling list

admin — Sat, 22 Jul 2006 16:19:48 +0000

Today on the postfix users mailling list:

Quote:

> Hi again,
> > I’ve been noticing a significant number of log entries like these:
> >
> > warning: Illegal address syntax from unknown[xxx.xxx.194.42] in MAIL
> > command: {WORD){WORD)@{MAIL_DOMAIN}

Broken spambots.

Shh — Don’t say anything life is better when the spambots are broken.

Try installing the NVIDIA kernel module again.

admin — Sat, 22 Jul 2006 16:17:07 +0000

Yes, my build stopped in the middle of the night. The nvidia modules won’t build. First they thought that I built my kernel with gcc 4.0 – which isn’t true, cos the whole system is built using 4.1. This was easily fixed by setting a system variable and therefore bypassing the gcc sanity check. But then it says that the nvidia modules are not compatible with the riva fb driver which is enabled in the kernel. Now I am asking myself which one – of those two others using this distro messed with the default kernel config. My guess is Raven, cos he – to my knowledge – is the only one with an ATI graphics adapter.

Oh well, I really shouldn’t be so lazy and include my own kernel config during the build process.

RecordBank

admin — Tue, 21 Jun 2005 15:38:40 +0000

Communicating via the telephone is still probably one of the easiest ways of communicating. Its fast and mobiles are hard to beat. Conversation is almost face to face, usually two ways, with fast decision time. (no waiting for that return email), however as far as a record of what occured, pretty hopeless. (unlike email). In suitable situations if we could combine the two ie. phone call + recording.. we might find communicating better, some mobiles already have this feature, but not fixed net. Example … You receive a call .. info is given …address etc…bye ..you hangup. Sometime later ..u think, now that address, what was it again, no problem, you have RecordBank.. just listen to it again. SECURITY – Definitely required.

Ending the security nightmare with Linux

admin — Tue, 17 May 2005 13:39:34 +0000

Internet threats have clearly become a lot more sophisticated and malicious.
The frequency and level of attacks on corporate networks and systems around the world have forced businesses to adopt a more vigilant approach towards security, and to review review the way applications are configured, be discerning in selecting software applications and emphasise security as a top priority in business. Any operating system is prone to security vulnerabilities. Attacks originate from insecure software. Companies like to acquire extra security applications such as intrusion detection systems and firewalls and throw money at the problem, but these applications also have vulnerabilities and the real solution lies in running secure code and being strategic about configuration and assembly. For example, if an application, such as the DNS server, is compromised, but is well configured, the attacker will only have access to modify the DNS settings and will not gain sufficient control to take over the entire server. Many commercial applications are monolithic in design and everything is interlinked, so if one service is compromised, it means the entire server is left vulnerable. The only way to achieve the required level of trust is to be open source, an approach that the majority of commercial suppliers are not willing to take. In the case of open source, a key consideration to keep in mind is the fact that the technology has been reviewed many times over by some of the world’s best and brightest in the field of computer security.

The perception that a Linux environment and open source software statistically has more vulnerabilities in comparison with other operating systems is only half true. Due largely to the ‘open’ nature of this environment, source code is made available for scrutiny by many parties. This means that vulnerabilities are picked up immediately and announced . And even if nothing is done by the original developers to fix the problem, it is almost guaranteed that someone, somewhere will create a patch and release it. This is one of the key advantages of Linux environment, from a security point of view. The other is that it is flexible, modular and built from the ground up with security in mind, so the risk and consequences of a security compromise are reduced. A significant aspect of Linux is that it is not vulnerable to viruses. It is also not prone to e-mail virus attacks or spam. Linux is an extremely flexible operation system and does not just set standards – standards are at the heart of its design.

It has made significant inroads within the server domain and is progressing within the desktop space, but common challenges – such as skills, short term business benefit over security requirements and general misconception – mean a long journey ahead for the local market in terms of adoption.

Full Circle

admin — Sat, 14 Aug 2004 15:42:07 +0000

Telstra has put a bid in to buy Damovo, price of around $100 Million. Telstra sold its CPE maintenance business (mainly PABX’s) to Damovo a few years back. This area of the Telecommunications Industry gave SME private companies a reasonable competive market to operate in, maybe not any more if this deal goes through. Scenario, client is looking at a new phone system for their premises, competively priced quotes roll in. Telstra ..a Carrier..says I will see you ..and raise you, lays a network on the table. SME looks into his empty pockets and says I dont have a Network…sorry. Ah ..the joys of competition. Ain’t it grand. That is one way of looking at it, another view is that the market price for goods and services is set by the major dominant..Telstra in this case, so like everything else… Price ( only one of the 4 P’s of marketing) comes into it. A ready made pricing structure ..so to speak, quick analysis.. and you are either in the game ..or out. Simple!! Oh and another interesting bit of news on the carrier front, Optus has just about finalised its complete purchase of Uuecom, looks like the competition is heating up…lol

Carrier BT to go all IP

admin — Wed, 23 Jun 2004 09:48:07 +0000

THE UK’s equivalent of Telstra, British Telecommunications, plans to gradually shut down its traditional circuit-switched telephone network in favour of IP technology. The new system – to cost an estimated £10 billion ($26.4 billion) – is expected to be operational for most of BT’s 28 million customers by 2008, the company said. The change will involve electronic and computer-system changes, not construction work such as digging up roads or pulling down phone lines, BT said. The new program “will deliver our vision of a converged, multimedia world where our customers can access any communications service from any device, anywhere – at broadband speed,” chief executive of BT Wholesale Paul Reynolds told reporters. It would give each subscriber the ability to have one phone number, and the same bill, for mobile and fixed-line services. The new system would bring customers features such as family conference calls, video streaming and voice-activated phones, Matt Beal, in charge of implementing the changes, said in a BBC interview.

WAN speed Record

admin — Tue, 22 Jun 2004 15:10:30 +0000

Internet2 Land Speed Record History

The Internet2 Land Speed Record (I2-LSR) competition for the highest-bandwidth, end-to-end networks is an open and ongoing contest.

Internet2 Land Speed Record entries are judged on a combination of how much bandwidth they used and how much distance they covered end-to-end, using standard Internet (TCP/IP) protocols. Complete rules and a summary of current records are available at the Internet2 Land Speed Record home page.

I2-LSR Timeline

Record Set: IPv4 Multiple Stream
I2-LSR Record: 68,431 terabit-meters per second
Team Members

California Institute of Technology (Caltech) – CERN

Network Distance: 10,949 kilometers
Data transferred: 499 gigabytes (approx.)
Time: 600 seconds (approx.)

Software notes:

Windows Server 2003 64-Bit Edition
NTttcp test tool (part of Windows 2000 DDK) with the Jumbo Frames (9000).
TCP Reno

Hardware notes:

sender and receiver: 4U Intel® Quad Itanium2 SR870BN4 Servers with Intel® E8870 chipsets
Network interfaces: sender-s2io 10GE NIC, receiver-Intel® 10GE LR NIC
Performance was tested with PCI clock frequencies 133-MHz in 64-bit mode

WiFi Cold Spots Spotted

admin — Fri, 14 May 2004 13:50:09 +0000

QUT Finds DOS weakness in 802.11

QUT’s School of Software Engineering and Data Communications staff and students have identified a flaw in the protocols that allow the disruption of 802.11 wireless lans using the DSSS physical layer (2.4GHz). Includes IEEE 802.11, 802.11b and low-speed (below 20Mbps) 802.11g wireless devices. Excludes IEEE 802.11a and high-speed (above 20Mbps) 802.11g wireless devices. By changing the setup of a standard wireless adaptor it can generate a signal that effectively causes other devices to think the network is “busy” , therefore other devices delay data transmissions. High powered jammers can disrupt, but are also relativley trackable but the ordinary adaptor is far less so. The flaw was discovered late last year, see the recently Auscert released security bulletin for further details.