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Getting Rid of SIP NAT Problems

The Problem

SIP Endpoints in a consumer environment are often behind a NATted DSL router.  This means they use a private IP address and mechanisms to allow SIP signaling and the voice data's separate RTP data stream to cross the NAT router and use the outside public IP address are needed.
There are a couple of mechanisms:

  • Client side (with server support): STUN, ICE
  • Server side: SBCs
  • NAT router: SIP ALGs
  • SIP addition: rport (RFC 3581)
  • Have the SIP client integrated to the NAT router and expose all necessary ports on the single common public IP address (does not allow UA flexibility)

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My wallet is full of plastic cards. Access cards, credit cards, loyalty cards, ID card, health insurance, stored value tickets and more.

I like to have things done easily, no filling of forms, not having a lot of cash "just in case". Getting things done with just presenting one of theses neat "smart" cards looks like a great solution. Being owner of the Nokia N9 smartphone with build-in NFC capability since a couple of month triggered my interest for NFC and RFID. There is recently also a of talk about mobile payment, which increased my interest. What standards are there? Would it be possible to transfer a part of my plastic load onto the phone and wave the phone instead of the single cards?
I try to summarize and give an overview about RFID (Radio-Frequency Identification) and NFC (Near Field Communication).

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What Motivates Us?

Here is something not technical that I want to share. Actually it is related. What makes open source work? Why dedicate thousands and maybe millions of people their unpaid time to technical projects? How could Linux succeed?

Watch the rather surprising truth here:

Are HR departments aware of this? Are they ready to learn? I am afraid not.

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Virtual Machines

I maintained a dual boot installation on my main desktop PC for some time now. Ubuntu is my default OS, providing all productivity tools like email client, OpenOffice for text documents and spread sheets, web browser, photo editing, network analysis and much more. But there are still applications requiring Windows. In my case it's the missing Linux support for my Canon 9000F scanner and my preference to use Paint Shop Pro over Gimp for some things. Therefore the XP on the second HD partition. But it's time consuming to reboot the PC to switch OS's.

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Nokia (NYSE:NOK) confirmed its forthcoming N8 device will be the last N-series smartphone release running the Symbian OS. "Going forward, N-series devices will be based on MeeGo," Nokia spokesman Doug Dawson told Reuters, adding the handset maker will continue to employ Symbian across lower-end handsets.

Read more: Nokia dumps Symbian for future N-series smartphones - FierceDeveloper
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