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The Mix Up

 

My brother in law gave me a late birthday present: The latest Beasty Boys album: The Mix-UP.

I have had a weak spot for the Beasty Boys for many years. I am not particularly fond of their rap style, its non melodic and almost old-school-cliche they do have ‘balls’. Their “Get it together” from the 1994 album “Ill Communication” is one of my all time favorite Rap tunes. The Boys seemed to have managed to merge Rock and Roll and Rap in a credible and sustained way.

 Il communication lead to “The Sound from Way Out“, an instrumental album that I enjoyed listening to with great pleasure.

I was a bit surprised to find the text “Their First-Ever Full Album of All-New Instrumental material”, obviously this fine marketing text needs to be close read to understand that its the first album with exclusive new material, in contrast to the Sound from the way out, that contained material from Ill Communication. Anyway, the marketeers have not spoiled the pleasure.

The sound of The Mix-Up is remarkably similar to the sound of the Sound from the way out. It seems (probably not by accident) that not much care have been taken to production value; 8-track, bedroom recordings is  my first impression. The seemingly low production  is the charm of the album; clean drum sounds, Hammond organ, wah-wah guitar, and bongo. Melodic music, with strong Bass and Guitar riffs and almost trivial melodies. Like the music that folk from the neighborhood are playing in the local community center.

To me the charm of the album is that it sounds like the music that I would like and could technically play. A couple of guys making fun without pretense, it is inspiring, and it comes close to what I think what Rock and Roll is all about.

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NAT too Smart

EDITED July 12 2007

The text below is an update from the original post (June 18, 2007), that original post turned out to contain a few errors.

We have an asterisk server installed back at work and for the teleconferencing purposes I got myself a  SNOM300 SIP phone. I configured the phone to do all its NAT magic using STUN and  tested that with my  linux based homebrewed NAT box.

That worked, but the setup did not migrate to a NATted network behind my new Speedtouch 780.

Turns out that in order to use SIP behind a Speedtouch 780, that has a SIP aware application level gateway that does all kind of weird tricks to your packets.

Having configured your SNOM to find its way through a NAT using Stun and the ALG in the Speedtouch does not work well, and generates weird timing issues that manifest themselves as ‘Authorization error” in the Sytem Information panel of the SNOM phone.

The degug output on asterisk (connect using asterisk -rc and use “sip set debug”) shows something of an explanation when following the SIP dialogue.

After the first registration attempt the server sends back a 401 Unauthorized message with all the parameters needed for proper authorization, including a so called ‘nonce’

<— Transmitting (NAT) to <public-ip>:52899 —>
SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP
(…skip…)
CSeq: 1 REGISTER
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Supported: replaces
WWW-Authenticate: Digest algorithm=MD5, realm=”asterisk”, nonce=”3d58a314”
Content-Length: 0

The response to that reply is a new request from the client, without any authentication info. And the reponse from the server is again a 401 reply, with a new nonce…

<— Transmitting (NAT) to <public-ip>:52896 —>
SIP/2.0 401 Unauthorized
(… skip …) CSeq: 2 REGISTER
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Supported: replaces
WWW-Authenticate: Digest algorithm=MD5, realm=”asterisk”, nonce=”1aa0547a”
Content-Length: 0

Only at the 3rd try the client registers with the authentication code… but it uses the nonce that was returned for the first request

<— SIP read from <public-ip>:52899 —>
REGISTER sip:nlnetlabs.nl SIP/2.0
(…skip…)
CSeq: 3 REGISTER
Max-Forwards: 70
Contact: ;q=1.0;flow-id=1;+sip.instance=””;audio;mobility=”fixed”;duplex=”full”;description=”snom300″;actor=”principal”;events=”dialog”;methods=”INVITE,ACK,CANCEL,BYE,REFER,OPTIONS,NOTIFY,SUBSCRIBE,PRACK,MESSAGE,INFO”(…skip…(…
(…skip…)
Authorization: Digest username=”username”,realm=”asterisk”,nonce=”3d58a314“,uri=”sip:nlnetlabs.nl”,response=”somehexcode”,algorithm=md5Expires: 3600
Content-Length: 0

At that moment the Asterisk debug output will show some critical information

<————>[Jul 11 12:01:48] NOTICE[89797]: chan_sip.c:8167 check_auth: Correct auth, but based on stale nonce received from ‘”username” ‘

What is probably relevant is that you see this happen when you turn on “Stun” and that the frequency of the registration attempts is correlated to the Stun interval you configure in the NAT settings for a the identity on your SNOM phone. Also the port on which the dialogue happen jumps for each Cseq.

After seeing this I’ve tried a number of permutations of settings, on the snom phone I tried all sorts of timing parameters and in the asterisk configuration I turned the NAT settings on and off. All with variable results.

Turns out that one can turn off the SIP ALG in the speedtouch 780, which solves the problem. You have to use the command line interface of your speedtouch. The CLI reference guide is available on-line.

The magic words are:

{Administrator}[connection]=>appconfig application=SIP SIP_ALG=disabled

NB: I have not been able to find a way to tell if the SIP_ALG is enabled or disabled using appinfo or any other command in the CLI, but I have not really been looking hard.

As soon as the SIP application level gateway has been disabled you are in business as long as:

  • You configured NAT=yes for this particular user in your Asterisk’s sip.conf
  • You have configured a stun server in the NAT settings (under the identity settings) on your SNOM phone.

In other words. Do not rely on the intelligence of the ALG in the speedtouch modem, use ‘classic’ nat traversal. The meta problem here seems to be that all components in the chain try to apply their own hacks to traverse through the NAT and they do not really work nice together.

One of these days I have to figure out if I can make the SNOM, the SpeedTouch, and the Asterisk server run over IPv6 (I hear evil laughter somewhere, because AFAIK at least two of these components will not work on IPv6 natively yet).  Life would be good if the ADSL modem would be able terminate a V6 tunnel,   do IPv6 route advertisements or DHCP6 and would not be using silly NAT tricks.

The benefit of this particular setup is that the RTP traffic from the phone will terminate at the Asterisk server, that will therefore act as a natural IPv6/IPv4 application gateway.

Keywords: NAT, Speedtouch 780, SNOM300, SIP, Asterisk

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Sopranos ….

 

I am a big fan of the Sopranos. However, Dutch television fails to broadcast the show on prime time so it never made it really popular in the NL. That leaves me nothing but SOBT (Stealing over BitTorrent) or waiting for the DVD series to come and pay 60 Euro.

Anyway, I am watching series 6 and the first episode started with a long scene, with a William S. Burroughs track accompagnying the images, that introduced in what state of life the family and their friends are. The William S. Burroughs track I didn't know but it sounded remarkably like the work he did with the "The Disposable Heroes of Hiphoprisy" (Michael Franti's old band). A plesant goosebump experience.

I try to understand why I like the Sopranos so much, one of the reasons is that the show is pure commedy. For instance, I couldn't stop laughing when one therapist, Eliot, was talking to the other, Melfi, and said, without a trace of cynicism: "This Omerta concept comes from a pre-therapeutic culture".

I fail to understand why the broadcast of the last episode made the Dutch news. They had to first explain that the Sopranos is a popular series in the US and then broadcasted the plot spoiler! 

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TPS Reports


Remember the stapler… That and those damned TPS reports lead to the fire that destroyed Initech.

It seems that Samir Nagheenanajar and Michael Bolton might have inspired the developer of the Corporate Ipsum Dashboard widget.

What would life be without TPS reports filled with paragraphs of texts, see below, that can only be found on those callendars with pictures with big black frames and ‘Big Words’ in big white fonts. Now… there is an idea for a Dashboard Widget. If only  Despair wouldn’t have had a “parody generator” of their own.

Uniquely streamline 2.0 information via pandemic alignments. Distinctively transition client-focused services after superior niches. Monotonectally seize web-enabled web-readiness for market-driven “outside the box” thinking.

Intrinsicly engineer go forward infrastructures whereas cross functional total linkage. Dramatically conceptualize maintainable initiatives vis-a-vis user-centric e-markets. Uniquely underwhelm distributed networks via cooperative experiences.

Enthusiastically drive sticky functionalities after timely results. Professionally architect future-proof methodologies before functionalized action items. Monotonectally productivate standardized metrics without holistic benefits.

Authoritatively iterate team driven e-tailers for multidisciplinary “outside the box” thinking. Distinctively enhance effective vortals and premier interfaces. Assertively incentivize enabled services for resource-leveling web services.

Dynamically syndicate highly efficient imperatives rather than next-generation intellectual capital. Collaboratively maximize open-source methodologies rather than highly efficient supply chains. Appropriately empower stand-alone manufactured products before cross-platform vortals.

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Wonder goo

We recently bought a house and we are now in the proces of painting it. Some walls need a little more than just a bit of paint. They need patching and fixing and, and that is really bad, removal of texture. I bought myself a grinder to perform the first step. The second step is where ARDEX commes in.

ARDEX is a plaster/synthetic material  that you apply to your walls or ceilings. I am completely unexperienced in plastering but this stuff works like a charm.

Its hard to get though. I had to call 5 hardware stores to find an ‘obscure’ specialized store that carried it.

I didn’t know I could be so enthousiastic about a bag of powder.

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ID/Loc Scotch Bof

The secret-wg’s contribution to the Scotch BOF:

There is this mess that is almost a soap
About addresses, routing, called ROAP
Heat your box, if you dare
or your wire, I don’t care
Drink a Scotch and there will always be hope

(for the universal deployment …. &c &c)

See www.secret-wg.org/Secret-Archive/ for more geeky limericks.

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From OpenCola to Bin Laden

OpenCola (source: wikimedia.org)

 

I just stumbled upon a Wikipedia lemma on opencola. The recipy contains a fair amount of Gum Arabic. That reminded me of a book by Dorrit van Dalen that recently appeared at Bert Bakker publishers that is high on my wishlist. What is below I read in review.

Apperantly Gum Arabic is one of those substances that is imposible to synthesize and that can only be retrieved from damaged barks of certain spiecies of the Accasia tree. In dutch the phenomena is called “Tranen der Accasias” (Accassia tears) which happens to be the title of one of the first novels by Willem Frederik Hermans. The circumstances under which the gum is produced is hardly known so that the production is hardly cultivated.

The name Gum Arabic stems from the fact that the Accasia species  can only be found in the subsahara regions. If I recall well the main production used to be in West Africa but has moved to East African Sudan.  Traditionally the traders in Gum Arabic are powerful men. It is one of the markets that has always been dominated by the traders. The first major buyers of the product were textile printers and they had no choice than to deal with the traders. Those traders needed to protect the sources for their product and therefore these became a pretty secretive bunch.

The book argues that the Bin Laden familly (Osama in particular) has a large stake as one of the Sudanese gum traders. Sudanese gum was one of the products that was kept out of economic embargos because it is one of the main substances for Coca Cola (and other food and drink). Wikipedia dismisses this as an urban legend. Which makes me want to read the book even more.

 

Also see the Wikipedia Gum Arabic lemma, that is also where I found the explanation why arabic gum is used in cola: Gum arabic reduces the surface tension of liquids, which leads to increased fizzing in carbonated beverages.

 

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