Monday, December 31, 2012

Pcap Touch: Read PCAP on iOS!

I finally joined the ranks of the iOS-enabled this Christmas, thanks to a gift of an iPod Touch.  As I was casting about for free/cheap apps (there's an inverse relationship between "number of kids" and "disposable income", and it's an exponential...), I stumbled across this gem - Pcap Touch!

It's a very basic app, in that it only displays pcap-format files; don't expect all the bells and whistles of Wireshark.  Nonetheless, a quick test drive suggests that Pcap Touch will be quite useful for taking a "quick look" at small capture files.  I can already envision using it in situations where we've already performed problem isolation and know exactly what packets are of interest in a given capture.

The only roll-your-own step is transferring the pcap files to your iOS device.  Out of sheer convenience, I used Dropbox; the Dropbox UI shows a "can't view this file" message upon download, but Pcap Touch shows up in Dropbox's "export file to app" UI automatically.

One VERY interesting side note: the app can also stream a live packet capture from a Linux system, via the open-source pcap-touch-server.  I have not tested this capability (yet), but its utility is obvious.

In summary: I wouldn't try to do full-blown capture analysis with this tool, but it's definitely going to come in handy for mobile/remote capture review on a regular basis.  The pairing of Dropbox and Pcap Touch can make the iOS platform useful to network engineers and hobbyists alike.  Have at it.

Monday, December 17, 2012

Today's Random #MPFreebie - Christmas in PDX

It's time for another in my irregular series of free music posts...this time with a regional flavor!

You may not know this, but Portland is home to a sprawling music scene; in fact, it has become so much of a music Mecca that The Oregonian now selects a Top 10 "Portland records" to give local artists their due. (Here's their #1 for 2012.)  You can hear just about anything in Portland, and XO Publicity has been bringing it home at Christmas time for 5 years now.  Each year, they pull together a holiday sampler from among their (rather large) clientele, and it's good stuff; I have found that at least one track from each year's offering has made its way into my 'standard' Christmas playlist.

"XO for the Holidays Volume 5" is no exception.  My First Listen Favorites (FLFs) would have to be Robert Burnham's uptempo White Christmas, the metal-grinding What Child of Magnuson, and Maybe Next Christmas from Blue Skies for Black Hearts.  Your mileage may vary; you'll find a good mix of genres here.

You can grab a copy of the sampler (and, if you're so inclined, its four predecessors in the series - I recommend them!) from the link below.  Time to bulk up your Christmas playlists, folks...

xo publicity - XO for the Holidays Volume 5

Friday, December 14, 2012

My All-Time Favorite Rock Christmas Song? Yep, Pretty Much...

Most of you know that I'm a TOTAL music geek.  I listen to just about everything--much to my family's frequent chagrin--and the Christmas season is no exception.  Of course, you can find Christmas music in just about any genre, but let's face it: rock is not always conducive to what we usually name "the Christmas spirit."  Well, there's at least one amazing exception to that notion, and it came out in 1963, courtesy of music industry legend Phil Spector and (now) Rock and Roll Hall of Famer Darlene Love - "Christmas (Baby Please Come Home)."

The first performance of this song in my memory was Love's first performance on Late Night with David Letterman in 1986.  I immediately began searching for the original album (most non-vinyl releases were titled "A Christmas Gift For You from Phil Spector"), and was not disappointed; that may well be the greatest rock Christmas collection EVER.  Love's appearances on Late Night became a tradition that continues today, and CBS recently released this mashup covering most of Love's 24 years of performing her signature tune.  I particularly enjoy Paul Shaffer's arrangements of the song; he pays homage to Spector's "Wall of Sound" approach while incorporating instrumentation and vocals that Spector could not. 

Just as Letterman has said on numerous occasions, it isn't really Christmas until I hear Darlene Love since this song.  Enjoy.

Saturday, December 08, 2012

Technology Behind the Scenes - IP Multicast and the Stock Market

One finds network documentation in the most unusual places...

While doing a bit of research into stock market operations, I stumbled across the Consolidated Tape Association.  Basically, the CTA is the group that disseminates real-time trade and quote information for securities listed on the NYSE, NYSE Arca, NYSE MKT, and other exchanges.  Now, I had never really considered the design implications of a free-for-all environment such as securities trading; we've all seen the movies with screaming traders, paper-littered floors and the like, but how do they get their data?

As it turns out, they use IP multicast.  This makes sense, since we're talking about data streams from a single authoritative source with no need for responses from recipients.  (Think about it - stock quotes are a one-way stream, right?)  Well, the Securities Industry Automation Corporation (now NYSE Technologies) has published a complete specification for the National Market Systems Common IP Multicast Distribution Network, and it's an interesting read for any IT/networking person.  It's interesting to see that flood of market data broken down into individual multicast streams, specified provider multicast IPs and specific UDP port numbers.  There's also a prepositioned/predefined disaster recovery addressing scheme, which may be of interest to those of you planning/gaming your own corporate DR scenario.  Those of you familiar with market operations might find it interesting to see "circuit breakers", open/close prices, and bid/offer semantics implemented as network messages, which you'll find in the CQS and CTS specifications on the page linked below.

All in all, I found this an interesting exercise in "double vision" - seeing financial & market imperatives (and raw data) defined in terms of data protocols really gave me a different perspective on the daily operations of the markets.  For the networking professional, this provides an interesting look into one of the most far-reaching IP multicast implementations you're likely to find.  If you're a networking geek, it's worth a look.

NYXdata > CTA

Thursday, December 06, 2012

Counting Down to IBM Connect 2013! (With JavaScript)

Well, today was an exciting day in the community, as all the folks who submitted abstracts for presentations at IBM Connect 2013 learned their fate.  It was, as usual, a highly competitive process with hundreds of great entries; those accepted can rightfully be excited about taking the stage at a fantastic conference.

For me, this day always starts the official "clock is ticking" mindset, so I decided to add a countdown timer to my blog.  For those of you who may want to do the same, it's a simple thing to do.  If you're using Blogger, just add the "HTML/Javascript" gadget to your layout, give it a nice title (I went with the simple "Countdown to IBM Connect 2013"), and insert the following Javascript:
<script language="JavaScript">TargetDate = "01/27/2013 10:00 AM";
BackColor = "white";ForeColor = "#ff6600";
CountActive = true;CountStepper = -1;
LeadingZero = true;DisplayFormat = "%%D%% Days, %%H%% Hrs, %%M%% Min, %%S%% Secs.";
FinishMessage = "It is finally here!"; </script>
<script language="JavaScript" src=""></script>

A big thanks to Robert Hashemian for making his countdown script publicly available!