Sunday, September 16, 2012

IPv6 panel at Internet2 meeting

Penn is co-hosting the Fall 2012 Internet2 Member meeting in Philadelphia, Oct 1st through the 4th. I'm moderating an IPv6 Deployment Panel at the conference (October 2nd, 1:15pm-2:30pm). Joining me will be John Brzozowski from Comcast, Allie Hopkins from Tulane University, Eric Kenny from Marist College, and Mark Kosters from the American Registry for Internet Numbers (ARIN).

The description says: "Several panelists will provide an update on IPv6 deployment activity and plans at their respective organizations, including both network infrastructure and application services. Other topics might include IPv6 security issues, network monitoring, technical support and training, etc"

John Brzozowski is Comcast's chief IPv6 architect. Comcast is one of the industry's leading adopters of IPv6, and I hope that John will share the latest news about IPv6 developments at Comcast. Mark Kosters is the Chief Technology Officer for ARIN. Allie Hopkins is an IT director at Tulane, but was formerly at Louisiana State University. I expect that Allie will be able to talk about the state of IPv6 deployment at LSU. As you may recall, LSU was on the list of the top IPv6 traffic generating sites during World IPv6 Launch. Eric Kenny is a network engineer from Marist College, which also made that list. I'll meet Eric for the first time at the conference. I've known the other panelists for a while.

In addition to deployment details, some combination of us will try to do a little bit of IPv6 evangelism. I'll also be asking Mark to do the usual ARIN update on the state of IPv4 address depletion.

I hope to see some of you at the conference. The panel session will also be netcast (and most likely archived video will be available to view later). If anyone has suggestions on specific IPv6 related topics the panel should discuss or comment on, feel free to let me know.

* IPv6 at Penn
* IPv6 at LSU
* Comcast IPv6 Information Center
* ARIN: IPv4/IPv6 the bottom line
* ARIN: IPv6 Wiki

Monday, September 3, 2012

Yosemite Photos

Some photos from a recent visit to one of my favorite places, Yosemite National Park.  A larger collection of photos is available on my Google Plus page.

The one small disappointment with visiting in late July is that many of the park's famous waterfalls are close to drying up. The rest of the outstanding natural scenery more than makes up for this though. There are few places in the world where you can see such stunning vistas in such close proximity to each other.

The photo below was taken from the Tunnel View turnout, near the Wawona tunnel, and looks eastward towards Yosemite Valley. Many of the valley's most famous landmarks and monoliths are visible in this scene, including El-Capitan, the giant granite block with the vertical face, Half Dome (in the center), the Cathedral Rocks and Bridalveil Fall.

Below: a close-up of El-Capitan (7,569 feet), which rises 3,000 feet above the valley floor. It's vertical face is a favorite challenge for experienced climbers.

Below: Half Dome, perhaps the most famous of the granite monoliths in the park. This view looks at the sheer vertical face; the other three sides are rounded and smooth. The peak (8,835 ft) rises 4,800 ft above the valley floor.

Another view of Half Dome with Cloud's Rest (I can see where that name comes from) to the left. Cloud's Rest at 9,931 feet is actually quite a bit taller than Half Dome.

Many of the famous waterfalls largely dry up by late July, early August.

Bridalveil Fall, below has mostly been reduced to a mist. When in fuller flow, this is an outstanding example of a waterfall leaping from a "hanging valley", a characteristic feature of many glaciated landscapes. The large glaciers that carved out much of Yosemite Valley left tributary streams like Bridalveil creek hanging high above the valley floor once the ice receded, and dropping from a cliff into the Merced river.

Vernal Fall (317 ft) flows throughout the year, but with much less volume in late July.

Yosemite Falls is almost dried up. Up close, some water can be see in the upper and lower portions of the falls.

Below: Half Dome and the Tenaya Canyon, viewed from Olmsted Point just off the Tioga Road.

Tenaya Lake, elevation 8150 ft, 222 acres in area, is a remnant of the Tenaya glacier. which retreated 15,000 years ago.

Below: "Roche Moutonnees" -- glacier and river carved, highly polished, granite domes in Tuolumne meadows. Many of these domes have an asymmetic profile, with a gentle slope on one side, and a much steeper slope on the other, indicating the direction of ice flow. These are geologically quite distinct from the various exfoliation domes seen around Yosemite Valley.

Pothome dome (8,766ft), rises 200 ft above the meadow floor. So named, because its south flank contains numerous deep cylindrical holes formed by subglacial rivers swirling rocks in a tight circle.

Lembert Dome (9,449 ft), another classic roche moutonnee, rises 700 ft above the surrounding meadow.

View from close to the top of Lembert Dome

Unicorn peak from Tuolumne Meadows.

Alpine meadows, strewn with glacial erratics, near the eastern end of the park near Tioga pass.

Tioga Pass, at the east entrance to the park, 9,943 ft.

Below: Giant Sequoia trees at the Mariposa Grove, in the south part of the park. Giant Sequioas are the largest living organisms on earth, and grow only in specific areas on the western slope of the Sierra Nevadas - there are groves in Yosemite, Sequoia, and King's Canyon national parks. The largest known Sequoias are actually in Sequoia national park's Giant Forest. But the Mariposa Grove has some pretty big ones too. The famous "Grizzly Giant" is 209 ft tall and 34,000 cubic feet in volume! California coastal redwoods (which I saw at Muir woods the day before arriving at Yosemite) are the world's tallest trees, but in sheer mass, they are dwarfed by the Giant Sequoias.

Looking north west towards "Taft Point". Apart from a small railing at the point, the cliffs around Taft point are completely unguarded, a 3,400 ft drop to the valley floor. Inching up to the edges, the views are incredible - but not for the acrophobic!

View from Taft Point.

Below: The upper chamber of Yosemite Valley (sometimes called Little Yosemite), from Washburn Point off the Glacier Point road. Half Dome is prominent in this view, as are Mt Broderick, Liberty Cap, Vernal and Nevada Falls, the Panorama cliffs, and in the distance, the vast panorama of the Sierra Nevadas.

Below: Also from Washburn Point, a zoomed in shot of the "Giant Staircase". The Merced river descends this staircase via two waterfalls that are at right angles to each other, Nevada Fall (594 ft) and Vernal Fall (317 ft), flanked by Libery Cap and Mount Broderick.

Yosemite Valley and the Tenaya Canyon from Glacier Point.

The Royal Arches - a collection of arches carved into the rock face by large sheet joints. Above the arches are several smoothly shaped granite domes, North Dome & Basket Dome. To the immediate right of the Arches is Washington Column, an enormous natural rock pillar.

Yosemite Valley from the Valley View turnout - another very popular photo-op.

More photos (including larger versions) are available on my Google Plus page.