The Plexnet is a set of open web standards that will hopefully allow for richer and more interoperable applications to be developed over the Open Web.
Table of Contents
The Plexnet is intended as an open source competitor to the various proprietary platforms that currently threaten to fragment the Open Web [Neuberg-2008]. Whilst the various proprietary efforts have lots of beautiful innovations, they suffer due to:
- Not being cross-platform — Nokia S60
- Not being truly open source — Microsoft Silverlight
- Having single-vendor “lock-in” — Facebook F8
- Lacking distributed extensibility — Apple iPhone
- Not carrying the spirit of the original internet — Adobe Flash
The Open Web is the only pervasive platform which doesn't suffer [Eich-2007]. But then, why do these alternative platforms exist? Because the Web is nearly 20 years old [Berners-Lee-1989]. Many of today's applications weren't expected back then.
Countless developers have had to independently solve the same problems over and over, e.g. identity, scalability, structured data, social networking, &c. And a lot of useful functionality isn't handled natively by most browsers, e.g. media delivery, better interfaces, voip, &c.
This is where many of the proprietary platform providers fit in. Unfortunately, innovation slows down as developers try to assess, learn, code, test and deploy for the various platforms. Again and again and again. Our collective efforts are wasted on working around technical incompatabilities and shortcomings instead of tackling the real problems of life.
“Ease developer pain and take innovation to the next curve”
Thus the time has come to take the Open Web to the next level [Leggett-2008]. To ease developer pain and take innovation to the next curve [Kawasaki-2006]. Letting the focus be on creating truly innovative, useful, fun applications again.
Begin With HTTP
It should come as no surprise that a central element of the Plexnet is a web server. AKA, a Plexnet Node. Nodes MUST be fully conformant to the HTTP/1.1 specification [RFC-2616]. Support for the following functionality, in particular, are key:
- The basic HTTP verbs: GET, HEAD, PUT, POST, DELETE, OPTIONS.
- Asynchronous file-serving (including range requests).
- Gzip compression to save on the bandwidth bill.
- Larger than 512 byte response bodies for errors like 404s.
- SSL/TLS connections [RFC-4346] for authentication/privacy.
- Inclusion of [Plexnet] in the Server field of response headers.
Given the high scalability needs of the modern web [Kegel-2001], it is RECOMMENDED that an event-driven approach is taken when implementing Nodes. If other approaches are used, care should be taken to ensure that the Node can support at least 10,000 concurrent persistent HTTP 1.1 connections on a modern computer.
One of the side-benefits of using Teredo is that it allows for better access of Nodes than is often possible with NAT-ed IPv4 web servers. Thus, direct Node-to-Node communication would be possible without expensive relays.
Of course the flip side is that the surface for attack vectors is increased. But that is a risk for operators of any internet service. Plexnet Nodes are no special in this regard.
The following public Teredo servers are available for use:
- debian-miredo.progsoc.org (Australia)
- teredo.ipv6.microsoft.com (USA)
- teredo.remlab.net (France)
- teredo.plexnet.org (Germany)
- 126.96.36.199 (Korea)
Accessible Globally & Locally
All Plexnet Nodes SHOULD be accessible over the “Public Internet”. This might seem like a rather draconian requirement, but it should be understandable given that net neutrality [Cerf-2006] may soon just be a beautiful dream we all once had.
A sample configuration file for a Node may look like:
node.id = '6409808a-3548-11db-f2fd-0016cb90e4dc'
node.ipv4 = '188.8.131.52'
node.ipv6 = '2001:4860:0:1001::68'
node.teredo_server = 'teredo.plexnet.org'
node.stun_server = 'stun.plexnet.org'
In the event that a Node's public IPv4 and IPv6 addresses are not set, its IPv4 address will be auto-detected through the use of STUN [RFC-3489]. Likewise, with the use of Teredo for IPv6. If both of these fail to resolve, then the Node SHOULD fail to operate.
The following public STUN servers are available for use:
In addition to binding to the given public addresses, a Node MUST also bind to localhost — 127.0.0.1 (IPv4) [RFC-3330] and ::1 (IPv6) [RFC-3513]. This is to ensure that Nodes are always accessible locally.
Nodes MUST run on the ports 8010 (HTTP) and 9010 (HTTPS). These ports have been registered with the IANA Port Registry and the harmonisation allows for ease of discoverability of Plexnet Nodes.
Thus the Node from the example configuration above, should be globally accessible via:
And locally accessible via:
“Nodes will behave in a P2P (Peer-to-Peer) manner”
Nodes have traditionally acted as just servers — responding to requests from browser clients. In contrast, Plexnet Nodes will behave in a P2P (Peer-to-Peer) manner.
It is expected that, instead of directly accessing web sites, users will access various resources through a Plexnet Node running locally. The Node will then access the resources from other Nodes using direct Node-to-Node communication.
To facilitate this, Nodes MUST generate a 128-bit node.id — using the MAC-based version 1 UUID protocol [RFC-4122]. Whilst this reveals the MAC-address, there is no requirement for the UUID to be generated on the same host machine as the Node.
These Node Identifiers serve a similar purpose to host names in the Domain Name System [RFC-1034]. DNS has served extremely well as the “phone book” of the internet. But, despite all of ICANN's great work, it is tainted by greed [Cheng-2008] and censorship [Ardia-2008] by the Registrars.
This should have been expected. “Projecting our notion of names onto DNS [subjects] the stability of links to the whims of political and social policy” [Frankston-2001]. The Plexnet solves this by handling the issue of naming with a separate Plexnames mechanism.
This separation also helps the longevity of URIs [Berners-Lee-1998] — which are currently dependent on yearly renewal of associated domain names. It is shocking that we entrust so much to a mechanism that is guaranteed to decay!
A side-benefit of all this is an expected decrease in crime. Cybersquatting and phishing cease to have any value in a world where Node Identifiers no longer represent people-friendly .com handles.
In addition, Nodes MUST generate a public/private keypair in the form of X.509 certificates [RFC-3280] for the purposes of acting as a Certificate Authority (CA). The Common Name (CN) field MUST be the 36-byte human readable format of the Node Identifier, e.g.
Standard precautions should be taken to ensure appropriate key length, duration and protection of the keys. The public key node.certificate MUST be DER encoded and node.fingerprint should be an ordered pair of the hash algorithm used, e.g. SHA-1 [FIPS-180-1], and the unencoded digest:
>>> node.fingerprint ('sha1', '\xa5\xcaX\xaf\xb9\x98Zcv\xa80\xf3\x97\x03ro\xab/\xc8\xdf')
When printed on paper for out-of-band exchange of certificates, the fingerprint SHOULD be presented in the format:
SHA1: A5CA 58AF B998 5A63 76A8 30F3 9703 726F AB2F C8DF
Ideally all exchange and verification of unknown certificates would happen in person. But given how lazy we all are, it is RECOMMENDED that Node operators at least use the phone to verify the fingerprint of new Trusted Nodes. Man-in-the-middle attacks are very real.
To Be Written
Private key — passphrase protected
def foo(entity_id, passphrase):
return sha256("%s:%s" % (entity_id, passphrase)).hexdigest()
“We need to learn new designs, design frameworks, and design approaches from naturally occurring, ultra large scale systems (e.g. biology, ecology)” [Gabriel-2007]
Level 3 — for self-authenticating services.
But special Seed Node will be available at https://seed.plexnet.org
In addition, Nodes are expected to:
- Support file upload monitoring via AJAX.
- Support powerful proxying and redirect (internal/external) capabilities.
- Have very simple request handlers — just register and go!
- Provide a pluggable logging/monitoring/statistics system.
Plexnet Sockets are similar in purporse to P2P sockets [Neuberg-2003].
Defence mechanism — drop connections if a primary violation is detected.
Proxy Nodes are intended to act as public-facing…
In addition to the official ports, a Proxy Node MUST also run on ports 80 and 443 for HTTP and HTTPS traffic.
node.host = 'tav.espians.com'
Also helps in enabling better interfaces. For example, imagining being able to transfer a file to someone working on the multi-touch console in front of you. Instead of having to resort to emailing the file to her, you could just throw the virtual file in the direction of her console.
“The vast majority of programmers are those building end-user applications, and the even greater population of potential programmers are the end-users themselves” [Edwards-2004]
Code is data. Data is code. This is a truth that Lisp hackers have known for decades. But it applies to all of computing [Cawley-2008].
Plexnet Serialisation Format
“A different performance issue is that the set of root inclusions grows monotonically, journaling all changes. It will be necessary to gradually forget the details of history by summarizing them into coarser versions, based on some configurable policy. In an end-user production environment, the policy might be to immediately forget history, enabling special optimizations.”
Functional reactive programming
Typed Text — Markdown
Service Definition — Help — Testing
Whether that be on a computer or a post-PC device.
Local device/drives support
def hello_world(var, foobar="hmz"):
"""This is just to test the syntax highlighting -- ignore."""
if var == 'foo' and (foobar < 20) or len(foobar) == sum([var]):
Foo <strong>Bar</strong> Yeah.
Gestures have been a key innovation in digital interaction. From the “drag” feature implemented on the early Apple Macintoshes to the implementations in the likes of Lionhead's Black & White game and the Opera browser to the recent day iPhone and Wii. [Saffer-2007]
“It only takes a couple of smart engineers to create quality software of immense value” [Iskold-2008]
Downloadable packages will eventually be available at http://plexnet.org for all major modern platforms.
In order to minimise bugs and maximise stability, test-driven [Beck-2002] and crash-only [Candea-2003] design approaches will be taken. The aim is for the reference implementation to be deployable within production environments.
Others are strongly encourage to port it to their favourite programming environments once a stable version has been released. This Plexnet specification is intended to be language-agnostic and fully portable.
Alternatives to TCP
Anyone who has suffered congestion caused by heavy TCP traffic on a wireless network will be aware of TCP's shortcomings. In some applications, e.g. VoIP, it doesn't matter if packets are dropped but that they are delivered in “real-time”.
Airhook [Egnor-2001] is an alternative to TCP [RFC-793] — implemented on top of UDP [RFC-768] — which may offer a solution to these problems. And since HTTP is protocol independent, Nodes can start supporting Airhook for Node-to-Node communications without need for support from operating system or browser vendors.
One interesting problem to solve would be to figure out how applications could take advantage of Airhook's flexibility from the HTTP level. Of course, even if Airhook does turn out to be a viable alternative, TCP won't disappear overnight. Both protocols would have to be concurrently supported for a while.
Whilst this document is not meant to be normative, it hopefully provides a basis for an official Plexnet set of Open Web standards to eventually emerge.
In the meantime, the key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” should be interpreted as described in RFC 2119 [RFC-2119].
The use of Python syntax in code snippets is only for the purposes of clarity in expression. It seemed to make better sense than inventing some arbitary pseudo-code syntax [Norvig-2000].
David Ardia, Citizen Media Law Project, February 2008.
Kent Beck, Addison-Wesley Professional, 2002.
Tim Berners-Lee, CERN, 1989.
Tim Berners-Lee, W3C, 1998.
Randy Bush, NANOG, 2007.
George Candea and Armando Fox, Proceedings of the 9th Workshop on Hot Topics in Operating Systems (HotOS-IX), Lihue, Hawaii, May 2003.
Piers Cawley, April 2008.
Vinton G. Cerf, U.S. Senate Committee on Commerce, Science, and Transportation Hearing on “Network Neutrality”, February 2006.
Jacqui Cheng, Ars Technica, April 2008.
Jonathan Edwards, June 2004.
Jonathan Edwards, MIT CSAIL, May 2006.
Jonathan Edwards, OOPSLA, October 2007.
Brendan Eich, Mozilla Corporation, 2007.
Dan Egnor, 2001.
National Institute of Standards and Technology, U.S. Department Of Commerce, April 1995.
Brad Fitzpatrick, August 2007.
Bob Frankston, August 2001.
Richard P. Gabriel, November 2007.
Alex Iskold, ReadWriteWeb, 2008.
Guy Kawasaki, 2006
Dan Kegel, 2001.
Russell Leggett, April 2008.
Raph Levien, February 2000.
Raph Levien, Draft Thesis, 2004.
Mark S. Miller and K. Eric Drexler, The Ecology of Computation, Bernardo Huberman (ed.) Elsevier Science Publishers/North-Holland, 1988.
Brad Neuberg, March 2003.
Brad Neuberg, April 2008.
Peter Norvig, 2000.
Jon Postel, August 1980.
IST, DARPA, September 1981.
Paul Mockapetris, November 1987.
Scott Bradner, March 1997.
Stephen E. Deering and Robert M. Hinden, December 1998.
Roy Fielding, et al., June 1999.
Brian E. Carpenter and Keith Moore, February 2001.
Russell Housley, et al., April 2002.
IANA, September 2002.
Jonathan Rosenberg, et al., March 2003.
Robert M. Hinden & Stephen E. Deering, April 2003.
Paul J. Leach, et al., July 2005.
Tim Dierks and Eric Rescorla, April 2006.
Christian Huitema, February 2006.
Dan Saffer, Adaptive Path, 2007.
Mark Slee, Aditya Agarwal and Marc Kwiatkowski, Facebook, 2007.
For their inspiration:
- Allen Short, Bryce Wilcox-O'Hearn, Daniel Biddle, Douglas Crockford, Luke Graybill, Mark S. Miller, Øyvind Selbek, Peter-Paul Koch, Simon Michael, Steve Alexander, Tavin Cole and Tim Jenks.
For being there when the Plexnet vision came to be, back in summer 2001:
- Mathew Ryden and Fenton Whelan.
For working on the first implementation:
- Aaron Swartz.
For having had the balls to try something equally ambitious decades ago:
- Ted Nelson.
For having created the Open Web in the first place:
- Tim Berners-Lee.
For improvements to this document:
- Mark Poole, Simeon Scott.
For being instrumental in forging the Plexnet from abstract vision to technical realism:
- Alex Tomkins, James Arthur, Jeffry Archambeault, Luke Graybill, Mathew Ryden, Øyvind Selbek, Phillip J. Eby, Sean B. Palmer, Stefan Plantikow, Thomas Salfield and Yan Minagawa.