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How the Net works

p2pnet.net special:- A public workshop on “Broadband Connectivity Competition Policy” featuring experts from business, government, and the technology sector, consumer advocates, and academics was hosted by the Federal Trade Commission, last month (February).

Said the FTC:

The workshop will explore issues raised by recent legal and regulatory determinations that providers of certain broadband Internet services, such as cable modem and DSL, are not subject to the FCC’s common carrier regulations. The workshop will examine, for example, the capabilities and incentives of broadband Internet service providers to discriminate against, degrade, block, or charge fees for prioritized delivery of unaffiliated content and applications. The workshop will also address the potential effects of network neutrality regulation on innovation and competition in the market for broadband access.

Free software enthusiast Jay Sulzberger (right), who also has a keen interest in p2p file sharing, was one of those in attendance. As a friend of his, fellow advocate Seth Johnson, recently summed it up, the “submitted tutorial carries the FTC through some illuminating commentary and richly rewards an attentive reading”. Johnson continued:

As he defines and illustrates the Internet and net neutrality for the FTC’s “Broadband Connectivity” workshop, he presents a lesson in ports, nmap, http daemons and browsers, mail transport agents, ssh, qotd, tinyP2P, and mentions a myriad of applications and protocols, inserting along the way the entire RFC for the qotd protocol and attaching the full IANA port numbers document [thereby extending his submission to 280 pages].

Posted by David Weinberger on his Joho the Blog, the presentation is a, “lucid explanation of how the Net works – ports ‘n’ protocols – and exactly why the Net is essentially different from cable TV.”

He also obserbves that although the .pdf 280 pages long, “Jay’s comments are are a mere 12 pages of typescript – easy and fun reading,” adding:

“Also of special interest: eBay’s comments and joint comments by Senators Dorgan and Snowe.”

Sulzberger’s comments are below, and you’ll find the entire paper here.

We should point out that the formatting in the p2pnet post isn’t identical to that in Sulzberger’s presentation, so if there’s any doubt, you should check the original.

>>>>>>>>>>>>>>>>>>>>>

Comments on the definition of the Internet and the importance of distinguishing the Net from cable TV, and from lower level signal transport systems, after the FTC Workshop of 13 and 14 February 2007 on Network Neutrality

I am Jay Sulzberger. I am a working member of New Yorkers for Fair Use, and I attended the 13-14 February 2007 FTC Workshop on Network Neutrality. This comment is not an official statement of New Yorkers for Fair Use.

The full name of the FTC workshop on 13 and 14 February 2007 included the phrase “broadband competition”. At the workshop, most of the discussions failed to address the real issue of Network Neutrality because no correct definition of the Net was presented.

Internet packets may be carried over slow communications links or over fast links. Most week days I use several different connections to the Net. Some days I use a dialup connection, which is much slower than the connection over lines owned by the Cable Company, or by the City of New York. But no matter whether I use slow lines or fast lines, I use the Net for private, for tribal, for business, and for public communications. And I use the Net in freedom. And some days I watch cable TV.

Now cable TV is not the Internet, but most speakers at the FTC’s workshop spoke of the Net in ways that treated it as if it were just a form of interactive TV, with some extra special services bundled with interactive TV, “web viewing”, email, and doubtfully, voice over IP.

Questions around building another, perhaps several other, cable TV networks, are not part of the issue of Network Neutrality, because the Net is not TV of any kind.

Use of the word “broadband” to mean both the Net and cable TV helps perpetuate the fundamental confusion.

We now state explicitly the main implicit error which underlies the FTC’s present failure to engage with the issue of Network Neutrality:

Main Implicit Error: The Internet is not some bundle of services delivered by the Telephone Company and/or the Cable Company.

The Net is difficult to understand unless you work with it productively to develop applications and therefore already know what it is; and in that case, it is still difficult to convey what the Net is, because some history and background information, is needed to grasp how different the Net is from cable TV.

I admit that many people who today visit web sites and do email do not clearly understand what the Net is. But certainly the FTC should clearly understand what the Net is.

When ranting on the topic of the Net in years past, I have often claimed that one can explain the Net without knowing anything of matters denominated in the popular press as “technical”. After the workshop, I now think that complete ignorance can impede understanding of the Net. One speaker at the workshop who spoke against Net Neutrality had never heard of a port. It is likely that part of his, and others, opposition to Net Neutrality is due to simple ignorance.

We distinguish several faces of the Net.

First let us define what the Net is for a user of the Net. This face of the Net is simple to explain. But the explanation may, at first, be hard to understand, not because of subtleties, but rather just the opposite, because of the simplicity and the extremity of the defining principles.

If you do not know what a port is, then likely you implicitly assume that the Duopoly invented the Net and gave us the World Wide Web, email, videos over the Net, massive virtual worlds/games, etc.. So, what is a port? For a good introduction to ports, see

http://en.wikipedia.org/wiki/TCP_and_UDP_port

http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers

Consider me sitting in front of my computer. My computer is connected to the Net. My computer has an Internet address, say 192.0.34.166. Every computer connected to the Net has such an address. (For now, the question of how long the hardware keeps the same address, and who decides the address, how other computers figure out the address, etc. are all irrelevant.)

Important point: We assume in this explanation that I am in full control of my computer.

Now I issue, as root, this command to my computer

nmap -sT -O localhost

and I get back:

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2007-02-2 19:25 EST Interesting ports on localhost.localdomain (127.0.0.1):

Not shown: 1656 closed ports

PORT STATE SERVICE

1/tcp open tcpmux

11/tcp open systat

15/tcp open netstat

25/tcp open smtp

79/tcp open finger

111/tcp open rpcbind

119/tcp open nntp

143/tcp open imap

540/tcp open uucp

635/tcp open unknown

993/tcp open imaps

1080/tcp open socks

1524/tcp open ingreslock

2000/tcp open callbook

6667/tcp open irc

12345/tcp open NetBus

12346/tcp open NetBus

27665/tcp open Trinoo_Master

31337/tcp open Elite

32771/tcp open sometimes-rpc5

32772/tcp open sometimes-rpc7

32773/tcp open sometimes-rpc9

32774/tcp open sometimes-rpc11

54320/tcp open bo2k

Device type: general purpose

Running: Linux 2.4.X|2.5.X|2.6.X

OS details: Linux 2.5.25 – 2.6.8 or Gentoo 1.2 Linux 2.4.19 rc1-rc7, Linux 2.6.3 – 2.6.10

Uptime 8.412 days (since Sun Feb 18 09:32:55 2007)

Nmap finished: 1 IP address (1 host up) scanned in 2.184 seconds

Ports, in the jargon of Internet engineers, are entrances and/or exits of my computer. They are entrances/exits for data. nmap is a program which knocks on every port of the specified computer. The knocks are delivered over the Net, that is, nmap is an Internet application. I specified in my command that nmap knock on the ports of my computer, here called “localhost”. (Irrelevant detail: from the vantage of my computer itself, my computer has by convention, sometimes, the Internet address 127.0.0.1.) nmap reports back which ports are open to incoming connections, that is, which ports will accept data coming in. nmap may be used to knock on the ports of any computer on the Net, even though in this example, I instructed nmap to only check my own computer.

The three columns of the first part of the data returned by nmap are:

1. the port, given by a number and what sort of data packets the port sends/receives

2. the state of the port

3. what service the people who built and run the Net have agreed should usually be listening at the port

The next part of the information returned by nmap, that is,

Device type: general purpose

Running: Linux 2.4.X|2.5.X|2.6.X

OS details: Linux 2.5.25 – 2.6.8 or Gentoo 1.2 Linux 2.4.19 rc1-rc7, Linux 2.6.3 – 2.6.10

Uptime 8.412 days (since Sun Feb 18 09:32:55 2007)

is nmap’s guess as to what sort of computer system nmap knocked on. The guess is that my computer is a general purpose computer running some version of the GNU/Linux operating system, and that it has been up “8.412 days”. (The uptime is not correct. nmap is not infallible.) Finally nmap tells what it did:

Nmap finished: 1 IP address (1 host up) scanned in 2.184 seconds

The information returned by nmap helps to show us what the Net is. My machine is connected to the Net. My machine has an address which allows other machines on the Net to send data to my machine in order, perhaps, to start two streams of data flowing between the two machines. Suppose that you also have before you a computer connected to the Net. Again, we assume that you have full control of your box.

We now present a well known, popular, and paradigmatic, use of the Internet:

You might have opened port 80 on your box, and placed a program called an “http daemon”, say Apache, to listen for incoming requests on port 80. I might start a Web browser, say Firefox, on my machine and tell my browser to ask for a web page on your machine. Firefox would now knock on port 80 on your machine, and request the page.

This is the mechanism by which web pages are delivered. Between your machine and mine lies the Net. Today, within the Net, there is no third party wiretapping our communication. There is no third party attempting to determine the value of our conversation to us, in order to charge us extra for valuable conversations. There is no third party examining our conversation in order to silence us if we say things the wiretapper’s boss finds unpleasant.

I should have said “In the best circumstances, there is no …” because, if your machine were in the United States, and mine in China, and if our conversation were to include mention of movements not favored by the government of China, then China might act to stop our conversation. And if your machine were in the United States and your “Internet Service Provider” refused to pass that first packet to port 80 on your machine, then our conversation could not even get started. The policy of refusing that first packet to port 80 is often called the “no servers allowed” rule. Both interferences result in something that is not the full and true Internet.

Let us list two other uses of the Net:

1. You might want to send me some email. By convention, usually port 25 is used for email. If I choose to get email by the usual means, I must open port 25, and place a “mail transport agent”, say exim, listening on the port. But we both might want to send email back and forth by other means. In that case, you and I might have agreed before hand to use another port, or set of ports, and we might have agreed on some other protocol for delivery of email. We are free to make our own arrangements, without asking permission of any third party.

2. Assume you are a master sysadmin and an old friend. I might be having trouble with my computer, and I might ask you, by telephone say, to come into my box and have a look around in order to help me. We might have agreed that you would come in via “secure shell”, that is, ssh. By convention, the usual port for ssh is port 22, and when I have opened up port 22, and set the ssh daemon listening, and granted you certain privileges on my system, you may run ssh on your box, ssh will open a connection to my box and you may now log in to my box. But we might, for some reason, choose not to use ssh and port 22. In that case, you and I might have agreed before hand to use another port, or set of ports, and we might have agreed on some other protocol by which you can log into my machine. We are free to make our own arrangements, without asking permission of any third party.

Here is the definition of the Internet. The definition comes in three parts.

1. My machine and yours stand equal as peers, in the sense that my or your machine can initiate, or attempt to initiate a conversation, without interference by third parties. And my machine or yours can accept such an invitation to converse, without interference by third parties. Naturally if your machine attempts to make a connection and my machine refuses, this is still the Net. But, up to bugs, communication occurs, or fails, by agreement, or disagreement, between you and me, as long as we have paid our ISPs.

2. If you and I agree on a protocol, and agree on a port, or ports, for our data streams to travel over, and we write, or otherwise obtain, two programs that use the protocol, we may set our programs running on our boxes, and we may communicate using the protocol we have together freely chosen, without interference by third parties. In particular, we are free to invent new protocols, and to write programs using the new protocols, and to set these programs running over the Net.

3. About one billion machines are connected and use the freely agreed on protocols that enable our conversations to be transported by the wires, fibers, through the routers, over the air, via satellites, carrier pigeons. And it all works because many people and companies and governments have built the pieces and connected them so that it does work to make possible the extraordinarily flexible and free communication specified in 1 and 2. The main underlying protocol of the Net is TCP/IP. Note that there are other networks which use the TCP/IP protocol, but are not the Net, because they do not allow on the order of one billion people to freely connect with each other with complete flexibility in their manner of communication, that is, in the protocols running atop TCP/IP. For example, various variants of cable TV may be delivered using the TCP/IP protocol. But such a cable TV network is not part of the Net.

Now we come face to face with the Main Error. If the Net were some bundle of services provided by the Duopoly, and perhaps, in future, by some other companies, then none of these defining conditions of the Net could be met. In order to be brief, we shall only explain why condition 2 would fail, if the Duopoly ran the Net:

ad 2. If the Duopoly provided the Net, then surely you and I could not design and deploy and use a new protocol without either working for the Duopoly, or negotiating with the Duopoly some arrangement by which the Duopoly would support the protocol. But this is exactly not how the Net was built. We adduce here a wonderful document, called the “port numbers”, which may be found at the website of the IANA, the Internet Assigned Numbers Authority:

http://www.iana.org/assignments/port-numbers

We append one version of this list, it is on occasion updated, as

Document IANA-port-numbers below.

Let us look at some lines from the list of ports:


	Keyword		Decimal	Description
			0/tcp	Reserved
			0/ud	Reserved
	#			Jon Postel
	tcpmux		1/tcp	TCP Port Service Multiplexer
	tcpmux		1/udp	TCP Port ServiceMultiplexer
	#			Mark Lottor
	compressnet		2/tcp	Management Utility
	compressnet		2/udp	Management Utility
	compressnet		3/tcp	Compression Process
	compressnet		3/udp	Compression Process
	#			Bernie Volz
	#		4/tcp	Unassigned
	#		4/udp	Unassigned
	rje		5/tcp	Remote Job Entry
	rje		5/udp	Remote Job Entry
	#			Jon Postel
	#		6/tcp	Unassigned
	#		6/udp	Unassigned
	echo		7/tcp	Echo
	echo		7/udp	Echo
	#		6/udp	Unassigned
	#			Jon Postel
	discard		9/tcp	Discard
	discard		9/udp	Discard
	#			Jon Postel
	discard		9/dccp	Discard SC:DISC
				IETF dccp WG, Eddie Kohler , [RFC4340]
	#			IETF dccp WG, Eddie Kohler , [RFC4340]
	#		10/tcp	Unassigned
	#		10/udp	Unassigned
	systat		11/tcp	Active Users
	systat		11/udp	Active Users
	#			Jon Postel
	#		12/tcp	Unassigned
	#		12/udp	Unassigned
	daytime		13/tcp	Daytime (RFC 867)
	daytime		13/udp	Daytime (RFC 867)
	#			Jon Postel
	#		14/tcp	Unassigned
	#		14/udp	Unassigned
	#		15/tcp	Unassigned [was netstat]
	#		15/udp	Unassigned
	#		16/tcp	Unassigned
	#		16/udp	Unassigned
	qotd		17/tcp	Quote of the Day
	qotd		17/udp	Quote of the Day
	#			Jon Postel
	msp		18/tcp	Message Send Protocol
	msp		18/udp	Message Send Protocol
	#			Rina Nethaniel <—none—>
	chargen		19/tcp	Character Generator
	chargen		19/udp	Character Generator
	ftp-data		20/tcp	File Transfer [Default Data]
	ftp-data		20/udp	File Transfer [Default Data]
	ftp		21/tcp	File Transfer [Control]
	ftp		21/udp	File Transfer [Control]
	#			Jon Postel
	ssh		22/tcp	SSH Remote Login Protocol
	ssh		22/udp	SSH Remote Login Protocol
	#			Tatu Ylonen
	telnet		23/tcp	Telnet
	telnet		23/udp	Telnet
#		Jon Postel
	24/tcp	any private mail system
	24/udp	any private mail system
#		Rick Adams
smtp	25/tcp	Simple Mail Transfer
smtp	25/udp	Simple Mail Transfer
#		Jon Postel
#	26/tcp	Unassigned
#	26/udp	Unassigned
nsw-fe	27/tcp	NSW User System FE
nsw-fe	27/udp	NSW User System FE
#		Robert Thomas
#	28/tcp	Unassigned
#	28/udp	Unassigned
msg-icp	29/tcp	MSG ICP
msg-icp	29/udp	MSG ICP
#		Robert Thomas
#	30/tcp	Unassigned
#	30/udp	Unassigned
msg-auth	31/tcp	MSG Authentication
msg-auth	31/udp	MSG Authentication
#		Robert Thomas
#	32/tcp	Unassigned
#	32/udp	Unassigned
dsp	33/tcp	Display Support Protocol
dsp	33/udp	Display Support Protocol
#		Ed Cain
#	34/tcp	Unassigned
#	34/udp	Unassigned
	35/tcp	any private printer server
	35/udp	any private printer server
#		Jon Postel
#	36/tcp	Unassigned
#	36/udp	Unassigned
time	37/tcp	Time
time	37/udp	Time
#		Jon Postel
rap	38/tcp	Route Access Protocol
rap	38/udp	Route Access Protocol
#		Robert Ullmann
rlp	39/tcp	Resource Location Protocol
rlp	39/udp	Resource Location Protocol
#		Mike Accetta
#	40/tcp	Unassigned
#	40/udp	Unassigned
graphics	41/tcp	Graphics
graphics	41/udp	Graphics
name	42/tcp	Host Name Server
name	42/udp	Host Name Server
nameserver	42/tcp	Host Name Server
nameserver	42/udp	Host Name Server
nicname	43/tcp	Who Is
nicname	43/udp	Who Is
mpm-flags	44/tcp	MPM FLAGS Protocol
mpm-flags	44/udp	MPM FLAGS Protocol
mpm	45/tcp	Message Processing Module [recv]
mpm	45/udp	Message Processing Module [recv]
mpm-snd	46/tcp	MPM [default send]
mpm-snd	46/udp	MPM [default send]
#		Jon Postel
ni-ftp	47/tcp	NI FTP
ni-ftp	47/udp	NI FTP
#		Steve Kille
auditd	48/tcp	Digital Audit Daemon
auditd	48/udp	Digital Audit Daemon
#		Larry Scott
tacacs	49/tcp	Login Host Protocol (TACACS)

The point here: None of the standard Net services listed above are services provided by the Duopoly to telephone customers or cable TV customers. If you look at the whole list below, we believe you will agree that these services are not offered by either the Telephone Company nor by the Cable Company.

Example of a Net service: Consider port 17/tcp. The people who built, and today, build and run the Net, have freely agreed, without coercion, without payments, without contracts, to use port 17/tcp for the Net application called qotd, which means “quote of the day”. For information about qotd see

http://en.wikipedia.org/wiki/QOTD

qotd is a very simple protocol/Net application. Here is an example of its use. I issue the command

telnet ota.iambic.com 17

and I get back

Trying 64.124.71.12…

Connected to ota.iambic.com.

Escape character is ‘^]’.

A good leader is a person who takes a little more than his share of the blame and a little less than his share of the credit | John C. Maxwell

Connection closed by foreign host.

Again I issue the command:

telnet ota.iambic.com 17

This time I get back:

Trying 64.124.71.12…

Connected to ota.iambic.com.

Escape character is ‘^]’.

If you have a procedure with 10 parameters, you probably missed some. | Alan J. Perlis

Connection closed by foreign host.

So we see that, likely, on port 17/tcp of the machine with Internet address 64.124.71.12, there is a qotd daemon running, which, in accordance with protocol, when we ask it, hands us a random quote of the day.

Now we adduce another document, the RFC for qotd. An Internet RFC, or request for comment, is a document which describes a protocol (or another useful standard thing) for use on the Net. The RFC for quote of the day has number 865, and may be found at

http://tools.ietf.org/html/rfc865

RFC 865 is short, as RFCs go. Here is the whole document:

Network Working Group J. Postel

Request for Comments: 865 ISI

May 1983

Quote of the Day Protocol

This RFC specifies a standard for the ARPA Internet community. Hosts on the ARPA Internet that choose to implement a Quote of the Day Protocol are expected to adopt and implement this standard.

A useful debugging and measurement tool is a quote of the day service. A quote of the day service simply sends a short message without regard to the input.

TCP Based Character Generator Service

One quote of the day service is defined as a connection based application on TCP. A server listens for TCP connections on TCP port 17. Once a connection is established a short message is sent out the connection (and any data received is thrown away). The service closes the connection after sending the quote.

UDP Based Character Generator Service

Another quote of the day service is defined as a datagram based application on UDP. A server listens for UDP datagrams on UDP port 17. When a datagram is received, an answering datagram is sent containing a quote (the data in the received datagram is ignored).

Quote Syntax

There is no specific syntax for the quote. It is recommended that it be limited to the ASCII printing characters, space, carriage

return, and line feed. The quote may be just one or up to several lines, but it should be less than 512 characters.

Postel [Page 1]

The Internet Engineering Task Force, or, in this case, perhaps a predecessor body, met and agreed that there was good reason to have such a standard protocol, and so this RFC was adopted. The working group that dealt with this RFC did not have to negotiate with the Duopoly a place for this protocol. Nor did the Duopoly have to consider pricing for delivery of qotd packet streams, nor whether, nor how, to introduce this new service to its customers, nor what regulatory bodies would have to approve the introduction of this new service, nor how this protocol should be dealt with by the Duopoly’s

hardware and software, etc.. None of these burdens attended the birth of the quote of the day protocol. None of these burdens today weigh down the deployment of the qotd service, none of these burdens weighed me down when I used the service a few minutes ago, and none of these burdens bore upon the owner of ota.iambic.com, when the owner started his qotd daemon running.

We shall not discuss how RFCs are created. Except to remark the central fact that the Duopoly has no direct business interest in the writing, nor adoption of any RFC. But if the Main Error were not an error, but a truth, then of course, the Duopoly would set its own standards, and create its own services, in the interest of, at least according to a now popular religious sect, stockholders in the Duopoly. But, of course, that is not how the Net was built. Rather the builders of the Net bought delivery of data, no better, signal, at the best price they could get, and they built the Net on top of the delivery of signal. There are over 5000 adopted RFCs, all hacked out without oversight of the Duopoly and without oversight of the FTC, nor of the FCC. We who think the Net we have is worth keeping, think that the radical freedom of association, with near zero external imposed frictions, is worth defending, because this is how we built the Net.

Again, we note at this point that the Duopoly never invented anything like the Net. But, under the rules of common carriage, and under contractual obligations to deliver signal, the Net was built, in freedom, atop the signal carriers’ faithful carriage of signal.

Those who are for Network Neutrality are not for regulation of the Net. We are for freedom of the Net. Without freedom to design, and freely use, new services and protocols and applications, there is no Net. This same freedom makes possible the setting of standards, that is, agreement on RFCs and adoption of RFCs.

We mention here a few of the applications/services/protocols which run on the Net: email, the World Wide Web, various voips, various vpns, ssh, usenet, rsync, cvs, apt-get, BitTorrent, ntp, ostiary, etc.. The IANA list of ports shows just how many services have been invented and, in measure, widely adopted. Of course, one also has services and protocols which are unlikely ever to be widely adopted. For example, Ed Felten and Alex Halderman’s TinyP2P, which may be found at

http://www.freedom-to-tinker.com/tinyp2p.html

was written to demonstrate how easy it is to write a “P2P filesharing” program. The program is less than one page of Python. This program demonstrates something larger and more important: it shows us the freedom and power of the Net. The program works, and perhaps some folks are using it today. But clearly the Duopoly is not today offering “Felten-Halderman TinyP2P” service. Nor does the Duopoly today have the practical means, nor the legal right, to suppress

a. the writing of the program

b. distribution of the program

c. installation of the program

d. use of the program

Well, my claim as to lack of legal right, is unfortunately, not entirely right today. If the Duopoly is providing signal transport at high speed for delivery of Net packet streams, then indeed the Duopoly might today have the legal power to suppress use of the program, due to the FCC’s denomination of certain higher speed signal transports as “information services”. Signal transport is not an “information service”.

Recommendation: Before considering any action on Network Neutrality the FTC should hold another workshop to help the FTC grasp what the Net is today. Necessarily this workshop will require some examination of the history of the Net. The Internet Society should be invited to partcipate at this workshop, and some designers of the Net we have today should be invited to speak.

One Response to “How the Net works”

Flaming Moe Says:
September 2nd, 2009 at 5:15 am
Im fuckin trolling you bitchass flaming

ONLY items referencing the post at hand, please. No links to personal sites, no personal attacks, trolling, freebie advertising, or off-topic posts. Thanks. And Cheers!

How the Net works

One Response to “How the Net works”

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