PSTN and Switching-Routing

I have noticed over the last 20 years a tendency by some people to consider PSTN to mean the Public Telephone Switched Network. It should come as no surprise to people who know me, that I take a different position.

Let us take a step back  to the first 100 hundred years of the telephone. Independent of who has the right to be called the inventor of the telephone, Alexander Graham Bell certainly brought the telephone to the public.

Each call across those telephone networks would consist of a set-up phase, a connected phase and a clear-down phase. Typically, at least in the days of the manual operator, the calling party would identify the called party by one of two means:

  1. A description of the end subscriber, such as Mr. Sherlock Holmes, 221B Baker Street, London
  2. The identity of the end point on the telephone network, such as London, Whitehall, 1212 i.e. the telephone exchange and the “local number” on that exchange. (Whitehall 1212 was, from about 1934 till the 1960s, the  London Metropolitan Police station known as Scotland Yard.)

In the first case the operator would do a check in the telephone directory to convert the subscriber identity to an end point identity. Once the end point identity was known the operator would select a transport path that would extend the call in the appropriate direction. This decision, based on the context of the call (target destination ), took in to account the resources available to the operator, and the decision was and still is called routing.

Every telephone call over the PSTN is routed.  Sorry, but I see no room for discussion on this.

Once the call set-up has reached the called party, and the called party answers the call, then the call set-up phase ends and the call connection phase starts. In the call connection phase there is an identifiable semi-permanent route (often called a path) between the caller and called party. That route/path took the form of a galvanic connection between the parties (in the analogue telephone system).

In the implementation of the telephone service that started in the mid 1980s the galvanic connection was replaced by a sequence of logical transformations on digital signals in time and space

It was common, even in the analogue telephone days, to refer to the infrastructure that handled the routing decision and that interconnected the transport paths as a telephone switch.

Now we must step back to the 1970’s and 1980’s. In the early 1970’s the basics of the Internetworking Protocol were established by Bob Kahn and Vincent Cerf. The resulting telecommunications networks, based on the Internetworking Protocol, led to the establishment of the Internet as we know it today:

a set of interconnected infrastructure that has a shared end-point addressing scheme and a shared understanding of the structure and interpretation of data packets that the infrastructure transports.

Now we enter the period in which the fledgling Internet caught the attention of financially orientated concerns.
One of the topics that was turned in to an issue, was whether companies who provided public access to the Internet were subject to the regulations normally applicable to providers of telecommunications services.

One argument against the applicability of the telecommunications regulations to the Internet hinged on questionable logic:

  • The PSTN is subject to regulations.
  • PSTN “stands” for the Public Switched Telephone Network.
  • The Internet is routed, and has nothing to do with “switched”.
  • The Internet should therefore not be subject to telecommunications regulations.

I think that an appropriate phrase to some up this logic, and its conclusion, is horse feathers.

Hmmm, this was  a wonderful application of the now common  alternative facts, and yes, it was spearheaded by companies based in the USA.

It was of course, totally ignored by such non-regulation preferring companies, that the Internet in the last 20 or so years makes extensive (i.e. massive) use of  switching in the MPLS cores and in the Ethernet access networks.

I have said it before, and I will say it again.

Wishy washy words lead to wishy washy thinking”.

If you want to muddy the waters of your opposition, start using wishy washy words, obfuscate the issue.

To quote that author whom I have already referred to:

Terry Pratchett – ‘A lie can run round the world before the truth has got its boots on.’

If you really want to understand something, then consider this: the tools of comprehension are words and sentences. If you use the wrong tools do not be surprised if the results are sub-optimal.

Curse the darkness, or speak out.

Once more I ask myself why I have created this blog.

I have spent some time discussing this with my son (studying physics at university and just starting his M.Sc. thesis), and about the only conclusion I have reached is summed up by the following quotation which I understand is too old to be definitivly attributed to anyone:

Yet it is far better to light the candle than to curse the darkness

I suppose that my use of this blog is similar to the classical 1950’s letter that took the form:

To the Editor of the Local Newpaper.

Dear Sir

It has come to my notice that …

                Yours faithfuly, a concerned citizen of our good village.


Well, the truth is out, I am I suppose a concerned citizen of our good village, except maybe I should consider myself to be a concerned citizen of our global village.

Is a blog an opportunity to speak out. If so, are there better ways?

Wishy washy words and wishy washy thinking.

I try to take words seriously. That means that I believe communications between people is easier if we use the right words.

I have many phrases which I spout forth, one of which is wishy washy words lead to wishy washy thinking. I often think of this phrase when I read about the USA and the ongoing saga of network neutrality in the context of telecommunications.

If you have seen my earlier blogs you might have noticed that I have a very clear interpretation of what a telecommunication service is.

A telecommunications service is when a service provider agrees to transport valid user-defined input, from an incoming service access point to one or more, user nominated, outgoing service points, and that transport is carried out to a understood service level agreement.

I get the feeling that some of the USA discussions about network neutrality hinge on the Internet being an information service and not a telecommunications service. Hmm, looks like we are getting the now famous American alternative facts from such people.

I will try to highlight some relevant facts about telecommunications.

  1. The legacy public telephone service, whether realised by analogue switching, digital (fixed network ISDN or its wireless version)) technology , is a telecommunications service providing network.  The PSTN (Public Service Telephone Network and not Public Switched Telephone Network as many people would like to name it!) has been carrying data (machine-to-machine) since at least the 1920’s. In the early 2000’s the PSTN in many countries was carring more data (machine-to-machine), measured in transport volume, than speech conversations.
  2. Even if we restrict our analysis to speech communications across the PSTN (please remember the PSTN includes both fixed and wireless access technologies), we can easily argue that the PSTN supported the exchange of information between users. Even if I only phone my family back in Wales and ask “how are you”, it is a classical case of information exchange! Fortunately no-one succeeded in reclassifing the PSTN as an information service since the PSTN is clearly the transporter and not itself the information provider.
  3. If we now consider the current situation as presented in various online news sites about the USA / FCC and network neutrality. It appears that the USA has classified the Internet as an Information service. Not strictly wrong, unless you try to twist that into meaning that the transport provider(s) are providing information services. They are clearly not providing information, they are transporting.
  4. We do not say that the postal service is an information service, even though they deliver large volumes of information, sometimes written, sometimes on DVDs or CDs.
  5. Why do some people try to twist the Internet transporters as providing an inforamtion service. A rhetorical question, to which the answer is for an advantage!

I take the position that is it not in any way technically justifiable to classify the transportation of data (irrespective of how that data is encoded or packeted or routed or switched) as an informational service.

Now, please note that I have not commented here on whether network neutrality is good/bad/right/wrong! I have only considered whether it is justifiable to label the transport providers of the Internet as providing an information or telecommunications service.

My prime concern is that when we start applying incorrect labels to things we start thinking about them incorrectly.

Before we can really understand the whole network neutrality issue we must must must understand correctly what we are talking about.

One of the facts  in the network neutrality debate is that telecommunications services are regulated  differently to information services.

One of the alternative facts that is popular in the network neutrality debate is that the Internet is an information service for all involved parties, including the transport providers.

When key players start trying to change the classification of a transport service to an information service so that they can avoid telecommunications regulations, well that’s when I get to intensely dislike the morals of some of my fellow human beings.

Or possibly not quite so sad, but probably more common, I get heartily disillusioned at the lack of understanding shown by people who should know better.

Digital Archives and the Right To Be Forgotten

Oh dear, I find that the opportunity to “blog” might turn me in to a loud-mouthed small-brained speaker standing on a soap-box, screaming at the passers-by.

I am a fan of a few web-sites. One of which is the a web-site that carries “news” articles and some editorial comments.

Well today it reported on 3 things that immediately got me thinking.

1) One was about an organisation that maintains an archive of the Internet and that by doing so might prevent the creation of “Memory Holes”.

Basically, I think, they take snapshots of many Internet web-sites and commit the snapshot to a “read-only” storage.

2) Another article that the  had was about Google and the European Court of Justice and the “right to be forgotten”. I do not have a broad enough understanding of the legal, or even moral issues, to form an informed opinion.  I sort of feel a bit “iffy” because a printed document (e.g. magazine, book, newspaper…) makes a statement and that statement is archived for ever. So I ask myself why the Internet should be different. The obvious difference is the ease of access to online information, so an incorrect statement once in the Internet is (sort of) forever, but then so is a printed report. The “right to be forgotten” seems to focus on a number of issues:

  • Removing factual incorrect statements that cause damage to the involved people.
  • Removing factual correct statements that the involved people do not want others to know. This in turn breaks down in to:
    • Facts that were legitimately put in the public domain, but never-the-less the involved people want to “hush-up”.
    • Facts that have been placed in the public domain by some-one who has no right to do so.

I have no problem with the idea of “the right to be forgotten” with the first and the last bullets, but the “hush-up” bullet is a real problem.

Anyway, what I find interesting is how the “the right to be forgotten” relates to the archived Internet which (if I understood it correctly) specifically wants to ensure that the “hush-up” bullet does not get hushed-up!

And then, just beause of the way I tick, I reflected back on my blog “Hyde Park Speakers Corner and Digital Dinosaurs Footprint” and wondered about the moral implications of the science fiction story I mentioned.

Without any further thought or analysis, if there is a “right to be forgotten” is there a right to “publish for perpetuity”

3) as I have said in an earlier blog, I am in the telecommunciations industry (since 1979) and have quite a few “hobby horses”. One of my “hobby horses” is about laws and regulations.

I have no, absolutely no, training in law! But my belief is that a law should be an unambigous statement of behaviour/activity that is not permitted.

(I wonder how true that is, there are laws such as “you shall not kill”, but no law “you shall be nice to people”. Laws seem to be, and I am not complaining, proscriptive in nature.)

So a law that says that you are not allowed to drive a automobile on a public highway, without having a valid licence, is okay with me.

Also okay with me is a law that says that providers of telecommunications services can be required to provide metadata and media streams to legally entitled authorities (lawful interception).  Haa, a law that says you shall rather than you shall not, I have just been hoisted by my own petard!

But, it all depends on “what is a telecommuncations service?”.  If I invest in creating a piece of software that enables users to send media streams between themselves, and I create a central databank that lets users see which other users are “online” and where they are (IP address), then I might be supporting telecommunications but I am not providing a telecommunications service. Please no NOT go on about providing addressing information to users is a telecommunications service. It is not, a public library might make copies of the telephone directories available. That tells us under what “address /(telephone number)” a user can be reached. But that is not not not a telecommunications service. Just because some companies provide such informational services “online” does not make their service a telecommunications service.

According to the report on the web-site , if I have understood it correctly, it seems that a Belgian court and Microsoft / Skype are in discussion over whether the Skype service is a telecommunications service.

Hmm, as I said, I am not an authority on legal issues, but I must ask the question: On what basis is Skype a telecommunications service?

I am 100% convinced that it is a telecommunications service IF it physically receives users’ media streams and passes them on, which I think Skype does when at least one of the users is identified by a E.164 public telephone number.

But between Skype to Skype users, identified by a Skype identity, I thought (please correct me if I am wrong) that the media leaves the user’s premises and is carried, without intervention by any Skype infrastructure, to the destination user’s premises. In my (non) humble opinion whatever service Skype provides in that specific situation, it is not a telecommunications service.

Telecommunications is not Communications, or am I getting OTT

Some things annoy me. One thing that really annoys me is when people use the word communications, when they mean telecommunications.

In my (not) humble opinion, telecommunications is about the transport of a set of well defined “inputs”, from a user selected input point, to a user defined output point, to an agreed quality of service.

Communications is about how one gets an idea from inside one’s head into the head of some-one else. It is about the selection of symbols that, to the originator, convey the idea. Hopefully that selection of symbols conveys the same idea to the receiver.

Picking a font for this web page is a communications issue, deciding whether to write in English, Welsh or German is a communications issue. Such factors affect how well my idea is conveyed to the audience.

Communications is about meaning, content, syntax, semantics and symbols.

Telecommunciations is about moving symbols from A to B, and does not get involved in the meaning, content, syntax, semantics and symbols.

Telecommunications <> Communications.

Gods protect me (see p.s.)  from hearing more people talk about OTT (Over The Top) service providers. OTT is a common expression in the telecommunications service provider world to describe companies such as WhatsApp and Skype: companies that receive a media stream from one user and pass it on to one or more other users.

In some cases companies such as NetFlix and other media providers, who do not “interconnect” users to one another, are also called OTT.

In all cases (WhatsApp, Skype, NetFlix…) the OTT players and the users pay for their Internet access. Never-the-less, the telecommunications service providers (i.e. the people who basically set the prices that the users pay) complain about the OTT players making money off the back of the telecommunications service providers. Hmm, that always was the purpose of telecommunications. The good old VPC equation.

                       V > P > C

The value of a telecommunications service should be higher to the user than the price that he must pay for the service. The price of the service must be higher that the cost of providing that service.

OTT’s are seen by most telecommunications service providers as free-loaders riding on the back of the telecommunications service providers.

Of course, they conveniently forget that the Internet was providing E-Mail and Chat services long before the telecommunications providers introduced SMS’.  Oh my, how we do twist the truth to suit our purposes. Or am I getting a bit OTT myself.

p.s. I am a fan of that dearly missed author, Terry Pratchett. Hence the “Gods“.

Hyde Park Speakers’ Corner and Digital Dinosaurs Footprints

I attended a team meeting at work today, I work for a management and telecommunications consultancy company. Amongst many topics we discussed the role of social media in marketing. This got me thinking about this web-site.

Is running a blog with no followers the same as standing at Hyde Park Speakers’ Corner and mouthing off when no one is listening.  Or is it like keeping a diary which you do not lock away.

I know that I do not care whether this blog is read by anyone, but after 38 years in the telecommunications industry I find it intriguing to think about the psychology of communications, especially communications made possible by digital technology.

In my old, static web-site, I referred to a science fiction story that I read back in the late 70’s. It was about a group of computer science students (set in the future, but it was written in the 50’s so it was quite primitive). These students were sent to a sort of bank that held in its computer “vaults” the electronic diaries of customers. The students job was to browse through the  diaries of customers who had died, and then decide whether the entires could be deleted. Sometimes the Internet makes me think of that story. The idea that web-sites, blogs and social media will create a digital footprint, and that we will leave tracks in the Infoverse that future generations might analysis as part of a reseach project, I find it quite interesting. although I should know better, any such research will be done by computer programs. Ah well! I wonder what they will make of this blog, my own electronic Hyde Park Speakers’ Corner.

I am a digital dinosaur, welcome to my foot prints!