-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 2014-05-06 12:25, Per Jessen wrote:
Well... in a way you did need matching devices in the earliest systems..
Yeah, I knew someone would want to point that out :-)
I was going to, just he got there faster :-) In my country, there were at the start about one phone company per city, or even more. Some interconnected, some not. The hardware was up to them, basically the Graham Bell phone. Later, they were all mandatorily absorbed into a state owned/controlled monopoly, I'm not sure if a General Electric subsidiary or AT&T. Compatibility was ensured because it was a monopoly, and then many countries did about the same thing. And then there were international agreements - but you only have to look at the configuration of a plain modem device to find out that each country defined their own parameters such as ring tone, duration, etc. And there are dozens of tones and parameters, all different. I think that only the voltage is the same everywhere: 48 volts. For an obvious reason: it was 4 car batteries in series. With positive ground (to avoid corrosion IIRC).
Some early phones were purely acoustic for example.
wire-and-tin-cans ?
Air voice pipes in ships...
Other phones were "party-line" systems that only worked with other "party-line" phones. Electricity was like that too, and there were proprietary systems that directly competed with each other on DC and AC transmission. Televisions went through a similar period (in the infancy) with mechanical vs electronic televisions. Even now, you have competing tech that requires matching devices (NTSC, PAL SECAM).
Ah no - not matching devices, only matching technology. The significant difference (when compared to the Skype situation) being that anyone is free to develop devices using either technology.
Not exactly free. Some technologies you have to pay for to even get the specs. Talking of phones, Europe is 64 KBit/s channel, the USA is 56. The USA uses µ-law digitalization (companding algorithm), Europe A-law. International phone calls are not that easy to implement. Digital cellular phones in Europe use GSM, which was a project developed by a consortium of states, with full definitions of what you had to implement, even up to the colours and symbols of the hang-up/hang-down buttons on the terminals. It is not GSM unless you abide to the rules. As it was not developed by a private company, phone companies could be forced to implement it in Europe, yes or yes, and compatibility was ensured, and roaming across Europe worked from scratch (abusive pricing notwithstanding). It was so successful that other countries chose to use it as well, even the USA. But there you get isolated islands. Private enterprising, you know. ;-)
For the Linux desktop, it's a mix of Skype, Viber, Ekiga, and lately I've started tinkering with Telepathy. I'd prefer to roll it all into one client that allows me to connect to SIP, Skype and Viber... but... so far no luck.
Yeah, if only SIP was as popular as Skype.
Because it is not "click and shoot" install. Years ago you had to configure routers, it was not simple. And SIP was not the only protocol. SIP was what the Internet people proposed, the phone companies proposed different solutions. - -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" (Minas Tirith)) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iF4EAREIAAYFAlNozd8ACgkQja8UbcUWM1wkKQD/abtuxyi7xodMBnOrK1xEqNfC TVfz0m6zTtoqtdps3pEA/iGblxJEyygJPgxjc5EUZm2OCbagLzCiBHISyM9LKjEg =hh2Z -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org