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  • [LINK] Netheads vs. bellheads redux: the strange victory of SIP over th

    From Computer Nerd Kev@21:1/5 to All on Wed Mar 29 07:38:58 2023
    Netheads vs. bellheads redux: the strange victory of SIP over the
    telephone network
    by Hugo Landau, 2023-01-27
    - https://www.devever.net/~hl/sip-victory

    "How much do you know about how the PSTN (that is, the public
    telephone network) works? At some point long long ago, it was
    signalled using in-band frequencies, which facilitated the infamous
    phreaking using so-called "blue boxes". This led to a switch to out
    of band signalling, ultimately culminating in something known as
    Signalling System 7 (SS7). SS7 traditionally was carried over
    things like a T1/E1 or similar. The standards for SS7 are defined
    by the ITU-T and have basically no "cultural" relation to the
    Internet or IP. Ultimately, it defines a circuit switched
    communications network based around separated signalling and
    time-division-multiplexed (TDM) voice channels.

    And then, of course, the internet happened. This led to an
    interesting conflict between two fundamentally different cultures
    of networking and associated visions. This has been popularly
    documented as the "netheads vs. bellheads" phenomenon. The
    difference between these worldviews is fundamental. The bellhead
    view saw communications in terms of circuit switching, and viewed
    applications as being integrated into a smart network and provided
    by the telco.

    It's actually interesting to note just how oblivious the bellhead
    world was to its ultimate fate. Once upon a time, I flipped through
    some old books about ISDN out of idle curiosity. One of the
    striking things was the repeated use of the term "datacom", a term
    which now seems basically extinct. The reason I found this striking
    is because it implies that, to those working in the telco field at
    the time, "datacom" was not the primary purpose of a network but a
    kind of strange aside, a peculiar niche addition. From the modern
    perspective this worldview seems almost comical; ironically, the
    term datacom is no longer relevant because everything is "datacom".
    " ...

    --
    __ __
    #_ < |\| |< _#

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Marco Moock@21:1/5 to All on Wed Mar 29 08:57:24 2023
    Am 29.03.2023 um 07:38:58 Uhr schrieb Computer Nerd Kev:

    "How much do you know about how the PSTN (that is, the public
    telephone network) works?

    That was a long time ago. At least in Germany, they switched it off in
    the 90s and completely replaced it by ISDN. Analog ports at the
    telephone exchange were available for people who liked to continue
    using the analog line.

    It's actually interesting to note just how oblivious the bellhead
    world was to its ultimate fate. Once upon a time, I flipped through
    some old books about ISDN out of idle curiosity. One of the
    striking things was the repeated use of the term "datacom", a term
    which now seems basically extinct. The reason I found this striking
    is because it implies that, to those working in the telco field at
    the time, "datacom" was not the primary purpose of a network but a
    kind of strange aside, a peculiar niche addition. From the modern
    perspective this worldview seems almost comical; ironically, the
    term datacom is no longer relevant because everything is "datacom".

    ISDN is a concept from the 80s - fax machines were modern, connections
    were expensive, Telex was still in broad use. The internet took over
    and for most people VoIP via SIP/RTSP is fine.
    Many young people don't have a "landline" phone anymore - they use
    different apps on the smartphone to phone people. In school I rejected
    to use them. People have to communicate with me via normal phone or email.

    ISDN - at least in Germany - has been switched off. Analog lines are
    still available via analog ports in MSAN (DSLAM), but are terminated to
    VoIP.
    Much cheaper for the ISP.
    ATM is also being phased out, many ISPs here switched it off and
    replaced it by Ethernet.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Alex Martini@21:1/5 to Computer Nerd Kev on Sat Apr 29 22:58:49 2023
    Computer Nerd Kev <[email protected]d> wrote:

    And then, of course, the internet happened. This led to an
    interesting conflict between two fundamentally different cultures
    of networking and associated visions. This has been popularly
    documented as the "netheads vs. bellheads" phenomenon. The
    difference between these worldviews is fundamental. The bellhead
    view saw communications in terms of circuit switching, and viewed
    applications as being integrated into a smart network and provided
    by the telco.

    Today, with video and audio routed over the internet, the circuit
    switching model's advantages come back. Being able to set up a virtual
    circuit at the start of a video call, with predictable latency and
    bandwidth, could go a long way towards making things work better. Not
    that I think we're likely to see this change -- but it's an interesting
    thought experiment about an internet that never was.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Scott Dorsey@21:1/5 to [email protected] on Sun Apr 30 14:57:27 2023
    Alex Martini <[email protected]> wrote:
    Computer Nerd Kev <[email protected]d> wrote:

    And then, of course, the internet happened. This led to an
    interesting conflict between two fundamentally different cultures
    of networking and associated visions. This has been popularly
    documented as the "netheads vs. bellheads" phenomenon. The
    difference between these worldviews is fundamental. The bellhead
    view saw communications in terms of circuit switching, and viewed
    applications as being integrated into a smart network and provided
    by the telco.

    Today, with video and audio routed over the internet, the circuit
    switching model's advantages come back. Being able to set up a virtual >circuit at the start of a video call, with predictable latency and
    bandwidth, could go a long way towards making things work better. Not
    that I think we're likely to see this change -- but it's an interesting >thought experiment about an internet that never was.

    The phone guys saw it coming and came out with ATM/Sonet which was designed from top to bottom to allow circuit-switched connections and packet-switched connections on the same network. But in the end, the cheapest possible solution won out instad.

    When I was a child, everyone predicted that when I grew up we would have electricity that was too cheap to meter. That didn't happen, but we did
    get long distance service that was too cheap to meter. Nobody ever predicted that one.
    --scott

    --
    "C'est un Nagra. C'est suisse, et tres, tres precis."

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)