Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that

[Lyle Giese <lyle () lcrcomputer net>]

64k vs 56k was the result of changing T1 framing from SF to ESF. SF 
utilized AMI(Alt Mark Inversion) required for copper T1 lines between 
Central Offices.  SF(Super Frame) robbed bits for signalling and limited 
each voice channel to 56k.  Conversion to fiber between TELCO offices 
allowed the conversion of SF to ESF, which dropped the AMI requirement 
and the resultant bit robbing, allowing 64k throughput per voice channel.

In other words, the limitation was in the inter-office T1's and the 
conversion of to fiber between TELCO offices cleared that hurdle.

Lyle Giese

LCR Computer Services, Inc.

On 2020-01-27 05:57, Mark Andrews wrote:
> The hardware support was 2B+D but you could definitely just use a single B.   56k vs 64k depended on where you where is 
> the world and which style of ISDN the telco offered.
>
>
> -- Mark Andrews
> > On 27 Jan 2020, at 22:32, Bryan Holloway<bryan () shout net>  wrote:
> >
> > I didn't think one could get a single 'B' channel over ISDN ... but I could be mistaken.
> >
> > In my early ISP days, ISDN was 2 x 64k (full-rate) 'B' channels and a 16k 'D' channel for signaling.
> >
> >
> > > On 1/26/20 5:58 AM, Joly MacFie wrote:
> > > IIRC that 64k was in fact 56k with 8k for overhead.
> > > I had one, and it would kick in a second channel if you pushed it, for a whopping 112k. Metered, came out to about 
> > > $500/mo.
> > > Joly
> > > On Fri, Jan 24, 2020 at 6:26 PM Ben Cannon <ben () 6by7 net  <mailto:ben () 6by7 net>> wrote:
> > >     I started what became 6x7 with a 64k ISDN line.   And 9600 baud modems…
> > >     in ’93 or so.  (I was a child, in Jr High…)
> > >     -Ben.
> > >     -Ben Cannon
> > >     CEO 6x7 Networks & 6x7 Telecom, LLC
> > >     ben () 6by7 net  <mailto:ben () 6by7 net>
> > > >     On Jan 24, 2020, at 3:21 PM,bzs () theworld com
> > > >     <mailto:bzs () theworld com>  wrote:
> > > >
> > > >
> > > >     On January 24, 2020 at 08:55aaron1 () gvtc com
> > > >     <mailto:aaron1 () gvtc com>  (Aaron Gould) wrote:
> > > > >     Thanks Jared, When I reminisce with my boss he reminds me that
> > > > >     this telco/ISP here initially started with a 56kbps internet
> > > > >     uplink , lol
> > > >     Point of History:
> > > >
> > > >     When we, The World, first began allowing the general public onto the
> > > >     internet in October 1989 we actually had a (mildly shared*) T1
> > > >     (1.544mbps) UUNET link. So not so bad for the time. Dial-up customers
> > > >     shared a handful of 2400bps modems, we still have them.
> > > >
> > > >     * It was also fanned out of our office to a handful of Boston-area
> > > >     customers who had 56kbps or 9600bps leased lines, not many.
> > > >
> > > >     --            -Barry Shein
> > > >
> > > >     Software Tool & Die    |bzs () TheWorld com
> > > >     <mailto:bzs () theworld com>              |http://www.TheWorld.com
> > > >     <http://www.theworld.com>
> > > >     Purveyors to the Trade | Voice: +1 617-STD-WRLD       | 800-THE-WRLD
> > > >     The World: Since 1989  | A Public Information Utility |*oo*
> > > --
> > > ---------------------------------------------------------------
> > > Joly MacFie 218 565 9365 Skype:punkcast
> > > --------------------------------------------------------------
> > > -