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

[Roy <r.engehausen () gmail com>]

Don't forget B8ZS which did way with the need for SFon copper data T1s

On 1/27/2020 10:43 AM, Lyle Giese wrote:
> 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.