[ih] ARPA initial IMP-IMP line speed

[Toru Nohzawa ,]

Dave,

Thank your for the information.

Do you know what modem they did use ?
50Kbps or 56Kbps whichever at that time, seems 10 or more times
faster than Chronologically told modem technology.
Who could provide it with what modulation method ?

Toru,


-----Original Message-----
From: Dave Crocker [mailto:dhc at dcrocker.net]
Sent: Monday, February 23, 2004 9:53 AM
To: Toru Nohzawa ,
Cc: internet-history at postel.org
Subject: Re: [ih] ARPA initial IMP-IMP line speed

Toru,

For simplification, all initial Arpanet links were 56Kbps.

This avoided having to deal with differential performace stemming from
different line speeds.

d/

TN> Hello, all,
TN> I have a following question about the subject.
TN> If you know the fact, please let me know it

TN> Question:
TN> There are lots of documents mentioning the initial line speed of ARPAnet
in
TN> 1969 was 50Kbps.
TN> As far as I know, the line speed at that time over the voice band
TN> transmission was
TN> less than 9,600bps. Most probably 4,800bps or 2,400bps.
TN> In addition, no modems for 50Kbps become available.
TN> Some document says 50Kbps over analog wideband. But this causes other
TN> question of what modem was used and who provided that.

TN> How many line speed is used with what modem at initial ARPA IMP-IMP?

TN> Regards,

TN> Toru Nohzawa
TN> nohzawa at w-tri.com




d/
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 Dave Crocker <dcrocker-at-brandenburg-dot-com>
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