[ih] Cisco origins (Was: when did APRANET -TIPs become known as -TACs)

[Barbara Denny]

 The TIU and port expander were developed in the Telecommunications Science Center(TSC) under Don Nielson at SRI.   Greg Satz and I were in TSC.  Bill Westfield was always in a different group at SRI as far as I know.  I am pretty sure Greg and Bill knew each other during the time they worked at SRI.  I have no recollection of the TIU being any part of the Cisco story.
barbara
    On Monday, September 29, 2025 at 11:28:13 AM PDT, Jack Haverty via Internet-history <internet-history at elists.isoc.org> wrote:  
 
 Perhaps a cisco terminal concentrator was descended from the TIU 
(Terminal Interface Unit) which I recall was created by Stanford/SRI?

The TIU was in common use in ARPA projects in the early 1980s, along 
with the SRI PE (Port Expander) which allowed a site to put additional 
TCP-only computers on the ARPANET but use only a single IMP port.  I've 
always wondered if any of SRI's work somehow migrated into commercial 
products.

Lots of TIU artifacts are online (at your MIT site!), including the code.

/Jack

On 9/29/25 02:15, Noel Chiappa via Internet-history wrote:
> My memory is that they did, roughly simultaneously, a multi-protocol router
> _and_ a terminal concentrator - in fact, they were more focused on the
> terminal concentrator at the very start. The router was based on prior work
> at Stanford - Bill Yeager's work. I don't know about the Cisco terminal
> concentrator - although I retain a vague memory that it had its roots in
> prior Stanford work too. (I did a Web search for "Cisco terminal
> concentrator origins", but nothing turned up.)