[ih] History of Network Operations

[Jack Haverty]

Hi John,

IMHO, the Hewitt system is interesting but isn't really very similar to 
IP Source Routing.  The difference is that, in the IP environment, 
Source Routing was a mechanism for the *user* of the network to override 
the routing decisions that the network would normally make.  For 
example, assuming your OS provided a facility for a user program to send 
and receive "raw" IP datagrams, you could write an app that would send 
datagrams through the network along a path that the network itself would 
never choose.

That concept of user-directed routing allowed users to write programs 
that were useful for debugging network problems, especially situations 
like performance issues where the "network management" tools themselves 
reported that "everything is running fine" while the users were 
complaining "The network is broken.  Fix it!".   It also could help 
verify that the routing mechanism was actually behaving as expected.  
Complex real-time distributed software of course never has bugs...?

In contrast, what you described sounds like a network that used some 
kind of routing scheme where a centralized server, or perhaps just 
static configuration tables on those floppies, dictated the route each 
packet would travel.  I suspect user programs had no way to override 
such decisions.   IIRC that's how SNA worked.

I've always been curious about the history of network operations as the 
Internet evolved and grew, what tools and features (such as Source 
Routing, SNMP, etc.) were used in all the emerging ISPs, and how their 
operators dealt with users' complaints.  Dave's question was spot on - 
what was useful, and what was abandoned?   Or perhaps the Users were 
just happy to have any connectivity, and tolerated whatever worked that 
day.   I changed the Subject line....

Jack Haverty


On 2/5/25 06:36, John Kristoff via Internet-history wrote:
> On Sun, 02 Feb 2025 18:37:09 +0000 (UTC)
> Dave Crocker via Internet-history<internet-history at elists.isoc.org>
> wrote:
>
>> I'm curious about a rough summary of when and how it was used and
>> when and why it lost favor.
> While not IP source routing, I worked at a corporate environment that
> had an extensive source route bridged network (token ring) and I was
> always told we had one of the largest source route networks in the
> world, and I think by an IBM rep.  I wouldn't be surprised if someone
> would dispute that claim now, but looking back it seems like a small
> miracle it worked as well as it did now.
>
> The company was Hewitt Associates (now gone).  I worked there from
> roughly 1994 to 1998.  The architecture was already designed, but I did
> help extend it by connecting multiple remote offices into the larger
> WAN. We used old IBM PC 55? as the WAN bridge.  We removed the hard
> drives and gave each bridge a slightly customized version of the
> bridging software and config on a 3 1/2" floppy (there was a backup
> floppy in a binder just in case there was a disk failure).  The network
> primarily carried SNA and IPX as I recall.  IP didn't come until much
> much later, and I think we may have bridged some of it until the turn
> of the century, eventually Bay (or whatever they were called at the
> time) began to replace them and do IP routing as that became impossible
> to avoid.
>
> Obviously this was much different than source routing in IP, but the
> concept was not dissimilar.  But, yes, one gigantic layer 2 network
> that spanned the US.  In addition to a multi-campus network at HQ in
> Northern Illinois I think we had about 30 offices around the country
> connective via some variation of T1 or smaller.  Some international
> offices were connected via Frame Relay or X.25 as I recall so the
> bridged network ended at country borders.
>
> I probably have some old design documents, network maps, ring numbering
> plans, and so on if anyone cares to see them.  We first provided
> IP (www browsing really) connectivity through a Lotus Notes gateway that
> ran IPX to end clients.  Good experience to have *had* but can't say I
> miss it.
>
> John

-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature.asc
Type: application/pgp-signature
Size: 665 bytes
Desc: OpenPGP digital signature
URL: <http://elists.isoc.org/pipermail/internet-history/attachments/20250205/3a0df7e0/attachment.asc>