2 Oct
2018
2 Oct
'18
10:34 a.m.
Does anybody know names / terms that correspond to the original 3 Mbps
Ethernet?
I.e. 10 Mbps Ethernet is also knows as Ethernet II (2) and D.I.X. (for
Digital, Intel, and Xerox).
Was the first 3 Mbps Ethernet simply called "Ethernet" with an implicit
"I" (1)? Was there a name to differentiate it from D.I.X.?
Grant. . . .
unix || die
2 Oct
2 Oct
10:46 a.m.
Ethernet was the name given to the Alto (XEROX) Aloha Network created (?)
by Bob Metcalff (sp?), which was based/inspired by an improved version of
the ALOHANET used by the U of Hawaii. I think Ethernet was a nickname,
eventually becoming the official name of what was originally the Alto Aloha
Network.
I did not look this up in Wikipedia, I am sure this must be somewhere
Bill
On Tue, Oct 2, 2018 at 1:35 PM Grant Taylor via cctalk <
cctalk at classiccmp.org> wrote:
Does anybody know names / terms that correspond to the
original 3 Mbps
Ethernet?
I.e. 10 Mbps Ethernet is also knows as Ethernet II (2) and D.I.X. (for
Digital, Intel, and Xerox).
Was the first 3 Mbps Ethernet simply called "Ethernet" with an implicit
"I" (1)? Was there a name to differentiate it from D.I.X.?
Grant. . . .
unix || die
10:50 a.m.
Not clear the 3 Mb one had a name of its own.
Note that Aloha is fundamentally different from Ethernet. Aloha is MA but not CS nor CD,
and its performance characteristics are very different from Ethernet.
paul
On Oct 2, 2018, at 1:46 PM, Bill Degnan via cctalk
<cctalk at classiccmp.org> wrote:
Ethernet was the name given to the Alto (XEROX) Aloha Network created (?)
by Bob Metcalff (sp?), which was based/inspired by an improved version of
the ALOHANET used by the U of Hawaii. I think Ethernet was a nickname,
eventually becoming the official name of what was originally the Alto Aloha
Network.
I did not look this up in Wikipedia, I am sure this must be somewhere
Bill
On Tue, Oct 2, 2018 at 1:35 PM Grant Taylor via cctalk <
cctalk at classiccmp.org> wrote:
> Does anybody know names / terms that correspond to the original 3 Mbps
> Ethernet?
>
> I.e. 10 Mbps Ethernet is also knows as Ethernet II (2) and D.I.X. (for
> Digital, Intel, and Xerox).
>
> Was the first 3 Mbps Ethernet simply called "Ethernet" with an implicit
> "I" (1)? Was there a name to differentiate it from D.I.X.?
>
>
>
> Grant. . . .
> unix || die
>
11:20 a.m.
To the best of my knowledge, at the time it was developed at PARC in
1973/74, it was referred to as "Ethernet" (or "The Ethernet") and
later was
referred to as "Xerox Experimental Ethernet" likely to differentiate it
from the developing 10mbit standards...
- Josh
On Tue, Oct 2, 2018 at 10:47 AM Bill Degnan via cctalk <
cctalk at classiccmp.org> wrote:
Ethernet was the name given to the Alto (XEROX) Aloha
Network created (?)
by Bob Metcalff (sp?), which was based/inspired by an improved version of
the ALOHANET used by the U of Hawaii. I think Ethernet was a nickname,
eventually becoming the official name of what was originally the Alto Aloha
Network.
I did not look this up in Wikipedia, I am sure this must be somewhere
Bill
On Tue, Oct 2, 2018 at 1:35 PM Grant Taylor via cctalk <
cctalk at classiccmp.org> wrote:
Does anybody know names / terms that correspond
to the original 3 Mbps
Ethernet?
I.e. 10 Mbps Ethernet is also knows as Ethernet II (2) and D.I.X. (for
Digital, Intel, and Xerox).
Was the first 3 Mbps Ethernet simply called "Ethernet" with an implicit
"I" (1)? Was there a name to differentiate it from D.I.X.?
Grant. . . .
unix || die
4:45 p.m.
On Tue, Oct 2, 2018, 11:47 Bill Degnan via cctalk <cctalk at classiccmp.org wrote:
I wasn't there, but I've never seen any source claim that it was a nickname.
eventually becoming the official name of what was originally the Alto Aloha
> Network.
I've never heard of an Alto being connected to an Aloha Network, nor of any
network inside Xerox being called "Aloha".
Ethernet was the name given to the Alto (XEROX) Aloha
Network
It wasn't an Aloha Network.
created (?)
by Bob Metcalff (sp?), which was based/inspired by an
improved version of
the ALOHANET used by the U of Hawaii.
In their CACM paper, Metcalfe and Boggs credit the Aloha Network, but
Ethernet was an entirely new network design, not an incremental improvement
to Aloha Network.
I think Ethernet was a nickname,
5:47 p.m.
On 10/2/18 4:45 PM, Eric Smith via cctalk wrote:
On Tue, Oct 2, 2018, 11:47 Bill Degnan via cctalk
<cctalk at classiccmp.org>
I've never heard of an Alto being connected to an
Aloha Network, nor of any
network inside Xerox being called "Aloha".
I just went back and reviewed every memo I can find that I have access to (going
back to March, 1974 when there were three Nova Ethernet boards and two Alto Ethernet
boards, and they are consistently calling it "Ethernet". In fact, the word
"Aloha"
never appears.
6:38 p.m.
On Tue, Oct 2, 2018 at 7:46 PM Eric Smith via cctalk <cctalk at classiccmp.org>
wrote:
On Tue, Oct 2, 2018, 11:47 Bill Degnan via cctalk
<cctalk at classiccmp.org>
wrote:
Ethernet was the name given to the Alto (XEROX)
Aloha Network
It wasn't an Aloha Network.
There is a difference between Alohanet and the alto aloha network. created (?)
Inspired by, but I did not claim them to be the same, just for the record.
by Bob Metcalff (sp?), which was based/inspired
by an improved version of
the ALOHANET used by the U of Hawaii.
In their CACM paper, Metcalfe and Boggs credit the Aloha Network, but
Ethernet was an entirely new network design, not an incremental improvement
to Aloha Network.
I think Ethernet was a nickname,
I wasn't there, but I've never seen any source claim that it was a
nickname.
I later looked this up to confirm. See where wizards stay up lote by Katie
Halner and matthew lyon.
eventually becoming the official name of what was
originally the Alto Aloha
Well there you go, now you have
b
Network.
I've never heard of an Alto being connected to an Aloha Network, nor of any
network inside Xerox being called "Aloha".
7:55 p.m.
On Tue, Oct 2, 2018 at 7:38 PM Bill Degnan <billdegnan at gmail.com> wrote:
On Tue, Oct 2, 2018 at 7:46 PM Eric Smith via cctalk
<
cctalk at classiccmp.org> wrote:
I've never heard of an Alto being connected to an Aloha Network, nor of any
Thanks! I stand corrected.
network inside Xerox being called
"Aloha".
Well there you go, now you have
8:20 p.m.
On Tue, Oct 2, 2018 at 10:55 PM Eric Smith via cctalk <cctalk at classiccmp.org>
wrote:
On Tue, Oct 2, 2018 at 7:38 PM Bill Degnan
<billdegnan at gmail.com> wrote:
Thanks! I stand corrected.
I think Metcalfe was just giving credit for where he got the idea of
letting packets collide like alohanet was doing. He took their idea and
improved with collision detection and borrowed the name of his improvements
and subsequent network "The Alto Aloha Network" i.e. it was his improved
"alto" version of the concept inspired by alohanet. In May 1973 (I later
found) he renamed his network system "Ethernet". There were a number of
other more established networks out there at the time, this was just the
start.
I think this whole area of research is very interesting.
b
On Tue, Oct 2, 2018 at 7:46 PM Eric Smith via
cctalk <
cctalk at classiccmp.org> wrote:
I've never heard of an Alto being connected to an Aloha Network, nor of
any
network inside Xerox being called
"Aloha".
Well there you go, now you have
4 Oct
4 Oct
3:45 p.m.
On 10/02/2018 09:20 PM, Bill Degnan via cctalk wrote:
I think Metcalfe was just giving credit for where he
got the idea of
letting packets collide like alohanet was doing. He took their idea
and improved with collision detection and borrowed the name of his
improvements and subsequent network "The Alto Aloha Network" i.e. it
was his improved "alto" version of the concept inspired by alohanet.
In May 1973 (I later found) he renamed his network system "Ethernet".
There were a number of other more established networks out there at the
time, this was just the start.
I think this whole area of research is very interesting.
According to the following link (which is purportedly an excerpt from
page 5 of "Ethernet: The Definitive Guide"), the 3 Mbps Experimental
Ethernet was indeed originally called Ethernet.
Link - Why is it called Ethernet?
- http://www.ethermanage.com/why-is-it-called-ethernet/
"""
In late 1972, Metcalfe and his Xerox PARC colleagues developed the first
experimental ?Ethernet? network system to interconnect Xerox Altos to
one another, and to servers and laser printers. The signal clock for the
experimental interface was derived from the Alto?s system clock,
resulting in a data transmission rate on the experimental Ethernet of
2.94 Mb/s.
Metcalfe?s first experimental network was called the Alto Aloha Network.
In 1973, Metcalfe changed the name to ?Ethernet,? to make it clear that
the system could support any computer? not just Altos? and to point out
that his new network mechanisms had evolved well beyond the Aloha
system. He chose to base the name on the word ?ether? as a way of
describing an essential feature of the system: the physical medium
(i.e., a cable) carries bits to all stations, much the same way that the
old ?luminiferous ether? was once thought to propagate electromagnetic
waves through space. Thus, Ethernet was born.
"""
I apparently need to pick up a copy of Ethernet: The Definitive Guide
and do some reading.
--
Grant. . . .
unix || die
2 Oct
2 Oct
9:58 p.m.
On 10/02/2018 07:38 PM, Bill Degnan via cctalk wrote:
I later looked this up to confirm. See where wizards
stay up lote by
Katie Halner and matthew lyon.
IMHO Where Wizards Stay Up Late is a *WONDERFUL* book. It's been too
long since I've read it. Perhaps I should (re)read it (again).
Somehow I missed the type of technical details that I'm looking for the
last time I read it.
Of course, when I'm reading for edutainment reasons, I frequently don't
retain hard core details. At least not on the first read.
Well there you go, now you have
;-)
--
Grant. . . .
unix || die
4:27 p.m.
On Tue, Oct 2, 2018, 11:35 Grant Taylor via cctalk <cctalk at classiccmp.org>
wrote:
Does anybody know names / terms that correspond to the
original 3 Mbps
Ethernet?
I.e. 10 Mbps Ethernet is also knows as Ethernet II (2) and D.I.X. (for
Digital, Intel, and Xerox).
Was the first 3 Mbps Ethernet simply called "Ethernet" with an implicit
"I" (1)? Was there a name to differentiate it from D.I.X.?
3 Mbps Ethernet is _NOT_ Ethernet I. Both Ethernet I and II were 10 Mbps
DIX standards, with II having only minor differences from I.
3 Mbps was sometimes referred to as experimental Ethernet, but AFAIK the
only official name was "Ethernet".
The best way to refer to it is probably "3 Mbps Ethernet".
9:55 p.m.
On 10/02/2018 05:27 PM, Eric Smith via cctalk wrote:
3 Mbps Ethernet is _NOT_ Ethernet I. Both Ethernet I
and II were 10 Mbps
DIX standards, with II having only minor differences from I.
Okay. Thank you for the correction ~> clarification.
Now I'll keep an eye out (but not quite search for) the differences
between Ethernet (I) and Ethernet II.
3 Mbps was sometimes referred to as experimental
Ethernet, but AFAIK
the only official name was "Ethernet".
ACK
The best way to refer to it is probably "3 Mbps
Ethernet".
:-)
--
Grant. . . .
unix || die
4 Oct
4 Oct
10:07 a.m.
On Tue, Oct 2, 2018 at 10:55 PM Grant Taylor via cctalk <
cctalk at classiccmp.org> wrote:
On 10/02/2018 05:27 PM, Eric Smith via cctalk wrote:
The Ethernet I and II standards are available from Bitsavers:
http://bitsavers.trailing-edge.com/pdf/xerox/ethernet/
3 Mbps Ethernet is _NOT_ Ethernet I. Both
Ethernet I and II were 10 Mbps
DIX standards, with II having only minor differences from I.
Okay. Thank you for the correction ~> clarification.
Now I'll keep an eye out (but not quite search for) the differences
between Ethernet (I) and Ethernet II From the preface of _The Ethernet_ Version 2.0:
Version 2.0 of the Ethernet specification reflects the experience of the
three corporations in designing equipment to the Version 1.0 specification.
Version 2.0 includes network management functions and better defines the
details of the physical channel signalling. Version 2.0 is upward
compatible with Version 1.0. Equipment designed to the two specifications
is interoperable.
10:25 a.m.
On 10/04/2018 11:07 AM, Eric Smith via cctalk wrote:
The Ethernet I and II standards are available from
Bitsavers:
http://bitsavers.trailing-edge.com/pdf/xerox/ethernet/
Cool.
From the preface of _The Ethernet_ Version 2.0:
Version 2.0 of the
Ethernet specification reflects the experience of the three corporations
in designing equipment to the Version 1.0 specification. Version 2.0
includes network management functions and better defines the details
of the physical channel signalling.
Okay. Intriguing.
Version 2.0 is upward compatible with Version 1.0.
Equipment designed
to the two specifications is interoperable.
My brain is having some trouble unpacking and understanding "upward
compatible". - I always think that it should be "new version is
/downward/ compatible with the old version" or "the old version is
/upward/ compatible with the new version".
It's also stumbling on "the two specifications is interoperable". Is
that "the (version) two specification is interoperable (with the version
one specification)" or "the two specification(s) /are/ interoperable"?
This might not make much difference. But my brain trips on are they
truly 100% interoperable (as in extra fields in version 2 that version 1
ignores) or is it a case of version 1 only understand version 1 and
version 2 is able to pretend to be version 1 when talking to version 1?
Sort of like a crude diagram:
v1 <--->| v2
v1 |<--->| v2
v1 |<---> v2
Which of the three is it?
I'll have to check out the documentation on Bitsavers. Thank you for
the link.
--
Grant. . . .
unix || die
10:26 a.m.
On Oct 4, 2018, at 1:07 PM, Eric Smith via cctalk
<cctalk at classiccmp.org> wrote:
On Tue, Oct 2, 2018 at 10:55 PM Grant Taylor via cctalk <
cctalk at classiccmp.org> wrote:
That's sort of accurate. A quick look shows some key differences: V2 adds the
"collision presence test" -- verifying the collision detect signal is working.
There is also the "jabber timer" -- a watchdog timeout that stops excessively
long frames. And V2 introduces the loopback protocol (protocol type 90-00).
The collision presence test is somewhat of an interoperability issue: if you attach a V1
transceiver to a V2 NIC, the NIC would complain on every transmit that it didn't get
the collision test signal.
paul
On 10/02/2018 05:27 PM, Eric Smith via cctalk
wrote:
The Ethernet I and II standards are available from Bitsavers:
http://bitsavers.trailing-edge.com/pdf/xerox/ethernet/
From the preface of _The Ethernet_ Version 2.0:
Version 2.0 of the Ethernet specification reflects the experience of the
three corporations in designing equipment to the Version 1.0 specification.
Version 2.0 includes network management functions and better defines the
details of the physical channel signalling. Version 2.0 is upward
compatible with Version 1.0. Equipment designed to the two specifications
is interoperable. 3 Mbps Ethernet is _NOT_ Ethernet I. Both
Ethernet I and II were 10 Mbps
DIX standards, with II having only minor differences from I.
Okay. Thank you for the correction ~> clarification.
Now I'll keep an eye out (but not quite search for) the differences
between Ethernet (I) and Ethernet II
10:30 a.m.
On 10/04/2018 11:26 AM, Paul Koning via cctalk wrote:
That's sort of accurate. A quick look shows some
key differences: V2 adds
the "collision presence test" -- verifying the collision detect signal
is working. There is also the "jabber timer" -- a watchdog timeout that
stops excessively long frames. And V2 introduces the loopback protocol
(protocol type 90-00).
That mostly sounds like the frame formats are the same on the wire and
that the differences are in the protocols that use said frame.
The collision presence test is somewhat of an
interoperability issue:
if you attach a V1 transceiver to a V2 NIC, the NIC would complain on
every transmit that it didn't get the collision test signal.
That makes me wonder about the "heartbeat" switch that I see on older
AUI transceivers.
--
Grant. . . .
unix || die
10:39 a.m.
On Oct 4, 2018, at 1:30 PM, Grant Taylor via cctalk
<cctalk at classiccmp.org> wrote:
On 10/04/2018 11:26 AM, Paul Koning via cctalk wrote:
Yes, I think that's the collision test. So in the OFF position you have a V1
compatible transceiver, ON is needed for V2.
paul
That's sort of accurate. A quick look shows
some key differences: V2 adds the "collision presence test" -- verifying the
collision detect signal is working. There is also the "jabber timer" -- a
watchdog timeout that stops excessively long frames. And V2 introduces the loopback
protocol (protocol type 90-00).
That mostly sounds like the frame formats are the same on the wire and that the
differences are in the protocols that use said frame.
The collision presence test is somewhat of an
interoperability issue: if you attach a V1 transceiver to a V2 NIC, the NIC would complain
on every transmit that it didn't get the collision test signal.
That makes me wonder about the "heartbeat" switch that I see on older AUI
transceivers. 
10:43 a.m.
On Thu, Oct 4, 2018 at 11:39 AM Paul Koning via cctalk <
cctalk at classiccmp.org> wrote:
Is that the same as SQE? I always had to turn that bad-boy off or risk
collision storms :(
Warenr
On Oct 4, 2018, at 1:30 PM, Grant Taylor via
cctalk <
cctalk at classiccmp.org> wrote:
On 10/04/2018 11:26 AM, Paul Koning via cctalk wrote:
> That's sort of accurate. A quick look shows some key differences: V2
adds
the "collision presence test" -- verifying the collision detect signal
is working. There is also the "jabber timer" -- a watchdog timeout that
stops excessively long frames. And V2 introduces the loopback protocol
(protocol type 90-00).
That mostly sounds like the frame formats are the same on the wire and
that the
differences are in the protocols that use said frame.
> The collision presence test is somewhat of an interoperability issue:
if you
attach a V1 transceiver to a V2 NIC, the NIC would complain on every
transmit that it didn't get the collision test signal.
That makes me wonder about the "heartbeat" switch that I see on older
AUI transceivers.
Yes, I think that's the collision test. So in the OFF position you have a
V1 compatible transceiver, ON is needed for V2.
11:16 a.m.
On Oct 4, 2018, at 1:43 PM, Warner Losh <imp at
bsdimp.com> wrote:
On Thu, Oct 4, 2018 at 11:39 AM Paul Koning via cctalk <cctalk at classiccmp.org>
wrote:
I had to look up SQE. http://www.ethermanage.com/ethernet/sqe/sqe.html It's
802-speak for the same signal.
That page says you have to turn it off for the transceiver connected to an 802.3 repeater,
but it should be on in all other cases. Sounds like the 802.3 people got the transceiver
design wrong and that rule is a workaround. There certainly is no similar rule in the
Ethernet spec, and repeaters are definitely part of that spec.
paul
On Oct 4, 2018, at 1:30 PM, Grant Taylor via
cctalk <cctalk at classiccmp.org> wrote:
...
That makes me wonder about the "heartbeat" switch that I see on older AUI
transceivers.
Yes, I think that's the collision test. So in the OFF position you have a V1
compatible transceiver, ON is needed for V2.
Is that the same as SQE? I always had to turn that bad-boy off or risk collision storms
:(
Warenr
2:36 p.m.
On 10/04/2018 12:16 PM, Paul Koning via cctalk wrote:
I had to look up SQE.
http://www.ethermanage.com/ethernet/sqe/sqe.html
It's 802-speak for the same signal.
I agree that it's the same concept and function. Though the link you
shared states that there is some timing difference between D.I.X.'s
"Collision Presence Test" (CPT) and IEEE's 802.3 "Signal Quality
Error"
(SQE).
That page says you have to turn it off for the
transceiver connected to
an 802.3 repeater, but it should be on in all other cases. Sounds like
the 802.3 people got the transceiver design wrong and that rule is a
workaround. There certainly is no similar rule in the Ethernet spec,
and repeaters are definitely part of that spec.
Given that CPT / SQE / HB are between the transceiver and the host NIC,
and NOT between the transceiver and the Ethernet, IMHO it makes sense
that CPT / SQE / HB should not be used with a repeater. After all, a
repeater is going between two (or more?) Ethernet segments.
As such, I don't think it's a problem with the specification or design
of transceivers.
I think the CPT / SQE / HB are in some ways a feedback loop between the
transceiver and the NIC to test the collision detection circuitry in the
NIC.
--
Grant. . . .
unix || die
1:31 a.m.
On Tue, Oct 02, 2018 at 11:34:54AM -0600, Grant Taylor via cctalk wrote:
Does anybody know names / terms that correspond to the
original 3 Mbps
Ethernet?
I.e. 10 Mbps Ethernet is also knows as Ethernet II (2)
and D.I.X. (for
Digital, Intel, and Xerox).
Was the first 3 Mbps Ethernet simply called
"Ethernet" with an implicit "I"
(1)? Was there a name to differentiate it from D.I.X.?
It was probably just known as "Ethernet". If there's only one kind, why give
it
a longer name to distinguish it from future variants that may never come to be?
My bumph tells me it was called "Experimental Ethernet", but I suspect
that's a
name given to it in retrospect.
"Ethernet I" and "Ethernet II" were 10Mb/s thicknet variants which
evolved into
the 802.3/10Base5 standards. The exact details of the differences are probably
lost in time. Although thicknet is finally dead -- we had to hammer many stakes
into the cable to make sure, but managed it in the end -- Ethernet II's layer 2
protocol remains in use in modern IP networks, and contemporary usage of
"Ethernet II" refers to just that rather than the older standard.
8:59 a.m.
On 10/04/2018 02:31 AM, Peter Corlett via cctalk wrote:
It was probably just known as "Ethernet". If
there's only one kind,
why give it a longer name to distinguish it from future variants that
may never come to be? My bumph tells me it was called "Experimental
Ethernet", but I suspect that's a name given to it in retrospect.
I agree that the "Experimental" in "Experimental Ethernet" is in fact
probably retroactive.
"Ethernet I" and "Ethernet II"
were 10Mb/s thicknet variants which evolved
into the 802.3/10Base5 standards. The exact details of the differences
are probably lost in time.
The contributions to this thread have satisfied my curiosity / question
that "Ethernet (I)" was not the 3 Mbps Experimental Ethernet.
Although thicknet is finally dead -- we had to hammer
many stakes into
the cable to make sure, but managed it in the end --
Um ? I'm somewhat reluctant to tell you that there's a Thicknet segment
in my basement with transceivers attacked. I've not sent traffic across
it /yet/. But I will. ;-)
Admittedly, it is purely for edutainment and hobbyist retro-computing /
retro-networking reasons.
Ethernet II's layer 2 protocol remains in use in
modern IP networks,
and contemporary usage of "Ethernet II" refers to just that rather than
the older standard.
Yep.
I need to re-read something to see if (a variant of) Ethernet II frames
are used for IP on WiFi or if they are closer to 802.2 LLC + SNAP
similar to what is used on other, non-Ethernet, 802 networks.
--
Grant. . . .
unix || die
2052
days inactive
2054
days old
22 comments
8 participants
participants (8)
-
abuse＠cabal.org.uk -
aek＠bitsavers.org -
billdegnan＠gmail.com -
cctalk＠gtaylor.tnetconsulting.net -
derschjo＠gmail.com -
imp＠bsdimp.com -
paulkoning＠comcast.net -
spacewar＠gmail.com