Hi all
Now that I've got my mail issues squared away, I did want to note (ha) that if anyone wants to carry on off-topic stuff in a NOTES fashion, feel free to add MISER::HECNET_OFF to your notebook.
A list->notes gateway I would need help with, although I would think a gateway would not be needed since the point is to move certain discussions off-list.
Regardless, it's there if folks want to use it. MISER:: is up 24/7 barring hardware problems or if the power goes out and I'm not around to fire up the generator before the batteries give out.
Cheers,
Fred
----
Lets call it for what it is - "legacy" is a term that people use in a
polite but derogatory manner to imply that the future direction they
prefer is not that which they view as the current direction.
There is ANF10 code for PDP11 that run on 40's or 34's.
Ah. I thought the DN92 was somehow related to ANF10.
Did ever anything but TOPS-10 support ANF10?
(Whatever code ran on the FE RSX system don't count... :) )
There are three DEC things that run on the FE PDP11:
rsx20f is the stuff that controls the KL and loads microcode
and acts as the connection for local terminal links.
(remember the dte is capable of 50kbit/s total...)
mcb rsx based decnet phase 3 frontend, while the host was
phase 4.. abortion.. that's why we did the DDP
devices..
anf10 Frontend code, don't use a OS, has a small kernel by
itself.
You could not mix this, so your minimum was 2 PDP11's and one is in
the main CPU.
Then there is MinITS for the frontend of MC KL10A and DL10
The PDP11 code can talk DDCMP over ASYNC or SYNC interfaces, DQ11,
DMR11, DMC11. So you can do Wan things. In Sweden we had DEC10's in
Stockholm and Linkoping networked with a 9.6K sync link.
The DEC2020 talks DDCP with a DUP11 and a KMC (I think it was KMC,
unibus card with microdode that basically did DDCMP.)
Yeah, I seem to remember that the KMC was the card with DDCMP on board.
Anf-10 has link-state routing like OSPF/ISIS but only one area.
I was very ignorant at the time I played with this stuff. Exactly what
could you do over ANF10? I remember connecting between machines
(interactive terminal sessions), but were there file transfer protocols,
or network based filesystems? Other features?
It depends..
There where sockets/services, but different nodes supports
different things. A shell is a socket/service only on the
mainframes and the X29/X25 gateway.
MCR shell
TSK process-process (file access is on top of this)
LPT line printer
CDR card reader
CDP card punch
TTY terminal line (very advanced "Telnet")
DDP tunnel used to carry IP and DECnet to front-end
PLT plotter
RDX remote data entry terminal
in netdev.mac...
TITLE NETCDR - NETWORK CARD READER ROUTINES - V001
TITLE NETDDP - NETWORK "DDCMP" DEVICE SERVICE ROUTINES - V001
TITLE NETLPT - NETWORK LINE PRINTER ROUTINES - V001
TITLE NETMCR - NETWORK MONITOR CONTROL ROUTINES VERSION 001
TITLE NETPLT - NETWORK PLOTTER ROUTINES - V001
TITLE NETRDX - REMOTE DATA ENTRY SERVICE ROUTINE TO SUPPORT MCS10 - V001
TITLE NETTSK - TASK TO TASK COMMUNICATION SERVICE ROUTINE - V001
TITLE NETVTM - VIRTUAL TERMINAL ROUTINES VERSION 001
-P
Kalpana also designed a bridge between ethernet and the appletalk network, right?
------Origineel bericht------
Van: Paul Koning
Afzender: owner-hecnet at Update.UU.SE
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] DECnet et al
Verzonden: 17 juli 2011 22:51
On Jul 17, 2011, at 4:39 PM, <hvlems at zonnet.nl> wrote:
Well the term bridge is firmly written in my own memory :-)
Tou mentioned that other company, and I'm trying to remember that name too. Was it something with 'sea" in it?
No... I just found it. Kalpana. Their technology claim to fame was cut through bridging, as opposed to store & forward, so they invented the term "switching" for that. But the cut through stuff is just an optimization, and on half-duplex Ethernet a questionable one at best. It existed somewhat with 100Mb Ethernet, I think, and disappeared in Gigabit Ethernet only to come back with 10G Ethernet. Interesting...
Still, though, it's just a bridge, no matter what you call it.
paul
Verzonden vanaf mijn draadloze BlackBerry -toestel
I understand the rationale for phase 5 and years ago when I could remember ncl it was great: lots of information, good for troubleshooting.
But today, 25 years later, I find myself predominantly installing NCP and not ncl.
Phase 5 takes a long time to start up on a VAXstation 3100 class machine (sub 10 VUPS) and is better handled on a VAXstation 4000 90A. Once it runs phase 5 performs on par with phase 4.
What I like best about phase 4 is the SHOW NET(/OLD) command because it tells me the nodes that are up and running. Very useful in a production environment.
I feel that if phase 5 would have had a similar command that it may have been a lot more popular. Why isn't it there ?
Verzonden vanaf mijn draadloze BlackBerry -toestel
On Jul 17, 2011, at 4:39 PM, <hvlems at zonnet.nl> wrote:
Well the term bridge is firmly written in my own memory :-)
Tou mentioned that other company, and I'm trying to remember that name too. Was it something with 'sea" in it?
No... I just found it. Kalpana. Their technology claim to fame was cut through bridging, as opposed to store & forward, so they invented the term "switching" for that. But the cut through stuff is just an optimization, and on half-duplex Ethernet a questionable one at best. It existed somewhat with 100Mb Ethernet, I think, and disappeared in Gigabit Ethernet only to come back with 10G Ethernet. Interesting...
Still, though, it's just a bridge, no matter what you call it.
paul
On 17.7.2011 23:17, Paul Koning wrote:
On Jul 17, 2011, at 2:29 PM,<hvlems at zonnet.nl> wrote:
What is the difference between a bridge and a switch? I don't want to get into a discussion about layer 2 and layer 3 swutching but afaik a bridge is a two port layer 2 switch.
No. "bridge" is the original term, and while the first bridges were 2 port, that never was a limitation.
"Switch" is a term invented by some company whose name escapes me (bought by Cisco way back when) for the purpose of confusing the public into thinking they had something different. Not so, it was just a bridge.
These days "switch" seems to be the common term, but the two words have always been synonyms.
paul
.
Paul answered already what I also was going to say; that bridge was the orginal term.
In fact, a switch is a multiport bridge. A switch can of course have additional features like VLAN support etc but basically it is a bridge with all ports connected together.
Kari
Well the term bridge is firmly written in my own memory :-)
Tou mentioned that other company, and I'm trying to remember that name too. Was it something with 'sea" in it?
------Origineel bericht------
Van: Paul Koning
Afzender: owner-hecnet at Update.UU.SE
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] DECnet et al
Verzonden: 17 juli 2011 22:17
On Jul 17, 2011, at 2:29 PM, <hvlems at zonnet.nl> wrote:
What is the difference between a bridge and a switch? I don't want to get into a discussion about layer 2 and layer 3 swutching but afaik a bridge is a two port layer 2 switch.
No. "bridge" is the original term, and while the first bridges were 2 port, that never was a limitation.
"Switch" is a term invented by some company whose name escapes me (bought by Cisco way back when) for the purpose of confusing the public into thinking they had something different. Not so, it was just a bridge.
These days "switch" seems to be the common term, but the two words have always been synonyms.
paul
Verzonden vanaf mijn draadloze BlackBerry -toestel
On Jul 17, 2011, at 1:38 PM, Johnny Billquist wrote:
On 2011-07-17 16.55, Bob Armstrong wrote:
Paul Koning wrote:
It is legal to have multiple areas on a single Ethernet;
the routing spec covers that case explicitly. If that is done,
end nodes will communicate directly to a destination on the
Ethernet even if off-area ...
Given that Johnny's bridge program effectively creates a big Ethernet,
does that imply that HECnet end nodes in different areas can communicate
without an area router?
Yes, at least partially.
They can comminucate directly with machines sitting on the same ethernet segment, even if those machines are in another area.
However, I think that an endnode will not pick any router in another area as its designated router.
Correct.
The endnode rule is:
1. If the destination is in the cache, send to it.
2. If there is a designated router (in my area), send to it.
3. Send directly.
"Directly" means to the MAC address formed by prefixing aa-00-04-00 onto the little endian node address.
The only difference between Phase IV and IV+ is how the cache works. In phase IV, it's an "on Ethernet" cache. A node sets a bit in the (long format, i.e., Ethernet) packet header when it originates a packet. A router clears that bit if it forwards onto a different circuit, but leaves it alone if it forwards onto the same Ethernet as the packet arrived on. The receiving end node makes a cache entry if the bit it set.
For Phase IV+, the cache is a "previous hop" cache. It remembers the node address (or MAC address, same thing) from the Ethernet source address of incoming packets, and associates that with the node address of the arriving packet. So if you have several routers, and the designated router is not the optimal path to destination X, phase IV will keep sending to the DR, but phase IV+ will send all packets after the first to the router that's best for X, because that's the router which sent the reply back to the endnode.
As for routers on a multi-area Ethernet, yes, the usual rules of the hierarchy apply: all areas must have L2 routers in them. And traffic from an L1 router will visit at least two L2 routers if it goes out of area. So in a multi-area Ethernet, out of area but on-Ethernet traffic from an L1 router will take 3 hops, but if the destination is an end node, the reply will go direct (Phase IV or IV+, either way). And if the source is L2, it will take 2 hops.
paul
On Jul 17, 2011, at 2:48 PM, Johnny Billquist wrote:
On 2011-07-17 20.35, hvlems at zonnet.nl wrote:
DECnet phase 4 is about as old as ethernet and VMS. Ethernet was the main driving force for phase 4 owing to the large number of adjacent nodes and the sheer number.
Not really. Phase IV is about as old as ethernet, yes. VMS is older...
Phase IV was invented for Ethernet support. Originally the plan was to do what became Phase V, but there was a lot of resistance against anything that complicated back in the early 1980s. So "Phase 3E" was invented, a small generalization of Phase 3, and that was subsequently renamed.
Phase 3 does not have areas and only recognizes 255 hosts max. It did have circuit routing (of course)
Yes. About the same thing as L1 routing. I think it might even be partially compatible, within the restrictions on the number of nodes...
Three major differences: Phase IV adds Ethernet support, including "long packet format". That, by the way, was intended to be compatible with the original "phase IV" which used link state routing. But that never saw the light of day; while DECnet Phase V uses link state routing also, and a number of the innovations carried over (like the sequence numbering), the packet format is completely different because of OSI. So the "long packet format" is effectively an orphan, a bit of extra complexity that ended up serving no purpose.
The second difference is that Phase IV adds hierarchical routing.
The third is that it adds partial routing messages. The routing table contains entries for every node in the area (L1) or every area (L2) but the corresponding routing messages can contain just a couple of entries, if only those changed. By contrast, Phase III always sends the entire routing table (up to 255 entries).
paul
On Jul 17, 2011, at 2:29 PM, <hvlems at zonnet.nl> wrote:
What is the difference between a bridge and a switch? I don't want to get into a discussion about layer 2 and layer 3 swutching but afaik a bridge is a two port layer 2 switch.
No. "bridge" is the original term, and while the first bridges were 2 port, that never was a limitation.
"Switch" is a term invented by some company whose name escapes me (bought by Cisco way back when) for the purpose of confusing the public into thinking they had something different. Not so, it was just a bridge.
These days "switch" seems to be the common term, but the two words have always been synonyms.
paul
