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My 2¢
worth: I like "continue" for messages that start on-ring and end on-ring,
and "egress" and "ingress" for messaging leaving and entering the ring.
Note, there are a lot of "continue" cases, including upstream path, downstream
path, wrap, and in the case of multi (>2) ringlets, switching from one
ringlet to another in a way that is other than wrapping.
I also believe that, like a real dictionary, having
simple diagrams that demonstrate what is meant could be quite useful in our
"terms and definitions" section. Certainly a picture showing the ingress
and egress paths to and from the upper layers, and the continue path, would
clarify the definitions.
.
Best regards,
Robert D. Love Chair, Resilient Packet Ring Alliance President, LAN
Connect Consultants 7105 Leveret Circle Raleigh, NC
27615 Phone: 919 848-6773 Mobile: 919
810-7816 email: rdlove@xxxxxxxx
Fax: 208 978-1187
----- Original Message -----
Sent: Thursday, May 24, 2001 10:51
AM
Subject: Re: [rprsg] (Terms & Defn)
topology terms
Mike and group,
Interesting problem.
Some alternatives are:
ring ingress (ringress) - ring egress (regress)
MAC ingress - MAC egress
departing - arriving
entering - exiting
injected - ejected
We could use add/drop, but then it seems that we should use 'continue'
instead of 'transit' to be consistent with the SONET use of add/drop/continue.
We could use inbound/outbound (and use receive/transmit on the ring)
but inbound/outbound has a railway connotation that makes it much more
appropriate for describing ring traffic.
We could also use ingress/egress in our MAC description, and acknowledge
that other layers may choose to redefine these terms relative to
themselves. In other words, ingress within our MAC specification would
be understood to mean ring or MAC ingress.
I agree on wrapping (opinion with Fujitsu hat on). It is confusing to
call it wrapping when you change ringlets but continue in the same direction.
Other opinions?
Bob
After showing various other curiosities, P.T. Barnum bought the American
Museum in New York City in 1841. The museum’s attractions included
ventriloquists, jugglers, educated dogs, dioramas, Albinos, giants, dwarfs,
and many other things of interest.Under Barnum’s management, the museum grew
in size and popularity.The lecture room was enlarged and soon held shows
everyday. The museum was particularly crowded on holidays when people would
bring their dinner and spend the day. Barnum did not like this because it
prevented a steady turnover in museum patrons. To solve this problem, Barnum
hung a sign that read “To the Egress” above
the exit door. The curious visitors did not want to miss anything, but when
they went through the door, they found the strange animal they had expected
did not exist, and they had been tricked out the door. The only way back in
was to pay again. (but were they headed to or from the ring?).
Mike Takefman wrote:
Bob et al,
The problem with "ingress" is that in our box, ingress refers to
traffic coming into layer 3 (i.e. traffic dropped from the ring).
How about "ring ingress".
Or we can always go with Add, Drop and Transit Traffic.
Also, I've been meaning to jump in on the question of "wrap"
protection placing traffic onto a different fiber in the same
direction as the failed span. I think this is confusing and
hence a
bad idea. "Everyone" associates wrap with sending
the traffic back the
other way. A different word/phrase is
needed to describe the protection
afforded by a 4 fiber BLSR ring.
my $0.02.
mike
Bob Sultan wrote:
>
> Brian,
>
> You make a
good case for 'transit'. The only problem would be visual confusion
with 'transmit', but I think we reduce
> the impact of this by using
'ingress' to describe traffic, buffers, etc. associated with the direction
from MAC-client
> towards ring and using the word 'transmit' only
when describing the act of sending a frame on the link. Other
>
opinions?
>
> Thanks, Bob
>
>
> Brian
Holden wrote:
>
> > On plug-and-play - you have it
>
>
> > As to tandem/transit, tandem gives a sense of arrangement
> > and transit gives a sense of conveyance. In the
> >
transportation world, you pass through O'Hare and Heathrow
> > in
tandem and you transit through 8 intersections.
> >
> >
The dictionary has tandem as "an arrangement of two
> > or more
persons or objects placed one behind the other".
> > It has
transit as "The conveyance of persons or goods
> > from one place
to another, especially on a local public
> > transportation
system".
> >
> > Transit is definitely more accurate
than tandem.
> > Other possibilities for the name of that traffic
are
> > "through", "conveyance", "pass", "pass-through",
"traverse",
> > "traversal", "relay", or "transfer".
> >
> > Brian H.
> >
> >
_______________________________________________
> > Brian
Holden PMC-Sierra, Inc.
>
> 3975 Freedom Circle, Santa Clara CA USA
> >
+1.408.239.8123 Fax +1.408.492.9862
> >
brian_holden@xxxxxxxxxxxxxx http://www.pmc-sierra.com
> >
> > -----Original Message-----
> > From: Bob Sultan [mailto:Bob.Sultan@xxxxxxxxxxxxxxx]
> > Sent: Wednesday, May 23, 2001 3:10 PM
> > To:
stds-802-rprsg@xxxxxxxx
> > Subject: Re: [rprsg] (Terms &
Defn) topology terms
> >
> > Brian, Allan,
> >
> > I agree that the disruption time should not be
specified. Using the definition I suggested as a base,
> >
this would leave us with:
> >
> > plug-and-play:
The property that a station be operational some time after physical
insertion of the
> > station into the ring and power-on of the
station, without a requirement for explicit station
> >
provisioning or configuration .
> >
> > Allan,
>
>
> > I think it simplifies the definition to use the
separately defined term 'operational'. I'm not sure why
> >
the work 'optional' is needed for ingress traffic (although I do remember
that this was discussed in the
> > meeting). If the station
has ingress traffic and there is a default provisioning and the traffic is
> > consistent with that provisioning, then I would assume that an
operational station would transmit that
> > traffic consistent
with the rules for ingress traffic. Also, I normally expect that a
plug-and-play
> > device would be fully operational with respect
to control activities (not just the ability to insert
> > control
messages).
> >
> > Your posting raises another
terminology issue. You refer to 'tandem' traffic, rather than
'transit'
> > traffic. The term 'tandem' has the advantage
that it is less likely to be mistaken for the term
> > 'transmit'
than is the case with 'transit'. On the other hand, 'transit' seems
more descriptive and
> > 'tandem' has an association with
telephony.. This is clearly a key term, how do others in the group
> > feel about this?
> >
> > Bob
> >
> > Allan Pepper wrote:
> >
> > > Brian,
Bob,
> > >
> > > I would prefer a definition for
plug and play that avoids mentioning specific times for protection
>
> > switching caused by inserting a station into a ring.
> >
>
> > > The original intent of the term plug and play was to
indicate that a new station could be inserted
> > > and pass
tandem frames, insert control frames, and optionally insert data frames
without any
> > > operator
> > > provisioning.
> > >
> > > Including Brian's suggestion, this
would make the definition for plug-and-play:
> > > The property
that a station be able to recieve and transmit tandem frames (and optionally
insert
> > > data
> > > frames) some time after
physical insertion of the station into the ring and power-on of the station,
> > > without a requirement for explicit station provisioning
or configuration.
> > >
> > > Thanks,
>
> > Allan Pepper
> > >
> > > Brian Holden
wrote:
> > > >
> > > > Bob,
> >
> >
> > > > Good definitions.
> > > >
> > > > The phrase "without disruption to transit traffic"
in your definition of plug-and-play is TBD in
> > > > the
standard. Unless we add specific capabilities in the standard, it is
likely that there will
> > > > be at least 50 ms of
disruption when you break the ring to put a new station in, and maybe more
> > > > when the ring is restored. Your definition can
be changed to reflect the current state of the
> > > >
motions by just dropping the words "without disruption to transit traffic
and". Another
> > > > possibility is to change
"without disruption" to "with minimal disruption" - either works for me.
> > > >
> > > > Thanks,
>
> > > Brian H.
> > > >
> >
> >
> > > >
> > > >
_______________________________________________
> > > >
Brian Holden PMC-Sierra, Inc.
> > > > 3975 Freedom Circle, Santa Clara CA USA
> > > > +1.408.239.8123 Fax +1.408.492.9862
> > > > brian_holden@xxxxxxxxxxxxxx http://www.pmc-sierra.com
> >
> >
> > > >
-----Original Message-----
> > >
> From: Bob Sultan [mailto:Bob.Sultan@xxxxxxxxxxxxxxx]
> > > > Sent: Wednesday, May
23, 2001 8:30 AM
> > > > To:
stds-802-rprsg@xxxxxxxx
> > >
> Subject: Re: [rprsg] (Terms & Defn)
topology terms
> > > >
> > >
> Brian,
> > > >
>
> > > I added your definition of
plug-and-play to a new category called 'activation'. I also
>
> > > added my own alternative, and a
definition of 'operational' used in that definition.
> > > >
> > >
>
activation
> > > >
plug-and-play : (Alt. 1) The requirement that a station be capable of
Topology
> > > > Discovery and
optional insertion and drop of user frames without manual intervention
> > > > other than the
physical connection of the equipment .
> > >
> (Alt. 2) The property that a station be
operational some time after physical insertion
> > >
> of the station into the ring and power-on
of the station, without disruption to transit
> > >
> traffic and without a requirement for
explicit station provisioning or configuration .
> > > >
> > > > operational : The state of a station in which
it transits traffic, inserts traffic consistent
> > > > with
explicit or default provisioning, copies and/or strips traffic destined for
the station, and
> > > > performs control activities
associated with the steady-state.
> > > >
> > >
> I modified 'topology database' and added 'topology discovery':
>
> >
>
topology/routing
> > > > topology database : A
representation of the connectivity and capabilities of stations and links
> > > > on the ring.
> > > > topology
discovery : The process by which the connectivity and capabilities of the
stations and
> > > > links on the ring is discovered by a
newly added station.
> > >
>
protection (resilience)
> > > > I replaced the definitions
of steering and wrapping:
> > > >
> > > >
steering: Placement of a frame on the outer ring or inner ring at the
ingress data-station based
> > > > on knowledge of the ring
topology . Steering provides resiliency by directing frames on a path
> > > > that does not transit a failed transmission link or
node.
> > > >
> > > > wrapping: The
transit of a frame such that it is received on one transmission ring and
> > > > retransmitted on the opposing ring. Wrapping
provides resiliency by allowing traffic to bypass a
> > > >
failed transmission link or node on the ring.
> > > >
> > > > steering : The placement of a frame on a
specific ringlet at the ingress station based on
> > > >
knowledge of the ring topology .
> > > >
> > >
> wrapping: The transit of a frame such that the frame is received
on one ringlet and retransmitted
> > > > on the opposing
ringlet . (footnote: The definition describes the case of a
dual-ring as agreed
> > > > in the May meeting. In the case
of a multi-ring, this might be changed to 'an opposing ringlet' or
>
> > > 'a different (or alternate) ringlet'. It might also be
unchanged, depending on what is considered
> > > > to be a
useful definition of wrapping in the multi-ring environment.)
> >
> >
> > > > Keep those definitions coming, I
will repost the doc after we have some more.
> > > > Bob
> > > >
> > > >
> > > >
Brian Holden wrote:
> > > >
> > > > > How
about:
> > > > >
> > > > > Topology
Database: A representation of the connectivity and capabilities of the
stations and
> > > > > links on the ring.
> >
> > >
> > > > > (Inevitably we will end up with
at least one bit of standards-based optional capability which
> >
> > > will need to be stored in the database.)
> > >
> >
> > > > > Topology Discovery: The process
by which the connectivity and capabilities of the stations and
> >
> > > links on the ring is discovered by a newly added station.
> > > > >
> > > > > and a new one from
the motions
> > > > >
> > > > > Plug
and Play: The requirement that a station be capable of Topology
Discovery and optional
> > > > > insertion and drop of
user frames without manual intervention other than the physical connection
> > > > > of the equipment.
> > > > >
> > > > > Brian H.
> > > >
>
> > > > >
_______________________________________________
> > > > >
Brian Holden PMC-Sierra, Inc.
> > > > > 3975 Freedom Circle, Santa Clara CA
USA
> > > > > +1.408.239.8123 Fax
+1.408.492.9862
> > > > >
brian_holden@xxxxxxxxxxxxxx http://www.pmc-sierra.com
> >
> > >
> > > > > -----Original Message-----
> > > > > From: Bob Sultan [mailto:Bob.Sultan@xxxxxxxxxxxxxxx]
> > > > > Sent: Tuesday, May 22, 2001 3:17 PM
>
> > > > To: stds-802-rprsg@xxxxxxxx
> > > > >
Cc: Allan Pepper; Brian Holden
> > > > > Subject: Re:
[rprsg] (Terms & Defn) In definitions of steering and
> > >
> > wrapping s/b ringl ets instead of rings
> > > >
>
> > > > > Brian,
> > > > > I
agree with your corrections, but we probably need to correct these further.
> > > > >
> > > > > Allan,
>
> > > > After seeing Brian's email, but before seeing your
email, I made a nearly
> > > > > identical
correction. I omitted the words 'and link failures' as I assumed that
> > > > > 'ring topology' means 'current ring topology'
and already includes any failed
> > > > > links.
Let me know if you disagree.
> > > > >
> > >
> > Wrapping is more interesting. In the case of a dual-ring,
'different ringlet'
> > > > > and 'opposing ringlet'
would have the same meaning. So, if the definition is
> >
> > > specific to a dual-ring, I prefer 'opposing ringlet'. I
think you intended your
> > > > > definition to be
sufficiently general to cover the multi-ring case. The
> >
> > > definition would allow 'wrapping' by shifting frames from one
clockwise ringlet
> > > > > to another clockwise
ringlet. This could be exactly what people have in mind for
>
> > > > wrapping on a multi-ring, but I'm not sure.
>
> > > >
> > > > > So, should our definitions
be specific to the dual-ring case (and we could update
> > >
> > them if the standard includes multi-rings) or should they all be
sufficiently
> > > > > general to include the multi-ring
case (and we could update them to make them
> > > > >
specific to the dual-ring case if multi-rings are not supported)? My
bias is
> > > > > towards describing the dual-ring case
(but it is a bias).
> > > > >
> > > >
> If we define our terms based on a multi-ring, I think I would need some
> > > > > understanding of how steering, wrapping,
discovery, etc. are described in the
> > > > > multi-ring
environment. If someone thinks we should define terms general enough
> > > > > for a multi-ring, can that person volunteer a
description of how this works?
> > > > >
> >
> > > Bob
> > > > >
> > > > >
Allan Pepper wrote:
> > > > >
> > > >
> > I belive the term node should also be replced with station.
Additionaly, the
> > > > > > definition does not need
to explain why the mechanism works. These changes
> > > >
> > would make the following definitions.
> > > > >
>
> > > > > > steering: placement of a frame on a
ringlet by the ingress station based on
> > > > > >
knowledge of ring topology and link failures.
> > > > >
>
> > > > > > wrapping: the transit of a frame such
that is is received by a station on one
> > > > > >
ringlet and re-transmitted on a different ringlet.
> > > >
> >
> > > > > > Thanks,
> > > >
> > Allan Pepper
> > > > > > Nortel Networks
> > > > > >
> > > > > > Brian
Holden wrote:
> > > > > > >
> > > >
> > > Bob, Group,
> > > > > > >
>
> > > > > > In the definitions of Steering and Wrapping,
the
> > > > > > > word "ring" should be replaced by
"ringlet" except in
> > > > > > > the phrases "ring
topology" and "node on the ring".
> > > > > > > The
phrase "node on the ring" could also be replaced
> > > >
> > > by "node".
> > > > > > >
>
> > > > > > Thanks,
> > > >
> > > Brian H.
> > > > > > >
> > > > > > >
_______________________________________________
> > > > >
> > Brian Holden PMC-Sierra,
Inc.
> > > > > > > 3975 Freedom Circle, Santa
Clara CA USA
> > > > > > >
+1.408.239.8123 Fax +1.408.492.9862
> > > > >
> > brian_holden@xxxxxxxxxxxxxx http://www.pmc-sierra.com
> >
> > >
--
Michael
Takefman
tak@xxxxxxxxx
Manager HW
Engineering, Cisco Systems
Chair
IEEE 802.17 Stds WG
2000 Innovation Dr, Ottawa, Canada, K2K 3E8
voice: 613-271-3399 fax:
613-271-4867
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