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Bob and Group,
I think the pictures are a good idea. Contributions are accepted.
I'll put candidates into the document for comment.
Also, an alternative to 'transit' and 'continue' might be 'pass'.
This would give us pass traffic, pass buffer, pass frames, etc. This
sounds better to me than 'passthru' in combination with other words.
The more I see 'transit' and 'transmit' the more I think the similarity
will be a problem.
Bob
RDLove wrote:
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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