RE: [rprsg] (Terms & Defn) topology terms
The first part of Allan's email goes back to the definition of plug and
play. My interpretation of the motion on plug and play is that the newly
inserted node will provide a transit/tandem path for frames on the ring;
supporting insertion of data frames without prior provisioning is optional.
I agree with Allan that the definition of plug and play should capture the
intent of the motion.
- Kanaiya
-----Original Message-----
From: Allan Pepper [mailto:acpepper@xxxxxxxxxxxxxxxxxx]
Sent: Thursday, May 24, 2001 9:51 AM
To: stds-802-rprsg@xxxxxxxx
Cc: Bob Sultan
Subject: Re: [rprsg] (Terms & Defn) topology terms
Bob,
Should it not be possible to preclude the addition of ingress traffic until
such
a time as a new station has been provisioned? I believe that some companies
wish
to do this.
Using transit is fine by me, I do think it will lead to confusion with
transmit.
They are both very similar visually and audibly. However, I have no problem
changing to use whatever term the group decides is best.
Thanks,
Allan.
Bob Sultan wrote:
>
> 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
> > > >