(resend) [rprsg] (Terms & Defn) topology terms

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_______________________________________________
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: Brian Holden
Sent: Wednesday, May 23, 2001 11:35 AM
To: stds-802-rprsg@xxxxxxxx
Subject: RE: [rprsg] (Terms & Defn) topology terms

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.

-----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/routingtopology 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