RE: [RPRWG] Unclear from D2.0 what Protection messages are transmitted on each ringlet.
Hi Michael,
See anwers inserted below. Let me know if you have further questions.
Jason Fan
Luminous Networks
-----Original Message-----
From: Michael Allen [mailto:michael_allen@xxxxxxxxxxxxxxx]
Sent: Monday, January 06, 2003 11:33 AM
To: stds-802-17@xxxxxxxx
Subject: [RPRWG] Unclear from D2.0 what Protection messages are
transmitted on each ringlet.
I am currently trying to implement the Protection algorithms from D2.0 and
am finding some ambiguities/missing detail.
The spec discusses a "Long" and "Short" protection message and describes
what each message indicates. What the spec does not indicate is what
messages are actually transmitted in IDLE/WRAPPED/PROTECTION conditions.
I.e. Is a short AND long message sent on each ringlet in each periodic
interval? This way both interfaces are described in both directions on the
ring. This would mean each station originates 4 messages per interval.
___________________________________________________________________________
[JF] Yes, 4 messages are generated per interval.
___________________________________________________________________________
If only a single message is sent on each ringlet, which interface is the
fail_status reporting and is it different for IDLE/WRAPPED/PROTECTION
states?
___________________________________________________________________________
[JF] See above.
___________________________________________________________________________
In 11.8.3 c), allowNonCoexistingProtection...
I find the statement "all link availability values in topology database not
corresponding to sideProtectionState and neighborProtectionState" quite
ambiguous.
1) For the comparison, is this all fail_status values on both ringlets
(except those noted)?
___________________________________________________________________________
[JF] Yes.
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2) Is neighborProtectionState to exclude the one for the neighbor state
received on the ringlet being processed, or for both the ringlet
neighborProtectionStates on neighbor?
___________________________________________________________________________
[JF] neighborProtectionState excludes the protection state of the neighbor
link on the same span. For example, in a ring A=B=C=A, for the state machine
on A covering the link B->A (receive on A), neighborProtectionState corresponds
to the link availability of A->B (receive on B).
___________________________________________________________________________
3) Is sideProtectionState to excluded just that for the ringlet being
processed.
___________________________________________________________________________
[JF] Yes. For example, in a ring A=B=C=A, for the state machine
on A covering the link B->A (receive on A), sideProtectionState corresponds
to the link availability of B->A (the link itself).
___________________________________________________________________________
Hope these questions are clear,
Regards,
Michael Allen
Chip Engines, Inc.