Subject: 30 sec bug

From: "Hattig, Myron" <[email-masked]>
Date: Fri, 17 Sep 1999 09:32:04 -0700

There is a bug in draft 18. Section 9.7 para two says:

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The owner of an existing channel mapping that wishes to release the
mapping SHALL commence a timer to measure the time remaining before the
anticipated release of the mapping and its associated channel. Until the
timer counts down to zero, the owner SHOULD continue to transmit MCAP
advertisements for the affected channel but SHALL adjust expiration in
each advertisement to reflect the time remaining until the channel is to
be deallocated. If the owner is unable to transmit MCAP advertisements
until the timer reaches zero, it SHALL initiate a bus reset. Otherwise,
the sequence of expiration times transmitted by the owner intending to
release the mapping SHALL decrease with each succeeding advertisement.
If other multicast source(s) are using the same channel mapping and
observe an expiration time less than or equal to 30 seconds, they SHALL
commence transmitting MCAP advertisements for the channel mapping with
refreshed expiration times greater than or equal to 30 seconds that
maintain the channel mapping. Any contention that occurs between
multiple sources that attempt to claim ownership of the channel mapping
SHALL be resolved as described in 9.6. If the original owner observes an
MCAP advertisement for the channel to be relinquished before its own
timer has expired, it SHALL NOT deallocate the channel number.
--------

The text should state:
"they SHALL commence transmitting MCAP advertisements for the channel
mapping with refreshed expiration times greater than or equal to 60
seconds that maintain the channel mapping."

If less than 60 seconds is used, it is not considered during the contention
resolution procedures described Peter's new text on the "redundant
channels mappings".

The other alternative is to change the 60 seconds to 30 seconds in Peter's
new text; however, I prefer to have the contention resolution for
redundant channel mappings the same as contention resolution for
overlapped channel mappings.

-myron