The use if statusDeterminationNumber in masterSlaveDetermination

Frank Derks frank.derks at PHILIPS.COM
Thu May 3 08:50:56 EDT 2001

C.2.1.4/H.245 states the following:

"If the terminal type numbers are the same, the statusDeterminationNumbers
are compared using modulo arithmetic to determine which is master

If both terminals have equal terminalType field values and the difference
between statusDetermination field values modulo 2^24 is 0 or 2^23, an
indeterminate result is obtained"

The first sentence states that "modulo arithmetic" must be used to compare
the numbers. I would say that that's a rather vague way of describing how
the comparison must be done. Furthermore it does not tell me what the result
must be for a terminal to be determined to be the master!

According to the second sentence, I know how to obtain an indeterminate
result. So any result that is not any of the two specified values is not
indeterminate, but I still do not know what the meaning of the result is.
"Modulo arithmetic" is, however, introduced, but it is not clear whether
this is the modulo arithmetic referred to in the first sentence. Furthermore,
what is the significance of a result of 2^23?

I assume that the same rules that apply to the comparison of the terminalType
field apply (i.e. the terminal with the higher value becomes the master),
but this is not stated explicitly.



For help on this mail list, send "HELP ITU-SG16" in a message to
listserv at

More information about the sg16-avd mailing list