Hello Elnaz,
You ask:
one of the external commands of msp linear 1+1 is exercise,
Correct.
my question is, exercise always issues only for working port?
Yes.
in another word, when the selector is on working we can use > exercise command to check whether or not signaling on KByte> are
acknowledged?
Correct.
and it doesn't work when the switch is on protection port?
In that case switch commands are exchanged via the KByte, so
the proper operation of the Kbyte is already verified/tested.
And there is no need for Exer in this case.
In ITU-T G.841 is just mentioned: " Issues an exercise request
for that signal and checks responses on APS bytes, unless > the protection section is in use. The switch is not actually
completed, i.e. the selector is released by an exercise request
on either the sent or the received and acknowledged K1 byte.
Indeed, the Exer is used to verify if the far-end APS is still
active and is able to respond to a protection switch request.
An inactive far-end APS can be reported and repaired before
actually a protection switch is necessary.
The exercise functionality may not exist in all MSP functions."
In very old implementations Exer does not exist.
I will appreciate if someone helps me.
I hope this clarified your question.
Best regards, Huub.
--
reply to hhelvooort with 2 'o's ================================================================
http://www.van-helvoort.eu/ ================================================================
Always remember that you are unique...just like everyone else...
--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)