Problem with SLC in message TRA

Hello everyone,

I work in telecom.I'm from Poland.
I have problem with number of parametr SLC in message TRA (Traffic Restart Allowed).
If I activate link between two switches, one of them sent message TRA within SLC=13.
Between two switches is only one link. Number is always SLC=13, didn't change.
Equipment vendor thinks that number SLC is not importent because message TRA is not connect with link, like message CBD,COO.
I read in Q.704 that SLC migth set "0" or SLC is connect with number links.

Does someone has any experience with TRA,SLC??

thanks, suggestions are kindly appreciated