I'm investigating superframes as a means of determining DSL uptime for rs-ux/w, but there seems to be little consistency between Broadcom-based routers on this measure. Some routers report the same value for both upstream and downstream, but others report different values, and it appears that for VDSL2 connections the value isn't reported at all.
The available literature mostly predates ADSL2+, so does it remain the case on all ADSL versions that there are 4000 frames per second, and a superframe consists of 68 normal frames plus one sync frame?
Does the above apply only to downstream, and if so, what is the situation with upstream?
Is there a corresponding figure for VDSL2?
Any information would be much appreciated.