I have a number of Cisco 837 DSL routers (ATM over DSL, ITU G.992.1 or G.DMT), running the command:
show dsl int atm0
I see the number of used DTM bits on carrier bin 66 (280KHz) as low on some routers and high on others. I know this to be the DSL Pilot Tone, what I can't figure out is, it evidence of anything wrong if your router has trained to use this carrier bin? Do all DSL circuits have a pilot tone?
Router A(see hex 41, dec 65): DMT Bits Per Bin
00: 0 0 0 0 0 0 0 7 7 7 9 A B B A B
10: B B A B B B B A A A A 9 8 8 0 0
20: 0 0 0 0 0 0 2 2 2 4 5 6 6 6 7 7
30: 8 8 8 9 9 9 9 9 9 A A A 6 A B A
40: B A A 7 8 A A A 6 B 2 9 B B B C ^this one = A
Router B: DMT Bits Per Bin
00: 0 0 0 0 0 0 0 6 6 7 9 A B B C C
10: C B B B B B B B A 9 8 8 8 8 0 0
20: 0 0 0 0 0 0 0 0 0 0 0 2 2 2 3 4
30: 4 4 5 5 5 6 6 6 6 6 7 7 7 7 7 7
40: 7 2 7 7 7 7 7 7 7 7 7 7 7 7 6 7 ^this one = 2