I checked on my 68R and everything looks like it gets enabled correctly. So I'll need some help from you to collect data on the N16 with the fix enabled....
telnet/ssh to the router.....
First, make sure the nvram is set correctly (this should return 1)
nvram get DSCP_fix_enable
next check the rules by entering
iptables -t mangle -L -v
you should see something like this right at the beginning....the key line is the line containing DSCP, showing it's active and processing packets. If this is correct, it would indicate that the fix is active and working.
Code:
Chain PREROUTING (policy ACCEPT 17M packets, 17G bytes)
pkts bytes target prot opt in out source destination
6519K 8402M CONNMARK all -- eth0 any anywhere anywhere CONNMARK restore mask 0x7
0 0 MARK all -- !eth0 any anywhere ip70-xxx-xxx-xxx.tc.ph.cox.net MARK set 0xb400
6519K 8402M DSCP all -- eth0 any anywhere anywhere DSCP set 0x00
if the above check fails (or just for completeness),
check that the DSCP module is available and loaded (should return a single line containing dscp)
lsmod | grep dscp
and finally that the correct module is available (again, should return a single line)
modprobe -l | grep dscp