Cisco Cisco IOS Software Release 12.2(10)
6
Release Notes for Cisco IOS Release 12.2(10)DA3 for Cisco DSLAMs with NI-2
OL-2702-01
Limitations and Restrictions
Limitations and Restrictions
This section describes the limitations and restrictions for Cisco IOS DSLAM releases.
Attainable Bit Rate Is Conservative on 4xflexi-DMT and 8xDMT
The reported DMT aggregate bit rate is less than the true attainable bit rate.
Limitations
Due to line condition variations between trains, the effect of trellis coding, interleave delay, FEC check
bytes, and so forth, the attainable bit rate estimate is not always 100 percent accurate. A conservative
approach was taken in making the estimate; therefore, in general, you can get a higher rate than what the
estimate suggests. For a fast-path scenario, the results should track fairly closely for the downstream rate
and err on the conservative side for the upstream rate. For an interleave path scenario, the results are
highly dependent on configurations.
bytes, and so forth, the attainable bit rate estimate is not always 100 percent accurate. A conservative
approach was taken in making the estimate; therefore, in general, you can get a higher rate than what the
estimate suggests. For a fast-path scenario, the results should track fairly closely for the downstream rate
and err on the conservative side for the upstream rate. For an interleave path scenario, the results are
highly dependent on configurations.
At a higher reach or where line conditions are not optimal, the effect of having trellis coding, interleave
delay, and FEC check bytes can provide a much higher rate than was estimated (greater than 128 kbps).
delay, and FEC check bytes can provide a much higher rate than was estimated (greater than 128 kbps).
Workaround
There is no workaround. The aggregate bit rate calculation is an estimate, which does not accurately
model all of the line conditions that affect the true attainable bit rate for a given profile. The calculations
for aggregate bit rate are performed as follows:
model all of the line conditions that affect the true attainable bit rate for a given profile. The calculations
for aggregate bit rate are performed as follows:
Step 11
rommon> set
If you see BOOTLDR after you enter this command, the
image in bootflash is already being used as the
bootstrap image; go to Step 15. Otherwise, go to Step
12 and enter the commands in Steps 12 through 14 to
force the system to use ni2-dboot-mz.121-5.bin as the
bootstrap image.
image in bootflash is already being used as the
bootstrap image; go to Step 15. Otherwise, go to Step
12 and enter the commands in Steps 12 through 14 to
force the system to use ni2-dboot-mz.121-5.bin as the
bootstrap image.
Step 12
rommon> unset BOOTLDR
Unset BOOTLDR to remove the variable.
Step 13
rommon> sync
Sync to save the state of rommon.
Step 14
rommon> b
When the NI-2 boots, it uses
ni2-dboot-mz.121-5da.bin as the bootstrap image.
ni2-dboot-mz.121-5da.bin as the bootstrap image.
Step 15
DSLAM# configure terminal
Enter global configuration mode. You have entered
global configuration mode when the prompt changes to
global configuration mode when the prompt changes to
DSLAM(config)#
.
Step 16
DSLAM(config)# config-register value
Set the config-register to the value you recorded in
Step 5.
Step 5.
Step 17
DSLAM(config)# exit
Return to enable mode.
Go to the
Command
Purpose