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New Member


Hi All

We are using AS5400 as MGW & we are observing following logs on our mGW.

IOS version- 12.4 (22)

DSpware vesrion=9.4

%C5510-1-NO_RING_DESCRIPTORS: No more ring descriptors available on slot 3 dsp 11

Can you tell me why this logs coming over MGW, is that affect on calls on perticular DSP (here dsp 11)?

How we can resolve this?


Cisco Employee

Re: AS5400 alert logs NO_RING_DESCRIPTORS

That error means that IOS had trouble communicating with the DSP.  DSP could have crashed, or just didn't respond for a little bit (and maybe gracefully recovered).  Worst case scenario, call drops and no audio.  Best case scenario, it doesn't effect calls and is a cosmetic error where the DSP recovers properly.

Always a bug when this error is seen (though if the issue is only ever on the same DSP, even after a reboot, it could be bad DSP hardware).

12.4(22)T should be running DSPware 23.8.x, not 9.4.x.  If you are running 12.4(22)T with 9.4.x, that's not supported, will cause issues, and you should delete all .rbf and .dsp files from flash and reload the router so that you are running the supported DSPware for that IOS release.

FWIW, DSPware < 9.4.14 in that DSP throttle is suceptible to CSCtf25886.

New Member

Re: AS5400 alert logs NO_RING_DESCRIPTORS


Thanks for your reply. i checked once again the DSpware version

IOS-Bundled Default               Version     Firmware-Type
==========================        =======     =============
system:/bundled_fw_image          9.4.809     c5510

it showing above result set & IOS  version is 12.4(15)T9

Please tell if such difference is there means calls may faield?how i can rectify teh same.



Cisco Employee

Re: AS5400 alert logs NO_RING_DESCRIPTORS

You are definately hitting a bug since you are seeing this message.

You could be hitting:

%C5510-1-NO_RING_DESCRIPTORS DSP resets observed in 12.4(15)T12

Upgrade top 12.4(15)T14 where this is fixed.  If the issue is still seen, open a TAC SR to troublehoot this further.  They'll want DSP crash dump and minilogger output as this error is thrown:

voice dsp crash-dump destination flash:dspcrashfile.dat
voice dsp crash-dump file-limit 2
voice dsp 0 command history buffer periodic 13600
voice dsp 0 command history buffer control 13600
voice dsp 0 command history max-logger-print 1000
voice dsp 0 command history enable