Asterisk console problem Regarding HDLC

Hi everyone,

I am working on asterisk since one month and after completing all the steps of configuration of Asterisk with SS7 and then when I am going to call for play an audio then after some time we got some notice and after some time it will automatically breaks the E1 links down and then we need to restart the Dahdi & Asterisk to make it working properly.


[b][NOTICE] SS7 got event: HDLC Overrun(7) on span 1/0
[NOTICE] SS7 got event: HDLC Overrun(7) on span 1/0
[NOTICE] SS7 got event: HDLC Overrun(7) on span 1/0
[NOTICE] SS7 got event: HDLC Overrun(7) on span 1/0
[NOTICE] SS7 got event: HDLC Overrun(7) on span 4/0
[NOTICE] SS7 got event: HDLC Overrun(7) on span 2/0
[NOTICE] SS7 got event: HDLC Overrun(7) on span 3/0
[NOTICE] SS7 got event: HDLC Overrun(7) on span 1/0

My Configuration is:



this is same for remaining 3 Span also , except channels(33-63)(65-95)(97-124) and signalling channels are (47,77,109) on each remaining span.



and this is also the same as like as above for remaining 3 span with different voice channels and signalling channels as I told you above.

Can anyone tell me the exact configuration to prevent this HDLC Overrun(7) error .

Help me in this regard ASAP.

HDLC implies the signalling channel. Overrun suggests that the software could not read data from hardware fast enough.

Is there anything funny about the hardware? Is there a heavy load from anything else on the same hardware?

Hi david55,

Thanks for your reply.

Actually, nothing is running on our OpenVox Card except asterisk.
I just want to share with you one more thing also. I have an another message together with this notice on the asterisk console.

[1] Got message smaller than the minimum SS7 SU length. Dropping

So , can you suggest me anything , what i need to do to prevent this notice on Asterisk console.

Anything wrong in my configuration or is it right.

tell me anything else in this regard.

Hardware fault. Bug at remote end. Not actually an SS7 trunk (although it wouldn’t work at all, in that case). Wrong signalling channel (again this wouldn’t work at all. Wrong timing source (generally the service provide will provide the timing.

Note that Asterisk runs on PCs, not on line cards.

Have you tried getting support from the card vendor?

Hi David,

I understand, what you are saying but when i am using above configuration then my all e1 lines are up and i can do asynchronous call , that’s why i am asking to you exactly what is the reason behind these errors.

Here I am trying to connect the OpenVox card with Telco.

An I/O operation on a dahdi kernel driver returned an exception status and a DAHDI_GETEVENT ioctl (I/O control system call) call returned code 7. It looks like it is a callback from the SS7 specific driver, but probably relating to a problem detected by the card driver or the hardware.

As you are using third party hardware, and possibly a third party hardware driver, you need to take this up with the hardware vendor.

However the normal reasons for an overrun is an overloaded main processor. If you are running anything but Asterisk on the PC, and in particular, if you are running a VM (some VM hosts allow custom hardware to be virtualised), you should move to an unloaded real machine.

A second possibility is that a higher, or equal, priority interrupt source has a driver with exceessive interrupt latency, or there is a driver that disables all interrupts for too long. In which case you need to remove that hardware, or reconfigure to ensure that the ISDN hardware has an adequately low interrupt latency.

(I’m assuming the normal, data comms, meaning of overrun, which is that more data arrived before the previous data had been read by the main computer, with the result that some data was lost.)