%HDLC32-4-NOHDLCCHANNEL: HDLC32 in slot 0: No HDLC channel

[mark.mcsherry]

Hi,

Has anyone seen the error messsage:

%HDLC32-4-NOHDLCCHANNEL: HDLC32 in slot 0: No HDLC channel available

The ISDN dials a number of channels then gets this message.

I am using the VWIC-MFT-E1 card, with DSPs to allow ISDN data dialling. I have a suspicion it may be to do with the DSP allocations

thanks,

Mark

[mihanlin]

Hi Mark,

My understanding of this error is that you may have exceeded the number of B channels available.

Can you let us know if this may be the cause?

Thanks,

Michael.

[mark.mcsherry]

Hi Michael,

Thanks for the note. I did a search on CCO before pasting and that confirmed what you are saying. You will see though from my config that the controller is configured for the 30 channels. It seems to make it to 29!

This is configured using a MFT card with DSP's which is why I am suspicious that is may be a DSP issue,

thanks,

Mark

[mark.mcsherry]

I have attached the config for you to take a look at.

[mihanlin]

No problems.

I can see that it's configured for 30 channels now (31 minus the one D-channel).

Just wondering what you used to establish that only 29 channels were taken up? I have noticed that ppp multilink is configured and therefore one data call may have multiple channels assigned to it.

Also, does this happen on both of your 30-channel PRI's, or just one?

Thank you,

Michael

[mark.mcsherry]

Hi Micheal,

I've attached a file to make things a little clearer.

You'll see that under normal circumstance I have 20 channels dialled in. I than then force another ten channels to dial, by getting the dialer watch to kick in.

You'll then see that 29 channels are up, but the show isdn status only says 20! It basically brings up 29 channels, then stops with the HDLC error message I detailled in my previous post,

Thanks,

Mark

[mihanlin]

Mark,

It looks like you're seeing 20 channels come up on Serial0/0/0, then another 9 channels come up on the other interface, Serial0/1/0. You will see the sh isdn status command splits the interfaces up between the two, and does not use the remaining channels on Serial0/0/0.

What is this router dialing in to? Is there enough channels free on the B-end router when the dialer watch kicks in?

The error message you are seeing is referring to slot0, which still only has 20 channels up at any one time.

I hope this is some help to you.

Regards,

Michael

[mihanlin]

In addition to my previous post, I have decoded the line "The Free Channel Mask" in your isdn stat command. This is basically a hex value which determines which channels are free when you convert it to binary.

So in binary,

1111 1111 1110 0000 0000 0000 0000 0000 (dsl 0 0xFFE00000)

1000 0000 0011 1111 0111 1111 1111 1111 (dsl 1 0x803F7FFF)

A '1' means you have a free channel, and a '0' indicates it is used. From right-to-left, is channels 1-31 respecitvely, and the highest order bit indicates if the DSL is actually ACTIVE (1 meaning yes).

This indicates that the other channels which aren't being used are indeed free - 22-30 on dsl0 and 1-22 (excluding 15) on dsl 1.

Can you please check the B-End for capacity and get back to me?

Thanks,

Michael.

[mark.mcsherry]

Michael,

Many thanks for all your efforts.

I have tried switching the E1 configs over, but it gives the same result, just on the different interface.

One thing I have noticed is that when it dials, the calling end adds channels from channel 29 down. The receiving end brings the channels up from 0 counting upwards.

Thanks,

Mark

The config from the far end is:

controller E1 0/0/0

framing CRC4 Australia

pri-group timeslots 1-31

interface Serial0/0/0:15

no ip address

encapsulation ppp

dialer pool-member 3

isdn switch-type primary-net5

isdn integrate calltype all

ppp authentication chap

ppp multilink

!

interface Dialer3

bandwidth 2048

ip address 10.40.6.37 255.255.255.252

encapsulation ppp

load-interval 30

dialer pool 3

dialer remote-name ROUTER1

dialer caller 386100

ppp authentication chap

ppp multilink

ppp multilink links maximum 30

ppp multilink links minimum 30

ppp multilink fragment disable

[mihanlin]

Mark,

Nothing looks too out of the ordinary with both configs.

Have you debugged isdn q931 and anything come up of interest from that? q931 handles signalling of call set-up and tear-down which may give some good ideas as to what it could be.

The below table has disconnect reasons for ISDN calls, which q931 should pick up:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios103/dcr/71863.htm#27122

The only other thing I can think of is bandwidth statements on the dialer, but as we all know this should not affect actual bandwidth of the link, just routing protocol metrics.

Cheers,

Michael.

[mark.mcsherry]

Hi Michael,

Thanks for the note. It was from the Q931 debug that I noted the channels coming up in different directions (ie from 0 upwards and from 29 downwards).

Its running on a simulator at the minute, so I'll check this next week when its running on a live ISDN link,

Thanks for all you info,

Mark