DAHDI_CHANCONFIG fail when using dynamic span with dahdi_dummy

Asterisk Asterisk Support
1

I am trying to configure TDMoE between two servers without E1/T1 hardware installed. Without dahdi_dummy all running well but with very bad sound quality(no synchronisation source).

system.conf:

dynamic=eth,eth3/A0:D3:C1:05:E8:97/0,31,0
bchan=1-31

loadzone=ru
defaultzone=ru

When trying to run dahdi_cfg with dahdi_dummy loaded, i receive a message:

DAHDI_CHANCONFIG failed on channel 31: Invalid argument (22)
Selected signaling not supported
Possible causes:
Signaling is being assigned to channel 16 of an E1 CAS span

So channel 31 is left unconfigured and doesn’t work, but if i make number of channels 32 or more, or add more dynamic spans, i can ignore this problem as i am using only first span with channels 1-31.

But i like to know if this problem can be solved in a more civilised way. Maybe i am missing something in config files ?

DAHDI Version: 2.11.1
CentOS release 6.3 (Final), Linux node1 2.6.32-279.el6.x86_64

2

Try somethink like

dynamic=eth,eth3/A0:D3:C1:05:E8:97/0,31,0

bchan=1-15,17-31
dchan=16

3

This i already tried, with the same result

4

What does dahditool show and what do the rest of your configs fro this look like. BUT dahdi_dummy is for when no dahdi channels are installed from memory so I can see why it may cough trying to load both.

5

dahdi_tool.png1684×2004 140 KB

full config:

dynamic=eth,eth3/A0:D3:C1:05:E8:97/0,31,0
#bchan=1-32
bchan=1-15,17-31
dchan=16

#dynamic=eth,eth3/A0:D3:C1:05:E8:97/1,31,0
#bchan=32-62

#dynamic=eth,eth3/A0:D3:C1:05:E8:97/2,31,0
#bchan=63-93

#dynamic=eth,eth3/A0:D3:C1:05:E8:97/3,31,0
#bchan=94-124

#echocanceller=oslec,1-15,17-31
loadzone=ru
defaultzone=ru

scan result:

# dahdi_scan
[1]
active=yes
alarms=UNCONFIGURED
description=DAHDI_DUMMY/1 (source: HRtimer) 1
name=DAHDI_DUMMY/1
manufacturer=
devicetype=DAHDI Dummy Timing
location=
basechan=1
totchans=0
irq=0
type=analog
[2]
active=yes
alarms=OK
description=Dynamic 'eth' span at 'eth3/A0:D3:C1:05
name=DYN/eth/eth3/A0:D3:
manufacturer=
devicetype=DYN/eth/eth3/A0:D3:C1:05:E8:97/0
location=
basechan=0
totchans=31
irq=0
type=digital-DYNAM
syncsrc=0
lbo=0 db (CSU)/0-133 feet (DSX-1)
coding_opts=B8ZS,AMI,HDB3
framing_opts=ESF,D4,CCS,CRC4
coding=
framing=CAS
6

Other than the the first one you have no other d channels defined.

7

Should i define another d channel somewhere in config ?

8

dynamic=eth,eth3/A0:D3:C1:05:E8:97/1,31,0
bchan=32-46,48-62
dchan=47
dynamic=eth,eth3/A0:D3:C1:05:E8:97/2,31,0
bchan=63-77,79-93
dchan=78
dynamic=eth,eth3/A0:D3:C1:05:E8:97/3,31,0
bchan=94-108,110-124
dchan=109

then comment out the dahdi dummy

and see if it loads

9

Without dahdi_dummy, received the same message, using config exactly from your post(without device /0)

DAHDI_CHANCONFIG failed on channel 94: Invalid argument (22)
Selected signaling not supported
Possible causes:
Signaling is being assigned to channel 16 of an E1 CAS span
[node1-192.168.22.68 dahdi]# lsmod |grep dahdi
dahdi_dynamic_eth 4429 0
dahdi_dynamic 10236 1 dahdi_dynamic_eth
dahdi 225824 1 dahdi_dynamic
crc_ccitt 1677 1 dahdi

And it loads without error when using device /0 and no dahdi_dummy

10

what is defined in the channels section of your dahdi config files in /etc/asterisk

11

There is no /etc/asterisk, because it is not installed. I am using only TDMoE between 2 servers with custom software that uses E1 devices to transfer HDLC signalling and voice.

12

What devices ? as redfone for example used ethmf not eth . but i missed this framing=CAS should be CCS T1 is CAS E1 is CCS

13

We are using Quasar, eth is just for testing purposes, as number of Quasar cards are limited and TDMoE “cards” are not.
On the servers where i am using TDMoE, no such hardware installed, it is only DAHDI on a basically clean CentOS.

14

Ok

but the error you are getting is beacuse of teh framing

framing=CAS

should be CCS, T1 is CAS E1 is CCS

15

But i didn’t found anywhere a way to set framing=CCS for dynamic spans, even here on asterisk support forum exists the same unanswered question. How to set coding,framing paramerters for dynamic span

16

Hi
Ok i only have ever used this as i said with ethmf and redfone.

so drop the dchan= definitions and switch to 31 channels per span and see if that works.

17

No, it doesn’t. Seems like i will just continue to use this little workaround with extra channel/span :slight_smile:
Also, i found something in dahdi jira, that may solve this problem but i am too lazy to check on it (also it is unapproved change): https://issues.asterisk.org/jira/browse/DAHLIN-338 , maybe it will help someone with more serious problem with dynamic spans.
Thank you for help very much !