# Pri E1 D-channel Down

**URL:** <https://community.asterisk.org/t/pri-e1-d-channel-down/32725>\
**Category:** Asterisk Support\
**Created:** [October 2, 2010, 9:39am UTC](https://community.asterisk.org/t/pri-e1-d-channel-down/32725 "2010-10-02T09:39:42Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/asterisk/original/2X/4/475d0c889911cfb84ac4881ad6df8b523e3f9105.png) [@system](https://community.asterisk.org/u/system)\
**Post date:** [October 2, 2010, 9:39am UTC](https://community.asterisk.org/t/pri-e1-d-channel-down/32725/1 "2010-10-02T09:39:42Z")

</div>

I have a very strange issue. The problem is that my asterisk server was working perfectly for 1 year but few days ago it started to loose e1 D-channel,  
Telco always says that their side is OK, what should i check from below output ? Where should i find some information in order to make a debug and talk to my telco.

i tried to Recompile/reinstall dahdi i even upgrade dahdi-linux-complete from version 2.2 to 2.4 but no avail

Digium TE420 ,asterisk-1.6.1.6,libpri-1.4.10.2,dahdi-linux-complete-2.4.0+2.4.0, Running on Debian Lenny

My Configuration

chan\_dahdi.conf

[trunkgroups]

[channels]

usecallerid=yes  
callwaiting=yes  
usecallingpres=yes  
callwaitingcallerid=yes  
threewaycalling=yes  
hidecallerid=no  
transfer=yes  
canpark=yes  
cancallforward=yes  
callreturn=yes  
echocancel=yes  
echocancelwhenbridged=yes  
callgroup=1  
pickupgroup=1

## group=1 switchtype=euroisdn signalling=pri\_cpe context=incoming channel =\> 1-15,17-31

system.conf

# Span 1: TE4/0/1 “T4XXP (PCI) Card 0 Span 1” (MASTER)

span=1,1,0,ccs,hdb3,crc4

# termtype: te

bchan=1-15,17-31  
dchan=16  
echocanceller=mg2,1-15,17-31

# Global data

loadzone = us  
defaultzone = us

* * *

## CLI\> pri show span 1 Primary D-channel: 16 Status: Provisioned, Down, Active Switchtype: EuroISDN Type: CPE Window Length: 0/7 Sentrej: 0 SolicitFbit: 0 Retrans: 0 Busy: 0 Overlap Dial: 0 Logical Channel Mapping: 0 T200 Timer: 1000 T203 Timer: 10000 T305 Timer: 30000 T308 Timer: 4000 T309 Timer: -1 T313 Timer: 4000 N200 Counter: 3 Overlap Recv: No

CLI\> Dahdi show status  
Description Alarms IRQ bpviol CRC4 Fra Codi Options LBO  
T4XXP (PCI) Card 0 Span 1 OK 0 0 0 CCS HDB3 CRC4 0 db (CSU)/0-133 feet (DSX-1)  
T4XXP (PCI) Card 0 Span 2 RED 0 0 0 CCS HDB3 CRC4 0 db (CSU)/0-133 feet (DSX-1)  
T4XXP (PCI) Card 0 Span 3 RED 0 0 0 CCS HDB3 CRC4 0 db (CSU)/0-133 feet (DSX-1)  
T4XXP (PCI) Card 0 Span 4 RED 0 0 0 CCS HDB3 CRC4 0 db (CSU)/0-133 feet (DS

* * *

CLI\> dahdi show version  
DAHDI Version: 2.4.0 Echo Canceller: MG2

## CLI\> pri show version libpri version: 1.4.10.2

## dmesg wct4xxp 0000:10:08.0: Setting yellow alarm span 2 [21.319643] wct4xxp 0000:10:08.0: Setting yellow alarm span 3 [21.319693] wct4xxp 0000:10:08.0: RCLK source set to span 1 [21.319699] wct4xxp 0000:10:08.0: Recovered timing mode, RCLK set to span 1 [21.321256] wct4xxp 0000:10:08.0: Setting yellow alarm span 4 [21.321256] wct4xxp 0000:10:08.0: RCLK source set to span 1 [21.321256] wct4xxp 0000:10:08.0: Recovered timing mode, RCLK set to span 1

CLI\>pri intensive debug span 1  
Enabled EXTENSIVE debugging on span 1  
Sending Set Asynchronous Balanced Mode Extended

> [00 01 7f]

> Unnumbered frame:  
> SAPI: 00 C/R: 0 EA: 0  
> TEI: 000 EA: 1  
> M3: 3 P/F: 1 M2: 3 11: 3 [SABME (set asynchronous balanced mode extended)]  
> 0 bytes of data

* * *

---

<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/asterisk/original/2X/4/475d0c889911cfb84ac4881ad6df8b523e3f9105.png) [@system](https://community.asterisk.org/u/system)\
**Post date:** [October 5, 2010, 5:52am UTC](https://community.asterisk.org/t/pri-e1-d-channel-down/32725/2 "2010-10-05T05:52:32Z")

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Hello! Try see on you server command cat /proc/interrupts. May be your PRI card conflicts with our device?  
Or cables will be damages.

[root@ss71 ~]# cat /proc/interrupts  
CPU0 CPU1  
0: 2681269 0 IO-APIC-edge timer  
1: 2 0 IO-APIC-edge i8042  
8: 3 0 IO-APIC-edge rtc  
9: 0 0 IO-APIC-level acpi  
12: 4 0 IO-APIC-edge i8042  
169: 0 0 IO-APIC-level uhci\_hcd:usb5  
201: 0 0 IO-APIC-level uhci\_hcd:usb4  
209: 19492 23049 IO-APIC-level ehci\_hcd:usb1, uhci\_hcd:usb2  
217: 0 0 IO-APIC-level uhci\_hcd:usb3, ata\_piix  
225: 15 1540 PCI-MSI eth0  
233: 2629612 0 IO-APIC-level wct2xxp