[asterisk-users] Dahdi T1 CRC4 errors?

[Jeremy Betts]

I have a system setup with two T1 circuits, the customer complains of 
call quality issues. I've checked logs and don't see anything too 
strange, but when I run "dahdi show status" I see:

Description                              Alarms  IRQ    bpviol CRC4   
Fra Codi Options  LBO
T2XXP (PCI) Card 0 Span 1                OK      0      0      19     
ESF B8ZS YEL      0 db (CSU)/0-133 feet (DSX-1)
T2XXP (PCI) Card 0 Span 2                OK      0      0      774    
ESF B8ZS YEL      0 db (CSU)/0-133 feet (DSX-1)

The value in the CRC4 column seems to be growing with time. From what I 
understand CRC4 has to do with E1 circuits not T1. I am I missing 
something? Is there any further debugging I can do? What could the CRC4 
errors mean? I have check the SIP devices latency times and they are all 
under 40ms so I'm pretty sure it's not an issue with the local network 
or SIP device. Thanks in advance.

Asterisk Version: 1.6.2.7
Dahdi: 2.3.0
Kernel: 2.6.18_164.15.1.el5


/etc/dahdi/system.conf

span=1,1,0,esf,b8zs
fxsls=1-22
echocanceller=oslec,1-22
unused=23-24
echocanceller=oslec,23-24
span=2,1,0,esf,b8zs
e&m=25-48
echocanceller=oslec,25-48

/etc/asterisk/chan_dahdi.conf

[channels]
language=en
echocancel=yes
echocancelwhenbridged=no
echotraining=800
rxgain=0
txgain=0
group=0
callgroup=0
pickupgroup=1
faxdetect=no
callreturn=yes
cancallforward=yes
transfer=yes
context=from-zaptel
signalling=fxs_ks
rxwink=300
usecallerid=yes
hidecallerid=no
callwaiting=no
usecallingpres=yes
callwaitingcallerid=yes
threewaycalling=no
immediate=no

signalling=fxs_ls
language=en
context=from-zaptel
echocancel=yes
echocancelwhenbridged=no
rxgain=0
txgain=0
faxdetect=no
immediate=no
group=0,1
callgroup=1
channel => 1-22

signalling=em_w
callgroup=1
group=0,2
immediate=no
faxdetect=no
txgain=0
rxgain=0
echocancelwhenbridged=no
echocancel=yes
context=from-pstn
language=en
channel => 25-48

sip show peers:
Name/username              Host            Dyn Nat ACL Port     Status
3200/3200                  10.10.2.63       D   N   A  5060     OK (32 ms)
3202/3202                  10.10.2.31       D   N      5060     OK (12 ms)
3204/3204                  10.10.2.88       D   N   A  5060     OK (13 ms)
3205/3205                  10.10.2.85       D   N      5060     OK (14 ms)
3206/3206                  10.10.2.65       D   N      5060     OK (12 ms)
3208/3208                  10.10.2.68       D   N      5060     OK (12 ms)
3210/3210                  10.10.2.59       D   N      5060     OK (9 ms)
3211/3211                  10.10.2.75       D   N   A  5060     OK (13 ms)
3213/3213                  10.10.2.72       D   N   A  5060     OK (8 ms)
3214/3214                  10.10.2.10       D   N   A  5060     OK (13 ms)
3216/3216                  10.10.2.91       D   N   A  5060     OK (13 ms)
3217/3217                  10.10.2.23       D   N   A  5060     OK (8 ms)
3219/3219                  10.10.2.66       D   N      5060     OK (8 ms)
3221/3221                  10.10.2.71       D   N   A  5060     OK (14 ms)
3223/3223                  10.10.2.80       D   N      5060     OK (12 ms)
3224/3224                  10.10.2.37       D   N   A  5060     OK (14 ms)
3226/3226                  10.10.2.83       D   N   A  5060     OK (14 ms)