TELUS British Columbia PRI Settings With Asterisk

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I am having some difficulties getting my Asterisk box to find the d-channel from a TELUS PRI and am waiting to hear back from one of their techs. In the meantime I thought I would check with the brilliant people of the mailing list.

As I understand it is a T1 connection, not an E1 and I am using a Digium TE121 with hardware echo cancellation. I have green lights on the back of the card and the PRI connection, which go red when I do a dahdi restart command and come back to green once it is finished.

I know from our other system that the frame and coding are ESF and B8ZS so it must be something in the signaling of the channels. My chan_dadhdi is below, the commented out lines are ones I have tried. I’ve also tried moving the dchannel around, 12 through 24. Does anyone see anything blatantly wrong?

Thanks, Jeremy

chan_dahdi.conf

[trunkgroups]
trunkgroup => 1,24
spanmap => 1,1,0,esf,b8zs

[channels]
#include /etc/asterisk/dahdi-channels.conf

;signalling => em
;signalling => pri_net
signalling => pri_cpe
;context=default
context=incoming
;switchtype=national
switchtype=dms100
;group = 1
bchannel => 1-12
dchannel => 24
echocancel=yes

16 thoughts on - TELUS British Columbia PRI Settings With Asterisk

  • I see …
    Chan_dahdi.c 2796 pri_find_dchan No D-channel available using Primary channel X as D-channel anyway.

    With X being whichever number I assigned to the D-channel in chan_dahdi and system.conf.

    Then when dialling I get an error 0 – unknown, which occurs when Asterisk tries to open a channel from softphone to PSTN.

    Jeremy

  • If you’re only using one span, is there a reason you are using trunkgroups?
    I believe those only get used for NFAS and GR-303

    Do you have anything defined in this file? Since it comes at the top, any
    changes you make below it won’t affect anything defined in that file.

    I didn’t think bchannel and dchannel were valid for chan_dahdi.conf. Don’t
    those only exist in system.conf?
    I believe you only declare ‘channel’ for the b-channels in chan_dahdi.conf.

    http://svn.asterisk.org/svn/asterisk/branches/1.6.2/configs/chan_dahdi.conf.sample

  • I’m not surprised both the conf file and myself are confused.

    I’ve pared things down in chan_dahdi.conf to …

    _________________________________________

    [channels]

    spanmap => 1,1,0,esf,b8zs

    #include dahdi-channels.conf

    switchtype => national

    signalling => pri_cpe

    context => default

    _____________________________

    As I read the instructions for chan_dahdi, the spanmap -> span = 1,
    timing = from PSTN, LBO = 0, framing = esf and coding = b8zs

    In the header of dahdi-channels.conf it specifies that it is intended to
    be included in chan_dahdi and I have noticed that if I remove that line
    then I only generate a pseudo channel and no PRI channels.

    ____________________________________________________

    ; Autogenerated by /usr/sbin/dahdi_genconf on Thu Aug 26 11:11:45 2010

    ; If you edit this file and execute /usr/sbin/dahdi_genconf again,

    ; your manual changes will be LOST.

    ; Dahdi Channels Configurations (chan_dahdi.conf)

    ;

    ; This is not intended to be a complete chan_dahdi.conf. Rather, it is
    intended

    ; to be #include-d by /etc/chan_dahdi.conf that will include the global
    settings

    ;

    ; Span 1: WCT1/0 “Wildcard TE121 Card 0” (MASTER) B8ZS/ESF ClockSource

    group=0,11

    context=from-pstn

    switchtype=national

    signalling = pri_cpe

    channel => 1-12

    group = 63

    ______________________________________________

    I still end up with messages telling me that a dchannel cannot be found.
    Any other suggestions?

    Thanks, Jeremy

    href=”mailto:asterisk-users-bounces@lists.digium.com”>asterisk-users-bounces@lists.digium.com
    [mailto:asterisk-users-bounces@lists.digium.com] On Behalf Of Charles
    Moye
    Sent: August 28, 2010 6:39 AM

    Oh, and that isn’t how a spanmap looks either. It looks like you have
    mixed some stuff from system.conf and chan_dahdi.conf here. My guess is
    your system.conf is configured at least mostly right, and that is why
    everything goes green.

    http://svn.asterisk.org/svn/dahdi/tools/branches/2.3/system.conf.sample

    If you’re only using one span, is there a reason you are using
    trunkgroups? I believe those only get used for NFAS and GR-303

    Do you have anything defined in this file? Since it comes at the top,
    any changes you make below it won’t affect anything defined in that
    file.

    I didn’t think bchannel and dchannel were valid for chan_dahdi.conf.
    Don’t those only exist in system.conf?

    I believe you only declare ‘channel’ for the b-channels in
    chan_dahdi.conf.

    http://svn.asterisk.org/svn/asterisk/branches/1.6.2/configs/chan_dahdi.c
    onf.sample

  • On 8/28/2010 12:59 PM,
    href=”mailto:Jeremy.Hellstrom@synovate.com”>Jeremy.Hellstrom@synovate.com wrote:
    I suggest you start over as I can see you are still confused about the
    content of the 2 files and still trying to use spanmap.

    Start with /etc/dahdi/system.conf:

  • Thats what he had originally in the file. I assumed he only wanted the
    first 12 channels. If that was an error, then by all means configure
    all 23.

    Andres

  • I tried those as you said, deleting my failed attempt. I’ve found that
    using hardhdlc=24 generates an error and reminds me that FXO uses FXS
    signalling and vice versa when running dadhi_restart, which seems to
    indicate that it is the wrong variable name.

    I also notice that if I change that variable to dchan in system.conf, I
    receive no error but no matter what value I put in Asterisk looks at
    channel 24 for the dchannel and as this is a half turned up PRI I have
    suspicions that the dchan is not 24 though I still need TELUS to get
    back to me to confirm that.

    Any other ideas as to what I am doing wrong or if I am making a bad
    assumption?

    Thanks, Jeremy

  • On 8/30/2010 11:42 AM,
    href=”mailto:Jeremy.Hellstrom@synovate.com”>Jeremy.Hellstrom@synovate.com wrote:
    That makes no sense. You are configuring a PRI, not an analog line.
    You should not be getting any messages regarding FXO or FXS. Take a
    look at the file again and delete any reference to analog channels if
    you are not using them.

    Andres
    http://www.neuroredes.com
    href=”mailto:asterisk-users-bounces@lists.digium.com”>asterisk-users-bounces@lists.digium.com
    href=”mailto:Jeremy.Hellstrom@synovate.com”>Jeremy.Hellstrom@synovate.com wrote:

  • The specific error message is as follows.
    _____________________________________________________________
    Changing signalling on channel 24 from Unused to Hardware assisted
    D-channel
    DAHDI_CHANCONFIG failed on channel 24: Invalid argument (22)
    Did you forget that FXS interfaces are configured with FXO signalling
    and that FXO interfaces use FXS signalling?
    _____________________________________________________

    I am using the simplified system.conf and chan_dahdi that you specified
    before.

    Thanks for continuing to help me and my gift for producing bizarre
    errors.
    Jeremy

  • I’d just like to thank everyone that helped me get this running. I thought I had a FAS PRI but it turns out it was NFAS so there was no dchannel on the second PRI. When getting the 2nd PRI changed, I received an email containing the cheat sheet TELUS employees use which I thought I should share, though quite a few settings will be obvious to Asterisk gurus.

    The TELUS cheat sheet
    ________________________________________________________

    Asterisk PRI provisioning
    =========================

    T1 span timing is provisioned in /etc/zaptel.conf or /etc/dahdi/system.conf

  • On Tue, Sep 28, 2010 at 11:23:16AM -0500,
    href=”mailto:Jeremy.Hellstrom@synovate.com”>Jeremy.Hellstrom@synovate.com wrote:

    Both have timing=0 . That is: that device sets the timing on the T1
    line. Shouldn’t it be ‘1’ instead?

    Note that anything after that ‘channel=>’ line has no effect on those
    channels.

    As of 1.6.0 . On 1.4 the default is ‘national’.

  • Thanks for the additional comments, I though the timing was odd as well
    as I had thought it would be the provider that set the timing but it is
    currently working here and apparently at other sites.

    I’ll let everyone know if it turns out to be incorrect somehow.