Issue With PRI Connection

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I have install libpri 1.4.12 + Asterisk 10.7.0

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

vi*CLI> pri show spans PRI span 1/0: Down, Active PRI span 2/0: Down, Active PRI span 3/0: Down, Active PRI span 4/0: Down, Active

vi*CLI> pri show span 2
Primary D-channel: 47
Status: Down, Active Switchtype: EuroISDN
Type: CPE
Remote type: Unknown node type Overlap Dial: 0
Logical Channel Mapping: 0
Timer and counter settings:
N200: 3
N202: 3
K: 7
T200: 1000
T201: 1000
T202: 10000
T203: 10000
T303: 4000
T305: 30000
T308: 4000
T309: 6000
T312: 6000
T313: 4000
T-HOLD: 4000
T-STATUS: 4000
T-CCBS1: 4000
T-CCBS2: 2700000
T-CCBS3: 20000
T-CCBS4: 5000
T-CCBS5: 3600000
T-CCBS6: 3600000
T-CCNR2: 10800000
T-CCNR5: 11700000
T-CCNR6: 11700000
Q931 RX: 0
Q931 TX: 0
Q921 RX: 0
Q921 TX: 304
Q921 Outstanding: 0 (TEI=0)
Total active-calls:0 global:0
CC records:
Overlap Recv: No

For some reason pri show spans does not show up. Can someone assist me to fix this issue.

18 thoughts on - Issue With PRI Connection

  • Is there any particular questions I can ask my provider, that can help us configure?

    Yes, this is a new system install, initially i had install libss7 and later when the provider told me it is ISDN PRI E1 I have to configure, I deleted all the asterisk and dahdi files and reinstalled with libpri. Can the switch be a issue as well? The data center where I am hosted we had checked the same link with a existing other servers and the PRI is surely turned up.

  • Ashish Agarwal wrote:

    If you’re sure that your signalling is correct. It’s my experience that this mean your provider hasn’t turned up your PRIs.

    Is this a new system install?


  • Ashish Agarwal wrote:

    Then I’d suggest that you review the settings of the working server.
    I’m not familiar with the setup of an E1. I’m in the US it’s primarily T1. In my case, it’d be:

    esf,b8zs with the d channel on 24.


  • A client had similar issues with providers in India until a wizard in their office figured out the correct cabling. Don’t go by what the provider tells you, figure out the cable connections yourself.


    — Raj

  • I wouldn’t know, since I’m not the wizard 🙂 But basically we had to do each provider’s connections from scratch — Airtel, BSNL, MTNL, Reliance, Tata. And as far as I recall, each provider had a different cable signalling scheme.

    Please don’t top-post, it may get your posts ignored on the list. Use bottom- or inline-posting, and trim your replies.


    — Raj

  • Signalling frm remote side is down.

    Also just add crc4 in span 1,0,0 in dahdi/system.conf just like other spans.

    what is signalling=” ” defined in your asterisk/chan_dahdi.conf ?

    Regards, Mitul Limbani, Chief Architech & Founder, Enterux Solutions Pvt. Ltd.
    110 Reena Complex, Opp. Nathani Steel, Vidyavihar (W), Mumbai – 400 086. India
    email: DID: +91-22-71967121
    Cell: +91-9820332422

  • Not necessarily. I guess you remember the problems we had in getting lines to work in Mumbai until we found the correct wire connections for each of our providers (Reliance and BSNL AFAIR). Eventually Raj Kumar
    (the wizard) did manage to figure it out and after that the lines worked just fine.


    — Raj

  • Hi,

    I have tried disabling and enabling crc4 before but that did not help.

    I have not defined any signalling value under chan_dahdi.conf

    Also, with respect to cabling we tried switching tx and rx but in that case we see alarm on the dahdhi status.

  • DAHDI is fussy about its configuration files. A single misconfiguration anywhere can break the whole thing, so get it working with just one span first.

    Make sure you set the jumpers on the card correctly for E1 operation (they are often set as T1 on delivery) and specify the correct channel to use as a D-channel (usually 16 on span 1; 1-15 and 17-31 are the B-channels. Add 31
    for span 2, and so forth) and the correct signalling system. Ask someone at your telco if not certain.

    Another thing that can go wrong is the cabling from the NTE to the Asterisk box. Sometimes you need a straight-through cable, other times you need a crossover. Usually the active pairs are 4 and 5, and 2 and 1; so you need to cross over 1 with 5 and 2 with 4. Sometimes the polarity on pins 4 and 5 is wrong (this is the only pair with the lower-numbered pin coloured and the higher-numbered pin white) and sometimes the equipment is bothered about this, so try also a crossover from 1-4 and 2-5. Again, ask someone from your telco if not certain.

    Once you’ve got span 1 working, bring up the others one by one; and don’t be afraid to grow your configs with comments where you have commented out lines and/or added explanations of what you have changed. It’s always easier to take extraneous stuff out later than to try to remember what you were thinking before something interesting happened.

  • A minor FYI not directly related to this discussion: Since DAHDI-Linux 2.6.0 the jumpers can be overridden in the wcte12xp [1]
    and wct4xxp [2] drivers with the “default_linemode” module parameter. Before that it could be set with the “t1e1override”
    module parameter


    The code in the drivers is present to set the linemode as part of the normal DAHDI configuration files (i.e. processed with dahdi_cfg)
    but the method of expressing that settings is not there yet. The vision is that dahdi_genconf will be able to pick a default line mode based on the locale information on the server.

  • Hello,

    Thanks for the help list. I reinstalled the OS and that has fixed the problem for me. I appreciate your contribution.