[asterisk-users] Asterisk 10/1.6.1 and Dahdi/Libpri compatilities in BRI /PtmP

[Olivier]

2012/6/21, Richard Mudgett <rmudgett at digium.com>:
>> My previous message was incomplete.
>>
>>
>> On thing to note is I had to forbid hfcmulti in modprobe.d in the
>> second box to comply with a warning from dahdi. Without that, I could
>> see this line in the output of lsmod:
>> mISDN-core  hfcmulti
>>
>>
>> 1. What is the root cause that makes a board change its sync source ?
>> How can I check this ?
>
> I would think layer 1 going down.
I'm aware of this energy save mode.
What surprises me a bit is the frequency with which this happens: a
rough estimee is 60s or less before the line going down.

Is there a practical way to double check that ? Using pri debug ?
"core set debug" ?


>  Many European telcos for BRI PTMP lines
> drop layer 2 and then layer 1 to conserve power.
>
> Is the switching of clock sources causing a problem?

Fortunately, beside having the log files cluttered with Alarm
messages, the system is working ok.
>
>> 2.  How can I get rid of these alarms ?
>
> See the chan_dahdi.conf.sample file about the following options.
>
> You could use the layer1_presence option to make Asterisk ignore those
> alarms.

This is the option I will try.
I'll report my findings here.
>
> You could use the layer2_persistence option to keep layer 2 up.  To use
> this option however, requires using libpri SVN 1.4 branch code as current
> released versions do not support the option.
I was aware of this improvement and I can't wait to see it published.

>  Using the layer2_persistence
> option restores behavior that was removed for better Q.921 conformance for
> PTMP after libpri v1.4.10.2 and is why you are seeing a behavior difference
> between versions.

So, in a way, a better confiormance to Q.921 introduced the
requirement to "explicitely ignore Layer1 status changes (in
BRI/TE/PtmP) in chan_dahdi.conf".

Though these layer1 and layer2 settings belongs to Asterisk's
chan_dahdi.conf file, maybe an UPGRADE.txt file inside libpri
directory would be useful to let sysadmins access to this information.

What about adding an UPGRADE.txt in libpri ?

>
>> 3. Shall I report this ?
>
> It is normal with BRI PTMP lines.  It is also the reason for the
> layer1_presence and layer2_persistence options.
>
>> 4. Waht would you suggest ?
>>
>> Regards
>>
>>
>>
>> 2012/6/21, Olivier <oza_4h07 at yahoo.fr>:
>> > Hi,
>> >
>> > After an upgrade, I discovered yesterday strange things I would
>> > like
>> > to share here.
>> >
>> > Basically, I'me comparing platforms:
>> > The first one is a 2.6.26 (Debian Lenny) platform, with Asterisk
>> > 1.6.1.18, Libpri 1.4.10.2, Dahdi revision 8853 (must be between 2.3
>> > and 2.5, I think).
>> > The second one is a 2.6.32 (Debian Squeeze) platform, with Asterisk
>> > 10.5.1, Libpri 1.4.12, Dahdi 2.6.1.
>> > Both are connected to telco BRI lines in TE/PtmP mode through a
>> > Junghanns QuadBRI board (wcb4xxp driver).
>> > Both handle incoming and outgoing calls correctly, as far as I can
>> > tell.
>> >
>> > But on the second one, though working fine, Dahdi keeps showing
>> > alarm
>> > messages such as:
>> > [71765.784120] wcb4xxp 0000:01:0e.0: new card sync source: port 1
>> > [71767.484151] wcb4xxp 0000:01:0e.0: new card sync source: port 1
>> > [71771.184119] wcb4xxp 0000:01:0e.0: new card sync source: port 2
>> > [71794.184164] wcb4xxp 0000:01:0e.0: new card sync source: port 1
>> >
>> > and "pri show spans" mostly (but not always) report worrying
>> > status:
>> > PRI span 1/0: Down, Active
>> > PRI span 2/0: In Alarm, Down, Active
>> >
>> > On the first box "pri show spans" constantly reports the line is
>> > up.
>> >
>> > On thing to note is I had to forbid hfcmulti in modprobe.d in the
>> > second box to comply with a warning from dahdi. Without that, I
>> > could
>> > see this line in the output of lsmod:
>> > mISDN-core
>
> Both mISDN and DAHDI have drivers for your BRI card.  Only one of them
> should be loaded.  Since you are using DAHDI and not mISDN, you should
> load the DAHDI version.
>
> Richard
>
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