DAHDI span timeing source

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Asterisk Users 5 Comments

You mean say

0=Slave (Use PSTN clock)
1=Master(generate Internal clock)

So best option is 0 for all span if you connected on PSTN right ?

Date: Fri, 27 May 2011 17:27:43 -0300
From: rafaelsnsa@gmail.com
To: asterisk-users@lists.digium.com
Subject: Re: [asterisk-users] DAHDI span timeing source

Hi
The timing source is the clock of the system. When a equipment is 0, the other should be 1. The correct is: 0=slave, 1=master. The default for private systems is “slave”.

5 thoughts on - DAHDI span timeing source

  • Not really. Looking in system.conf.sample in dahdi-tools [1]

    Choose 1 to make the equipment at the far end of the E1/T1/BRI link the
    preferred source of the master clock. Choose 2 to make it the second
    choice for the master clock, if the first choice port fails (the far end
    dies, a cable breaks, or whatever). Choose 3 to make a port the third
    choice, and so on. If you have, say, 2 ports connected to the PSTN, mark
    those as 1 and 2. The number used for each port should be different.

    If you choose 0, the port will never be used as a source of timing. This
    is appropriate when you know the far end should always be a slave to
    you. If the port is connected to a channel bank, for example, you should
    always be its master. Likewise, BRI TE ports should always be configured
    as a slave. Any number of ports can be marked as 0.

    [1] http://svn.asterisk.org/view/dahdi/tools/trunk/system.conf.sample?view=co

  • Got it but still confused. As per your example I should go with

    Port 1
    Span=1,1,0

    Port 2
    Span=2,2,0

    Correct me if I’m wrong.

  • Thanks also let me clear one thing this pri is PSTN connected to AT&T
    techo.

    So they are master.

  • Really, You’re right. This option define the priority of the interface as
    regenerator of clock:
    priority 0 = its own clock
    priority 1 = the clock of the telco

    2011/5/27 Satish Patel