Asterisk iax qualify

iax.conf: peer configuration - qualify

The qualify, qualifyfreqok and qualifyfreqnotok settings are used to determine the status availability of an IAX peer.


qualify=no|yes|xxx ("qualify=yes" is equivalent to "qualify=2000")

where "xxx" is an integer specifying milliseconds.


qualifyfreqok=60000 (60 sec)
qualifyfreqnotok=10000 (10 sec)

How qualify works.

If a peer is consdered to be in a reachable (OK or LAGGED) state, it is queried for availability every "qualifyfreqok" milliseconds. If it is considered to be in an UNREACHABLE state, it is queried for availability every "qualifyfreqnotok" milliseconds.

The qualify= setting turns the qualify system on (if the "yes" or xxx options are used) or off (if qualify=no, which is by default). The millisecond value of the qualify= setting specifies the maximum response time of the availability acknowledgement before the peer is considered to be in a "LAGGED" state.

Usefulness in NAT

This feature may be used to keep a UDP session open to a device that is located behind a network address translator (NAT). By sending the availability requests, the UDP port binding in the NAT (on the outside address of the NAT/firewall device) is maintained by sending traffic through it. If the binding were to expire, there would be no way for Asterisk to communicate with the IAX peer.

Problems with some IAX clients

Some IAX clients — including firefly, diax, IAXphone, IAXComm, JackenIAX — don't seem to like being monitored with the qualify option. If you have this option, you will see messages like this on the console:
Peer '2004' is now UNREACHABLE!
The IAX Softphone IAXComm gives output like:
Timeout for a non-existant session. Dropping
For those clients, set qualify=no.


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Created by: fuf, Last modification: Wed 04 of Jul, 2007 (15:27 UTC) by swatchy
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