Fax Buffer Overflow Detected

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I’m running Asterisk 1.8.15-cert3 with the newest version of spandsp. I’ve even tried unloading that and using Digium‘s FFA module but I receive the same error on an outbound transmission:

[2014-02-06 14:35:14] ERROR[19066]: udptl.c:294 encode_open_type: UDPTL
(SIP/XXXXXXXXXXX_outbound-00000000): Buffer overflow detected (59 + 127 >

I only get this with one specific upstream provider. Has anyone seen this before? Any help at all would be greatly appreciated.



One thought on - Fax Buffer Overflow Detected

  • Not sure if this relates to T38FaxMaxDatagram, here is an extract from a sample sip.conf file.

    ; In some cases, T.38 endpoints will provide a T38FaxMaxDatagram value
    (during T.38 setup) that
    ; is based on an incorrect interpretation of the T.38 recommendation, and results in failures
    ; because Asterisk does not believe it can send T.38 packets of a reasonable size to that
    ; endpoint (Cisco media gateways are one example of this situation). In these cases, during a
    ; T.38 call you will see warning messages on the console/in the logs from the Asterisk UDPTL
    ; stack complaining about lack of buffer space to send T.38 FAX packets. If this occurs, you
    ; can set an override (globally, or on a per-device basis) to make Asterisk ignore the
    ; T38FaxMaxDatagram value specified by the other endpoint, and use a configured value instead.
    ; This can be done by appending ‘maxdatagram=‘ to the t38pt_udptl configuration option,
    ; like this:
    ; t38pt_udptl = yes,fec,maxdatagram=400 ; Enables T.38 with FEC error correction and overrides
    ; ; the other endpoint’s provided value to assume we can
    ; ; send 400 byte T.38 FAX packets to it.