<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">we know that fax over g711 is not the best solution but most of our upstream carriers do not support t.38 but in fact we have approx. 0.7 to 2ms delay over fiber to the upstream crriers TDM switches. We’ve done a lot of testing and we’ve done statistics over several thousand fax attempts with multi page faxes and the result is pretty good at about 95% success rate within the first attempt.<div class=""><br class=""></div><div class="">Another fact is that if i send a fax through our system as described below and the customer side is another FreeSWITCH it works perfectly! We tested with several t.38 capable pots adapters and it is not really deterministic if the problem exists. First we thought that it only exists if we have several hundred calls on the switch but the issue exists also if there are only 1-3 calls on the switch. Sometimes it works but mostly FreeSWITCH drops the call during the re-Invite.</div><div class=""><br class=""></div><div class="">When this issue occurs the call comes via interconnect (A-leg), customer equipment (B-leg) is answering the call. Call is established with g.711a and after about 6 seconds FAX is detected by the end user equipment and an re-Invite is sent back to routing FreeSWITCH. This answers with trying, busy here, bye on the B-leg and also hangs up A-leg with a bye.</div><div class=""><br class=""></div><div class="">Screenshot enclosed.</div><div class=""><br class=""></div><div class="">I can also pm you the full sip trace of the call.</div><div class=""><br class=""></div><div class="">Thanks,</div><div class="">Roman</div><div class=""><div class=""><br class=""></div><div class=""><img apple-inline="yes" id="2B6F0538-4719-48B2-9456-5E31C30CABDE" width="1145" height="625" src="cid:221E048F-565F-4DE2-9F9C-FB3B03C90B6D" class=""><br class=""><div class=""><div><br class=""><blockquote type="cite" class=""><div class="">Am 06.12.2019 um 07:56 schrieb Giovanni Maruzzelli <<a href="mailto:gmaruzz@gmail.com" class="">gmaruzz@gmail.com</a>>:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class="">Just a couple thoughts :</div><div class=""><br class=""></div><div class="">- fax over G711 VoIP is totally unreliable, hit or miss, random. It's a fact of nature, no matter how good your internet lines are<br class=""></div><div class="">- maybe you want try to answer the incoming, wait for 1 second so RTP flow is well established, and then bridge</div><div class=""><br class=""></div><div class="">-giovanni</div><div class=""><br class=""></div><div class=""><br class=""></div></div><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Dec 6, 2019 at 1:57 AM Roman Dissauer <<a href="mailto:roman@dissauer.net" class="">roman@dissauer.net</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="overflow-wrap: break-word;" class=""><div dir="auto" style="overflow-wrap: break-word;" class="">this is our topology:</div><div dir="auto" style="overflow-wrap: break-word;" class=""><br class=""></div><div dir="auto" style="overflow-wrap: break-word;" class="">customer pbx <-> kamailio + rtpengine <-> several FreeSWITCH Machines <-> kamailio <-> several interconnection carriers</div><div dir="auto" style="overflow-wrap: break-word;" class=""><br class=""></div><div dir="auto" style="overflow-wrap: break-word;" class="">what we have to address for inbound/outbound calls:</div><div dir="auto" style="overflow-wrap: break-word;" class="">inbound call comes from any interconnection carrier which mostly does NOT have t.38 faxing what is no issue because we have reliable internet lines to our carriers. Our customers want to have t.38 faxing because of reliability of faxing over standard internet lines. So we have to transcode g.711a codec to t.38 in freeswitch. Same is true for outbound calls where customer pbxes send t.38 re-Invite but the upstream interconnection carrier does not accept t.38.</div><div dir="auto" style="overflow-wrap: break-word;" class=""><br class=""></div><div dir="auto" style="overflow-wrap: break-word;" class="">sometimes faxing is fine with this mechanism but mostly the fax is rejected by a „NORMAL CLEARING“ as soon as the re-Invite is coming in. FreeSWITCH is sending BYE to both call legs.</div><div dir="auto" style="overflow-wrap: break-word;" class=""><br class=""></div><div dir="auto" style="overflow-wrap: break-word;" class="">what we intend to do with our dialplan on an example - incoming calls</div><div dir="auto" style="overflow-wrap: break-word;" class=""><br class=""></div><div dir="auto" style="overflow-wrap: break-word;" class="">1. call is coming in via external profile with g.711a Codec</div><div dir="auto" style="overflow-wrap: break-word;" class="">2. set refuse_t38=true sets t38 to be rejected coming from a-leg - external carrier</div><div dir="auto" style="overflow-wrap: break-word;" class="">3. export fax_enable_t38=true will enable t38 both call legs</div><div dir="auto" style="overflow-wrap: break-word;" class="">4. export nolocal:sip_execute_on_image=t38_image=t38_gateway self nocng will enable t38 only on b-leg - customer side</div><div dir="auto" style="overflow-wrap: break-word;" class="">5. call is being bridged to kamailio where it gets routed to the customer</div><div dir="auto" style="overflow-wrap: break-word;" class=""><br class=""></div><div dir="auto" style="overflow-wrap: break-word;" class="">thank you!</div><div dir="auto" style="overflow-wrap: break-word;" class=""><br class=""></div><div dir="auto" style="overflow-wrap: break-word;" class="">best regards,</div><div dir="auto" style="overflow-wrap: break-word;" class="">Roman</div><div dir="auto" style="overflow-wrap: break-word;" class=""><div class=""><br class=""><blockquote type="cite" class=""><div class="">Am 04.12.2019 um 14:02 schrieb Giovanni Maruzzelli <<a href="mailto:gmaruzz@gmail.com" target="_blank" class="">gmaruzz@gmail.com</a>>:</div><br class=""><div class=""><div dir="ltr" style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><div dir="ltr" class="">On Tue, Dec 3, 2019 at 11:19 PM Roman Dissauer <<a href="mailto:roman@dissauer.net" target="_blank" class="">roman@dissauer.net</a>> wrote:<br class=""></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">we have an issue with t38_gateway where calls which should be transcoded from PCMA to t38 get hangup non-deterministic. It doesn’t matter if there is only one call or if there are hundrets of calls on the freeswitch. Sometimes it happens that we get several faxes transcoded but then we again have several faxes which don’t go through. problem exists (tested) on FreeSWITCH 1.6 and FreeSWITCH 1.10.<br class=""><br class="">this is the dialplan section where t38_gateway is set up for b-leg on an inbound call:<br class=""><br class=""><context name="hosted_numbers"><br class=""> <extension name="43732601458-DDI" continue="true"><br class=""> <span class=""> </span><condition field="${outside_call}" expression="^true$" break="never"/><br class=""> <span class=""> </span><condition field="${dialed_extension}" expression="^(43732601458)(\d{0,4})$“><br class=""> ...<br class=""> <action application="set" data="refuse_t38=true"></action><br class=""> <action application="export" data="fax_enable_t38=true"></action><br class=""> <action application="export" data="nolocal:sip_execute_on_image=t38_gateway self nocng"></action><br class=""> <action application="bridge" data="{sip_cid_type=pid,sip_contact_user=accountcode,absolute_codec_string='PCMA@20i,PCMU@20i,G729'}sofia/internal/<a href="mailto:accountcode@10.23.101.10" target="_blank" class="">accountcode@10.23.101.10</a>^+${<a href="mailto:dialed_extension%7D@10.23.101.10" target="_blank" class="">dialed_extension}@10.23.101.10</a>"></action><br class=""> ...<br class=""> <span class=""> </span></condition><br class=""> </extension><br class=""> <span class=""> </span></context><br class=""><br class=""></blockquote><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Would you detail, line by line, what is the intended purpose of each line of dialplan?</div><div class=""><br class=""></div><div class="">Also, your topology, and the intended result<br class=""></div><div class=""><br class=""></div><div class="">-giovanni</div><br class=""></div></div><span style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;float:none;display:inline" class="">_________________________________________________________________________</span><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><span style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;float:none;display:inline" class="">The FreeSWITCH project is sponsored by SignalWire<span class=""> </span></span><a href="https://signalwire.com/" style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank" class="">https://signalwire.com</a><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><span style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;float:none;display:inline" class="">Enhance your FreeSWITCH install with disruptive priced SMS and PSTN services.</span><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><span style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;float:none;display:inline" class="">Build your next product on our scalable cloud platform.</span><br 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style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank" class="">https://signalwire.community</a><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><span 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style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><a href="https://freeswitch.com/" style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank" class="">https://freeswitch.com</a><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><span style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;float:none;display:inline" class="">Official FreeSWITCH Sites</span><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><a href="https://freeswitch.com/oss" 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style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none" class=""><a href="https://freeswitch.com/" style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank" class="">https://freeswitch.com</a></div></blockquote></div><br class=""></div></div>_________________________________________________________________________<br class="">
<br class="">
The FreeSWITCH project is sponsored by SignalWire <a href="https://signalwire.com/" rel="noreferrer" target="_blank" class="">https://signalwire.com</a><br class="">
Enhance your FreeSWITCH install with disruptive priced SMS and PSTN services.<br class="">
Build your next product on our scalable cloud platform.<br class="">
<br class="">
Join our online community to chat in real time <a href="https://signalwire.community/" rel="noreferrer" target="_blank" class="">https://signalwire.community</a><br class="">
<br class="">
Professional FreeSWITCH Services<br class="">
<a href="mailto:sales@freeswitch.com" target="_blank" class="">sales@freeswitch.com</a><br class="">
<a href="https://freeswitch.com/" rel="noreferrer" target="_blank" class="">https://freeswitch.com</a><br class="">
<br class="">
Official FreeSWITCH Sites<br class="">
<a href="https://freeswitch.com/oss" rel="noreferrer" target="_blank" class="">https://freeswitch.com/oss</a><br class="">
<a href="https://freeswitch.org/confluence" rel="noreferrer" target="_blank" class="">https://freeswitch.org/confluence</a><br class="">
<a href="https://cluecon.com/" rel="noreferrer" target="_blank" class="">https://cluecon.com</a><br class="">
<br class="">
FreeSWITCH-users mailing list<br class="">
<a href="mailto:FreeSWITCH-users@lists.freeswitch.org" target="_blank" class="">FreeSWITCH-users@lists.freeswitch.org</a><br class="">
<a href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users" rel="noreferrer" target="_blank" class="">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a><br class="">
UNSUBSCRIBE:<a href="http://lists.freeswitch.org/mailman/options/freeswitch-users" rel="noreferrer" target="_blank" class="">http://lists.freeswitch.org/mailman/options/freeswitch-users</a><br class="">
<a href="https://freeswitch.com/" rel="noreferrer" target="_blank" class="">https://freeswitch.com</a></blockquote></div><br clear="all" class=""><br class="">-- <br class=""><div dir="ltr" class="gmail_signature">Sincerely,<br class=""><br class="">Giovanni Maruzzelli<br class="">OpenTelecom.IT<br class="">cell: +39 347 266 56 18<br class=""><br class=""></div>
_________________________________________________________________________<br class=""><br class="">The FreeSWITCH project is sponsored by SignalWire <a href="https://signalwire.com" class="">https://signalwire.com</a><br class="">Enhance your FreeSWITCH install with disruptive priced SMS and PSTN services.<br class="">Build your next product on our scalable cloud platform.<br class=""><br class="">Join our online community to chat in real time <a href="https://signalwire.community" class="">https://signalwire.community</a><br class=""><br class="">Professional FreeSWITCH Services<br class=""><a href="mailto:sales@freeswitch.com" class="">sales@freeswitch.com</a><br class="">https://freeswitch.com<br class=""><br class="">Official FreeSWITCH Sites<br class="">https://freeswitch.com/oss<br class="">https://freeswitch.org/confluence<br class="">https://cluecon.com<br class=""><br class="">FreeSWITCH-users mailing list<br class="">FreeSWITCH-users@lists.freeswitch.org<br class="">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users<br class="">UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users<br class="">https://freeswitch.com</div></blockquote></div><br class=""></div></div></div></body></html>