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Fax Machines and Lync RRS feed

  • Question

  • Hello All,

    I have a question regarding the analog devices support and documentation there: http://technet.microsoft.com/en-us/library/gg398314.aspx

    As far as I understand, it says when you set AnalogFax to $true, it will hairpin the call to the GW where the call comes from. And that the GW where the fax is connected must be connected to the PSTN. Finally, that you have to use media bypass. Does that mean that it is impossible to have fax machines connected to an ATA with FXS ports (like audiocodes MP1XX) ?

    If I am right, the goal is to achieve signaling through Lync infrastructure, and then it is hairpinned to the GW thanks to media bypass (instead of going through mediation server). So it is then GW responsibility to route the calls to its FXS port, or, to any IP ATA device in the network -Audiocodes is suggesting this scenario, which requires more licence on the device for ip2ip calls.

    Fact is, I have connected a Fax Machine to my ATA. My ATA is declared as a PSTN gateway and my fax machine registered as an analog device through this gateway. I set AnalogFax to false to get the call routed to my ATA, not hairpinned to the originating PSTN GW. Media bypass is set, and g711 signaling for faxes are configured in both gateways. And it works perfectly ! I can see the call established directly between the gateway and transparent fax going through it. Even with TLS and SRTP...

    Of course if I set AnalogFax to $true, I can see my call routed back to the gateway, and there it goes in a loop because the gateway has no route but  PSTN for outbound IP calls.

    So any idea, advice, comment on that ?

    Friday, August 26, 2011 12:55 AM

Answers

  • I had the same issue a few weeks ago.  I started down your path, and got nowhere.  My solution was actually very simple, but was dependent on a feature of my gateway (NET UX2000).  I had a Cisco ATA186, btw.  Instead of trying to get the ATA signaling to go through Lync, I enabled the SIP Registrar function of the UX.  The ATA registers to it, and then the UX handles call routing to/from the numbers associated with the ATA.  Lync isn't involved at all.  If your gateway can act as a SIP registrar, this is a simpler solution, IMO.  

    Hope this helps!

    • Proposed as answer by Sean_Xiao Tuesday, August 30, 2011 8:19 AM
    • Marked as answer by Sean_Xiao Thursday, September 1, 2011 9:19 AM
    Friday, August 26, 2011 1:27 AM

All replies

  • I had the same issue a few weeks ago.  I started down your path, and got nowhere.  My solution was actually very simple, but was dependent on a feature of my gateway (NET UX2000).  I had a Cisco ATA186, btw.  Instead of trying to get the ATA signaling to go through Lync, I enabled the SIP Registrar function of the UX.  The ATA registers to it, and then the UX handles call routing to/from the numbers associated with the ATA.  Lync isn't involved at all.  If your gateway can act as a SIP registrar, this is a simpler solution, IMO.  

    Hope this helps!

    • Proposed as answer by Sean_Xiao Tuesday, August 30, 2011 8:19 AM
    • Marked as answer by Sean_Xiao Thursday, September 1, 2011 9:19 AM
    Friday, August 26, 2011 1:27 AM
  • Hi martin_sc.

    Are you saying that you were successful in sending and receiving faxes via a fax machine connected to your ATA?  Pardon my astonishment, but I have been struggling with this.

    I have been trying to accomplish this with a Mediatrix 4102S.  I suspect that I am missing something in my setup to accomplish the Media Bypass properly.  Would you please share some info about your Region and Site setup?  The Mediatrix supports disabling T-38 and can run the fax traffic over G.711.

    Thanks.

    Chris

    Monday, November 21, 2011 2:33 PM
  • I know this is an old thread but how did you get the Cisco 186 to talk the UX2000?

    I have been struggling with this for weeks!!!!

    Mark


    Mark Steinbach

    Friday, January 29, 2016 5:37 PM