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Rich_Betson's avatar
Rich_Betson
Copper Contributor
May 24, 2024

Teams Transfer fails in the US

Hi All, 

 

We have come across an issue with transferring calls in the US. We have AC SBC's around the world configured for Direct Routing with multiple customers on. All sites are configured the same way, however we have come across an issue in the US SBC's were transferred calls are failing intermittently. 

 

We have had a case raised with MS for months and they are finally saying that our SBC isn't responding to the REFER message. When we asked the source they say it's coming from https://gbr01.safelinks.protection.outlook.com/?url=http%3A%2F%2Furl.uk.m.mimecastprotect.com%2Fs%2FOmhMCpY48IO0rAYfJgG4M%3Fdomain%3D70.37.163.146%2F&data=05%7C02%7Crichard.betson%406dg.co.uk%7C64e18b02c8574610ee5a08dc7b938bf8%7C143952042e944daeafa877e66aa6a292%7C0%7C0%7C638521120873831872%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=oe4m0hGuaei2hSUSnKwPmLi%2BaTg6YbKdBCfGIHgnyoE%3D&reserved=0, which is in a range that's not in the DR documentation, nor anywhere else I can find. 

 

We want to open the firewalls but really need to know what this range is and MS support are taking weeks to reply. 

 

Thanks, 

 

microsoft teams

2 Replies

  • Holger_Bunkradt's avatar
    Holger_Bunkradt
    MCT
    Jun 20, 2024
    Hi Rich_Betson, which firmware do you use on the AC SBC's in US. Older fw has an issue with DNS rsolution on AC SBC's maybe this is the reason, why the refer is send to the wrong IP if the SBC is correct configured for refer from Teams.
  • fowler_23's avatar
    fowler_23
    Iron Contributor
    Jun 20, 2024
    That IP is owned by Microsoft but never known any Teams signaling\media traffic to come from there and not in their published worldwide endpoints. It would be blocked on our firewall as well. MS are quite clear on their IP's.
    I think the info. you have been provided isn't correct re: Source IP

    Do you actually see the REFER appear on your SBC as part of the call as you haven't said that?
    If you do, then you want to be creating a rule on your SBC that sends it back to MS. There's Audicocodes documentation available to help you if not sure.