Microsoft Teams Direct Routing Outbound Calls not working (error 504)

[Lopicl]

Hello,

I am trying to configure Direct Routing on my tenant, using my carrier's hosted multi-tenant SBC.

They connected to my tenant with powershell and made all the needed configurations with these Powershell commands, after they validated the SBC domain in my office 365 tenant and created a user with that domain:

1. Set-CsOnlinePstnUsage -Identity Global -Usage @{Add ="TeamsVoice"}
2. New-CSOnlineVoiceRoute -Identity "DefaultRoute" -NumberPattern ".*" -OnlinePstnGatewayList <sbc fqdn> -Priority 1 -OnlinePstnUsages "TeamsVoice"
3. New-CsOnlineVoiceRoutingPolicy "VP-TeamsUser" -OnlinePstnUsages "TeamsVoice"
4. Set-CsUser -Identity user@domain.com -EnterpriseVoiceEnabled $true -HostedVoiceMail $true -OnPremLineURI tel:<phonenumber>
5. Grant-CsOnlineVoiceRoutingPolicy -Identity "user@domain.com" -PolicyName "VP-TeamsUser"

Don't need to add the SBC because of the multi-tenant config as specified in this article https://docs.microsoft.com/en-us/microsoftteams/direct-routing-sbc-multiple-tenants

Inbound calls are working correctly, but outbound calls are not.

My carrier's SBC is not receiving anything, and if I go to my PSTN direct routing report I get the SIP Error 504 "Unable to deliver INVITE: No such host is known" with the microsoft final code 569002.

My carrier believes it is a Microsoft Teams backend problem because they have other customers with the same config and they work properly.

What can I do? I also opened a ticket with Microsoft but I wanted to double up by also asking in here.

My user has got Office 365 E3 + Microsoft Phone System licenses and I have access to the number dial pad in the calls section of the app.

Thanks for the help

[#2 · Accepted solution]

Ok me and my carrier found the issue.

The DNS record for the SBC FQDN was not properly set, thus not redirecting to the SBC IP.

[#3]

Can you expand on what was not correctly configured on the DNS record? I'm having exactly the same issue. Thanks in advance.

[#4]

@bluecat In our case the DNS A record for the SBC was misspelled.

For instance instead of sbc.contoso.com it was set as sbv.contoso.com, so it was not possible to reach, as teams was looking for sbc.contoso.com.

From what I understood this error comes from a misspelled SBC hostname, or unreachable DNS name.

[#5]

OK, Thanks for the reply.

[#6]

where it was wrong? in the domains in office365 or in the SBC side? we are having the exact same issue.

[#7]

hey @bluecat did you solved that issue? what it was?

[#8]

@SergioGaray We did not solve the issue, we had to work around it by adding the the SBC's (i.e. New-CsOnlinePSTNGateway -Fqdn <SBC FQDN> -SipSignalingPort <SBC SIP Port> -MaxConcurrentSessions <Max Concurrent Sessions the SBC can handle> -Enabled $true)

[#9]

@Lopicl 

Off-topic question: How did you generate the report with the cause codes for the failed calls?

This part below, I have no idea how to do this and I need to know why some outbound calls are failing from my Teams Direct Routing environment.

---

My carrier's SBC is not receiving anything, and if I go to my PSTN direct routing report I get the SIP Error 504 "Unable to deliver INVITE: No such host is known" with the microsoft final code 569002.

---

Thanks

Joe

[#10]

@My-Username , you can generate the report at Microsoft Teams Admin Center > Analytics & Reports > Usage Reports > View reports > PSTN and SMS (Preview) Usage > Last 7 days > Run Report

Once the report gets generated, on the report, switch to the Direct Routing tab.

[#11]

Thank you, I hadn't dug very deep into that tool, it has more data than I realised 🙂

[#12]

If Teams outbound calls won't work, check if you can make calls via the Web App. Then, delete the app cache, reinstall Teams, and contact your admin. If you're an IT admin, be sure to assign phone numbers to users, and create a new voice routing policy.

Regards,
Rachel Gomez

[#13]

Thank you for the tips 🙂 I'll keep them for future issues we have.

The issue turned out to be a config issue on our SBC. Somehow a few lines of config got lost between our test SBC and the production one.