We help IT Professionals succeed at work.

Skype for Business server

Jiří Beneš
Last Modified: 2018-04-04
Hey guys,

I´ve been experiencing issue with my Skype for Business server - not a cloud version...we have 2 virtual servers for skype for business - frontend and edge. We have 2 domains in SFB.

Problem is that users from user@firstdomain.com can contact users in user@seconddomain.com and also can contact users outside company.
but users from second domain user@seconddomain.com cannot contact users outside company.

I´ve tried everything and I´m out of ideas what could be wrong...

Thank you guys for any help!

Watch Question

Jian An LimSolutions Architect
Top Expert 2016

if it works internally, check your dns externally to see whether it has properly registered + check the SSL certificate on the EDGE server
Mohammed HamadaSenior IT Consultant

That's because your SSL certificate on Edge might not contain the second domain. for Federation you will need to include the sip.firstdomain.com, webconf.firstdomain.com, sip.seconddomain.com, webconf.seconddomain.com on your certificate.

Your DNS must also include the SRV records that points to the SIP A record on your DNS which should be NATted to your Edge server's SIP service IP .
Senior advisor
Unlock this solution and get a sample of our free trial.
(No credit card required)
Jiří BenešIT Support


Hey guys,

I´ve created all DNS records as u mentioned above but it still doesnt work...

Actually 1st level domains are different  first is .cz and second  is .pl
Jiří BenešIT Support


But I think that problem is on Access Edge service it should listen on port 443 not 5061 i guess
Mohammed HamadaSenior IT Consultant

It should listen on both. 443 is the SIP access edge service, 5061 is also using sip access edge service but its utilized for federation if you are using 3 public IP addresses on Edge.
This could also be different if you are using single public IP address on Lync. then SIP access edge and federation would listen on 5061 only and the A/V Edge service would listen on 443 port.

Gain unlimited access to on-demand training courses with an Experts Exchange subscription.

Get Access
Why Experts Exchange?

Experts Exchange always has the answer, or at the least points me in the correct direction! It is like having another employee that is extremely experienced.

Jim Murphy
Programmer at Smart IT Solutions

When asked, what has been your best career decision?

Deciding to stick with EE.

Mohamed Asif
Technical Department Head

Being involved with EE helped me to grow personally and professionally.

Carl Webster
CTP, Sr Infrastructure Consultant
Empower Your Career
Did You Know?

We've partnered with two important charities to provide clean water and computer science education to those who need it most. READ MORE

Ask ANY Question

Connect with Certified Experts to gain insight and support on specific technology challenges including:

  • Troubleshooting
  • Research
  • Professional Opinions
Unlock the solution to this question.
Thanks for using Experts Exchange.

Please provide your email to receive a sample view!

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.


Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.