Skype for Business/Lync Federation is a functionality which allows users to communicate with others outside their organization. All features included in your license will be available (read the Knowledge Base article on Skype for Business Standard Vs. Skype for Business Enterprise for more information).

Note: Skype for Business/Lync Federation can be set up on a domain-per-domain basis. If you need federation to be enabled with several domains, each setup will be performed individually.

We cannot set up federation with or Office 365 (Lync Online) at this time.

In order to enable that functionality, perform the following steps:

  1. Create _sipfederationtls._tcp. SRV record. SRV record (a Service record) is a specification of data in the Domain Name System defining the location (i.e. the hostname and port number) of servers for specified services.
    The syntax of the SRV record is as follows: SRV 0 0 5061 - for the Exchange domains < EXCH082, EXCH500 and EXCH580
    - for the Exchange domains > EXCH083
    for EXCH084
    for EXCH091

    SRV record
    The correct settings can be found under  CONTROL PANEL > Services > Domain Name > Click on your domain name > click Display DNS records > click Show System Records.
  2. Contact Technical Support to submit Skype for Business/Lync: Federation extended service request. Provide the domain name you wish to federate.


  • Even if both accounts are hosted with Smarsh Hosted Services, but on different lyncsip.XX.XX.XX / skypesip servers:
    1. create SRV record for both domains;
    2. submit Extended Service request for each account (Skype for Business/Lync: Federation).
  • If both accounts are on the same lyncsip.XX.XX.XX / skypesip server:
    • submit Extended Service request for each account(Skype for Business/Lync: Federation).
  • If it is necessary to add regular Skype users:
    • submit Extended Service request (Skype for Business/Lync: Federation). 
      Note: in Customer Notes, state that federation is required to add regular Skype users, other fields can be left blank.

After the federation is set up, in order to send a message to external contact, search the contact using full email address:
Federated user

Note: there are currently some issues with Skype For Business and Consumer Skype federation. Read the Knowledge Base article on Skype For Business And Consumer Skype Federation Known Issues for more information.