Posted in Exchange UM, Lync Server 2013, Skype for Business

Exchange Web Services (EWS)

Exchange Web Services (EWS) is a service used by Lync/SfB to integrate with Exchange. Successful integration obtains:

  • Calendar
  • Free/Busy information
  • Save Conversation History
  • High Resolution Photos
  • Voice Mail Access

Lync/SfB Client process to connect to Exchange Web Services (EWS)

1. Client will attempt to read any existing Autodiscover data with a valid Time-to-Live (TTL), which may have been previously retrieved by Outlook.
2. Client or device will extract the SMTP domain from the user’s presence document.
3. Client or device will then use the user’s SMTP domain to construct DNS queries for the following URLs:
a. https:///autodiscover/autodiscover.xml -if fails, goes to b.
b. https://autodiscover./autodiscover/autodiscover.xml -if fails, goes to c.
c. http://autodiscover./autodiscover/autodiscover.xml -if fails, goes to d.
d. Autodiscover uses DNS SRV lookup for, and then “” is returned.
4. Client asks permission from the user to continue with Autodiscover to post to
5. Autodiscover’s POST request is successfully posted to

Posted in Exchange UM, Lync Server 2013, Skype for Business

Script: Creating Self-signed Exchange UM Certificate

Here’s the thing, I want to post this since I always forgot this syntax every time I’m in the field integrating Lync/SfB and Exchange UM. I tested it over Exchange 2013 UM and setup is on-premise.

New-ExchangeCertificate -FriendlyName ‘LyncUM’ -PrivateKeyExportable $true -KeySize ‘2048’ -SubjectName ‘C=SG, O=LNC,’ -DomainName ‘’ -Services ‘UM,UMCallRouter’ -Server ‘’