Topic Last Modified: 2013-03-15

The certificates that you need for federating with Microsoft Lync Server 2013, Lync Server 2010 and Office Communications Server will typically be met by the certificates that you configure, request and assign to your Edge Server.

Certificate requirements for enabling and establishing communications with extensible messaging and presence protocol (XMPP) partners require addition of entries for your XMPP domains. The record that is included on the certificate as a subject alternative name (SAN) will be the domain that can participate in XMPP communications. The domain can be the root-level domain (for example, if you want to enable XMPP for your entire domain, or can be selected child domains (for example,, if you are enabling XMPP for a subset of users.

To configure certificates for public Instant Messaging connectivity, note that there is nothing different from other SIP federation types or even standard Edge Server certificates, except that America Online (AOL) requires a the certificate or certificates (in the case of an Edge pool) to also contain the client EKU. The client EKU is an addition to the certificate, and is part of the external public certificate that is assigned to your Edge Server.

To confirm that you have met the correct certificate requirements for your Edge Server deployment, review the topics listed in the section titled See Also.

Component Subject name Subject alternative names (SAN) Comments

External/Access Edge

To support the XMPP namespace

To support the SIP namespace

To support the XMPP namespace

The certificate must be from a Public CA, and must have the server EKU and client EKU if public IM connectivity with AOL is to be deployed. The certificate is assigned to the external Edge Server interfaces for:

  • Access Edge service

  • Web Conferencing Edge service

  • A/V Edge service

Technically, a certificate is not assigned to the A/V Edge. Secure communication and authentication is managed by way of the Media Relay Authentication Service (MRAS). MRAS uses the certificate assigned to the Edge Server internal interface.

Note that SANs are automatically added to the certificate based on your definitions in Topology Builder. You add SAN entries as needed for additional SIP domains and other entries that you need to support. The subject name is replicated in the SAN and must be present for correct operation.

See Also