Symptoms
A Public Switched Telephone Network (PSTN) user (user A) makes a call to a Lync 2010 user (user B). Then, user B forwards or transfers the call to another PSTN user (user C).
In this situation, the call history on the Mediation server only shows the call from user A to user C. The call history does not show any information about user B.
Resolution
To resolve this issue, install the following cumulative updates:
2502810 Description of the cumulative update for Lync Server 2010, Mediation Server: April 2011
2500442 Description of the update for Lync Server 2010: April 2011
More Information
After you apply the cumulative update, you must configure the Mediation server to pass the referred-by header, which contains the telephone number of user B. To do this, add the following configuration entry in the configuration file on each Mediation server that you intend to enable:
<appSettings>
<add key="<FQDN or IP address of the PSTN gateway>.ReferredBySupported" value="true"/>
</appSettings>
And then restart the Mediation server.
Note If you have more than one PSTN gateway deployed for the Mediation server pool, an entry for each PSTN gateway (with the corresponding PSTN gateway address, as configured in Topology Builder) needs to be added to the configuration file. After you add this entry, the configuration file resembles the following:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<appSettings>
<add key="<FQDN or IP address of the PSTN gateway>.ReferredBySupported" value="true"/>
</appSettings>
<runtime>
<generatePublisherEvidence enabled="false"/>
</runtime>
</configuration>
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
