Symptoms
You upgrade a Microsoft Lync Server 2013 environment by applying a cumulative update that is dated October 2013 or January 2014. In this situation, the bandwidth that is used by SIP traffic may increase significantly in the environment. For example, the bandwidth may triple.
If the available bandwidth is limited, the significant increased bandwidth may cause Lync clients in the environment to frequently disconnect and reconnect.
Additionally, if you monitor the environment by using System Center Operation Manager, you may receive many alerts such as "SIP/2.0 500 Compression algorithm refused" or "SIP/2.0 488 Compression algorithm refused".
Resolution
To resolve this issue, install the following cumulative update:
2937310 August 2014 Cumulative Update 5.0.8308.738 for Lync Server 2013 (Front End Server and Edge Server)
More Information
For more information about the October 2013 cumulative update for Lync Server 2013, click the following article number to view the article in the Microsoft Knowledge Base:
2881684 Description of the cumulative update 5.0.8308.556 for Lync Server 2013 (Front End Server and Edge Server) : October 2013 For more information about the January 2014 cumulative update for Lync Server 2013, click the following article number to view the article in the Microsoft Knowledge Base:
2905048 Description of the cumulative update 5.0.8308.577 for Lync Server 2013 Front End Server and Edge Server: January 2014
