The Polycom VVX series "call hold", "transfer", and "resume" features may fail after you install the July 2019 Cumulative Update for Skype for Business Server 2015.
Consider the following scenario:
- You install the July 2019 Cumulative Update for Skype for Business Server 2015.
- A user receives an inbound call from PSTN that is answered by a Polycom VVX device.
- The VVX user tries to place the PSTN call on hold or transfer the call to a Skype for Business user.
- The hold or transfer fails. Additionally, if the call is resumed, one-way audio is experienced.
- SipStack component tracing on the Front End shows the VVX device is receiving a SIP response with the following SIP headers.
- Start-Line: SIP/2.0 400 Malformed route header
- ms-diagnostics: 2;reason="See response code and reason phrase";HRESULT="0xC3E93C2E(SIPPROXY_E_ROUTE_SIGNATURE_INVALID)";source="sepool.contoso.com"
This issue is currently under investigation. This article will be updated when additional information is available.
Roll back the Skype for Business Server 2015 CU10 (July 2019) update by following the instructions in the "Uninstallation methods" section of the following Knowledge Base article:
- 3061064 Updates for Skype for Business Server 2015