Hab’s Blab

Environment:

Skype for Business Standard Edition

Sonus 1000

Toshiba PBX

Toshiba <-> Sonus <-> Skype for Business

Issue:

When on a SFB Conference call  and a user dials in from Toshiba PBX via Sonus to the SFB Conference, after exactly 5 minutes the call would hang up.

Resolution:

Here were the steps to troubleshoot the issue:

1. The Sonus was on an old rev so we upgraded the device to the latest release
2. We checked the Trunk configuration
   1.  Here is what we found, the RTCPActiveCalls , RTCPCallsOnHold were set to True and SessionTimer was False : PS C:\Windows\system32> Get-CsTrunkConfigurationIdentity : Global
      OutboundTranslationRulesList : {}
      SipResponseCodeTranslationRulesList : {}
      OutboundCallingNumberTranslationRulesList : {}
      PstnUsages : {}
      Description :
      ConcentratedTopology : True
      EnableBypass : False
      EnableMobileTrunkSupport : False
      EnableReferSupport : True
      EnableSessionTimer : False
      EnableSignalBoost : False
      MaxEarlyDialogs : 20
      RemovePlusFromUri : False
      RTCPActiveCalls : True
      RTCPCallsOnHold : True
      SRTPMode : Optional
      EnablePIDFLOSupport : False
      EnableRTPLatching : False
      EnableOnlineVoice : False
      ForwardCallHistory : False
      Enable3pccRefer : False
      ForwardPAI : False
      EnableFastFailoverTimer : True
      EnableLocationRestriction : False
      NetworkSiteID
   2. I have seen issues when these options are set to True where that the SFB Client or Server can disconnect the call if it does not receive RTCP packets. So we need to turn those options off and by doing so enable session timer.
      1. Set-CSTrunkConfiguration -RTCPActiveCalls:$False -RTCPOnHoldCalls:$False -EnableSessionTimer:$True
      2. Identity : Global
         OutboundTranslationRulesList : {}
         SipResponseCodeTranslationRulesList : {}
         OutboundCallingNumberTranslationRulesList : {}
         PstnUsages : {}
         Description :
         ConcentratedTopology : True
         EnableBypass : False
         EnableMobileTrunkSupport : False
         EnableReferSupport : True
         EnableSessionTimer : True
         EnableSignalBoost : False
         MaxEarlyDialogs : 20
         RemovePlusFromUri : False
         RTCPActiveCalls : False
         RTCPCallsOnHold : False
         SRTPMode : Optional
         EnablePIDFLOSupport : False
         EnableRTPLatching : False
         EnableOnlineVoice : False
         ForwardCallHistory : False
         Enable3pccRefer : False
         ForwardPAI : False
         EnableFastFailoverTimer : True
         EnableLocationRestriction : False
         NetworkSiteID
3. The above did not solve our problem, so we looked towards the Sonus 1000
   1. We needed to disable Silence Suppression in the Sonus 1000
      1. Expand Media -> Media List -> Default Media List (or your media list)-> Silence Suppression set to Disabled and Save

Once we saved the configuration the calls would no longer drop.