We are currently experiencing a problem with calls hanging after the remote end of the call hangs up along with audio that goes from talking to dead air in the middle of a conversation. After reviewing our Syslogs for our Mediant 1000 MSBG, I am receiving the following logs around the time the remote party hangs up and the call remains active, or when the audio goes silent but remains active: 6/6/2017 1:49:41 PM Dst=7451 PType=6] ErrMgs=7 -- Invalid RTCP packet SSRC: Expected = 0x4a703e1e Received = 0xa9e3fbf7 [Code:3700e] [CID:169] [Time: 12-19-2016@11:32:31] 6/6/2017 1:49:41 IR:1 [Code:5004] [CID:169] [Time: 12-19-2016@11:32:32] I am searching for documentation anywhere that shows what "IR:1" or "Code:5004" means. The problem is very very intermittent and so far I cannot duplicate the issue. Information about our Mediant 1000 MSBG: Version ID: 6.40A.039.008 Flash Version: 700

Possibly related? http://www.b4z.co.uk/audiocodes-mediant-1000-msbg-audio-quality-issue.html a-law vs. mu-law setting is off somewhere in that case. Also, a case of the same issue as yours but with Lync: https://social.technet.microsoft.com/Forums/systemcenter/en-US/81de4b4b-2aab-41bd-a66e-0e461f32d5ed/invalid-rtcp-packet-ssrc-invalid-rtp-version-0?forum=ocsvoice Hope that gives you some ideas...seems to point to TDM clocking or transcoding...maybe?

Thanks, I did see the documents you outlined below and this Mediant I am referencing is purely sip trunk so no TDM involved. I found the document that I was looking for that discusses the the error codes and meanings in the syslog events and I also discovered that our device needs to have a firmware upgrade and after further examining I found that we are suffering from packet loss from our Wan interface to the provider, and I am guessing this is a provider issue at the moment. I attached the PDF to this thread and here are the error code reasons: AA Invalid Accumulated Packets Counter AC Invalid Channel ID AL Invalid Header Length AO Invalid Codec Type AP Unknown Aggregation Payload Type AR Invalid Routing Flag Received AT Simple Aggregation Packets Lost CC Command Checksum Error CE Invalid Cell Coder Code CS Command Sequence Error ES 8 sec Timeout Before Disconnect HO Host Received Overrun IA Invalid AMR Payload IC Invalid CID Error IG Invalid G723 Code IP Invalid payload length IR Invalid RTCP Packet IS Invalid SID Length LC Transmitter Received Illegal Command LF Lost Fax Frames In High Speed Mode LM Lost Modem Frames In High Speed Mode MI Misalignment Error MR Modem Relay Is Not Supported OR DSP JB Overrun PH Packet Header Error PL RTP Packet Loss RB Counts the number of BFI Frames Received From The Host RD No Available Release Descriptor RO RTP Reorder RP Unknown RTP Payload Type RS RTP SSRC Error UF Unrecognized Fax Relay Command AA Invalid Accumulated Packets Counter AC Invalid Channel ID AL Invalid Header Length AO Invalid Codec Type AP Unknown Aggregation Payload Type AR Invalid Routing Flag Received