Cisco MCS-7825-H3-IPC1 Service Guide - Page 505

Chapter 6 Cisco Unified Serviceability Alarms and CiscoLog Messages Warning-Level Alarms The MOH allocation can also fail due to codec mismatch or capability mismatch between the endpoint and the MOH server. If there is a codec mismatch or capability mismatch (such as the endpoint using IPv6 addressing but MOH server supporting only IPv4), an MTP or transcoder should be allocated. If the MTP or transcoder is not allocated then either MediaResourceListExhausted (with Media Resource Type as Media termination point or transcoder) or MtpNoMoreResourcesAvailable alarm will be generated for the same Media Resource Group List and you should first concentrate on that alarm. The MOH allocation may even fail after checking the region bandwidth between the regions to which the held party belongs and the region to which the MOH server belongs. Increasing the region bandwidth may be a solution to the problem, but that decision should be made after careful consideration of the amount of bandwidth you're willing to allocate per call between the set of regions. You'll need to weigh different factors such as the total amount of available bandwidth, the average number of calls, the average number of calls using the MOH servers, approximate bandwidth use per call, and so on, and accordingly calculate the region bandwidth. Another possible cause is that the bandwidth needed for the call may not be available. This can occur if the MOH server and endpoint belong to different locations and the bandwidth that is set between the locations is already in use by other calls. Examine the bandwidth requirements in your deployment to determine whether bandwidth between the locations can be increased. However, please note that increasing the bandwidth between these two locations means that you may need to reduce the bandwidth between other locations. Refer to the System Guide, SRNDs, and related Unified CM documentation for more details. Be aware that reducing the bandwidth or removing the higher bandwidth codecs from configuration may result in poor voice quality during call. Consider increasing the total amount of network bandwidth. Another reason for the MOH allocation failure may be due to meeting the maximum number of unicast or multicast streams supported by the MOH server. If all available streams are already in use, none can be allocated. Finally, check the Music On Hold Audio Source Configuration window in Cisco Unified CM Administration to confirm that at least one audio source is configured. If an audio source is not configured, upload an audio file and then configure the audio source in Cisco Unified CM Administration (refer to the Music On Hold configuration documentation for specific details). MtpNoMoreResourcesAvailable Media termination point or transcoder allocation failed. The alarm occurs when allocation of a media termination point (MTP) or transcoder fails for all the registered MTPs or transcoders belonging to the Media Resource Group List and Default List. Each MTP or transcoder may fail for different reasons. Following are some of the reasons that could cause an MTP or transcoder allocation to fail: a capability mismatch between the device endpoint and MTP/transcoder, codec mismatch between the endpoint and the MTP/transcoder; a lack of available bandwidth between the endpoint and the MTP/transcoder; or because the MTP/transcoders resources are already in use. A capability mismatch may be due to the MTP/transcoder not supporting one or more of the required capabilities for the call such as Transfer Relay Point (which is needed for QoS or firewall traversal), RFC 2833 DTMF (which is necessary when one side of the call does not support RFC 2833 format for transmitting DTMF digits and the other side must receive the DTMF digits in RFC2833 format, resulting in conversion of the DTMF digits), RFC 2833 DTMF passthrough (in this case, the MTP or transcoder does not need to convert the DTMF digits from one format to another format but it needs to receive DTMF digits from one endpoint and transmit them to the other endpoint without performing any modifications), passthrough (where no codec conversion will occur, meaning the media device will receive media streams in any codec format and transmit them to the other side without performing any codec conversion), IPv4 to IPv6 conversion (when one side of the call supports only IPv4 and the other OL-22523-01 Cisco Unified Communications Manager Managed Services Guide 6-271