Reducing bandwidth is key in corporate WANs. Flash-based MOH provides this functionality at no additional cost.
Music on hold servers are, by traditional design, the CallManager servers. Because of this practice, there are a number of corporations’ offices consuming bandwidth if their clusters are centralized in a data center or corporate office. In the event that the customer can agree to a method by which they can simplify their music on hold strategy using flash-based MOH, you can accomplish a major win on the war on rising bandwidth needs.
First and foremost, evaluate whether this solution is viable for you. If you can localize your music on hold traffic and use a looping music file on the flash, then this is perfect. If you’re very set on using a live stream, then consider multicast music on hold and the proper deployment of PIM. If you have a specific need for localized live music (the local office has an existing Muzak setup perhaps), then you can still use a 4-wire E&M trunk to accomplish localized streaming. For the purposes of this post, we’re only going to consider option 1 – localizing music using a file on the flash.
If you’ve decided that you can use this solution, then let’s next insure you can meet the requirements for the technology. You must be able to provide a file that will first, fit on your flash, and second, be formatted correctly to be streamed. The first objective is straightforward and should be easily accomplished. Your streaming music should not be much more than a megabyte or two at most. Remember, most people aren’t on hold that long, and have grown accustomed to music repeating. Second, the easiest way to get your music in the right format is to take a regular wav file and put it through the MOH translator service on CCM. This translator will pop out a G.711 file for you which you can distribute to your sites.
For the actual configuration and setup, you only need to accomplish a few steps to get everything up and running. First, push the file out to your remote sites simply using ftp to upload the file to the flash on your remote site router. Once it is on the router, you will enter your SRST configuration (call-manager-fallback) to begin the configuration of the file. You can have multiple music files (maybe a song for Christmas time, another that has springtime advertisements, etc.) but the only one that will play is the one configured within your SRST config.
Once in SRST configuration mode, you will need to specify the file source and multicast MOH source IP and port. Note these settings, we’re going to use them later when we configure the CCM multicast moh servers.
One last item to configure on the gateway is the ccm-manager music-on-hold command in global config. This enables the device to stream music on hold while we’ve got callmanager. The SRST config and ccm-manager commands are very important!
Now, to the CallManager to make these changes. Typically, CCM is configured with a device pool, that has a MRGL–>MRG–>MOH Server relationship. Inside the Device Pool (or Common Profile if in 4.2) you have the MOH Audio Source for network and user. If your site is already using Multicast MOH today, you can skip this paragraph and go to the next. If you’re not doing Multicast streams today, then keep reading. You can either add a new MOH Audio source (consult Cisco docs) or you can change one of your existing sources to support multicast. Regardless, you must have at least one audio source that is multicast enabled.
Once you have configured your source we will configure at least one MOH server within the MRG–>MRGL–>Device Pool relationship to support multicast. If you already have multicast today, you have likely adjusted your TTL to accommodate the scope of your network. If you do not have multicast, you will need to enable multicast on the server within the MRG/MRGL/DP you are attempting to modify. Once enabled, adjust the TTL to 1. Then, insure your increment value is set to “Increment on Port”. This last statement here is what drives the moh multicast command on our routers. If we ever adjust our MOH audio sources on the CCM server, CCM will automatically increment every source up a port number. This can be bad if you’re not aware of the caveat. To insure this does not happen, make sure you always reset your MOH servers after adjust your MOH Audio Sources.
Make sure that our MOH Server/MRG/MRGL/DP all support the multicast audio source and server we configured, reset the device pool. (This will reset all phones, make sure you’re ready to do this!) If everything is configured correctly, we should be able to login to our remote office router and issue show ccm-manager music-on-hold and see a live stream once a caller is placed on hold.
Questions? Comments? Let me know.
Reference Link: Cisco documentationfor Flash-based MOH