We are a music on hold provider and we are currently attempting to integrate our solution for a hosted snomONE system here in Australia.
Our solution is capable of delivering content for music on hold in a number of live and non-live ways, coming down to three main sections - streaming, file-based, or analogue audio jack. All of our solutions deliver or attempt to deliver a 'live stream' sounding experience for a number of sections of each business.
We are trying to implement a number of different clients' live streams on the same machine - there are several businesses which all have their own promotional on-hold material whom all use the same hosted system. Given this, we have two options: deliver files, or deliver stream. File delivery often poses security questions as providers rarely will let you upload files directly to their hosted systems. In this circumstance, considering we need to deliver multiple on-hold sources to the same machine, we need to use the RTP stream method.
For example, one of our clients (non-SNOM) uses a total of three on-hold 'playlists' which are played back depending on which queue the caller dials into - the sales queue promotes product, the support queue answers FAQs and the general on-hold promotes the business itself. Their system supports this by the use of multiple RTP streams, it is not capable of three audio inputs and the MoH system must be restarted to change source files.
That being said, we are experienced in delivering RTP streams to be used for content within a SIP session. We are also capable of delivering audio via a SIP session itself - our device registers as an extension and answers any phone calls with the MoH content requested via URI. We have attempted to setup our solution delivering to the snomONE system as detailed above but have run into some issues.
There are a few, but the main issue is that for every second person whom is placed on hold, the music on hold does not work correctly - a horrible loud looping static-y noise is played instead.
The steps we have taken to produce this issue is:
• Create a MoH Source of type RTP Stream – any port (we chose 5005)
• Set a queue to use this source as a ringback or extension to use for hold music
• Send an RTP audio stream in ulaw to the listening port with 20ms packet timing
• Have one caller placed on hold or in the ringback queue – this should work successfully
• Keep the first caller on hold as a ‘test’ – put another extension on hold.
• Both callers will receive the horrible static noise (first callers MoH will stop and be replaced by this)
• Keeping both calls on hold, place ANOTHER call on hold.
• All three calls resume normal MoH activity
It seems as if the PBX is swapping between one source and another. Packet capturing on the PBX reveals that the audio content switches between what is being received on the RTP port, and '7f7f7f7f7f7f7f7f7f7f7f' - capturing the payload of the stream and saving it to a wave file, you can hear it switching between each stream.
Additionally, if you create a MoH source of the type 'RTP Stream' and set nothing up to send to it, place someone on hold, you receive this noise (7f7f7f7f7f7f7f). I would expect if nothing is being received on the RTP port then this stream would have silence - instead it's got this odd content being generated - where from? Upon receiving something to the port, it starts to send this information instead.
We have logged a ticket with snom via the provider we are integrating with, however I thought I would post on the forums to see if anyone has had any experience with delivering RTP streams to SNOM.