Hi lyndidon
Thank you for your well thought out and helpful response. I shall work my way through your suggestions, and report back accordingly.
Worst case is that I packet capture on the switch and analyse what passes between the Playout Centre and the remote multicaster when it is working and then when it isn't working. But I'm a software designer not a network engineer, I'm not practiced at this.
The sip configuration is very relevant because I am moving towards an all VoIP office environment, and I am going to have to get my head around this stuff sooner rather than later.
I tried to submit a case to Juniper but they told me to naff off as my supplier is responsible for both hardware and software maintenance. I have asked the supplier to have a look at the problem, but I am not sanguine about the likely outcome, pre-sales their response to my questions was to merely restate my original question, I think this is a technique more usually encountered in offshore call centres.
Your statement - "The thing that bothers me about issues like this is it appears as though Juniper does not monitor these forums, so that problems like this can be addressed. Tell if the feature is supported, if not when, will it be, or publish an article on it", really resonated with me. I've developed some significant systems, monitoring what the punters thought was always right at the top of the list. Some of my previous posts have deliberately contained statements that I had imagined would catch the attention of a Juniper Networks staffer.
My gut feel is that the SRX300, with the most recent Junos release is almost brilliant, but I wonder if the developers really know what happens at the branch / SOHO level. For example, they have sensibly upgraded the the USB port to version 3, but neglected to add the LTE modem failback support, why else upgrade it? Considering the RFPs I've seen recently, what branch gateway would not support LTE?
Thanks again for your interest.