One of the unique challenges of CSR FM is it’s structure, where it is part funded by two separate universities each with a presence in Canterbury (University of Kent and Christ Church University) and their respective student unions (Kent Union and CCCU). Student members could be enrolled at either institution, and as such each institution has it’s own radio studio on campus – each of which has an equal chance of being put on air. The station also invites members of the community to participate.
This has presented a challenge, in that live audio needs to make it’s way from either studio to the transmitter, hosted at the University of Kent in Eliot College. From the outset of the CSR project, the route between the two has always been over IP – there was no other reasonable option. Up until recently, that was realised using a IP Codec – with it’s packets being routed over the institution’s networks.
This is perfectly fine, and for the most part worked very well. However, recently CSR has had a fundamental infrastructure change to it’s audio distribution (as part of the Student Media Center project), which has made every single audio source and destination available using Axia’s Livewire Audio over IP protocol over their internal network. This allows fantastic flexibility and allowing studios to route any source to their mixing consoles, as well as increased interoperability with our automation systems and customisable GPIO control.
However, the second studio (Studio Blue) was still connected via an IP codec link, which was not integrated into the system at all and offered limited capacity for routing over the link (only a stereo pair to and from the router). Unfortunately the link between the two sites, over the academic networks that link the universities, would not be suitable to transport Livewire (for a number of very good reasons, lack of multicast and custom QoS being one). It was therefore necessary that we provided a Layer 2 link between the two locations to carry this traffic, which we had complete control over.