Why do you need a Diameter Routing Agent (DRA) in a VoLTE deployment?

Hello fnm500, thanks for your question. At this moment in time it is very early days of VoLTE signaling and operators deploying VoLTE have not seen capacity issues yet to make them prioritize VoLTE signaling. But once that will be done there could be various ways to do it (like on IMSI, on specific AVP content, prioritizing SIP signaling bearer, etc.). My expectation is that in general it won't be visible in Wireshark other then comparing timestamps (but guess that is more theoritical then practical). The priority/routing decisions will be made by the DRA (so inside) and no visible marks to the diameter signaling. Hope this helps?!