What are your grounds for saying this?
I've never seen any SSDP broadcast packets from the TV in the MC Media Network screen. Of course, MC only shows some packets it sees in that function, so maybe they arrive at my PC but MC chooses not to display them. Nope - see below.
I do regularly see the HTTP GET command responses from the TV, as per the above image.
I haven't checked for them using Wireshark though. I should do that...
Nope. No SSDP broadcasts from the TV, which is on. Plenty from the Workstation MC Server and the router. Plenty of HTTP GET commands from the TV, and HTTP/1.0 200 OK responses from the Workstation MC Server though.
Wait. I had the TV sitting in the Music App to give it the best chance of being seen, as it is a DLNA Renderer. But the TV had switched to its "resting state" for want of a better description. Showing a background image and the time. When I switched it back to the Music App the TV sent SSDP packets. This is the first time I have ever seen it do that. I left the TV sitting on the Music App and active, but not playing anything. It sent more SSDP packets about five minutes later, then again about seven minutes later.
I switched the TV back to its home screen and restarted the trace. SSDP packets appeared after 20 seconds, then again after 7.5 minutes (at 470 seconds), then again at 920 seconds, 1370 seconds, 1820seconds. So at 450 second or 7.5 minute intervals. The TV seemed to pretty consistently send 32 broadcast packets.
I restarted the trace and switched the TV back to HDMI input from the HTPC, then checked in MC and the SSDP packets from the TV were showing up in Media Network. In Wireshark these arrived at 80, 300, 750 and 1200 seconds. So a bit of a burst early, then back to 450 second intervals. There were even 12 OK responses from the Workstation to the first lot of packets, but none after that, and the TV still never showed up under Playing Now in MC. MC saw all 32 of the broadcast packets sent which each group, so no packets were being lost through clashes.
So it appears that the Sony TV does send SSDP packets under certain conditions, such as when the Music App is first opened, but it doesn't send them very often. I've looked quite hard for those packets in MC previously, but not using Wireshark. I'm wondering if something changed, or I just didn't wait long enough previously. I guess we shall never know.
However, if the TV doesn't show up in MC under Playing Now, the whole observation is just interesting, and doesn't solve the problem or make sending media to the TV acting as a DLNA Renderer any easier.
Inconsistency is the biggest issue for me with DLNA. For example, BubbleUPnP usually always sees the TV as a DLNA and Chromecast Renderer. However, just now BubbleUPnP couldn't see TV DLNA Renderer but could see the Chromecast Renderer. JRiver for Android could see the TV DLNA Renderer but couldn't play to it. I played a movie from the Workstation MC DLNA Server to the phone running BubbleUPnp and JRiver for Android. I was about to try playing to the TV Chromecast Renderer... when the TV DLNA Renderer appeared in the BubbleUPnP list. I was able to play the movie to the TV DLNA Renderer at that stage. The TV DLNA Renderer still never appeared in the Workstation MC Server (IP Address 192.168.0.10) Playing Now list as a Zone... even though it was serving the movie up to the TV (IP Address 192.168.0.12) at the time! See the image.