I've been doing some more testing and I think I have made some progress. My config is as follows:
Before today I could intermittently use Live View with poor reliability and better performance from 4G than on my home wifi. When motion was detected Live View wouldn't start while the doorbell was capturing the motion clip.
- Ring Doorbell Pro
- RT-AX88U main router with wired connection to downstream RT-AC68U providing dedicated network for the Ring
- RT-AC68U set up in routing mode with NAT DISABLED, 5Ghz WiFi only on a clear channel group, IGMP Snooping enabled
- Upstream ISP Router from Sky in the UK resulting in Double NAT (nothing I can do about this) but RT-AX88U is in DMZ
- RT-AX88U in Symetric NAT mode, SIP Helper Disabled, Multicast Routing enabled in IPTV settings
- Cake configured - 50/10, triple-isolate, Diffserv4 (don't think this is important), nowash (don't think this is important), Regional (don't think this is important)
- Cake nat is on for me and doesn't seem to affect the results
- Cake no-ack-filter is set on both upload and download - this seems to improve things
Today I tried the 'nonat' option which doesn't seem to affect me, but what does seem to have made a difference is turning off ack-filtering which I previously had active on my upload only. Live View now seems to start quickly and I can view the doorbell when I receive a motion alert.
At the moment (and it's too early to be sure) it seems that my Ring Doorbell Pro is now behaving properly with cake-qos. I plan to leave this configuration in place for a few days and if everything remains as good as it is now I will start to reverse some of the settings I don't think are having an influence. The Nat Passthrough SIP Helper setting will be one of the last as I know Ring use SIP and I think this helped me get some form of functionality in the first instance.
I couldn't get my Ring Floodlight Cams to play nice with Cake - no settings seemed to change my ability to view live streams. My Ring Doorbell2 had no problems though, and I don't understand why the doorbell worked perfectly, and the Floodlight Cams struggled.
Uninstalled Cake and went with Flex. Ring cameras are snappy and bring up live streams within 2-3 seconds.