Hi All,
After consuming masses of time chasing a very elusive problem with VoIP , we have finally found out the cause.
Router OS 6.47.x basically.
Our scenario is we use RB wifi routers, usually in bridge mode at customer locations but also in some infrastructure glue "switches/routers" and we use TOS/DSCP marking for QoS over our network.
This means although the router is basically in bridge mode, we turn off "allow fast path" and turn on "use IP firewall" under the bridge settings.
This way we can mark packets with a DSCP/ToS value using mangle for some IP ranges.
This worked fine until 6.47.x.
A test setup would be to have either a HAP AC or the 951 single band equivalent or even a AC lite/HAP/rb750/hex poe etc.. Set up as a bridge, with ports 2 to 5 hardware bridged and port 1 software bridged to them.
connect a VoIP base to ethernet 1, this being software bridged will mean the packets can be processed by the mangle rule.
this setup works fine in earlier versions, such as the long term 6.45.9 and many 6.46 versions
However if you have the same setup on 6.47.x then as soon as you set the Bridge fast path/firewall settings as above, the VoIP basically becomes unusable. put them back and it restores.
Roll the router back to 6.45.9 and all is fine again in both on/off.
This has cost us many many hours of chasing what was basically an invisible problem when you checked the router remotely and it annoyed a lot of customers.
Rolling back to 6.45.9 across all router OS devices was not without problems too, there is still a bug present that has been present for a long time whereby static routes do not restore after a upgrade/downgrade and have to be manually disabled/enabled to restore them.
I would STRONGLY suggest you rename 6.47.x as Beta/Testing as it is NOT stable, either that or perform far more thorough testing before releasing it.
We can only assume this has happened due to the major changes you made to the way Router OS works, as it also broke VLAN's for use with Bonding completely.
Bill - Kijoma