I have been fighting an issue with a lot of delay in the setup of sip calls on wireless sip clients when connected to any mikrotik device with a ar9300 chipset.

Currently I have tested two wireless phones one with ar6102 chip works fine with any wireless cards in rb433

When I test with a wireless phone based on Murata LBWA1ZZVK7-539 chipset and ar9300 in rb I have at least 10 second delay before two way RTP starts. If I change wireless cards from the ar9300 to ar5413 I get no delay with either phone.

Is there an updated driver for the AR9300 or something? any other suggestions?