LAN sync on Yealink Multi-Cell DECT requires precision time protocol v2 with <500ns deviation. As of writing PTP is supported on Mikrotik switches:

  • CRS326-24G-2S+ supported only on Gigabit Ethernet ports
  • CRS328-24P-4S+ supported only on Gigabit Ethernet ports
  • CRS317-1G-16S+ supported on all ports
  • CRS326-24S+2Q+ supported on SFP+ and QSFP+ interfaces
  • CRS312-4C+8XG supported on all ports
  • CRS318-16P-2S+ supported only on Gigabit Ethernet ports

Mikrotik Ref: 

Yealink Ref:

Assuming ports are members of the same bridge and IGMP snooping on the bridge has been enabled so that bases are automatically found by the DM.

Enable PTP and add the ports required into the group. In this case 'ptp-1' and ports 10, 18 and 24

/system ptp
add delay-mode=e2e name=ptp-1 transport=l2
/system ptp port
add interface=ether24 ptp=ptp-1
add interface=ether10 ptp=ptp-1
add interface=ether18 ptp=ptp-1

Enable LAN sync on the bases as per the documentation, on the LAN Master Base Station disable "Ext PTP Master" feature. This allows the switch to remain the master clock source.

'Base Status' and 'Cluster Graph' under 'Status>>Base Station Group' should both show Active and synced for all bases. PTP offset can be chosen as a column by clicking the 'eyeball' in the top right hand corner of the screen. A reboot of the bases may be required to get the first sync. 

NOTE: If linking multiple switches into the clock sync group one device must be elected as a (grand)master source. As of writing this doesn't automatically happed when priority is left as auto. Manually set a switch to be a master by setting the priority value lower as per the below example where is has been set to 30 (default/auto is 128)

/system ptp
add delay-mode=e2e name=ptp-1 priority1=30 transport=l2