Issue: Mitel 5312 IP phone screen is stuck on "Contacting RCS…" message.

When you restart the phone (by unplugging the network cable), it shows “VLAN None” then “Option 129 Missing

Reason: There is no VLAN set on the phone. It should be set to a VLAN. In this case, it needs to be VLAN number 3. You may have to find your correct VLAN number.


  1. Unplug the network cable which powers the phone.
  2. While the phone is booting, press and hold the Up and Down arrow keys simultaneously.
  3. Network Parameters? *=Yes    #=No   will show up.
  4. Press * for yes.
  5. View Current Netwrk? *=Yes      #=No will show up.
  6. Press * for yes, so we can confirm what is set on VLAN.
  7. Press arrow down until you see the VLAN ID parameters. Keep pressing down and it will prompt for question as follows, and just press # for No.
    • View Current Netwrk?
    • View All IP Addrs?
    • View DHCP Values?
    • View Current Values?
  8. When it prompt for Static QOS?, press * for Yes.
  9. You can press # for No when it asked for View QOS Params?
  10. Press * for Modify QOS Params?
  11. Scroll down until you see the VLAN ID.
  12. Press 3 then scroll down again.
  13. It will ask to save the settings, so save it and it will ask to be rebooted.