Hi Cisco peeps,
I'm facing a weird scenario whereby some phones unable to register to CUCM 8. Some information regards to this matter:
1. All Phone previously land to CM5, works fine. After migrated to CUCM8, few phone unable to reg to CUCM8.
2. Only occurs to some phones which connected via FW (VPN connection).
3. We noticed that phone that affected were updated to latest firmware.
4. Despite not registered to CUCM, phone still able to pull corporate directory data.
5. No issue with network as it only happens to some phones.
6. When we bring back the afftected phones and connect to local LAN, it can register as usual.
My question is, is the latest firmware caused this? Could it be on the FW policy? i'm puzzled.