With your description then we can determine that the IP phone isn't actually upgrading but is failing to obtain and IP address when it's in upgrade mode (small text).
What type/model switch is the IP phone connected to? Let me look at your packet trace and I'll update this post.
Update:I looked at your packet trace (5c-81_ug_fail1.pcap) and see a few issues... your packet trace doesn't include any 802.1q VLAN tags. If you used a laptop to perform the packet trace you need to configure the NIC to 'not' strip the 802.1q VLAN tags. Have a look at this
article on the WireShark wiki for more information.
I also see multiple DHCP offers but I don't see the initial DHCP discover requests from the IP phone, very odd. Where you performing the packet trace at the edge switch port and capturing both Tx and Rx traffic?
In any event in frame 92 you can see that you are returning DHCP options 128 and 191. This is a problem and can confuse some of the phones depending on the firmware version and configuration, you should only return DHCP option 191 in the data VLAN (assuming this is the first DHCP request and this frame is in the data VLAN) there is no need to return DHCP option 128 yet.
In frame 101 we can see the IP phone release the initial DHCP address and then in frame 129 we can see a DHCP offer with DHCP option 128 and the phone appears to boot up properly to me.
Hint: you can right click on the UDP/5000 and UDP/7300 packets and click 'Decode As' and select UNISTIM.
In frame 457 I can see the UNIStim command to upgrade the phone using firmware /u/fw/x25.fw, this packet comes from 10.101.1.20 (Succession Signaling Server?) but in the packet the file server IP address is 119.47.120.50 - does this IP address ring any bells?
In frame 519 I can see the DHCP offer from your DHCP server (again no DHCP Discover? - problem in the packet trace) but the DHCP server is offering both DHCP option 128 and DHCP option 191 which might be confusing the 'upgrade boot code'.
I can also see from the trace that you are using VLAN 2069 for your voice VLAN, however, in your post below you mention VLAN 2060? Is this just a typo in your post?
I see multiple DHCP offers to 00:21:e1:fe:5c:81 so can I assume that you have multiple routers on those VLANs? I'm going to guess that's the case.
So I would remove DHCP option 128 from the DHCP scope in your data VLAN and see how that works.
Good Luck!