I am implementing a solution with the UC520 24 users with Cisco 7931 Receptionist phones and Cisco 521SG phones. I am facing several issues, and my customer is not impressed so far.
No matter what I do, I simply cannot get the switchport on the phone to activate. The ethernet port on my laptop does not see any activity when I connect the cable to it. The phone is labelled 521S, on the box it says 521SG and the customer is expecting an extra switchport at every desk. On the UC 520, it picks up some as 521G and some as 524G!!!!!! wtf.
After connecting all the phones to the 2960 PoE switch that I have, I see that the PoE negotiates correctly, and picks up the correct phone, in this case IP Phone CP-521S. After a while, it drops a whole bunch of them to Ieee PD. The phones still work, but I can no longer see these devices as CDP neighbors.
Also, on one occassion, all phones were switch ofd, except the 7931 Receptionist phone which connects to the same Ethernet switch.
I was told by the dealer to update the IOS and the phone load for that phone to the latest version, which I did, but still no luck.
Customer was also given a Polywell/Trixbox solution as well, but decided to go with Cisco to avoid the problems that I am presenting them with.