I have installed exactly one UC540, it seems to be working pretty well. Need to hammer-out some issues, but...
I have another small office interested in switching to a SIP trunk to save on phone costs. They insist they need no remote phones. The UC320W has pretty good reviews on Amazon. Some people on these forums express displeasure with it.
What am I giving up, exactly, going from the UC540 to the UC320? I know remote phones are out. Can I use all the same phones locally, though? Things like auto-attendant and voice mail, are they more limited? Call handling? SIP trunks?
I have a follow-up question in regards to switches. Do I have to use Cisco switches with the UC320 and UC540 servers, or if a customer already has a POE switch from another vendor, will that work instead?
To be a fully supported deployment, yes you need to use Cisco switches. [and be sure you use CDP capable Cisco switches, I recommend the 300 series switches]
Cisco phones can be made to work with other vendors... but it is a pain and will limit support from Cisco if you have issues.
The important part of using Cisco switches is that the phones use CDP (Cisco Discovery Protocol) to automatically find the voice VLAN and connect to it. I do not know of any other vendors that have CDP support in their switches. (which isn't to say there aren't any...)
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