I have three sites that have a Edgewater Networks EdgeConnect 2402PoE Switch
http://edgewaternetworks.com/products/edgeconnect-switch/overview.html (We use a TON of these switches for out hosted SIP service and they just work, never have to touch them once setup)
All three of these sites are relatively smaller, with 15-24 IP phones that are all Mitel 53xx series phones, and are basic, flat networks... no VLANs, one DHCP server with option 43 built, etc. with v5.0 or v5.1 Mitel 5000 HX systems, and the switches are all just factory defaults except for an IP address appropriate for the network and PC's connected through the phones. The issue that seems to crop up is about once every month two is if a phone is unplugged and reconnected, it won't reconnect to the 5000, it gets DHCP and sees option 43 then goes all the way to the "SET IP: xx.xx.xx.xx ICP: xx.xx.xx.xx" screen and just sits there and never connects. All the other phones continue to work properly, even if their DHCP expires and is renewed, but if any phone is unplugged the same issue occurs and they just get stuck at the same screen. Power cycling the switch solves the problem in every instance. PC's and other devices that are disconnected/reconnected have no issues. The kicker is that I have the same switches installed on smaller Mitel 3300's with similar phones and this issue never occurs, I also have these switches installed in two sites that have VLANs configured, never had an issue either. Any thoughts?