VLAN information is currently delivered to the phone via either DHCP option strings or via 802.1ab (LLDP or LLDP-MED) TLV's.
802.1ab (the ITU standardized version of Cisco's CDP protocol) is becoming very popular. In fact many customers are pushing Cisco to support it on their data switches in addition to CDP.
In addition to VLAN information, 802.1ab will be able to provide other valuable information to any IP device such as Location Information for E911 services, hardware information, etc. There a several great whitepapers on 802.1ab, and it's something that you may want to make sure is on somebody's RADAR for your network. It has tons of uses beyond VoIP, but is something that can really improve VoIP deployment and operational capabilities. |