Transparent Service Migration
The Cisco IAD2430 enables service providers to transparently migrate end customers from TDM-based GR.303 voice service to call agent-based packet voice services without the need for a truck roll to the end-customer site. The provider can choose H.323, MGCP, and SIP for VoIP protocols, based on the services that need to be delivered.
http://www.cisco.com/en/US/prod/collateral/voicesw/ps6790/gatecont/ps887/ps5321/product_data_sheet09186a008019aded.html
