Since February 2009 all T-Mobile calls flow through at least one of our SGA products: the SGA-EIR. The Equipment Identity Register (EIR) is a central element of the digital mobile architecture, present in all textbooks and included on all network drawings – along with Home Location Register (HLR). This important network element keeps account of the actual relation between all SIM cards and their respective cellular phones, and can also disable them. The device monitors around 1 million calls every hour.