E. 214 is a telephone numbering plan used for delivering mobility management related messages in GSM networks. The E. 214 number derived from the IMSI E. 214 numbers are composed of two parts. The first, the E. 164 part, is made up of a country code followed by the network code. The second part of the number is made from the MSIN part of the IMSI which identifies an individual subscriber. For more details on the derivation of the E. 214 number from the IMSI, see the article about the IMSI.