Abstract: When establishing a virtual connection, a pair of identifiers VPI-VCI of Lp+Lc bits is adopted, and data (Id_Cx) relating to said virtual connection is stored in a table in relation to its identifier pair. At the arrival of each ATM cell whose header includes the identifier pair of one of the virtual connections, the data relating to said virtual connection is read from the table. The table includes p.2m storage areas organized as 2m rows and p columns. The data relating to a virtual connection are stored in an area of the table whose row is labelled by an m-bit index calculated by applying a systematic cyclic code, having a generating polynomial of degree m, to a binary word extracted from a sequence of Lp+Lc bits which consists of the bits of one of the identifiers arranged in order of decreasing significance, followed by the bits of the other identifier arranged in order of increasing significance.