HP 0231A56S - MSR 1-Port FXS SIC module (SIC-1FXS) - Smart Interface Card (SIC) analog subscriber line module with one RJ-11 phone connector for analog telephone, fax access and also can connect AT0 loop trunks of exchanges Retail
HP 0231A62S - MSR 4-port CE1/PRI FIC module (FIC-4E1) - Flexible Interface Controller (FIC) channelized E1/PRI interface module with one DB 25 connector that features transmission, receiving and processing of E1 data traffic Retail