3Systematic TelephonyThe OpenCom 100 / Aastra 800 communications system, referred to hereafter as “theOpenCom 100 / Aastra 800”, enables the connection of standard terminals (standardanalogue telephones, ISDN telephones and cordless GAP telephones). SMS-enabledterminals and SIP terminals can also be used. It is possible to operate the so-calledstandard terminals on an Aastra 800 communications system if the system isequipped with the corresponding telephony interface cards.With this configuration you can telephone conveniently and use the features of theOpenCom 100 / Aastra 800 via code-number procedures. This guide describes howyou operate your telephone in order to use the desired functions. In most cases, youcan do this by pressing the key combination * and #, R, together with a specificsequence of digits.Please note the specific operating characteristics of your telephone:On standard analogue telephones featuring pulse dialling, it is not possible to enterdata with the star key * or hash key #.As a result, the functionality of the OpenCom 100 / Aastra 800 features is onlyavailable to you on a limited basis. It is thus better to use telephones equipped withdual-tone multi-frequency (DTMF) dialling. Modern telephones often allow you toswitch between the two dialling modes.When telephoning via SIP (i. e. telephoning via the Internet Protocol “Session Initi-ation Protocol”) entry of the hash key # is only permitted at the end of a code-number procedure or of a call number. You can thus only use a part of the code-number procedures on a SIP terminal. Furthermore, some SIP terminals offer oper-ation of features at the mere press of a button. Please review the user guide of themanufacturer.In the case of ISDN telephones, certain features can be operated via menus orfunction keys. Refer to the operating instructions of these telephones for details.On telephones with a display, you can read the caller’s call number if the telephonesupports this feature and the caller has activated it. What other information is dis-played depends on the telephone. Charge display (ISDN telephones only) requiresprior configuration by your network operator.