User Port Address. If UserPortType is PSTN, valid range is 0..32767. If UserPortType is ISDN, valid range is 0..8175. Maximum value is 32767. The actual address range is further limited by the following rules: PSTN: v52IgPstnLayer3StartAddress <= v52UserPortAddress < v52IgPstnLayer3StartAddress + maximum_PSTN_users_allowed_per_IG ISDN: v52IgIsdnEnvFuncStartAddress <= v52UserPortAddress < v52IgIsdnEnvFuncStartAddress + maximum_ISDN_users_allowed_per_IG Further, the total number of user ports is restricted by the following rule: Total_Pstn_User_Ports + 2*Total_Isdn_Bri_User_Ports <= Total_User_Ports_Supported_Per_Platform. ISDN PRI is not supported by the current release. For the current 8 E1 release of Sechtor 100: maximum_PSTN_users_allowed_per_IG is 1920. maximum_ISDN_users_allowed_per_IG is 960. maximum users supported on the entire Sechtor 100 is 4800. The maximum number of PSTN and ISDN user ports supported for the 16 E1 release will be updated in the near future.