Description: This is the table for the address screens. There can be up to s individual address screens and up to s group address screens per SNI (sniScreenIndex). The initial value for s (screenIndex) is equal to 4. In the future a higher value of s may be supported. The screens are distinguished by their screenType (i.e., individual or group) and by the screenIndex (i.e., a value between 1 and s).

This list identifies the s screens associated with an SNI accompanied by an indication (screenStatus) of whether the screening comprises 'allowed addresses' or 'disallowed addresses' (i.e., whether the screen is applied as an inclusionary or exclusionary restriction), or whether the screen is not used (i.e., screening is turned off and all SIP L3_PDUs are allowed; this is identified by an empty list) or multiple individual and group address screens are not supported by the network supporting SMDS.

Different addresses on an SNI may be associated with different address screens (one individual and one group address screen per associated SNI individual address, and one individual address screen per associated SNI group address). This information is included in the associatedAddressesIndScreenTable and associatedAddressesGrpScreenTable. The associatedAddressesIndScreenTable includes all the addresses (associatedAddressInd) assigned to an

SNI (i.e., both individual and group addresses) that are associated with a particular Individual Address Screen (associatedScreenIndIndex). The associatedAddressesGrpScreenTable includes all the addresses (associatedAddressGrp) assigned to an SNI (i.e., only individual addresses) that are associated with a particular Group Address Screen (associatedScreenGrpIndex).

For every SNI, there are: 1) defIAScreenForIAs; the default Individual Address Screen used for destination address screening at the network ingress and source address screening at the network egress of individually addressed L3_PDUs when the associated SNI address is an Individual Address. 2) defGAScreenForIAs; the default Group Address Screen used for destination address screening at the network ingress of group addressed L3_PDUs. The associated SNI address will always be an Individual Address (i.e., it is the Source Address). 3) defIAScreenForGAs; the default Individual Address Screen used for source address screening at the network egress of individually addressed L3_PDUs when the associated SNI address is a Group Address (i.e., it is the Destination Address).

The individual address screen (all the iAScreeningAddresses for the s iAScreenIndices in the individualAddressScreenTable) and the group address screen (all the gAScreeningAddress for the s gAScreenIndices in the groupAddressScreenTable) together consist of up to n addresses. The initial value of n (numberValidEntries in the numberAndDefaultScreeningTable) is defined as 128. In the future a value of n up to 2048 may be supported.

The individual address screen (iAScreeningAddress in the individualAddressScreenTable) is used to perform Destination Address Screening for individually addressed data units (performed at the network ingress) and Source Address Screening for all data units (performed at the network egress). The group address screen

(gAScreeningAddress in the groupAddressScreenTable) is used to perform Destination Address Screening for group addressed data units.