1

Scope

1.1

General ISO/IEC ISP 10613 is applicable to interworking units concerned with operating in the Open Systems Interconnection (OSI) environment. It specifies a combination of OSI base standards that collectively provide a network-relay function for the connectionless-mode Network Service.

This part of ISO/IEC ISP 10613 defines the RA54.1121 profile, which is applicable to interworking units operating between FDDI LAN subnetworks and PSDNs using virtual calls over a digital data circuit/CSDN leased line permanent access.

1.2

Position within the Taxonomy The taxonomy of profiles is defined in ISO/IEC TR 10000-2. This part of ISO/IEC ISP 10613 defines the profile

RA54.1121

Relaying the Connectionless-mode Network Service between FDDI LAN subnetworks and PSDNs using virtual calls over a digital data circuit/CSDN leased line permanent access.

1.3

Scenario Figure 1 illustrates the configuration of systems to which the RA54.1121 profile is applicable. The figure shows two reference points, but an implementation of this profile may include more attachments to FDDI LAN subnetworks and PSDNs, with a reference point at each.

As this profile is a member of the RA group, it is intended that a conforming implementation is capable of interworking with other profiles of the RA group and with End Systems implementing profiles from the TA or UA groups, provided that suitable relays are in place in the case of those members of these groups which relate to different elements of the subnetwork taxonomy.

This part of ISO/IEC ISP 10613 specifies the required functions from the supporting protocol stack shown in figure 2.